Tetracycline derivative

Abstract

The present invention relates to tetracycline derivatives and their use as pharmaceuticals in the treatment or prevention of diseases selected from the group consisting of or including amyloidosis, pain, neurodegenerative diseases and neuroinflammatory diseases.

Description

Technical Field

[0001] The present invention relates to tetracycline derivatives and their use as medicaments in the treatment or prevention of diseases selected from or consisting of diseases including, in particular, amyloidosis, pain such as neuropathic pain, neuroinflammatory diseases and neurodegenerative diseases.

Background Art

[0002] The pathophysiology of many diseases is related to neurons, particularly by protein aggregation or inflammation. For example, the aggregation of the protein α-synuclein into amyloid fibers contributes to the etiology of synucleinopathies, a group of neurodegenerative diseases including Parkinson's disease and other related diseases. Another example is the aggregation of tau protein into neurons, which contributes to the onset of Alzheimer's disease.

[0003] In the prior art, a wide range of tetracycline derivatives have been described for the treatment of neurodegenerative diseases. For example, WO 2004 / 064728 discloses certain tetracycline derivatives and their use for treating diseases or conditions associated with underlying inflammatory processes, particularly including neuropathy. However, the antibacterial action of tetracycline is a potential obstacle to the treatment of neurodegenerative diseases. This is because the long-term treatment required for these conditions may favor the emergence of antibiotic-resistant pathogens.

[0004] Therefore, there remains a need to develop tetracycline derivatives that have anti-protein aggregation and anti-inflammatory properties and do not have antibiotic activity.

[0005] The inventors of the present invention have surprisingly found that the tetracycline derivative, which is a compound of formula (I) according to the present invention, has a neuroprotective effect and / or an anti-inflammatory effect and / or an anti-aggregation activity superior to those of the tetracycline derivatives of the prior art, while having no antibiotic activity and being particularly easy to produce from doxycycline or oxytetracycline having an excellent safety profile.

SUMMARY OF THE INVENTION

[0006] The present invention relates to a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof for use in the treatment or prevention of a disease selected from the group consisting of amyloidosis, pain, neurodegenerative diseases and neuroinflammatory diseases, wherein the above formula (I) is

CHEM.

[0007] Advantageously, the compound of formula (I) is a compound of formula (Ibis) or a pharmaceutically acceptable salt, solvate or mixture thereof, wherein the above formula (Ibis) is

CHEM.

[0008] More advantageously, the compound of formula (I) is a compound of formula (Ia) or a pharmaceutically acceptable salt, solvate or mixture thereof, wherein the above formula (Ia) is

CHEM.

[0009] More advantageously, the compound of formula (I) is a compound of formula (Ib) or a pharmaceutically acceptable salt, solvate or mixture thereof, wherein the above formula (Ib) is [Chemistry] It is (Ib).

[0010] Advantageously, the compound of formula (I) is a compound of formula (Ic), or a pharmaceutically acceptable salt, solvate or mixture thereof, wherein the above formula (Ic) is [Chemistry] It is (Ic).

[0011] Advantageously, the above-mentioned diseases are selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases, and neuroinflammatory diseases.

[0012] Advantageously, the above-mentioned neurodegenerative disease or neuroinflammatory disease is selected from the group consisting of Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, Alzheimer's disease, prion disease, multiple sclerosis, limbic-predominant age-related TDP-43 encephalopathy (LATE), and Huntington's disease.

[0013] Advantageously, the above-mentioned neurodegenerative disease is Parkinson's disease or Alzheimer's disease, and preferably, the neurodegenerative disease is Parkinson's disease.

[0014] The present invention also relates to a method for producing a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof as defined above, the method comprising a) reacting a compound of formula (II) or a pharmaceutically acceptable salt, solvate or mixture thereof with a reducing system, wherein the formula (II) is [Chemistry] It is (II), wherein R2 and R3 are each independently selected from the group consisting of a hydrogen atom and a hydroxyl group, and then, b) isolating the compound of formula (I) as defined above and produced in step a) or a pharmaceutically acceptable salt, solvate or mixture thereof; comprises.

[0015] Advantageously, the reducing system in step a) comprises a reducing metal, preferably a zinc metal, and optionally an acid, preferably acetic acid.

[0016] Advantageously, the reducing system in step a) is an acid. More advantageously, the acidic reducing system in step a) comprises acetic acid.

[0017] Advantageously, the isolation of the compound of formula (I) as defined above or a pharmaceutically acceptable salt, solvate or mixture thereof is carried out by chromatography, preferably by chromatography selected from the group consisting of column chromatography and reverse-phase high performance liquid chromatography (reverse-phase HPLC).

[0018] The present invention also relates to a pharmaceutical composition comprising the compound of formula (I) as defined above or a pharmaceutically acceptable salt, solvate or mixture thereof, and at least one pharmaceutically acceptable excipient.

[0019] Advantageously, the at least one pharmaceutically acceptable excipient is selected from the group consisting of microcrystalline cellulose, magnesium stearate, povidone, hydrogenated castor oil, colloidal anhydrous silica, sodium carboxymethyl starch, and combinations thereof.

[0020] The present invention also relates to the pharmaceutical composition as defined above for use as a medicament.

[0021] The present invention further relates to a pharmaceutical composition as defined above for use in the treatment or prevention of a disease selected from the group consisting of amyloidosis, pain, neurodegenerative diseases and neuroinflammatory diseases. Preferably, the neurodegenerative disease is selected from the group consisting of Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, Alzheimer's disease, prion disease, multiple sclerosis, limbic-predominant age-related TDP-43 encephalopathy (LATE), and Huntington's disease. More preferably, the neurodegenerative disease is Parkinson's disease.

[0022] The present invention further relates to a pharmaceutical composition as defined above for use in the treatment or prevention of a disease selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases and neuroinflammatory diseases. Preferably, the neurodegenerative disease is selected from the group consisting of Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, Alzheimer's disease, prion disease, multiple sclerosis, limbic-predominant age-related TDP-43 encephalopathy (LATE), and Huntington's disease. More preferably, the neurodegenerative disease is Parkinson's disease.

[0023] Advantageously, the pharmaceutical composition is administered by an administration route selected from the group consisting of oral route, intraspinal route, intraarterial route, intravenous route, intramuscular route and subcutaneous route, and preferably, the pharmaceutical composition is administered by the oral route.

[0024] The present invention further relates to 12a-deoxytetracycline for use in the treatment of pain.

[0025] Advantageously, the above 12a-deoxytetracycline is selected from the group consisting of the following compounds:

Chemical formula

Chemical formula

Chemical formula

Chem.

Chem.

Chem.

[0026] Advantageously, the pain is selected from the group consisting of neuropathic pain, nociceptive pain, or central pain.

[0027] More advantageously, the pain is a disease selected from the group consisting of osteoarthritis, rheumatoid arthritis, and cancer, preferably nociceptive pain induced by cancer.

[0028] More advantageously, the pain is neuropathic pain induced by diabetic neuropathy.

[0029] More advantageously, the pain is central pain induced by a disease selected from the group consisting of fibromyalgia, irritable bowel syndrome, or tension headache.

[0030] Definition In the present invention, the following terms have the following meanings:

[0031] A number or "about" before a number refers to plus 10% or minus 10% of the amount of that number or number. In one embodiment, "about" before a number or number refers to plus 5% or minus 5% of the amount of that number or number.

[0032] "Active agent" refers to an agent having a therapeutic effect. This agent can be a chemical or a biological substance. Preferably, the active agent is a chemical substance. The therapeutic effect can be the prevention, delay, alleviation, or suppression of the severity and / or frequency of at least one symptom associated with a pathological condition, or the prevention, deceleration, or suppression of the root cause of a pathological condition, or the improvement or repair of damage.

[0033] "Alzheimer's disease" (AD) refers to a neurodegenerative disease that usually starts slowly and worsens gradually. It generally involves impairments in memory, judgment, attention, and problem-solving abilities, as well as a general loss of cognitive abilities.

[0034] "Chlortetracycline" refers to a molecule of the following formula.

Chem.

[0035] "Comprising" or "comprise" is interpreted in an open and inclusive sense, but not limited thereto. In one embodiment, "comprising" means "consisting essentially of". In one embodiment, "comprising" means "consisting of" and is interpreted as being limited thereto.

[0036] "Demecycline" refers to a molecule of the following formula.

Chem.

[0037] "Dosage" refers to the amount of the active agent administered at one time. Preferably, the oral dosage is administered to a subject once at intervals of 8 hours to 1 week, preferably at intervals of 12 hours to 24 hours, more preferably at intervals of about 24 hours. More preferably, the above oral dosage is a human dosage, and the human dosage is a standard human dosage for a 70 kg male.

[0038] "Doxycycline" refers to a molecule of the following formula.

Chemical formula

[0039] "Excipient" refers to any inert ingredient required for the formulation of the active agent in a suitable dosage form. In one embodiment, "excipient" refers to any solvent, diluent, carrier, filler, extender, binder, disintegrant, polymer, lubricant, glidant, surfactant, isotonic agent, thickening agent or emulsifier, stabilizer, absorption enhancer, flavoring agent, preservative, antioxidant, buffer, gelling agent, solubilizing agent, or any combination thereof.

[0040] "X to Y" refers to the range of values between X and Y, and the boundaries X and Y are included in that range.

[0041] "Neurodegenerative disease" refers to a disease or disorder associated with progressive damage to the structure or function of neurons, including neuronal death or demyelination. According to the present invention, the neurodegenerative disease may also be a neuroinflammatory disease.

[0042] "Neuroinflammatory disease" refers to a disease or disorder caused by an excessive inflammatory response of the nervous system.

[0043] "Neurodegenerative disease and / or neuroinflammatory disease" refers to a disease or disorder involving progressive damage to the structure or function of neurons, including neuron death or demyelination, and / or a disease or disorder caused by an excessive inflammatory response in the nervous system. Advantageously, the neurodegenerative disease and / or neuroinflammatory disease is Alzheimer's disease, dementia associated with Alzheimer's disease (e.g., Pick's disease), Parkinson's disease, diffuse Lewy body disease, senile dementia, Huntington's disease, encephalitis, Gilles de la Tourette syndrome, multiple sclerosis, amyotrophic lateral sclerosis (ALS), progressive supranuclear palsy, epilepsy, schizophrenia, depression, post-traumatic stress disorder, Lou Gehrig's disease, Creutzfeldt-Jakob disease, stroke, fragile X syndrome, multiple system atrophy (MSA), pure autonomic failure (PAF) with synuclein deposition, hereditary neurodegeneration with brain iron accumulation, incidental Lewy body disease in the elderly, Lewy body type Alzheimer's disease, Down syndrome, progressive supranuclear palsy, essential tremor with Lewy bodies, familial Parkinson's syndrome with or without dementia, tau and progranulin gene-related dementia with or without Parkinson's syndrome, bovine spongiform encephalopathy, secondary Parkinson's disease, parkinsonism caused by exposure to neurotoxins, drug-induced parkinsonism with α-synuclein deposition, limbic-predominant age-related TDP-43 encephalopathy (LATE), and sporadic or hereditary spinocerebellar ataxia, and may be selected from the group consisting of or including these. Preferably, the above neurodegenerative disease or neuroinflammatory disease is a synucleinopathy. More preferably, the above neurodegenerative disease or neuroinflammatory disease is a synucleinopathy selected from the group consisting of or including Parkinson's disease, diffuse Lewy body disease, and multiple system atrophy. Even more preferably, the above neurodegenerative disease or neuroinflammatory disease is Parkinson's disease.

[0044] "Neuropathic pain" refers to pain initiated or caused by a primary lesion, dysfunction, or temporary disorder of the peripheral or central nervous system.

[0045] "Oxytetracycline" refers to a molecule of the following formula: [Chemistry]

[0046] Parkinson's disease is a neurodegenerative disorder that causes involuntary or uncontrollable movements such as tremors, stiffness, and difficulty with balance and coordination.

[0047] A "pharmaceutical composition" refers to a combination of at least one active agent and at least one pharmaceutically acceptable excipient.

[0048] "Pharmaceutically acceptable" refers to those that are generally safe, non-toxic, and not biologically, physiologically, or otherwise undesirable for mammals, particularly humans and non-human mammals.

[0049] A "placebo" or "vehicle" refers to a pharmaceutical composition that contains only pharmaceutically acceptable excipient(s) and does not contain an active agent.

[0050] "Prevent" or "preventing" refers to any act that enables the prevention of at least one symptom associated with a condition or the prevention of the underlying cause of the condition.

[0051] "Proteinopathy" refers to a class of diseases in which the structure of a specific protein is abnormal, thereby impairing the function of the body's cells, tissues, and organs. Examples of proteinopathies include, but are not limited to, Parkinson's disease, Huntington's disease, Alzheimer's disease, and limbic-predominant age-related TDP-43 encephalopathy (LATE). In one embodiment, the proteinopathy is selected from the group consisting of or including Parkinson's disease, Huntington's disease, Alzheimer's disease, and limbic-predominant age-related TDP-43 encephalopathy (LATE).

[0052] The "reducing system" refers to one or more reagents capable of reducing the compound of formula (II) according to the invention to the compound of formula (I) according to the invention. Advantageously, the reducing system may comprise a reducing metal. The reducing metal may be a reducing transition metal such as zinc, copper, iron, silver, gold, palladium, rhodium, iridium, platinum, or nickel. Advantageously, the reducing metal is zinc metal. The reducing metal may be used, for example, in the form of a metal powder. Advantageously, the reducing metal of the reducing system may be combined with an acid selected from the group consisting of, for example, hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, and mixtures thereof. Even more advantageously, the reducing metal of the reducing system may be combined with acetic acid.

[0053] "Salt of a compound" refers to an acid addition salt or a base addition salt of the compound. Acid addition salts are formed using pharmaceutically acceptable organic or inorganic acids; base addition salts are formed when the acid protons present in the compound are replaced by metal ions or coordinated with pharmaceutically acceptable organic or inorganic bases. In one embodiment, the acid addition salts are selected from the group consisting of acetate, adipate, aspartate, benzoate, besylate, bicarbonate / carbonate, bisulfate / sulfate, borate, camcylate, citrate, cyclamate, edisylate, esylate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hibenzate, hydrochloride / chloride, hydrobromide / bromide, hydroiodide / iodide, isethionate, lactate, malate, maleate, malonate, mesylate, methyl sulfate, naphthylate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate / monohydrogen phosphate / dihydrogen phosphate, pyroglutamate, saccharate, stearate, succinate, tannate, tartrate, tosylate, trifluoroacetate, and xinafoate. In one embodiment, the base addition salts are selected from the group consisting of salts of aluminum, arginine, benzathine, calcium, choline, diethylamine, 2-(diethylamino)ethanol, diolamine, ethanolamine, glycine, 4-(2-hydroxyethyl)-morpholine, lysine, magnesium, meglumine, morpholine, olamine, potassium, sodium, tromethamine, and zinc.

[0054] "Solvate of a compound" refers to a molecular complex containing the above compound and one or more pharmaceutically acceptable solvent molecules. "Hydrate of a compound" refers to a molecular complex containing the above compound and one or more pharmaceutically acceptable solvent molecules, where the solvent is water.

[0055] "Subject" or "patient" refers to a mammal, and "mammal" refers to a human or a non-human mammal. Preferably, "subject" or "patient" refers to a human (male or female). More preferably, "subject" or "patient" refers to a human who is at least 18 years old, advantageously at least 40 years old, more advantageously at least 50 years old, even more advantageously at least 60 years old, and even more advantageously at least 70 years old or at least 80 years old.

[0056] "Synucleinopathy" refers to a neurodegenerative and / or neuroinflammatory disease characterized by abnormal accumulation of aggregates of α-synuclein protein in neurons, nerve fibers, and / or glial cells. Advantageously, synucleinopathy can be selected from the group consisting of or including Parkinson's disease, diffuse Lewy body disease (DLB), multiple system atrophy (MSA), pure autonomic failure with synuclein deposition (PAF), hereditary neurodegeneration with brain iron accumulation, incidental Lewy body disease in the elderly, Lewy body type Alzheimer's disease, Down syndrome, essential tremor with Lewy bodies, familial Parkinson's syndrome with or without dementia, tau and progranulin gene-related dementia with or without Parkinson's syndrome, Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, secondary Parkinson's disease, parkinsonism due to exposure to neurotoxins, drug-induced parkinsonism with α-synuclein deposition, sporadic or hereditary spinocerebellar ataxia, and amyotrophic lateral sclerosis (ALS).

[0057] "Tetracycline" refers to a molecule of the following formula:

Chem.

Chem.

[0058] "Tetracycline derivative" refers to a molecule having a formula similar to that of tetracycline, particularly having a skeleton of four condensed rings, but with at least one chemical group different from the formula of tetracycline. For example, a molecule whose chemical formula differs from that of tetracycline in 1 to 6 chemical groups, preferably 2 to 4 chemical groups.

[0059] "12a - deoxytetracycline" refers to a tetracycline derivative having a chemical formula in which the hydroxyl group linked to carbon number 12a in the tetracycline formula is replaced by a hydrogen atom.

[0060] The "therapeutically effective amount" or "effective amount" of an active agent or composition refers to an amount of the active agent or composition that is non - toxic but sufficient to produce the desired therapeutic effect.

[0061] "To treat" or "treatment" refers to any act that delays, reduces, or suppresses at least one symptom's severity and / or frequency related to a pathological condition, or slows down or suppresses the root cause of a pathological condition, or enables the improvement or repair of damage. In one embodiment, "treatment" refers to curative treatment.

Mode for Carrying Out the Invention

[0062] The compound of formula (I) The present invention describes a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof, and the above - mentioned formula (I) is

Chemical formula

[0063] Advantageously, the compound of formula (I) is a compound of formula (Ibis), or a pharmaceutically acceptable salt, solvate or mixture thereof, and the above - mentioned formula (Ibis) is [Chemical formula] It is of formula (Ibis), wherein R1 is a hydrogen atom or a hydroxyl group.

[0064] More preferably, the compound of formula (Ibis) is selected from the group consisting of the compound of formula (Ia) and the compound of formula (Ib), and formula (Ia) is [Chemical formula] (Ia), and formula (Ib) is [Chemical formula] (Ib).

[0065] More preferably, the compound of formula (I) is the compound of formula (Ia). The chemical name of the compound of formula (Ia) is (4aS,5R,5aR,6R)-3,5,10,12-tetrahydroxy-6-methyl-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide (named using ChemBioDraw® Ultra version 12.0 (PerkinElmer)).

[0066] More preferably, the compound of formula (I) is the compound of formula (Ib). The chemical name of the compound of formula (Ib) is (4aS,5R,5aR,6S)-3,5,6,10,12-pentahydroxy-6-methyl-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide (named using ChemBioDraw® Ultra version 12.0 (PerkinElmer)).

[0067] Preferably, the compound of formula (I) is the compound of formula (Ic), or a pharmaceutically acceptable salt, solvate or mixture thereof, and the above formula (Ic) is [Chemical formula] It is (Ic).

[0068] A compound of formula (I) for use as a medicament The present invention also describes a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof for use as a medicament in a subject in need thereof.

[0069] The present invention also describes a method for preventing and / or treating a disease by administering to a subject in need thereof an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof.

[0070] The present invention also describes the use of a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof for the manufacture of a medicament.

[0071] The present invention also describes the use of a compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof for the prevention and / or treatment of a disease in a subject.

[0072] A compound of formula (I) for use in the treatment of a disease The present invention relates to a compound of formula (I) according to the present application or a pharmaceutically acceptable salt, solvate or mixture thereof for use in the prevention and / or treatment of a disease selected from the group consisting of or including amyloidosis, pain (preferably neuropathic pain), neurodegenerative diseases and neuroinflammatory diseases.

[0073] The present invention also relates to a method for preventing and / or treating a disease selected from the group consisting of or including amyloidosis, pain (preferably neuropathic pain), neurodegenerative diseases and neuroinflammatory diseases by administering to a subject in need thereof an effective amount of a compound of formula (I) according to the present application or a pharmaceutically acceptable salt, solvate or mixture thereof.

[0074] The present invention also relates to the use of a compound of formula (I) according to the present application, or a pharmaceutically acceptable salt, solvate or mixture thereof, for the manufacture of a medicament for the prevention and / or treatment in a subject of a disease selected from the group consisting of or including amyloidosis, pain (preferably neuropathic pain), neurodegenerative diseases and neuroinflammatory diseases.

[0075] The present invention also relates to the use of a compound of formula (I) according to the present application, or a pharmaceutically acceptable salt, solvate or mixture thereof, for the prevention and / or treatment in a subject of a disease selected from the group consisting of or including amyloidosis, pain (preferably neuropathic pain), neurodegenerative diseases and neuroinflammatory diseases.

[0076] Advantageously, the compound of formula (I) is a compound of formula (Ibis) according to the present invention.

[0077] More advantageously, the compound of formula (I) is a compound of formula (Ia) according to the present invention.

[0078] More advantageously, the compound of formula (I) is a compound of formula (Ib) according to the present invention.

[0079] Advantageously, the compound of formula (I) is a compound of formula (Ic) according to the present invention.

[0080] In one embodiment, the disease is pain. Preferably, the pain is selected from the group consisting of neuropathic pain, nociceptive pain, or central pain. More preferably, the pain is nociceptive pain. Even more preferably, the pain is nociceptive pain induced by a disease selected from the group consisting of osteoarthritis, rheumatoid arthritis, and cancer, preferably cancer. Even more preferably, the pain is neuropathic pain induced by diabetic neuropathy. More preferably, the pain is central pain induced by a disease selected from the group consisting of fibromyalgia, irritable bowel syndrome, or tension headache.

[0081] In one embodiment, the disease is a neurodegenerative disease and / or a neuroinflammatory disease.

[0082] In one embodiment, the disease is a proteinopathy.

[0083] Advantageously, the neurodegenerative disease or neuroinflammatory disease is selected from the group consisting of Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, Alzheimer's disease, prion disease, multiple sclerosis, limbic-predominant age-related TDP-43 encephalopathy (LATE), and Huntington's disease.

[0084] More advantageously, the neurodegenerative disease is selected from the group consisting of Parkinson's disease and Alzheimer's disease.

[0085] In one embodiment, the neurodegenerative disease is Parkinson's disease.

[0086] In one embodiment, the neurodegenerative disease is Alzheimer's disease.

[0087] In one embodiment, the neurodegenerative disease is limbic-predominant age-related TDP-43 encephalopathy (LATE).

[0088] In one embodiment, the disease is a neuroinflammatory disease. The inflammatory disease can be caused by various factors, including, for example, toxic compounds, autoimmunity, aging, infectious pathogens (such as viruses, bacteria, or parasites), nervous system damage, and contaminants.

[0089] In one embodiment, the neuroinflammatory disease is caused by a virus. Examples of viruses that can cause neuroinflammatory diseases include, for example, encephalitis virus, human immunodeficiency virus, poliovirus, and coronavirus.

[0090] In one embodiment, the neuroinflammatory disease is caused by a coronavirus such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-Cov-2). Thus, in one embodiment, the neuroinflammatory disease is COVID-19.

[0091] In one embodiment, the subject in need thereof is a subject in whom the disease defined above is prevented.

[0092] In one embodiment, the subject in need thereof has the disease defined above, preferably is diagnosed with the disease.

[0093] In one embodiment, the subject is pre-symptomatic, i.e., it means that the subject does not exhibit symptoms of the disease. In one embodiment, the subject exhibits symptoms, which means that the subject exhibits symptoms of at least one disease.

[0094] In one embodiment, the subject in need thereof has Parkinson's disease, preferably is diagnosed with Parkinson's disease.

[0095] Examples of symptoms of Parkinson's disease include, but are not limited to, tremors in the hands, arms, legs, jaw, or head, muscle rigidity (muscles remain contracted for a long time), slowness of movement, and decreased balance and coordination (which may lead to falls).

[0096] Methods for diagnosing Parkinson's disease are well known to those skilled in the art and include, for example, neurological examinations, and tests such as the Unified Parkinson's Disease Rating Scale (UPDRS), and Dopamine Transporter Scan (DaTscan).

[0097] In one embodiment, the subject in need thereof has Alzheimer's disease, preferably is diagnosed with Alzheimer's disease.

[0098] Examples of symptoms of Alzheimer's disease include, but are not limited to, confusion, disorientation, difficulty planning or making decisions, speech or language problems, personality changes, as well as mood swings and anxiety.

[0099] Methods for diagnosing Alzheimer's disease are well known to those skilled in the art and include, for example, physical examinations, neurological examinations, and psychiatric examinations.

[0100] In one embodiment, the subject in need thereof suffers from neuropathic pain and is preferably diagnosed with neuropathic pain.

[0101] Examples of symptoms of neuropathic pain include, but are not limited to, spontaneous pain, evoked pain, pain that may be relieved in response to stimuli that usually involve pain.

[0102] Method for producing a compound of formula (I) The present invention also relates to a method for producing a compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof.

[0103] The method comprises the following consecutive steps: a) reacting a compound of formula (II) or a pharmaceutically acceptable salt, solvate or mixture thereof with a reducing system, wherein formula (II) is

Chemical formula

[0104] Preferably, the method comprises the following consecutive steps: a) Reacting a compound of formula (IIbis) or a pharmaceutically acceptable salt, solvate or mixture thereof with a reducing system, wherein formula (IIbis) is [Chemical formula] (IIbis), wherein R2 is a hydrogen atom or a hydroxyl group, and then b) Isolating the compound of formula (I) or a pharmaceutically acceptable salt, solvate or mixture thereof produced during step a). comprising.

[0105] Advantageously, the compound of formula (I) is selected from the group consisting of the compounds of formula (Ibis) and (Ic) according to the present application.

[0106] Advantageously, the compound of formula (I) is selected from the group consisting of the compounds of formula (Ia), (Ib) and (Ic) according to the present application.

[0107] Advantageously, the compound of formula (I) is selected from the group consisting of the compound of formula (Ia) according to the present invention and the compound of formula (Ib) according to the present application.

[0108] Advantageously, the compound of formula (I) is the compound of formula (Ia) according to the present application.

[0109] Advantageously, the compound of formula (I) is the compound of formula (Ib) according to the present application.

[0110] Advantageously, the compound of formula (I) is the compound of formula (Ic) according to the present application.

[0111] Advantageously, R2 is a hydrogen atom.

[0112] Advantageously, the compound of formula (II) is doxycycline, preferably doxycycline hydrochloride.

[0113] Advantageously, R2 is a hydroxyl group.

[0114] Advantageously, the compound of formula (II) is oxytetracycline.

[0115] Advantageously, the compound of formula (I) is a compound of formula (Ia) according to the present invention, and the compound of formula (II) is doxycycline, preferably doxycycline hydrochloride.

[0116] Advantageously, the compound of formula (I) is a compound of formula (Ib) according to the present invention, and the compound of formula (II) is oxytetracycline.

[0117] Step a) is carried out before step b).

[0118] Advantageously, the reduction system in step a) contains a reducing metal, preferably zinc metal.

[0119] Advantageously, the reduction system in step a) is an acid. More advantageously, the acidic reduction system in step a) contains acetic acid. In fact, the inventors of the present invention have surprisingly found that the acidic reduction system enables the acquisition of a large amount and preferably the compound of formula (I) obtained. Further, when the reduction system of step a) is an acid, there is only one reduction step in the process, and this step enables the double reduction of the compound of formula (II) and the acquisition of the compound of formula (I).

[0120] Advantageously, the reduction system in step a) contains an acid such as acetic acid.

[0121] More advantageously, the reduction system in step a) contains a reducing metal and an acid, preferably zinc metal and acetic acid.

[0122] Advantageously, the amount of the reducing metal may be a catalytic amount, a stoichiometric amount or an excess amount, preferably an excess amount, relative to the compound of formula (II). In particular, the amount of the reducing metal may be contained in an amount of 3 to 30 equivalents, preferably 5 to 15 equivalents, relative to the compound of formula (II).

[0123] Advantageously, step a) may be carried out at a temperature of 0 °C to 50 °C, preferably 15 °C to 35 °C, more preferably about 25 °C.

[0124] Advantageously, step a) can be carried out for at least 2 hours, preferably at least 4 hours, more preferably about 8 hours.

[0125] Advantageously, step a) can be carried out at a pressure of 1 atmosphere.

[0126] Advantageously, in step b), the isolation of the compound of formula (I), or a pharmaceutically acceptable salt, solvate or mixture thereof, is carried out by chromatography. Preferably, the chromatography is selected from the group consisting of column chromatography and reverse-phase high performance liquid chromatography (reverse-phase HPLC). More preferably, the chromatography is column chromatography.

[0127] Pharmaceutical composition The present invention also relates to a pharmaceutical composition comprising a compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof, and at least one pharmaceutically acceptable excipient.

[0128] Advantageously, the compound of formula (I) is selected from the group consisting of the compounds of formula (Ibis) and (Ic) according to the present application.

[0129] Advantageously, the compound of formula (I) is selected from the group consisting of the compounds of formula (Ia), (Ib) and (Ic) according to the present application.

[0130] Advantageously, the compound of formula (I) is the compound of formula (Ibis) according to the present invention.

[0131] Even more advantageously, the compound of formula (I) is the compound of formula (Ia) according to the present invention.

[0132] More preferably, the compound of formula (I) is the compound of formula (Ib) according to the present invention.

[0133] Preferably, the compound of formula (I) is the compound of formula (Ic) according to the present invention.

[0134] Preferably, the pharmaceutical composition comprises from 0.1% to 99% by weight, preferably from 1% to 50% by weight, more preferably from 5% to 25% by weight, even more preferably about 20% by weight, of the compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof, based on the total weight of the pharmaceutical composition.

[0135] Preferably, for oral administration, the pharmaceutical composition can be formulated into conventional oral dosage forms such as tablets, gels, capsules, powders, granules, and liquid preparations such as syrups, elixirs, and concentrated drops. Non-toxic solid carriers or diluents may be used, and they include, for example, pharmaceutical grade mannitol, lactose, starch, magnesium stearate, sodium saccharin, talc, cellulose, glucose, sucrose, magnesium carbonate, etc. For compressed tablets, a binder, which is an agent that imparts adhesiveness to the powder material, is also necessary. For example, saccharides such as starch, gelatin, lactose or dextrose, and natural or synthetic gums can be used as binders. A disintegrant is also necessary in the tablet to promote the disintegration of the tablet. Examples of disintegrants include starch, clay, cellulose, algin, gums, and cross-linked polymers. Furthermore, lubricants and glidants are also included in the tablet to prevent the tablet material from adhering to the surface during the manufacturing process and to improve the flow properties of the powder material during manufacturing. Colloidal silicon dioxide is most commonly used as a glidant, and compounds such as talc or stearic acid are most commonly used as lubricants.

[0136] Advantageously, at least one pharmaceutically acceptable excipient of the pharmaceutical composition is selected from the group consisting of microcrystalline cellulose, magnesium stearate, povidone, hydrogenated castor oil, colloidal anhydrous silica, sodium carboxymethyl starch, and combinations thereof.

[0137] Advantageously, the pharmaceutical composition can be formulated to release the compound of formula (I) according to the invention or a pharmaceutically acceptable salt, solvate or mixture thereof substantially immediately after administration, or at any predetermined time or period after administration.

[0138] Pharmaceutical composition for use The present invention also relates to a pharmaceutical composition according to the invention as described above for use as a medicament.

[0139] The present invention also relates to a method of preventing and / or treating a disease by administering an effective amount of the pharmaceutical composition according to the invention as described above to a subject in need thereof.

[0140] The present invention also relates to the use of a pharmaceutical composition according to the invention as described above for the manufacture of a medicament.

[0141] The present invention also relates to the use of a pharmaceutical composition according to the invention as described above for the prevention and / or treatment of a disease in a subject.

[0142] The present invention also relates to a pharmaceutical composition according to the invention as described above for use in the prevention and / or treatment of a disease selected from or consisting of amyloidosis, pain, neurodegenerative diseases and neuroinflammatory diseases.

[0143] The present invention also relates to a pharmaceutical composition according to the invention as described above for use in the prevention and / or treatment of a disease selected from or consisting of amyloidosis, neuropathic pain, neurodegenerative diseases and neuroinflammatory diseases.

[0144] The present invention also relates to a method of preventing and / or treating a disease comprising or selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases, and neuroinflammatory diseases by administering to a subject in need thereof an effective amount of the pharmaceutical composition according to the present invention as described above.

[0145] The present invention also relates to the use of the pharmaceutical composition according to the present invention as described above for the manufacture of a medicament for the prevention and / or treatment in a subject of a disease comprising or selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases, and neuroinflammatory diseases.

[0146] The present invention also relates to the use of the pharmaceutical composition according to the present invention as described above for the prevention and / or treatment in a subject of a disease comprising or selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases, and neuroinflammatory diseases.

[0147] In one embodiment, the disease is pain. Preferably, the pain is selected from the group consisting of neuropathic pain, nociceptive pain, or central pain. More preferably, the pain is nociceptive pain. Even more preferably, the pain is nociceptive pain induced by a disease selected from the group consisting of osteoarthritis, rheumatoid arthritis, and cancer, preferably cancer. Even more preferably, the pain is neuropathic pain induced by diabetic neuropathy. More preferably, the pain is central pain induced by a disease selected from the group consisting of fibromyalgia, irritable bowel syndrome, or tension headache.

[0148] The advantageous features described in the "Compound of Formula (I) for Use in the Treatment of Diseases" section of the present application are applied mutatis mutandis to pharmaceutical compositions for use in the prevention and / or treatment of diseases comprising or selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases, and neuroinflammatory diseases.

[0149] Route of administration and dosage Advantageously, the compound of formula (I) according to the invention or a pharmaceutically acceptable salt, solvate or mixture thereof, or the pharmaceutical composition of the invention is administered by enteral or parenteral routes of administration.

[0150] Advantageously, the compound of formula (I) is selected from the group consisting of the compounds of formula (Ibis) and (Ic) according to the present application.

[0151] Advantageously, the compound of formula (I) is selected from the group consisting of the compounds of formula (Ia), (Ib) and (Ic) according to the present application.

[0152] Advantageously, the compound of formula (I) is the compound of formula (Ibis) according to the invention.

[0153] Even more advantageously, the compound of formula (I) is the compound of formula (Ia) according to the invention.

[0154] Even more advantageously, the compound of formula (I) is the compound of formula (Ib) according to the invention.

[0155] Advantageously, the compound of formula (I) is the compound of formula (Ic) according to the invention.

[0156] Even more advantageously, the enteral route can be selected from the group consisting of the buccal route (such as the sublingual route and the sublingual route), the oral route and the rectal route. Preferably, the compound of formula (I) according to the invention or a pharmaceutically acceptable salt, solvate or mixture thereof, or the pharmaceutical composition of the invention is administered by the oral route.

[0157] Parenteral includes any route that is not enteral. More preferably, the parenteral route can be selected from the group consisting of epidural route, intraspinal route, intracerebral route, intraventricular route, cutaneous route, transdermal route, intradermal route, subcutaneous route, nasal route, intraarterial route, intraarticular route, intravenous route, intramuscular route, intraperitoneal route, intraocular route, intravitreal route, intrathecal route and intravitreal route. Preferably, the compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof, or the pharmaceutical composition of the present invention is administered by the intravenous route.

[0158] Advantageously, the single dose of the compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof, or the pharmaceutical composition according to the present invention is administered regularly, preferably 3 times a day to once a month, more preferably 3 times a day to once a week, even more preferably 3 times a day to once a day. Even more preferably, the single dose of the compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof, or the pharmaceutical composition according to the present invention is administered once, twice or three times a day, preferably once a day.

[0159] Advantageously, the dosage of the compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof administered to a subject is about 1 to 100 mg / kg of the subject's body weight by intravenous, intramuscular injection or oral route, preferably oral route.

[0160] Advantageously, the dosage of the compound of formula (I) according to the present invention or a pharmaceutically acceptable salt, solvate or mixture thereof administered to a subject is in the range of 50 mg to 150 mg, preferably 70 mg to 130 mg, and more preferably, the dosage is about 100 mg.

[0161] 12a-Deoxytetracycline for use in the treatment of pain The present invention also relates to 12a-deoxytetracycline for use in the treatment of pain.

[0162] The present invention also relates to a method of preventing and / or treating pain by administering to a subject in need thereof an effective amount of 12a-deoxytetracycline.

[0163] The present invention also relates to the use of 12a-deoxytetracycline for the manufacture of a medicament for the prevention and / or treatment of pain in a subject in need thereof.

[0164] The present invention also relates to the use of 12a-deoxytetracycline for the prevention and / or treatment of pain in a subject in need thereof.

[0165] Advantageously, 12a-deoxytetracycline is selected from the group consisting of the following compounds:

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0166] Indeed, as demonstrated in Example 10 of the present application, 12a-deoxytetracycline has an anti-nociceptive effect.

[0167] Advantageously, the pain is selected from the group consisting of neuropathic pain, nociceptive pain, or central pain.

[0168] More preferably, the pain is nociceptive pain induced by a disease selected from the group consisting of osteoarthritis, rheumatoid arthritis, and cancer, preferably cancer.

[0169] More preferably, the pain is neuropathic pain induced by diabetic neuropathy.

[0170] More preferably, the pain is central pain induced by a disease selected from the group consisting of fibromyalgia, irritable bowel syndrome, or tension headache.

[0171] Preferably, 12a-deoxytetracycline is a compound of formula (Ia), and the subject is female.

[0172] Preferably, 12a-deoxytetracycline is a compound of formula (C), and the subject is male.

[0173] Indeed, as demonstrated in Example 10 of the present application, there is a gender-dependent analgesic effect of the compound of formula (C) and the compound of formula (Ia). BRIEF DESCRIPTION OF THE DRAWINGS

[0174]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0175] Example The present invention will be further illustrated by the following examples. Example 1: Synthesis of the compound of formula (Ia) according to the present invention Materials and methods In a 500 mL round-bottom flask, doxycycline monohydrate (5.5 g, 11.9 mmol, 1.0 equivalent) was suspended in water (50 mL), stirred, and then 35% HCl (1.5 mL, 17 mmol, 1.4 equivalents) and AcOH (50 mL) were added. After dissolution of the mixture, zinc powder (7.8 g, 119 mmol, 10 equivalents) was added and the reaction mixture was stirred at room temperature for 4 hours. The resulting mixture was filtered through a small pad of celite with acetic acid (AcOH). The organic phase was extracted with CH2Cl2, washed with HCl (1 M) and brine, dried over MgSO4, filtered off, and concentrated under vacuum. Purification of the residue was carried out by automated combi flash chromatography [petroleum ether: acetone + 1% HCOOH; silica gel column Buchi Flashpure 120 g; from 0% to 10% acetone over 20 minutes, then from 10% to 11.3% acetone over 5.1 minutes, then isocratic for 22.7 minutes, then from 11.3 to 20% acetone over 10.4 minutes (total 58.2 minutes)].

[0176] The reaction scheme is as follows:

Chemical formula

[0177] The chemical structure of the compound of formula (Ia) obtained according to the present invention was verified by proton (1H) and carbon (13C) NMR (nuclear magnetic resonance) analysis performed on an NMR spectrometer. Chemical shifts (δ) were expressed in parts per million (ppm). The residual solvent peak was used as a reference. The following abbreviations were used 1 in the notation of the H spectrum: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet. Coupling constants (J) were expressed in Hz and determined for doublets, triplets, and quartets.

[0178] Results The compound of formula (Ia) according to the present invention was obtained in a yield of 21% by weight based on the total weight of the product doxycycline and had a purity higher than 95%.

[0179] For the compound of formula (Ia) according to the present invention: 1 1H NMR (400 MHz, acetone-d6) δ = 18.49 (s, 1H), 14.91 (s, 1H), 12.15 (s, 1H), 9.24 (s, 1H), 7.70 (s, 1H), 7.51 (t, J = 7.9 Hz, 1H), 6.84 (d, J = 7.5 Hz, 1H), 6.76 (d, J = 8.3 Hz, 1H), 4.54 (brd, J = 6.6 Hz, 1H), 3.94 (d, J = 4.9 Hz, 1H), 3.71 (q, J = 7.5 Hz, 1H), 3.35 (ddd, J = 10.5, 9.0, 5.0 Hz, 1H), 2.81 (d, J = 4.6 Hz, 1H), 2.63 (ddd, J = 13.5, 8.7, 4.6 Hz, 1H), 2.44 - 2.31 (m, 2H), 1.48 (d, J = 7.4 Hz, 3H). 1313C NMR (101 MHz, acetone-d6) δ = 201.06, 197.50, 191.26, 174.77, 168.87, 163.67, 148.75, 138.28, 120.90, 116.20, 115.53, 103.93, 99.86, 70.98, 49.05, 46.74, 39.82, 37.30, 32.34, 22.96.

[0180] The calculated mass of the compound of formula (Ia) according to the present invention is 386.1234 g / mol -1 and the observed mass was 386.1238 g / mol in HRMS (high-resolution mass spectrum). -1 (HRMS (ESI) m / z: calculated value [M+H] + 19 20 22 19 1NO7 386.1234; observed value 386.1238).

[0181] Example 2: Evaluation of the anti-aggregation effect of the compound of formula (Ia) according to the present invention Materials and methods The anti-aggregation effect of the compound of formula (Ia) according to the present invention on α-synuclein (αS) was evaluated in vitro by measuring the fluorescence intensity of probe thioflavin T (ThT), a molecule that specifically binds to the cross-β structure, which is a characteristic of amyloid-like aggregation. The compound of formula (Ia) was dissolved in dimethyl sulfoxide to reach a concentration of 50 μM. In this assay, 70 μM of α-synuclein was incubated at 37 °C for 5 days with and without 10 μM, 20 μM, and 50 μM of the compound of formula (Ia) under orbital stirring (600 rpm). After the incubation time, ThT was added to each sample, and the change in the emission fluorescence spectrum (λex = 450 and λem = 480 nm) was monitored using a Horiba Fluoromax CP4 spectrofluorometer.

[0182] By using a transmission electron microscope (TEM), the aggregation of α-synuclein in the presence of 20 μM of the compound of formula (Ia) was studied under the same conditions as above. To mount the samples, 5 μL of a 7 μM α-synuclein solution was adsorbed onto a copper grid (Electron Microscopy Sciences) coated with a formvar carbon film and stained with uranyless.

[0183] Results The data obtained are related to the changes in the emission fluorescence spectrum, indicating that the compound of formula (Ia) of the present invention significantly inhibits the aggregation of α-synuclein in a dose-dependent manner at 10 μM (p = 0.0360), 20 μM (p = 0.0077), and 50 μM (p = 0.0002) compared to the control (αS) (see Figure 1A).

[0184] Photographs taken from different fields of view are consistent with the ThT results (Figure 1A), revealing that the presence of 20 μM of the compound of formula (Ia) according to the present invention clearly reduces the amount of α-synuclein protofibrils compared to the control (α-synuclein only) where typical protofibril morphology can be seen (Figure 1B).

[0185] Example 3: Comparison of the antimicrobial activity of the compound of formula (Ia) according to the present invention with that of prior art compounds Materials and methods The bacterial strains used in this study were: Staphylococcus aureus (S. aureus) (ATCC25923), Escherichia coli (E. coli) (ATCC25922), Enterococcus faecalis (E. faecalis) (ATCC29212), and Pseudomonas aeruginosa (P. aeruginosa) (PA01). The strains were maintained at -80 °C in 15% (v / v) glycerol for cryoprotection. The bacteria were cultured regularly in Mueller-Hinton (MH) broth at 37 °C.

[0186] The susceptibility of bacterial strains to antibiotics and compounds was measured in microplates using the standard broth dilution method according to the recommendations of the Comité de l’Antibiogramme de la Société Française de Microbiologie (CA-SFM) (Members of the SFM Antibiogram Committee, R. Int. J. Antimicrob. Agents 2003, 21, 364). Briefly, the minimum inhibitory concentration (MIC) was measured by inoculation of 10 5 CFU in 200 μL of MH broth containing two-fold serial dilutions of each drug. The MIC was defined as the lowest concentration of the drug that completely inhibited visible growth after inoculation at 37 °C for 18 h. The measurements were repeated independently three times to determine all MICs.

[0187] The compounds of formula (Ia) according to the invention were tested against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis) of clinical isolates. The minimum inhibitory concentration (MIC) was tentatively determined and compared with known antibiotics tetracyclines (doxycycline, demeclocycline, chlortetracycline) and the compound of formula (B) disclosed in Example 1 of the present application. The tests were reproduced twice and the average MIC was calculated.

[0188] Results These results are shown in the following table:

[0189] [Table 1]

[0190] As can be seen in Table 1, surprisingly and interestingly, the compounds according to formula (Ia) of the invention showed no activity against Gram-positive and Gram-negative bacteria up to 200 mg / mL and were less active against Staphylococcus aureus than the compound of formula (B).

[0191] Example 4: Comparison of the neuroprotective effect of the compound of formula (Ia) according to the present invention with that of a compound of the prior art Materials and methods In the primary culture of dopaminergic neurons, TH+ neurons are subjected to oxidative stress and neuronal death occurs after several days. When cultured in the presence of a positive reference (apotransferrin), dopaminergic neurons survive. The neuroprotective effects of 10 μM doxycycline (DOX) and 3 μM or 5 μM of the compound of formula (Ia) according to the present invention were evaluated in comparison with the effect of 100 μg / mL apotransferrin (APO).

[0192] Results The results are shown in Figure 2. As can be seen in Figure 2, compared with doxycycline showing a neuroprotective effect at 10 μM, the compound of formula (Ia) according to the present invention was highly protective even at only 3 μM and 5 μM.

[0193] Example 5: Comparison of the anti-inflammatory effect of the compound of formula (Ia) according to the present invention with that of a compound of the prior art Materials and methods Microglia are responsible for protecting neurons. However, under stress conditions, microglial cells are the cause of inflammatory phenomena and ultimately lead to neuronal death.

[0194] The anti-inflammatory effects of 5 μM and 20 μM of the compound of formula (B) shown in Example 1, 5 μM and 20 μM of the compound of formula (Ia) according to the present invention, and 50 μM doxycycline (DOX) were evaluated in comparison with the effect of 2.5 μM dexamethasone (DEX).

[0195] Results The results are shown in Figure 3. As can be seen in Figure 3, the compound of formula (Ia) inhibits the inflammatory process (produced by LPS) in a more efficient manner than both doxycycline and the compound of formula (B).

[0196] Example 6: Comparison of the anti-inflammatory effect of the compound of formula (Ia) according to the present invention with that of a compound of the prior art Materials and Methods Microglia are responsible for protecting neurons. However, under stress conditions, microglial cells are the cause of inflammatory phenomena and ultimately lead to neuron death.

[0197] The anti-inflammatory effects of the compounds of formula (C) according to the invention at 10 μM and 20 μM ("10 μM (C)" and "20 μM (C)") and of the compounds of formula (Ia) at 10 μM and 20 μM (hereinafter "10 μM (Ia)" and "20 μM (Ia)") were evaluated in comparison with the effect of 2.5 μM of dexamethasone (hereinafter "DEX").

[0198] The "compound of formula (C)" refers to a molecule of the following formula. [Chemical formula] Compound of formula (C).

[0199] Results The results are shown in Figure 4. As can be seen in Figure 4, the compounds of formula (Ia) inhibited the inflammatory process (generated by LPS) in an efficient manner, while the compounds of formula (C) were unable to inhibit the inflammatory process.

[0200] Example 7: Comparison of the properties of the compounds of formula (Ia) according to the invention with the properties of compounds of the prior art Materials and Methods The properties of tetracycline derivatives containing the compounds of formula (Ia) according to the invention were compared with respect to neuroprotective effect, anti-inflammatory effect, anti-aggregation activity, and antibiotic activity. These properties were evaluated as described above.

[0201] The following compounds were tested: the compound of formula (Ia) according to the invention, the compound of formula (C) disclosed in Example 6 of the present application, the compound of formula (D), the compound of formula (E), doxycycline, the compound of formula (B) disclosed in Example 1 of the present application, chlortetracycline, the compound of formula (F), the compound of formula (G), and the compound of formula (H).

[0202] The "compound of formula (D)" refers to a molecule of the following formula:

Chem.

[0203] The "compound of formula (E)" refers to a molecule of the following formula:

Chem.

[0204] The "compound of formula (F)" refers to incyclinide (CMT-3, COL-3) having the CAS number 15866-90-7 and the following formula:

Chem.

[0205] The "compound of formula (G)" refers to a molecule of the following formula:

Chem.

[0206] The "compound of formula (H)" refers to a molecule of the following formula.

Chem.

[0207] Results An overview of the properties of the tetracycline derivatives is shown in the following table.

Table 2

[0208] EC50 and IC50 are determined graphically. * Rescue of dopamine neurons from spontaneous oxidative stress; ** Inhibition of TNFα release under LPS exposure,# Weak antibiotic activity against only one of the three bacterial strains (i.e., Staphylococcus aureus). ## Strong antibiotic activity against all three bacterial strains. ### Significant antibiotic activity against two bacterial strains.

[0209] As shown above in the present specification, the compounds of formula (Ia) according to the present invention exhibit advantageous properties as compared to other tetracycline derivatives. In particular, the compounds of formula (Ia) according to the present invention have a neuroprotective effect, an anti-inflammatory effect, and an anticoagulant effect, and do not have antibiotic activity.

[0210] Example 8: Comparison of the neuroprotective effect of the compound of formula (Ib) according to the present invention with the neuroprotective effect of a compound of the prior art Materials and methods Midbrain mouse cultures were subjected to a maturation step until day 7 in vitro (div), and then gradually exposed to phenol red-supplemented DMEM / nutrient mixture F12 Ham supplemented with 20 μg / mL insulin and 2 μM NMDA receptor antagonist MK-801. Under these conditions that promote a low level of persistent oxidative damage and ultimately result in dopamine cell death, treatment with the compound of formula (Ib) according to the present invention (at a concentration range of 0.1 - 5 μM), as well as treatment with or without the reference tetracycline antibiotic doxycycline (DOX; 10 μM) and the glycoprotein apotransferrin (APO; 100 μg / mL) used as a reference neuroprotective agent, was carried out. At div 14, the cultures were fixed and then subjected to tyrosine hydroxylase (TH) immunocytochemistry to estimate the survival of dopamine neurons.

[0211] Results The results are shown in Figure 5. As can be seen in Figure 5, compared to doxycycline, which shows a neuroprotective effect at 10 μM, the compound of formula (Ib) according to the present invention was highly protective at only 0.5 μM, 1 μM, and 5 μM. Thus, these results indicate that the compound of formula (Ib) according to the present invention effectively protects dopamine neurons from degeneration.

[0212] Furthermore, the effect of the compound of formula (Ib) according to the present invention is reproduced by glycoprotein apotransferrin, a molecule having iron chelating ability, suggesting that the compound of formula (Ib) according to the present invention acts by preventing the harmful consequences of the Fenton-type reaction that generates hydroxyl radicals and the resulting oxidative degradation of lipids. Overall, these results support that the compound of formula (Ib) according to the present invention has potential value against the low-level oxidative stress damage that occurs chronically particularly in the process of PD neurodegeneration.

[0213] Example 9: Comparison of the antimicrobial activity of the compound of formula (Ib) according to the present invention with that of the compounds of the prior art Materials and methods The bacterial strains used in this test were: Staphylococcus aureus (S. aureus) (ATCC25923), Escherichia coli (E. coli) (ATCC28922), Enterococcus faecalis (E. faecalis) (ATCC29212), and Pseudomonas aeruginosa (P. aeruginosa) (PA01). The minimum inhibitory concentration (MIC) was estimated using a standard protocol (Mawabo et al, J. Infect. Public Health 2015).

[0214] Results These results are shown in the following table:

[0215] [Table 3]

[0216] As can be seen in Table 2, surprisingly and interestingly, the data show that oxytetracycline has an antimicrobial effect against three of the four test bacterial strains, while the compound of formula (Ib) according to the present invention is not effective against any of them.

[0217] Example 10: Analgesic effects of the compound of formula (Ia) according to the present invention and the compound of formula (C) described in Example 6 Materials and methods

[0218] The analgesic effects of the compound of formula (C) described in Example 6 (administered at doses of 5 mg / kg animal, 10 mg / kg animal, 20 mg / kg animal) and the compound of formula (Ia) according to the present invention (administered at doses of 10 mg / kg animal, 20 mg / kg animal, 40 mg / kg animal) were tested using the formalin-induced nociceptive pain model (disclosed in the literature "A refinement to the formalin test in mice [version 2; peer review: 2 approved]" F1000Research 2019, 8:891 by Lopes DM, Cater HL, Thakur M et al.).

[0219] Results These results showed that the non-antibiotic tetracyclines of formula (Ia) and formula (C) reduced pain-related responses in mice subjected to the formalin test.

[0220] In particular, subchronic treatment regimens (six subcutaneous injections per day) of adult male C57 / BL6 mice with the compound of formula (C) at 5 mg / kg were found to be very effective in reducing nociceptive pain in both the first and second phases of the study. These effects were indistinguishable from those of similarly administered morphine (10 mg / kg). The compounds of formula (Ia) were also effective, exhibiting analgesic effects at 20 - 40 mg / kg in the first and second phases of the study. Interestingly, a single injection of the compound of formula (C) (10 mg / kg) prior to formalin injection produced a potent nociceptive effect in both the first and second phases of the study, which was indistinguishable from that of morphine (10 mg / kg). A single injection of the compound of formula (Ia) (40 mg / kg) prior to formalin injection also produced a nociceptive effect in both phases. Notably, in the second phase of the formalin test, male mice exhibited a better analgesic response to a single injection of the compound of formula (C) (10 mg / kg), while female mice responded more effectively to the corresponding treatment with the compound of formula (Ia) (40 mg / kg). This suggests a gender - dependent analgesic effect of the compounds of formula (C) and formula (Ia).

[0221] Therefore, these results demonstrated that 12a - deoxytetracycline has a nociceptive effect.

[0222] Example 11: Ability of the compound of formula (Ia) according to the invention and the compound of formula (C) described in Example 6 to penetrate into the brain Materials and methods Adult Swiss mice were given a single subcutaneous injection of the compound of formula (Ia) according to the present invention at 40 mg / kg, the compound of formula (C), or doxocycline diluted in physiological saline containing 5% DMSO and 5% Tween 80 (doxocycline was used as reference tetracycline). The mice were sacrificed 30 minutes, 1 hour, 8 hours, and 24 hours after treatment. After sacrifice, brain and serum samples were collected and processed at each time point for tetracycline administration using a UHPLC system combined with a triple quadrupole mass spectrometer LCMS-8030 (Shimadzu Corporation, Kyoto, Japan).

[0223] Results The brain / plasma ratios calculated from the area under the concentration-time curve in the brain and plasma were 0.27 ± 0.13, 0.21 ± 0.05, and 0.11 ± 0.03 (n = 3) for the compound of formula (C), the compound of formula (Ia), and doxocycline, respectively, suggesting that the compounds of formula (C) and formula (Ia) penetrate the brain better than doxocycline.

[0224] Example 12: Inhibition of phosphorylation of protein tau by the compound of formula (Ib) according to the present invention and the compound of formula (C) described in Example 6 Materials and methods Using a culture model of cortical neurons derived from mouse fetal brains, the neuronal cells were subjected to a maturation step until day 7 in vitro (div), and then gradually exposed to phenol red-free DMEM / nutrient mixture F12 Ham supplemented with 20 μg / mL insulin and 2 μM NMDA receptor blocker MK-801 (DF12i).

[0225] Results Under these conditions that promote persistent low-level oxidative damage, due to the presence of a small amount of catalytic iron in the DF12i medium, a significant proportion of microtubule-associated protein 2+ neurons exhibit high levels of p-tau (AT8 immunoreactivity) (p-tau = tau protein phosphorylated at Ser202 and Thr205 residues) in their cell bodies and neurite extensions when degeneration is progressing. Specifically, after 4 days of exposure to DF12i, 10-15% of the surviving neurons show very strong AT8 immunoreactivity in their cell bodies, while only 1-1.5% of the neuron cell bodies are found to be immunoreactive under conditions where oxidative stress is suppressed by treatment with bovine apotransferrin (APO, 100 μg / mL, Sigma Aldrich), a glycoprotein with iron chelating properties. Similarly, the overexpression of p-tau in cortical cell bodies is decreased by two non-antibiotic tetracycline compounds, a compound of formula (C) (3 μM) and a compound of formula (Ib) (3 μM). See the following table:

[0226]

Table 4

[0227] In conclusion, there is inhibition of the pathological phosphorylation of tau by the compounds of formula (Ib) according to the invention and by the compounds of formula (C) described in Example 6. The phosphorylation of tau is the first step towards its aggregation. Indeed, in Alzheimer's disease and related disorders called tauopathies, tau becomes hyperphosphorylated and mislocalized, which can contribute to its aggregation and toxicity. Thus, the compounds of formula (Ib) and the compounds of formula (C) according to the invention are therapeutically interesting in the treatment of diseases in which the protein tau is involved, in particular Alzheimer's disease and related disorders called tauopathies.

[0228] Example 13: Comparison of the neuroprotective effect of the compounds of formula (Ic) according to the invention with the neuroprotective effect of compounds of the prior art Materials and methods Midbrain mouse cultures were subjected to a maturation step until day 7 in vitro (div), and then gradually exposed to phenol red - supplemented DMEM / nutrient mixture F12Ham supplemented with 20 μg / mL insulin and 2 μM NMDA receptor antagonist MK - 801. Under these conditions that preferentially and ultimately lead to dopamine cell death with a low level of persistent oxidative stress, treatment with the compounds of formula (Ic) according to the invention (at concentrations in the range of 0.1 - 5 μM), and treatment with or without the glycoprotein apotransferrin (APO; 100 μg / mL) used as a reference neuroprotective agent were carried out. At div14, the cultures were fixed and then subjected to tyrosine hydroxylase (TH) immunocytochemistry to estimate the survival of dopamine neurons.

[0229] Results The results are shown in Figure 6. As can be seen in Figure 6, the compounds of formula (Ic) according to the invention were highly protective at just 0.5 μM, 1 μM, and 5 μM. Thus, these results show that the compounds of formula (Ic) according to the invention efficiently protect dopamine neurons from degeneration in a concentration - dependent manner.

[0230] Furthermore, the compounds of formula (Ic) according to the invention do not show any antimicrobial effect against bacteria.

[0231] Furthermore, the compounds of formula (Ic) according to the present invention have an anti-inflammatory effect against 10 ng / mL of LPS at 5 μM, 25 μM, and 50 μM.

[0232] Example 14: Analgesic effect of the compounds of formula (Ia) and (C) according to the present invention Materials and methods To examine the analgesic effect of the compounds (Ia) and (C) according to the present invention, a formalin pain test was conducted, which consisted of subcutaneous injection of 50 μl of 5.0% formalin solution into the right hind paw of adult C57 / BL6 mice (Taylor and Basbaum, J Pain, 2000) before scoring pain behavior. The intensity of pain was estimated by recording the cumulative time (seconds) during which the animal licked / bitten in response to formalin injection. This response was divided into a transient initial phase (Phase I) and a subsequent longer-term late phase (Phase II). Pain scoring was performed by an experimenter blinded to the test treatment using video recordings of formalin-induced pain behavior.

[0233] Results These results are shown in FIGS. 7, 8, and 9. As can be seen, both compounds (Ia) and (C) according to the present invention showed an analgesic effect.

[0234] Example 15: Anti-inflammatory effect of the compound of formula (Ib) according to the present invention Materials and methods Primary mouse microglial cells cultured in Dulbecco's Modified Eagle Medium (DMEM) without serum and 15 mM Hepes were challenged with lipopolysaccharide (LPS, 10 ng / ml) for 24 hours in the presence or absence of the compound of formula (Ib) according to the present invention at concentrations of 1 μM, 5 μM, 25 μM, and 50 μM. Subsequently, the release of the pro-inflammatory cytokine TNF-α was estimated using an ELISA kit (ThermoFisher Scientific).

[0235] Results The results are shown in Fig. 10. As can be seen in Fig. 10, these results indicate that the compound of formula (Ib) according to the present invention significantly reduces the inflammation-inducing effect of LPS at a concentration of 5 μM to 50 μM.

Claims

1. A composition for use in the treatment or prevention of a disease selected from the group consisting of amyloidosis, pain, neurodegenerative diseases and neuroinflammatory diseases, comprising a compound of formula (I) or a pharmaceutically acceptable salt, solvate, or mixture thereof, wherein the compound of formula (I) is 【Chemistry 1】 And in the formula, R １ and R ３ Each of these is independently selected from the group consisting of hydrogen atoms and hydroxyl groups.

2. The compound of formula (I) is a compound of formula (Ibis) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ibis) is 【Chemistry 2】 And in the formula, R １ The composition according to claim 1, wherein is a hydrogen atom or a hydroxyl group.

3. The compound of formula (I) is the compound of formula (Ia) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ia) is 【Transformation 3】 The composition according to claim 1.

4. The compound of formula (I) is the compound of formula (Ib) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ib) is 【Chemistry 4】 The composition according to claim 1.

5. The compound of formula (I) is the compound of formula (Ic) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ic) is 【Transformation 5】 The composition according to claim 1.

6. The composition according to any one of claims 1 to 5, wherein the disease is selected from the group consisting of amyloidosis, neuropathic pain, neurodegenerative diseases, and neuroinflammatory diseases.

7. The composition according to any one of claims 1 to 5, wherein the neurodegenerative disease or neuroinflammatory disease is selected from the group consisting of Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, Alzheimer's disease, prion disease, multiple sclerosis, limbic-dominant age-related TDP-43 encephalopathy (LATE), and Huntington's disease.

8. The composition according to any one of claims 1 to 5, wherein the neurodegenerative disease is Parkinson's disease or Alzheimer's disease, preferably Parkinson's disease.

9. A pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and at least one pharmaceutically acceptable excipient, wherein the compound of formula (I) is 【Transformation 6】 And in the formula, R １ and R ３ Each of these is independently selected from the group consisting of hydrogen atoms and hydroxyl groups, and is a pharmaceutical composition.

10. The compound of formula (I) is a compound of formula (Ibis) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ibis) is 【Transformation 7】 And in the formula, R １ The pharmaceutical composition according to claim 9, wherein is a hydrogen atom or a hydroxyl group.

11. The compound of formula (I) is the compound of formula (Ia) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ia) is 【Transformation 8】 The pharmaceutical composition according to claim 9.

12. The compound of formula (I) is the compound of formula (Ib) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ib) is 【Chemistry 9】 The pharmaceutical composition according to claim 9.

13. The compound of formula (I) is the compound of formula (Ic) or a pharmaceutically acceptable salt, solvate, or mixture thereof, and the compound of formula (Ic) is 【Chemistry 10】 The pharmaceutical composition according to claim 9.

14. The pharmaceutical composition according to any one of claims 9 to 13, wherein the at least one pharmaceutically acceptable excipient is selected from the group consisting of microcrystalline cellulose, magnesium stearate, povidone, hydrogenated castor oil, colloidal anhydrous silica, sodium carboxymethyl starch, and combinations thereof.

15. A pharmaceutical composition according to any one of claims 9 to 13, for use as a pharmaceutical.

16. A pharmaceutical composition according to any one of claims 9 to 13, for use in the treatment or prevention of a disease selected from the group consisting of amyloidosis, pain, neurodegenerative diseases and neuroinflammatory diseases, wherein the neurodegenerative disease is selected from the group consisting of Parkinson's disease, diffuse Lewy body disease, multiple system atrophy, Alzheimer's disease, prion disease, multiple sclerosis, limbic-dominant age-related TDP-43 encephalopathy (LATE), and Huntington's disease, and more preferably the neurodegenerative disease is Parkinson's disease.

17. A pharmaceutical composition according to any one of claims 9 to 13, which is administered by a route of administration selected from the group consisting of an oral route, an intraspinal route, an intraarterial route, an intravenous route, an intramuscular route, and a subcutaneous route, preferably administered by an oral route.

18. A composition comprising 12a-deoxytetracycline for use in the treatment of pain.

19. The 12a-deoxytetracycline is the following compound: 【Chemistry 11】 A composition according to claim 18, selected from the group consisting of the following.

20. The composition according to claim 18 or 19, wherein the pain is selected from the group consisting of neuropathic pain, nociceptive pain, or central pain.

21. The composition according to claim 18 or 19, wherein the pain is nociceptive pain induced by a disease selected from the group consisting of osteoarthritis, rheumatoid arthritis, and cancer, preferably by cancer.

22. The composition according to claim 18 or 19, wherein the pain is neuropathic pain induced by diabetic neuropathy.

23. The composition according to claim 18 or 19, wherein the pain is central pain induced by a disease selected from the group consisting of fibromyalgia, irritable bowel syndrome, or tension headache.

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