Compounds derived from dihydropyridine, pharmaceutical compounds comprising said compounds, and methods of treating muscle disorders comprising administering said compositions

Abstract

The invention of the present application relates to compounds derived from tetrahydrofuran [3, 4-b] pyridine-3-carboxylic acid esters, pharmaceutical compositions comprising said compounds, and methods of preventing and treating muscle conditions comprising administering said pharmaceutical compositions in a subject in need thereof to restore muscle function.

Description

Technical Field

[0001] The invention of the present application relates to a compound derived from tetrahydrofuran[3,4-b]pyridine-3-carboxylate, a pharmaceutical composition comprising the compound, and the therapeutic use of the pharmaceutical composition in restoring muscle function. Background Art

[0002] Muscles are organs composed primarily of contractile fibers that aid movement and are part of the body's functional machinery. Each muscle is composed of thousands, or even tens of thousands, of small fibers that contribute to its elastic and contractile properties. The body has three types of muscle: smooth muscle, cardiac muscle, and skeletal muscle. These different types of muscle have different functions, each of which is susceptible to a number of problems or diseases that can lead to weakness, pain, or even paralysis.

[0003] Some known causes of the problem are: injury or overuse (e.g., sprains and strains, spasms, or tendinitis); genetics, such as muscular dystrophy; cancer; inflammation, such as myositis; neurological diseases that affect muscle; and infection. In addition to underlying pathological conditions that affect muscle tissue, aging gradually affects the muscular system because lean body mass naturally decreases over time, and this decrease is partly due to a loss of muscle tissue (atrophy).

[0004] The speed and severity of muscle changes can be caused by genetics, but they typically begin in men at age 20 and in women at age 40. Due to normal changes in muscle tissue and changes in the nervous system with aging, muscles lose tone and their ability to contract, leading to stiffness, reduced endurance, and decreased strength. Muscle weakness also leads to fatigue and decreased tolerance for physical activity. Joint problems, ranging from mild stiffness to debilitating arthritis (osteoarthritis), are very common.

[0005] In mammals, aging is associated with a decrease in skeletal muscle mass and function, known as sarcopenia. In humans, sarcopenia means a reduced ability to perform activities of daily living, leading to loss of independence. In fact, low skeletal muscle mass or strength has been reported to be the most common cause of disability in older adults (Fielding, 2011, Potes et al., 2019) and a predictor of morbidity, loss of independence, frailty, and mortality, independent of other risk or disease factors (Nair, 2005).

[0006] Sarcopenia is characterized by muscle fiber atrophy, with a greater reduction in type 2 fast-twitch muscle fibers compared to type 1 slow-twitch muscle fibers, accompanied by increased intramuscular fiber size heterogeneity and an increase in non-contractile tissue (fat and connective tissue) (Romanick et al., 2013). Effective treatment of skeletal muscle atrophy is difficult due to a lack of understanding of the underlying biological mechanisms. Oxidative stress, as in obesity, is one of the factors that can contribute to the pathogenesis of sarcopenia (Scicchitano et al., 2018). Whether insulin resistance manifests as a direct consequence of aging remains controversial (Oya, 2014; Soriguer, 2014); however, there is evidence that a decrease in lean body mass and a relative increase in fat mass (also known as sarcopenic obesity) directly contribute to insulin resistance in older adults (Srikanthan et al., 2010). Recent reports indicate that muscle mitochondrial function declines with aging (Theurey and Pizzo, 2018, Del Campo et al., 2018), and that this age-related decline in mitochondrial function contributes to insulin resistance in elderly men (Chow, 2018).

[0007] The inventors of the present application have made important contributions in recent years to the understanding of the cellular mechanisms involved in skeletal muscle adaptation to exercise; in particular, they described a mechanism linking electrical stimulation to changes in gene expression (Casas et al., 2014), which relies on the sequential activation of Cav1.1 (or DHPR) as a voltage sensor and the pan-connexin-1 channel (Panx1) as a pathway for ATP efflux from muscle cells, followed by activation of purinergic P2Y receptors, leading to different signaling cascades that affect gene expression (e.g., IL-6, Bustamante et al., 2014), metabolism, and redox homeostasis (Araya et al., 2003, Buvinic et al., 2009, Casas et al., 2010, Jorquera et al., 2013, Díaz-Vegas et al., 2018).

[0008] Furthermore, signaling pathways described for normal young adult skeletal muscle show significant alterations in conditions such as muscular dystrophy, aging, and obesity (Valladares et al., 2013, Altamirano et al., 2013, DelCampo et al., 2018), and these changes are likely involved in the muscle wasting phenomenon characteristic of malnutrition, sarcopenia, and sarcopenic obesity (Kalinkovich and Livshits, 2017). Furthermore, ATP is involved in the activation of NADPH oxidase 2 (NOX2) in skeletal muscle (Díaz-Vegas et al., 2015), and reactive oxygen species (ROS) are important second messengers in skeletal muscle at low concentrations, involved in processes such as gene expression, insulin-dependent glucose transport, and mitochondrial biogenesis (Henríquez-Olguín et al., 2015, 2019). On the other hand, at higher concentrations, ROS are mediators of obesity-associated phenotypes, including insulin resistance and diabetic skeletal muscle atrophy, as well as muscle wasting in aging (Espinosa et al., 2016).

[0009] In a signaling pathway described in normal young muscle, skeletal myofibers release ATP in response to electrical stimulation, which constitutes a physiological signal for gene expression leading to muscle adaptation (Jorquera et al., 2013). ATP is released through Panx1 channels (Jorquera et al., 2013) and can act on P2Y purinergic receptors to trigger an intracellular signaling cascade in skeletal muscle (Buvinic et al., 2009, Díaz-Vegas et al., 2015), including activation of PI3 kinase and phospholipase C, and the production of diacylglycerol (DAG) and IP3 (Eltit et al., 2006). Panx1 channels are regulated in the plasma membrane through their functional interaction with the voltage sensor Cav1.1 (Arias-Calderón et al., 2016, Jaque-Fernández et al., 2021). Indeed, pharmacological inhibition of Cav1.1 using nifedipine suppressed ATP release induced by electrical stimulation in normal myofibers (Jorquera et al., 2013).

[0010] Extracellular ATP, through activation of PKC by DAG and calcium, induces ROS production by activating NADPH oxidase (NOX-2) (Díaz-Vegas et al., 2015), and NOX-2 is the primary source of ROS during skeletal muscle exercise (Henríquez-Olguín et al., 2019). It is important to note that both extracellular ATP and ROS contribute to the inflammatory response (Kawamura et al., 2012). NOX-2-dependent ROS production involves NFκB activation and nuclear translocation in skeletal muscle fibers (Díaz-Vegas et al., 2015).

[0011] Importantly, the healthy physiological processes described in skeletal muscle are dramatically disrupted in several pathological conditions. Indeed, basal ATP release through Panx1 channels is dramatically increased in myofibers from malnourished mice (Valladares 2013), aged mice, and mice fed a high-fat diet (Jorquera et al, 2021).

[0012] Dystrophic mice are characterized by progressive and severe myofiber loss due to cell death, inflammation, and oxidative stress (Altamirano et al., 2013). Excess extracellular ATP in their myofibers is proapoptotic, inducing Bax, BIM, and PUMA transcription and increasing levels of activated Bax (Valladares, 2013). Importantly, nifedipine treatment normalizes the excessive basal ATP release in dystrophic myofibers in vitro (Valladares et al., 2013) and in vivo (Altamirano et al., 2013), with daily injections of the drug for one week reducing mRNA levels of prooxidant (p47(phox)NOX2 subunit) and proapoptotic (Bax) genes, lowering creatinine levels and serum kinase (a marker of muscle damage), and improving muscle function (Altamirano, 2013). This is particularly relevant given its similarities to models of sarcopenia and obesity. Indeed, basal extracellular ATP levels have been found to be elevated in obese and aged mice, and nifedipine treatment also improved muscle function in both models. Thus, a common pathway is shown to underlie muscle wasting and dysfunction, and that for at least these three muscle conditions: dystrophy, sarcopenia, and obesity, this pathway relies on excessive release of ATP from myofibers.

[0013] To date, there are no effective treatments that target skeletal muscle to halt wasting and restore function. Understanding the pathways that lead to muscle dysfunction offers the potential for identifying new therapeutic targets for these conditions. The expression of proinflammatory genes can be significantly reduced using Panx1 channel blockers (Jorquera et al., 2021).

[0014] Since in skeletal muscle fibers, Cav1.1 activation is upstream of ATP release through Panx1 channels, and Cav1.1 blockers (such as nifedipine) can modulate ATP release, the inventors of the present application designed a drug (MP-2) that interacts with Cav1.1 channels in skeletal muscle but not with CAV 1.1 channels in arterial smooth muscle to inhibit ATP release from muscle fibers without producing hypotensive side effects in patients.

[0015] Existing technology

[0016] Muscular dystrophy is a group of diseases that cause progressive weakness and loss of muscle mass. In muscular dystrophy, abnormal genes (mutations) interfere with the production of proteins needed to build healthy muscles. There are many types of muscular dystrophy, where symptoms may begin in early life, primarily in men, while other types do not appear until middle age or later. All forms of muscular dystrophy worsen as muscles weaken, and most people with this condition eventually lose the ability to walk.

[0017] There is no cure for muscular dystrophy, but medications and treatments can help control symptoms and slow the progression of the disease. These include physical and speech therapy, orthopedic devices, surgery, and medications. Some people with muscular dystrophy have mild cases that worsen slowly; others have disabling and severe cases.

[0018] Sarcopenia is the loss of muscle mass that occurs with aging. Thus, muscle mass begins to be lost gradually around age 30, accelerating from age 60. This can lead to disability and a lack of independence, as well as a significant risk of falls, fractures, or injuries. Ultimately, as the body's muscle mass decreases, fat tissue increases, leading to a significant risk of developing high blood pressure, obesity, or diabetes. Symptoms of sarcopenia are low or gradual loss of muscle mass, decreased muscle strength, and reduced physical function.

[0019] People with this condition often experience feelings of weakness, with difficulty rising from a chair or slow walking speed being common, as well as repeated falls. It is also common for them to describe recent, unexplained weight loss or loss of muscle mass. In the long term, the development of this pathological condition can be associated with adverse consequences such as bone fractures, physical disability, increased hospital admissions, worsening quality of life, and mortality.

[0020] The main causes of sarcopenia are the passage of time and aging, as several factors interact in this process: genetics, hormones, lifestyle changes, weight loss, and loss of motor units in the spinal cord. Physical activity and an active lifestyle can prevent and delay the onset and progression of sarcopenia, leading to longer lifespan and greater independence.

[0021] Sarcopenia can be treated with pharmacological and nonpharmacological measures. Since there is no specific treatment for this pathological condition, some approaches focus on delaying its onset:

[0022] -Testosterone therapy: This is used for patients with low testosterone levels in their blood, as testosterone is associated with the presence of muscle mass and strength in the legs.

[0023] -Growth hormone therapy: This approach can improve muscle mass and strength in patients with hypopituitarism.

[0024] -Nutritional therapy: A high-protein diet and other specific nutrients provide strength and reduce the risk of sarcopenia progression.

[0025] -Physical Movement: Training and physical movement are key to combating sarcopenia and improving strength, endurance, and balance. Patients need to follow a training routine for several weeks, which is very effective in increasing muscle mass and improving the patient's independence.

[0026] - Immune system intervention: In some cases, substances such as pentoxifylline can be used to modulate the production of cytokines (substances that lead to loss of muscle mass).

[0027] -The use of cytokines (myokines) or myokine receptor agonists remains experimental.

[0028] The prior art describes a series of compositions, formulations, and procedures for obtaining dihydropyridines and some tetrahydrofuro[3,4-b]pyridine compounds (including homologous compounds). These documents establish homologous properties and mechanisms of action based on their effects on dihydropyridine receptors. Methods for synthesizing homologous compounds are also described. However, these documents identify the use of these compounds for the treatment of other diseases, such as cardiovascular disease.

[0029] In the prior art, the following patent documents are particularly relevant:

[0030] Document US 4532248 (A) relates to compounds derived from 1,4-dihydropyridine of the formula

[0031]

[0032] in:

[0033] n is 0, 1, or 2, and

[0034] And R 1 to R 7 The compounds, which can have a wide variety of meanings, have inotropic effects, many of which are novel and can be used to increase Ca entry into cells, in particular to combat coronary and vascular diseases, hypertension, swelling in mucous membranes, and diseases involving elevated blood sugar or an incorrect balance of salts and fluids.

[0035] This document discloses (in Example 5) a compound having the following chemical structure:

[0036]

[0037] 2-Methyl-4-(3-nitrophenyl)-5-oxo-1,4-dihydropyridine-5,7-dihydrofuro[3,4-b]pyridine 3-carboxylate.

[0038] However, such compounds disclosed in US 4532248(A) have long-lasting vasodilatory and antihypertensive effects and are therefore not recommended for the treatment of muscle disorders.

[0039] Document WO 2009144450 A1 discloses a compound of the following formula (I) or a pharmaceutically acceptable salt, hydrate, complex or prodrug thereof:

[0040]

[0041] where R 1 and R 2 One of them is H, and the other is selected from alkyl C 1-8 , cycloalkyl C 3-6 and C 1-8 Alkyl-C 5-10 Aryl; R 3 is selected from tert-butyl, cyclopentyl and 1-methylcyclopentyl; R 9 Selected from the different compounds detailed in this patent application.

[0042] The present invention also relates to pharmaceutical compositions comprising compounds of formula (I), and to the use of said compounds in the treatment of a variety of diseases, such as osteoporosis, Paget's disease, Chagas disease, malaria, gum disease, hypercalcemia, metabolic bone diseases, diseases involving matrix or cartilage degradation, and bone cancer conditions such as bone metastases and associated pain.

[0043] However, this document differs from the invention of the present application in that it does not disclose compounds with a dihydropyridine structure, nor compounds derived from a tetrahydrofuran[3,4-b]pyridine core. Structurally, the present invention and the document WO2009144450 A1 differ significantly in the pharmacophore groups that constitute their respective inventions, meaning that the molecules of the present invention and the cited document target different therapeutic targets.

[0044] Therefore, there is a need for new pharmaceutical compositions for the prevention and treatment of malnutrition and sarcopenia. This patent application aims to solve the technical problem of providing effective and safe drugs that can improve muscle function in elderly patients and have low or no side effects on vasoconstriction.

[0045] More specifically, the present application aims to provide a hitherto unresolved treatment for myasthenia in the elderly by providing derivatives of the tetrahydrofuro[3,4-b]pyridine nucleus that have dihydropyridine receptor binding ability due to their chemical structure, which do not affect Ca +2 channel current, which allows for safe treatment of sarcopenia by reducing the amount of Ca +2 Cardiovascular effects of the channel. Summary of the Invention

[0046] The present invention relates to compounds derived from tetrahydrofuran[3,4-b]pyridine-3-carboxylate, pharmaceutical compositions comprising the compounds, therapeutic uses of the compositions for preventing and treating muscle disorders in subjects in need thereof, and methods for preventing and treating muscle disorders, the methods comprising administering the compositions to restore muscle function in patients suffering from malnutrition and sarcopenia.

[0047] One of the objects of the present invention is to provide compounds and pharmaceutical compositions derived from DHP which have little or no side effects on vasoconstriction and have high therapeutic potential for muscle weakness and muscle disorders such as malnutrition, cachexia and / or sarcopenia, and which are capable of improving muscle strength and endurance in subjects in need thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The 1H proton NMR spectrum of MP2 is shown.

[0049] Figure 2 Shows the MP2 13 C carbon nuclear magnetic resonance spectrum.

[0050] Figure 3 The infrared spectrum of MP2 is shown.

[0051] Figure 4 Shown are the effects of selected dihydropyridines (nifedipine) on vasoconstriction compared to MP-2.

[0052] Figure 5 Shown is the basal ATP release from isolated myofibers as a function of age.

[0053] Figure 6 Inhibition of ATP release by electrical stimulation in myofibers is shown.

[0054] Figure 7 Shown is muscle strength in aged mice as a function of time.

[0055] Figure 8 It is shown how MP-2 treatment improves both strength and muscle endurance.

[0056] Figure 9 It was shown that extracellular ATP levels can induce the expression of pro-inflammatory genes. DETAILED DESCRIPTION

[0057] According to studies performed by the present inventors, it has been shown that the use of molecules from the dihydropyridine (DHP) family targeting dihydropyridine receptors (or Cav1.1 calcium channels) normalizes gene expression in myofibers and functional parameters of dystrophic and sarcopenic muscles.

[0058] In light of the foregoing, the present patent application discloses compounds derived from tetrahydrofuran[3,4-b]pyridine-3-carboxylate that are capable of improving muscle strength and endurance in subjects and patients suffering from malnutrition and sarcopenia.

[0059] The disclosed compounds have the following chemical structure:

[0060]

[0061] in:

[0062] R 1 It's nitro;

[0063] R 2 is hydrogen or alkyl C1-C3;

[0064] R 3 is hydrogen or alkyl C1-C3;

[0065] R 4 is hydrogen, or

[0066] Its pharmaceutically acceptable salt.

[0067] In one embodiment of the present invention, the compound is selected from:

[0068] 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0069] 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0070] 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0071] 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0072] 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0073] 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0074] 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0075] 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0076] 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0077] 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0078] 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0079] 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0080] 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0081] 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0082] 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0083] 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0084] 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0085] 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0086] 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0087] 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0088] 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0089] 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0090] 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0091] 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0092] 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0093] 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0094] 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0095] 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0096] 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0097] Propyl 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylate.

[0098] The present application also discloses a pharmaceutical composition comprising the following and a pharmaceutically acceptable carrier: a compound derived from tetrahydrofuran [3,4-b] pyridine-3-carboxylate or a pharmaceutically acceptable salt thereof, wherein the compound has the following chemical formula:

[0099]

[0100] in:

[0101] R 1 It's nitro;

[0102] R 2 is hydrogen or alkyl C1-C3;

[0103] R 3 is hydrogen or alkyl C1-C3;

[0104] R 4 It's hydrogen.

[0105] In one embodiment, the pharmaceutical composition comprises a compound selected from the group consisting of:

[0106] 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0107] 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0108] 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0109] 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0110] 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0111] 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0112] 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0113] 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0114] 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0115] 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0116] 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0117] 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0118] 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0119] 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0120] 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0121] 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0122] 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0123] 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0124] 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0125] 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0126] 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0127] 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0128] 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0129] 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0130] 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0131] 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0132] 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0133] 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0134] 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0135] Propyl 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylate.

[0136] The present application also discloses a pharmaceutical composition for preventing or treating muscle disorders in a subject in need thereof, comprising the following and a pharmaceutically acceptable carrier: a compound having the following chemical formula or a pharmaceutically acceptable salt thereof:

[0137]

[0138] in:

[0139] R 1 It's nitro;

[0140] R 2 is hydrogen or alkyl C1-C3;

[0141] R 3 is hydrogen or alkyl C1-C3;

[0142] R 4 It's hydrogen.

[0143] In one embodiment, the pharmaceutical composition comprises a compound selected from the group consisting of:

[0144] 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0145] 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0146] 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0147] 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0148] 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0149] 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0150] 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0151] 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0152] 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0153] 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0154] 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0155] 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0156] 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0157] 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0158] 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0159] 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0160] 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0161] 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0162] 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0163] 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0164] 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0165] 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0166] 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0167] 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0168] 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0169] 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0170] 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0171] 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0172] 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0173] Propyl 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylate.

[0174] In another embodiment, the muscle disorder is selected from cachexia, sarcopenia, or muscular dystrophy.

[0175] In another embodiment, the composition is administered to a subject in need thereof intravenously, intramuscularly, transmucosally, intrathecally, systemically, intraperitoneally, ophthalmically, and / or subcutaneously.

[0176] In another embodiment, the subject is a mammal. In another embodiment, the mammal is selected from the group consisting of humans, dogs, cats, and horses.

[0177] Finally, the present application also discloses a method for preventing or treating muscle disorders, which comprises administering a therapeutically effective amount of a pharmaceutical composition comprising the following and a pharmaceutically acceptable carrier: a compound having the following chemical formula or a pharmaceutically acceptable salt thereof:

[0178]

[0179] in:

[0180] R 1 It's nitro;

[0181] R 2 is hydrogen or alkyl C1-C3;

[0182] R 3 is hydrogen or alkyl C1-C3;

[0183] R 4 It's hydrogen.

[0184] In one embodiment, the pharmaceutical composition comprises a compound selected from the group consisting of:

[0185] 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0186] 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0187] 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0188] 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0189] 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0190] 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0191] 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0192] 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0193] 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0194] 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0195] 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0196] 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0197] 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0198] 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0199] 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0200] 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0201] 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0202] 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0203] 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0204] 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0205] 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0206] 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0207] 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0208] 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0209] 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0210] 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0211] 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester;

[0212] 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester;

[0213] 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester;

[0214] Propyl 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylate.

[0215] In another embodiment, the muscle disorder is selected from cachexia, sarcopenia, or muscular dystrophy.

[0216] In another embodiment, the composition is administered to a subject in need thereof intravenously, intramuscularly, transmucosally, intrathecally, systemically, intraperitoneally, ophthalmically, and / or subcutaneously.

[0217] In another embodiment, the subject is a mammal. In another embodiment, the mammal is selected from the group consisting of humans, dogs, cats, and horses.

[0218] Example

[0219] The present inventors have identified a key role for the dihydropyridine receptor (DHPR) (L-type calcium channel, Cav1.1) as a sensor of adult myofiber membrane depolarization, which allows the activation of signals that regulate gene expression. Following electrical stimulation of myofibers, the release of ATP through the pan-connexin-1 (Panx1) channel plays a key role as a mediator of this process.

[0220] Activation of the Panx1 channel causes the release of ATP from the muscle fiber, which subsequently activates the P2Y type purinergic receptors present in the fiber membrane. This signaling cascade is the beginning of a series of processes that culminate in changes in gene expression. The key role of DHPR in triggering this process has been demonstrated using 1,4-dihydropyridine (DHP) molecules that are able to bind to DHPR and modulate its function. Nifedipine, a DHP antagonist of DHPR, which causes a decrease in Ca2+ through this channel, has been shown to be a promising target for the development of new drugs. 2+ On the other hand, (S)-(-)-BayK-8644 (a DHP agonist of DHPR that increases Ca2+ through this channel) causes almost complete inhibition of ATP efflux after electrical stimulation of muscle fibers. 2+ The use of nifedipine also inhibited ATP release. These results led the inventors to hypothesize a new function for DHPR, different from its role as a Ca2+ transporter during muscle contraction (EC coupling). 2+ Function of channels and ryanodine channel activators.

[0221] This function is associated with the activation of Panx1 channels following electrical stimulation of myofibers at a certain frequency, which induces the release of ATP into the extracellular medium and subsequently activates signaling pathways that lead to changes in gene expression. In addition, and consistent with the results presented above, myotubes lacking DHPR (forming Ca 2+ KO mice (a gene product that inhibits the pore of the DHPR channel) show no ATP release after electrical stimulation but do have abnormally high basal levels of extracellular ATP, suggesting a central role for DHPR in both activating ATP release after electrical stimulation and maintaining low levels of extracellular ATP under resting or basal conditions. The importance of the relationship between DHPR and ATP release from Panx1 channels is reinforced by results showing that DHPR and Panx1 colocalize in the transverse tubules (T tubules) of muscle fibers.

[0222] The described excitation-signaling coupling mechanism involving the DHPR-Panx1-ATP release axis was found to be altered in various muscle pathologies. In particular, the inventors investigated the role of this mechanism in a mouse model of sarcopenia. In this model, findings such as high basal levels of extracellular ATP, abnormal responses to electrical stimulation of these fibers, and altered expression of pro-inflammatory and pro-apoptotic genes were observed (preliminary results).

[0223] The results showed that treatment of old mice (age >18 months) with the new drug MP-2 significantly improved their muscle strength.

[0224] It is important to note that the 1,4DHP family of molecules is known to act on Ca2+ through channels formed by the DHPR in the sarcolemma. 2+ In this sense, MP-2 is a step forward in the safe treatment of sarcopenia, as it is a molecule designed based on 1,4DHP to ensure its binding to DHPR, but with the caveat that it reduces its ability to regulate Ca2+ through this channel. 2+ The result is a molecule with a chemical base similar to (but not identical to) DHP that has a strong inhibitory or activating effect on the Ca flow through this channel. 2+ The electric current has minimal effect, in particular, minimal effect on the inhibition of vasoconstriction.

[0225] Example 1

[0226] Synthesis of methyl 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylate (MP2)

[0227] The MP2 compound was synthesized according to the synthetic routes described in the publication “Methods for the synthesis of 4-pyrazolyl-and 4 pyridyl-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridines”, Chemistry of Heterocyclic Compounds, Vol. 31, pp. 841 to 846 (1995) and in US Pat. No. 4,567,268A (Process for preparation of certain tetrahydrofuro[3,4-b]pyridines).

[0228] Physical and Chemical Characteristics of 2-Methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic Acid Methyl Ester (Molecular Formula "C16 H14 N2 O6")

[0229]

[0230] Molecular weight

[0231] 330.29 g / mol

[0232] Melting point (experimental)

[0233] Value: 259 to 262°C | Conditions: Solvents: Acetone (67-64-1); Hexane (110-54-3)

[0234] Boiling point (predicted)

[0235] Value: 545.5±50.0℃ | Conditions: Pressure: 1atm (760 Torr)

[0236] Density (predicted)

[0237] Value: 1.44±0.1g / cm 3 | Conditions: Temperature: 20°C Pressure: 1 atm (760 Torr)

[0238] pKa (predicted)

[0239] Value: -1.47±0.70 | Condition: Basic temperature: 25℃

[0240] Spectral analysis / signal identification:

[0241] I) Bruker TopSpin 3.5pl2 program was used to perform [ 1 H] Proton spectroscopy analysis: For the sample, 11 signals were observed.

[0242] 1 H NMR (300MHz, DMSO, TMS, 25℃) δ: 9.95 (s, 1H, Ha), 7.81 (dd, 1H, Ar-Hb), 7.65 (td, 1H, Ar -Hc),7.46(dd,1H,Ar-Hd),7.41(td,1H,Ar-He),5.52(s,1H,Hf),4.92,4,83(quartet AB,2H,Hg,Ja=16.18Hz,Jb=16.11Hz),3.37(s,3H,Hh),3.32(s,H2O),2.5(s,DMSO),2.3(s,3H,Hi).

[0243] A schematic diagram of molecule 1 is shown below and the 1H proton NMR spectrum is shown below and Figure 1 Shown in.

[0244]

[0245] II) Carbon 13 spectra were analyzed using Bruker TopSpin 3.5pl2 program [ 13 C]. For the sample, 17 signals were observed.

[0246] 13 C NMR (75.47MHz, DMSO, TMS, 25℃) δ: 171.3 (C1), 167.1 (C2), 157.5 (C3), 148.3 (C4), 147.3 (C5), 140.8 (C6), 133.9 (C7), 131 ,8(C8),128.0(C9),124.0(C10),102.9(C11),100.6(C12),65.7(C13),51.3(C14),39.98(DMSO),32.2(C15),19.5(C16).

[0247] A schematic diagram of molecule 2 is shown below and the 13C NMR spectrum is shown below. Figure 2 Shown in.

[0248]

[0249] III) Infrared spectroscopy analysis Figure 3 Shown in: ATR-FTIR (cm-1) 3232 (νNH), 1731 (νC=O lactone), 1701 (νC=O ester), 1525 (νasymmetric NO), 1354 (νsymmetric NO). *2359 (νC=O residual CO2).

[0250] A complete assignment of the protons and carbons of the methyl 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylate molecule was performed based on analysis by NMR spectroscopy in one and two dimensions.

[0251] Example 2

[0252] Isolation of adult skeletal muscle fibers

[0253] The separation of skeletal muscle fibers was carried out in C57BL / J6 mice aged 8 to 10 weeks. The isolated fibers were obtained from flexor digitorum brevis (FDB) and gastrocnemius muscle, which were enzymatically digested with 400U / mL type II collagenase for 90 minutes (Worthington Biochemicals Corp., Lakewood, NJ, USA) and mechanically dissociated with a Pasteur pipette as previously described (Casas et.al, 2010). The isolated fibers were seeded in a culture dish coated with a matrigel layer in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% horse serum, 50U / mL penicillin and 50mg / mL streptomycin. Cell culture was used approximately 20 hours after the fiber inoculation process. All protocols were previously approved by the Bioethics Committee of the Faculty of Medicine of the University of Chile.

[0254] Example 3

[0255] Electrical stimulation of muscle fibers in vitro

[0256] Isolated skeletal muscle fibers were stimulated using platinum electrodes connected to an electrical stimulator (Grass S48; W. Warwich, RI, USA). The protocol consisted of applying 270 square pulses of 0.3 millisecond duration at a frequency of 20 Hz, as previously described (Jorquera et al. 2013). During stimulation experiments, fibers were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% horse serum, 50 U / mL penicillin, and 50 mg / mL streptomycin. In addition, fibers were incubated with 50 μM N-benzyl-p-toluenesulfonamide (BTS, Sigma-Aldrich) to inhibit muscle contraction. All experiments were performed at room temperature between 21 and 23°C.

[0257] Whole-cell voltage clamp: L-type Ca 2+ Current measurement

[0258] An electrophysiology kit consisting of a Digidata 1322A amplifier (Axon Instrument, Austin, TX) in whole-cell configuration and a confocal microscope (Zeiss, Pascal 5) was used for the assay. Clampex 9.2 software, coupled to an A / D / A converter (Axon Instruments, Austin, TX), was used for command pulse generation and data acquisition.

[0259] Ca 2+ Current measurements were performed on single skeletal muscle fibers isolated from C57 mouse FDB muscle (Collet, 2004; Pouvreau, 2007). Due to the variability observed between muscle fibers, one fiber was used as a self-control. Borosilicate capillaries were used and microelectrodes with a resistance of 2 to 5 MΩ were generated, which were large enough to diffuse into and enter cells without damaging them, as described in the literature (Pouvreau, 2007; Hernández-Ochoa, 2012).

[0260] Single fibers were isolated with silicone to allow whole-cell controlled potentiometric measurements on a small portion of the fiber tip.

[0261] Prior to this, the bottom of the plate was uniformly coated with a thin layer of industrial silicone (previously shown not to cause damage or cell death). Myofibers obtained by mechanical dissociation were then directly deposited in a DMEM solution containing 10% horse serum. The fibers were loaded with 20 mM EGTA for 30 minutes. Next, 5 to 10 fibers per plate were siliconized using a microsyringe containing industrial silicone (which has a lower liquefaction than the industrial silicone used in the plate base) over 80% of their length, leaving a small section free for use under the microscope.

[0262] Once the fibers have been siliconized on the plate, replace the DMEM solution (10% FBS) with 2+The external solution for the current measurement experiment is as follows. Whole-cell controlled potentiometry was performed with a microelectrode filled with an internal solution containing (in mM): 140 potassium glutamate; 5 Na2-ATP; 5 sodium phosphocreatine; 5.5 MgCl2; 5 D-glucose, 5 HEPES, adjusted to pH 7.2 with KOH. The external solution contained (in mM) 140 tetraethylammonium methanesulfonate (TEA); 2.5 CaCl2; 2 MgCl2; 0.002 tetrodotoxin (TTX); 1 4-aminopyridine (4-AP); 10 HEPES, adjusted to pH 7.2. EGTA was used as a Ca in the internal solution. 2+ Chelators to prevent intracellular Ca 2+ The free level rises to the point where muscle contraction occurs. TEA and 4-AP are used in the external solution to block voltage-gated and non-gated K + TTX is a selective blocker of voltage-gated Na + toxins that target the mitochondria (McGold, 2002; Pouvreau, 2007; Hernández-Ochoa, 2012).

[0263] For each experiment, a different microelectrode was used, and its resistance was checked each time it entered the external solution. Next, the microelectrode was inserted into the isolated portion of the fiber through the silicone. Analog compensation (load current increased, and therefore time constant decreased) was performed in the amplifier to reduce the effect of series resistance. After 20 minutes after entering the cell and EGTA diffusion, Ca was recorded. 2+ Current flow through Cav1.1 was controlled at a basal potential of -80 mV. Starting from this basal potential, command pulses of 500 milliseconds were applied from -40 to 80 mV, with amplitudes increasing by 10 mV in steps of 10 mV, every 30 seconds. This protocol was repeated three times per fiber, with 5-minute intervals between pulses. Each command pulse was preceded by a -20 mV hyperpolarizing prepulse, which was identical for all voltages.

[0264] Using the P / 1 scheme, the linear leakage component of the current is removed by subtracting a proportional value from the measured current generated by the preceding pulse.

[0265] All experiments were performed at room temperature between 20 and 22 °C.

[0266] Effect on L-type current

[0267] To ensure that MP-2 interacts with Cav1.1 channels (dihydropyridine receptors), L-type calcium currents were measured in isolated fdb myofibers treated with 10 μM concentrations of five different dihydropyridines (nifedipine, nitrendipine, nicardipine, nimodipine, and nisoldopine) or with 10 μM MP-2 (Table 1). DHP inhibited the current by 14.3% to 83%, and MP-2 produced 50% ± 8% inhibition, thus indicating that Cav1.1 channels are the target of MP-2.

[0268] Table 1: Effects of dihydropyridines and MP-2 on L-type calcium peak currents in mouse skeletal muscle fibers

[0269]

[0270] At least three fibers (from two to three different mice) were used for each drug tested. The control in each condition was the maximum current in the absence of drug.

[0271] Example 4

[0272] vasoconstriction

[0273] MP-2 has a low effect as a vasodilator

[0274] The diameter of pulmonary vessels was measured in thin sections of rat lung using microscopy as described by Henríquez et al. 2018.

[0275] Some DHP derivatives can induce strong vasodilator effects, representing an undesirable side effect in the treatment of muscle disorders. Figure 4 Results of an ex vivo vasoconstriction test are shown, where MP-2 inhibited only 10% of the pulmonary vasoconstriction induced by 50 mM KCl depolarization, whereas standard DHP (nifedipine) inhibited 90% to 100% of the contraction under the same conditions.

[0276] Because of the need to control the low vasoconstrictor effects of MP-2, the effects of various dihydropyridines other than MP-2 on high potassium-induced pulmonary venous ring constriction were tested. Figure 4 Shown are the effects of selected dihydropyridines (nifedipine) on vasoconstriction compared to MP-2. Figure 4 Shown are mean ± SEM percent inhibition of nifedipine-induced vasoconstriction (approaching 100% inhibition of contraction), whereas contractile responses in the presence of MP-2 were less than 10% inhibited compared to control vessels without drug (n=7 vessels).

[0277] Example 5

[0278] Inhibition of ATP release

[0279] Extracellular ATP concentration was determined by luciferin / luciferase assay.

[0280] use Luminescent cell viability assay kit (Promega) is used to determine the extracellular ATP concentration. 25 μL of extracellular culture medium is obtained from DAGe and DAGne cultures at different times (0 to 900 seconds). 25 μL of reconstructed reagent (buffer substrate) is added. After incubation for 10 minutes in the dark at room temperature, the sample is quantified in an FB12 (Berthold) luminometer. In the meantime, a standard curve is made using the same kit protocol based on 1 fmol to 100 pmol of ATP (Sigma Aldrich). The values obtained for the samples are interpolated in the standard curve to determine the ATP concentration in each condition. The results obtained are normalized to the extracellular ATP in pmol per μg of total RNA in each plate. RNA normalization is superior to total protein normalization because adult fiber cultures are seeded on matrix films that have a large amount of protein and can change the quantitative process.

[0281] Basal ATP release is greatly increased in myofibers from aged mice.

[0282] Basal extracellular ATP levels were measured in fdb myofibers from mice of different ages (without electrical stimulation). Basal ATP levels were strongly elevated in fibers from 16-month-old and older mice. N=5 for each age. Mean ± SEM are plotted.

[0283] Figure 5 Shown is the basal ATP release from isolated myofibers as a function of age. Old mice (16 months old) have a much higher release than younger mice. ATP release in myofibers of old mice is greatly increased.

[0284] Example 6

[0285] MP-2 inhibits ATP efflux induced by 20 Hz electrical stimulation in muscle fibers

[0286] Pre-incubation of fdb muscle fibers with 10 μM MP-2 for 30 minutes inhibited the ATP efflux triggered after electrical stimulation of muscle fibers at 20 Hz. Maximum ATP release was observed in electrically stimulated control fibers (black bars), and inhibition (light gray bars) and inhibition (dark gray bars) were achieved by pre-incubating fibers with nifedipine. It was observed that MP2 inhibited in a manner similar to nifedipine. ####: p<0.001 (20 Hz) vs (20 Hz MP-2). (N=5). Mean ± SEM was plotted. ****: p<0.001. Data are shown as fold changes relative to control (no drug, stimulated at 20 Hz).

[0287] Isolated mouse fdb myofibers were electrically stimulated at 20 Hz in the presence of nifedipine or MP-2. As previously reported, nifedipine almost completely blocks ATP release and here the effect of MP-2 is almost identical to that of nifedipine.

[0288] Example 7

[0289] Function

[0290] Muscle strength decreases dramatically in aging animals

[0291] Muscle strength was measured in mice of different ages using the reverse grip test and reported as pulses (N*seconds), which takes into account the amount of time each mouse supported its own weight in the test. A decrease in pulses was observed starting at 8 months of age and was significantly reduced in mice older than 16 months of age. N = 4 for each age. Mean ± SEM is plotted. *: p < 0.05; **: p < 0.01. Muscle strength was significantly reduced in older mice.

[0292] Example 8

[0293] Treatment of aged mice with 1 mg / kg MP-2 daily for 12 days improved muscle function

[0294] The standardization of this test of endurance and strength is evaluated in the treadmill equipment for rodents.The test is composed of 5 links, and wherein animal is adapted to 5 minutes with the minimum speed of 0.3Km / hour of equipment, and the number of injections of compressed air that keeps animal trotting is counted.Once the adaptation process ends, animal is evaluated in the incremental test, and the test is composed of: carrying out 2 minutes of ramp motion (ramp) with minimum speed, and subsequently increasing 0.1Km / hour after 2 minutes, until animal can no longer run. Each link of this maximum effort test is only carried out once, and when animal arrives at the bottom of slope and accumulates 10 injections of compressed air in the time period of 10 seconds, then think and complete.

[0295] The muscle function of old mice (19 to 21 months old) was assessed with an incremental strength test (weight lifting) and an incremental treadmill running test. The measurements were taken after 12 days of treatment with MP-2 (1 mg / Kg / day) administered by intraperitoneal injection. As a control, mice injected with vehicle were used in the same manner as the drug-injected mice. Recovery of muscle function can be observed after treatment. Data analysis is the change in test performance of each mouse at the end of treatment relative to the beginning of treatment. It was observed that the treatment improved the strength parameters by more than 4 times relative to the control. The endurance test (incremental treadmill test) also showed a significant increase of almost 5 times relative to the control. Mean ± SEM has been plotted. For each group, N = 5, *: p < 0.05

[0296] Functional tests were performed twice in control (saline injected) and MP-2 treated (1 mg / kg MP-2 injected intraperitoneally daily for 12 days) mice. Figure 6 As observed in the 2012 study, animals treated with MP-2 showed a 64.4% improvement in the weight test (a measure of strength), and a 25% improvement in the treadmill test (a measure of endurance). MP-2 treatment significantly improved both strength and endurance.

[0297] Example 9

[0298] High extracellular ATP levels induce the expression of pro-inflammatory genes

[0299] Real-time qPCR

[0300] TRIzol (Invitrogen) was used to extract the total RNA from the isolated myofiber cultures according to the manufacturer's protocol. Enzyme SuperScript II (Invitrogen) was used according to the manufacturer's protocol to obtain cDNA by reverse transcription from 1 μg of the total RNA. Real-time qPCR was performed using a thermal cycler (Stratagene Mx300P, Agilent) according to the following protocol. The reaction mixture was prepared by 1 μL 10 × dNTP, 0.5 μL sense primer (10 pmol / μL), 0.5 μL antisense primer (10 pmol / μL), 4 μL EVA green (Invitrogen) and 1 μL cDNA. The final volume of the mixture was brought to 20 μL by adding nuclease-free water. All primers had optimal amplification efficiency (between 90% and 110%). In any case, the correction of the amplification cycle of each gene was considered to be analyzed according to the amplification efficiency of the primer. Thermal cycling conditions were as follows: 1 cycle at 95°C for 12 minutes, followed by 40 cycles at 95°C for 15 minutes, 60 to 65°C for 20 minutes, and 72°C for 20 minutes. 18S gene expression values were normalized and reported as log2 fold change (ddCt). Ct values were determined by MXPro software when the fluorescence level was 25% higher than the basal fluorescence. PCR products were verified by visual inspection of the melting curves.

[0301] Increases in proinflammatory markers have been reported in the muscles of elderly individuals as part of the muscle mass loss process. Therefore, the effects of chronic exposure to high levels of extracellular ATP on the mRNA levels of proinflammatory genes were evaluated. It was observed that when myofibers of normal mice were exposed to high levels of extracellular ATP (300 μM for 2 hours), mRNA levels of proinflammatory genes (such as TNF-α and IL-6) were increased. Mean ± SEM is plotted, *: p < 0.05. (n = 4).

[0302] From the above results, it can be concluded that using MP-2 has obvious advantages:

[0303] - It responds to the need to treat muscle weakness in the elderly, going beyond a palliative approach.

[0304] -Proof of concept in mouse models demonstrated significant improvements in muscle function

[0305] -MP-2's mechanism of action is upstream of many abnormalities present in sarcopenia: activation of pro-inflammatory and pro-apoptotic genes, activation of reactive oxygen species production.

[0306] - Due to its low vasoconstrictor effect, low or no side effects are expected from this molecule. This makes the inventors optimistic that this treatment will be safe and easily administered in the general population.

[0307] The compounds provided herein for the treatment of sarcopenia are fundamentally different from currently available compounds. The most popular current treatment is based on hormone replacement therapy, which has numerous harmful side effects and very limited effectiveness. Given this background, the DHP derivative MP-2 claimed in the present invention constitutes a novel alternative that can improve the symptoms of muscle disorders by acting on biological targets involved in the loss of muscle mass that accompanies them, showing the potential to prevent the progression of these symptoms caused by aging.

[0308] The present invention offers a simple solution by targeting the inhibition of the altered molecular mechanisms in diseased muscle fibers that are responsible for the loss of motor function observed in humans with aging, using drugs with few or no side effects.

[0309] References

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Claims

1. A compound having the following chemical formula: in: R 1 It's nitro; R 2 is hydrogen or alkyl C1-C3; R 3 is hydrogen or alkyl C1-C3; R 4 is hydrogen, or Its pharmaceutically acceptable salt.

2. The compound of claim 1, wherein the compound is selected from: 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester.

3. A pharmaceutical composition comprising a compound having the following chemical formula or a pharmaceutically acceptable salt thereof: in: R 1 It's nitro; R 2 is hydrogen or alkyl C1-C3; R 3 is hydrogen or alkyl C1-C3; R 4 It is hydrogen; The pharmaceutical composition further comprises at least one pharmaceutically acceptable carrier.

4. The pharmaceutical composition of claim 3, wherein the compound is selected from: 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester.

5. A pharmaceutical composition for preventing or treating a muscle disorder in a subject in need thereof, comprising a compound having the following chemical formula: in: R 1 It's nitro; R 2 is hydrogen or alkyl C1-C3; R 3 is hydrogen or alkyl C1-C3; R 4 It is hydrogen; The pharmaceutical composition further comprises at least one pharmaceutically acceptable carrier.

6. The pharmaceutical composition of claim 5, wherein the compound is selected from: 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester.

7. The pharmaceutical composition of claim 5 or 6, wherein the muscle disorder is selected from cachexia, sarcopenia or muscular dystrophy.

8. The pharmaceutical composition of claim 5 or 6, wherein the composition is administered to a subject in need thereof intravenously, intramuscularly, transmucosally, intrathecally, systemically, intraperitoneally, ophthalmically, and / or subcutaneously.

9. The pharmaceutical composition of claim 5 or 6, wherein the subject is a mammal.

10. The pharmaceutical composition of claim 9, wherein the mammal is selected from the group consisting of humans, dogs, cats, and horses.

11. A method for preventing or treating a muscle disorder, comprising administering a therapeutically effective amount of a pharmaceutical composition comprising a compound having the following chemical formula: in: R 1 It's nitro; R 2 is hydrogen or alkyl C1-C3; R 3 is hydrogen or alkyl C1-C3; R 4 It is hydrogen; The pharmaceutical composition further comprises at least one pharmaceutically acceptable carrier.

12. The pharmaceutical composition of claim 11, wherein the compound is selected from: 2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(2-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(4-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(5-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-methyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid methyl ester; 1,2-ethyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid ethyl ester; 1,2-propyl-4-(6-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester; 1,2-propyl-4-(3-nitrophenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]pyridine-3-carboxylic acid propyl ester.

13. The pharmaceutical composition of claim 11 or 12, wherein the muscle disorder is selected from cachexia, sarcopenia, or muscular dystrophy.

14. The pharmaceutical composition of claim 11 or 12, wherein the composition is administered to a subject in need thereof intravenously, intramuscularly, transmucosally, intrathecally, systemically, intraperitoneally, ophthalmically, and / or subcutaneously.

15. The pharmaceutical composition of claim 11 or 12, wherein the subject is a mammal.

16. The pharmaceutical composition of claim 15, wherein the mammal is selected from the group consisting of humans, dogs, cats, and horses.

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