Ethano-terpene solvent, method for preparing same and uses thereof

Abstract

The present invention discloses a novel green ethano-terpene solvent of plant origin formed of a synergistic mixture of terpenes and ethanol. It relates to the method for obtaining this solvent, which is based on the recovery of terpene compounds from plants through low-temperature solid-liquid extraction, using ethanol as a GRAS solvent, the method being characterised in that it comprises the following steps: washing the plants with water; removing the washing water; grinding the plants; bringing the plant material into contact with ethanol; removing the residues; decolourising the extract by vacuum evaporation to obtain a transparent solvent rich in terpenes. The green ethano-terpene solvent is characterised by its purity, selectivity, recyclability, biodegradability, and its wide usage in processes for the extraction and / or solubilisation of plant and / or animal and / or prokaryotic biological materials, in synthesis and formulation in the food, pharmaceutical, cosmetic, chemical, perfume and fuel industries, as well as in cleaning and disinfection processes.

Description

Ethano-terpene solvent, process for its preparation and its uses [1] TECHNICAL FIELD [2] The present invention is in the field of green chemistry. It specifically relates to a new green, transparent and natural solvent of plant origin, rich in terpene compounds extracted from fresh plants, as well as its manufacturing process and its various uses. [3] OBJECTIVE OF THE INVENTION [4] The objective of this invention is to develop an innovative process for the preparation of a transparent and natural ethano-terpene solvent, derived from plants of the Magnoliophyta phylum used in their fresh state. This solvent, which consists mainly of terpenes, ethanol (preferably bioethanol) and a small proportion of phenolic compounds, is obtained via a solid-liquid extraction process at room temperature followed by vacuum purification. The main steps include washing the plants, grinding them with ethanol in a ratio of 1:10, filtering the plant residues, and finally decolorizing the extract by vacuum evaporation to obtain a transparent liquid. [5] This process is distinguished by its use of fresh plants of different terpene-rich species, such as mint, rosemary, thyme, verbena, caraway, and lavender, to name a few. The objective is to maximize the extraction of terpene and phenolic compounds through iterative techniques that determine the optimal ratio between plant mass and ethanol volume. By using ethanol as a solvent, the invention not only ensures a high yield of terpenes but also maintains the purity of the extracts, which is crucial for food and pharmaceutical applications, where safety and the absence of toxic residues are paramount. [6] STATE OF THE ART [7] Natural solvents, or agro-solvents, derived from green chemistry, are increasingly sought after for their benefits in terms of human health, their low environmental impact, and their efficiency in eco-extraction, guaranteeing safe and high-quality extracts, usable as ingredients in the pharmaceutical, cosmetic, agri-food, fine chemical and biofuel industries. [8] In solid-liquid extraction, the choice of solvent is crucial for the quality of the extraction, influencing the yield and purity of the extract. This choice depends mainly on the affinity of the solvent for the substance to be extracted and the possibility of reusing the solvent. [9] Among the solvents commonly used in eco-extraction, supercritical carbon dioxide (CO2) is the most widely used. It is valued for its non-toxicity and chemical inertness. During extraction, supercritical CO2 is used beyond its critical points (critical temperature of 31 °C and critical pressure of 74 bar). This eco-extraction method has advantages such as the absence of residual toxic solvent and low solvent cost. However, it remains expensive in terms of process and sometimes limited, because supercritical CO2 is non-polar and has limited dissolving powers, making its use as a solvent unsuitable for polar solutes.

[0010] Ethanol, as a low-carbon alcohol, is widely used in eco-extraction. It can extract a wide range of bioactive compounds, such as essential oils, terpenes, flavonoids, and other plant components. However, the selectivity and solubility of some substances in ethanol are limited, resulting in less selective extraction and reduced purity of the final product.

[0011] Agro-solvents are derived from wood, cereals (starch or sugar) and oilseeds, allowing the production of terpene derivatives, alcohols (ethanol, butanol, 1,3-propanediol), furfural derivatives or methyl esters (Formule Verte No. 08 December 2011, pages 28-32).

[0012] Terpenes, a class of hydrocarbons produced by many plants, especially conifers, are major components of resin and the turpentine derived from it. They have two fundamental properties: an odoriferous capacity (as in geranium) and a rapid interaction with light. Terpenes have a skeleton of 5 carbon atoms called an isoprene unit (C5H8). Depending on the number of isoprene units, terpenes are classified as hemiterpenes (1 unit: C5), monoterpenes (2 units: C 10 ), sesquiterpenes (3 units: C 15 ), diterpenes (4 units: C 20 ), sesterpenes (5 units: C 25 ), triterpenes (6 units: C 30 ), tetraterpenes (8 units: C 40 ) and polyisoprenes (n units: C 5n ) (Perveen et al., Terpenes and Terpenoids (2018)).

[0013] Document EP2632559 A1 describes a process for preparing water-soluble and oil-soluble antioxidant compositions extracted from herbs of the Labiatae family, using a mixture of alcohol and water as solvent. This process includes a simple but effective purification step for separating the water-soluble antioxidant fractions, mainly consisting of rosmarinic acid, from the antioxidant fractions fat-soluble compounds containing mainly carnosic acid and carnosol, without requiring tedious acid / base separation steps. The described process comprises the following main steps: contacting the Labiatae herbs with a solvent composed of a mixture of ethanol and water, where ethanol is present at a concentration of 40-90% in water; filtration to obtain a solution containing water-soluble and oil-soluble fractions; vacuum removal of 50-97% of the solvent from the solution until the ethanol level drops to 0-35% and the pH decreases to 3-5; separation of the solid and liquid fractions obtained; and, optionally, purification of the solid fraction containing carnosic acid and carnosol. Removal of residual water and ethanol from the liquid fraction produces a second solid fraction containing rosmarinic acid. The process mainly uses distillation, an energy-intensive technique.

[0014] JP2022102755 A discloses a method for producing a refined rosmarinic acid-containing composition that enables a highly transparent aqueous solution to be obtained by reducing the amount of luteolin while causing the rosmarinic acid to remain in the solution. The method comprises a step of contacting with activated carbon in a 30-50% by volume ethanol solution, a rosmarinic acid-containing composition that is obtained by an extraction step for extracting rosmarinic acid from a plant belonging to the Lamiaceae family and in which the contained amount of rosmarinic acid in solid content is 7% by mass or more. The method is based on the use of activated carbon for the extraction of rosmarinic acid.

[0015] Patent document JP2020203958 A describes an extract derived from plants of the genus Mentha, family Lamiaceae, and a method for producing the same. The extract contains "p-cymene and terpinolene" in small amounts, which do not impair the aroma, and is fresh with a rich and refreshing aroma. Provided is an extract containing L-menthol or L-carvone as the main aroma component, with total amounts of p-cymene and terpinolene of 500 ppm or less. The method uses conventional extraction techniques such as distillation, supercritical CO2, or steam, which are energy-intensive.

[0016] The solutions of the prior art are complex, expensive and limited in terms of application, particularly with regard to selectivity. The present invention aims to fill these gaps by means of a simple, efficient and less expensive process for preparing a transparent green solvent rich in terpene compounds, having a high affinity (selectivity) with the substances to be extracted, for a better extraction and / or solubilization yield.

[0017] STATEMENT OF THE INVENTION

[0018] The objective of this invention is achieved by a process for the preparation of a natural transparent ethano-terpene solvent of plant origin, from plants of the Magnoliophyta phylum used in the fresh state, via a solid-liquid extraction process at room temperature and vacuum purification. The solvent obtained comprises terpene compounds, ethanol (preferably bioethanol) and a small proportion of phenolic compounds. The main steps of the process are as follows: The plants are washed with water and then drained to remove the wash water. These plants are selected according to specific criteria that meet a particular need for terpene richness. Fresh plants, including all their parts (stems, leaves, flowers, etc.), are ground with ethanol in a ratio of 1:10; that is, for each gram of plant, 10 mL of ethanol (or bioethanol) is added. The solid-liquid mass ratio is determined by iterative tests following the following protocol: 1 g of plant mass is mixed with different volumes of ethanol in mL, and the extraction yield, defined as the recovery rate, is measured. The term 'recovery rate' refers to the efficiency of the transformation of the crude plant into a concentrated terpene product (initial mass relative to the final mass after transformation). The test results are summarized in the table below: It is observed that from a ratio of 1:5, the recovery rate of terpenes becomes significant. For maximum recovery, the ratio is set at 1:10 for the rest of the process. The plant residues are separated from the colored extract resulting from the ethanolic extraction by filtration using a suitable filter, in order to eliminate as much residue as possible and recover only the liquid phase. A recycling phase is possible at this stage to extract a maximum of terpenes from the filtration residues. To do this, the equivalent of 50% ethanol is added to the residue and maceration is carried out. The mixture is filtered again and the liquid obtained is added to that of the first filtration. - The colored extract is then decolorized by vacuum evaporation to obtain a transparent liquid composed of ethanol and terpenes, with a low content of phenolic compounds. Under specific conditions (heating to 90°C), this treatment eliminates plant pigments and recovers a transparent ethano-terpene solvent.

[0019] BRIEF DESCRIPTION OF THE FIGURES

[0020] The characteristics and advantages of the invention appear better in the detailed description which follows, referring to Figure 1 illustrating the steps of the process for preparing the ethano-terpene solvent with the experimental conditions of each step.

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention relates to a process for preparing a plant-derived ethano-terpene solvent, consisting of a synergistic mixture of terpenes and ethanol. This process is applicable to a variety of terpene-rich plants, in particular Magnoliophytes.

[0023] The present invention uses a bio-based process for the ethanol extraction of bioactive materials, including both terpenes and phenolic compounds, from plants of the classes Magnoliopsida and Liliopsida.

[0024] Extracts can be obtained from plants of the genera Mentha, Rosmarinus, Thymus, Verbena, Carum, Cymbopogon and Lavandula. These plants are known to produce significant amounts of terpene and phenolic compounds.

[0025] Preferably, terpene compounds represent between 30 and 70% of the total weight of the extract, with an optimal concentration between 40 and 60%.

[0026] Terpenes can be partly oxygenated and / or hydrocarbon terpenes.

[0027] The proportion of oxygenated terpenes in the extract must be at least 80% of the total terpenes. These oxygenated terpenes include alcohols, ketones, aldehydes, ethers, and esters. According to a particular configuration: Alcohols and phenols represent between 10 and 60% of oxygenated terpenes: Aldehydes and esters represent more than 40%; Ketones and ethers represent between 5 and 65%.

[0028] The terpenes present in the extracts according to the invention are preferably chosen from one or more of the following oxygenated terpenes and hydrocarbon terpenes: linalool, geraniol, menthol, verbenone, citronellol, eucalyptol, citronellol, thymol, eugenol, camphor, cryptone, a-pinene, limonene, myrcene, carvone, menthone, linalyl acetate and carvacrol. In particular, they are chosen from: Menthol and menthone (peppermint); Thymol and carvacrol (thyme); Citral (verbena); Eucalyptol, a-pinene and camphor (rosemary); Linalool and linalyl acetate (lavender); Geraniol (palmarosa); Carvone and limonene (caraway).

[0029] Peppermint leaves typically contain more than 300 identified compounds. Terpenes are the most represented class, with approximately 52% monoterpenes and 9% sesquiterpenes. Among the monoterpenes, menthol is the major constituent (35-60%), followed by menthone (2-44%) (Riachi et al., Food Chem., 176: 72-81 (2015)). Menthol, a cyclic monoterpene alcohol, possesses hydroxyl groups that confer various biological properties, such as antimicrobial, anticancer, and anti-inflammatory activities (Brahmi et al., Aromatic and Medicinal Plants - Back to Nature, 10: 47-79 (2017)). Menthone, a ketone analogue of menthol, also exhibits anti-inflammatory and anti-allergic activities (Su et al., Int. J. Mol. Sci., 23: 4011 (2022)).

[0030] Menthol and menthone possess a hydrophilic (hydroxyl) group and a hydrophobic (alkyl) group, making them surface-active compounds. Therefore, they are soluble in both non-polar and polar solvents such as ethanol (absolute and 70%) (Ejaz et al., Biol. Clin. Sci. Res. J. (2020); Zeng et al., J. Chromatogr. A, 1674 (2022)).

[0031] Thyme is a medicinal plant with beneficial properties for human health, mainly due to its content of phenolic compounds. Thymol, a monoterpene phenol, is often the main component (10-64%) of thyme, followed by carvacrol (0.4-20.6%) (Salehi et al., Phytother Res., 32: 1688-1706 (2018)). Thymol has antimicrobial, antioxidant, antibacterial, antitussive, antispasmodic, and expectorant properties (Hôferl et al., J. Essent. Oil Res., 21: 459-463 (2009)). Carvacrol, another monoterpenoid phenol, possesses a wide range of biological activities, including antimicrobial, antioxidant, and anticancer properties (Sharifi-Rad et al., Phytother. Res., 32: 1675-1687 (2018)).

[0032] Thymol and carvacrol are non-polar isomeric phenolic compounds, slightly soluble in water but extremely soluble in ethanol and other organic solvents (Aghamohammadi et al., Pharm. Biomed. Res., 2: 8-13 (2016)).

[0033] Verbena officinalis (common verbena) is a widely distributed medicinal plant used in folk medicine in various countries. The main terpene compound of V. officinalis is citral (14.8-45.5%) (Kubica et al., Planta Med., 86: 1241-1257 (2020)). Citral, an acyclic monoterpene aldehyde, has important therapeutic properties, such as antioxidant, antimicrobial, anti-inflammatory, anticancer, and antidiabetic (Sharma et al., Med Chem., 17: 2-12 (2021)).

[0034] Citral is a natural mixture of two isomeric monoterpene aldehydes: geranial (trans-citral, citral A) and neral (cis-citral, citral B) (Lima et al., Pharm. Biol., 50: 1536-1541 (2012)). Although non-polar, citral is readily soluble in ethanol (Tian et al., J. Sci. Food Agric., 97: 2991-2998 (2017); TigneH et al., Orient. J. Chem., 36: 513-523 (2020)).

[0035] The biological activities of rosemary are associated with its main compounds. Rosemary has a characteristic camphor-like odor. Eucalyptol (15-55%), a-pinene (9-26%), and camphor (5-21%) are its main monoterpenes (Aziz et al., S. Afr. J. Bot. (2021)). 1,8-Cineole, a cyclic monoterpene ether known as eucalyptol, is a major component of eucalyptus (Eucalyptus globulus) and is also found in large quantities in rosemary (Kolassa, Regul Toxicol Pharmacol., 65: 115-118 (2013)). It has potent antibacterial and antiviral properties (Lesnik et al., Phytochem. Rev., 20: 1273-1328 (2021)). α-Pinene, the main constituent of pine wood (Pinus spp.), is also present in large quantities in rosemary and exhibits antimicrobial effects against various microorganisms (Lesnik et al., Phytochem. Rev., 20: 1273-1328 (2021)).Camphor, a bicyclic monoterpene ketone, is present in camphor tree (Cinnamomum camp ho ra ) and rosemary (Lesnik et al., Phytochem. Rev., 20: 1273-1328 (2021)). H has many pharmaceutical applications, including as a topical analgesic, antiseptic, antispasmodic, antipruritic, anti-inflammatory, and anti-infective (Hamidpour et al., Int. J. Case Rep. Images, 4: 86-89 (2013)).

[0036] Camphor and 1,8-cineole are very slightly polar hydrocarbons, while a-pinene is an example of a non-polar compound belonging to the hydrocarbons. They are therefore poorly soluble in water, but soluble in ethanol (Jarvis et al., Phytochem Anal: Int. j. Plant. Chem. Biochem. Tech., 8: 217-222 (1997); da Cruz et al., J. Supercrit. Fluids, 31: 263-271 (2004); Zielinska et al., Molecules, 24: 2683 (2019)).

[0037] Caraway (Carum carvi L.), belonging to the Apiaceae family, is a major medicinal and aromatic plant (El-Banna et al., J. Soil Sci. Agric. Eng. 9: 237-241 (2018)). Its antimicrobial and pharmacological properties are mainly due to its active components, including carvone (50-65%) and limonene (up to 45%). Carvone, responsible for the olive oil-like odor of caraway, has various pharmacological properties such as antioxidant, antibacterial, antifungal, antiparasitic, anti-inflammatory, anti-neuraminidase, and anticancer (Bouyahya et al., Biomolecules., 11: 1803 (2021)). Limonene, widely used in soft drinks, cosmetics, and other flavoring products, also exhibits antimicrobial, anti-inflammatory, anticancer, antioxidant, and antiparasitic properties (Erasto et al., Nat. Prod. Commun., 3 (2008)).

[0038] Carvone and limonene are slightly polar or non-polar terpenes, sparingly soluble in water, but soluble in organic solvents such as ethanol (Qin et al., J. Mol. Eiq., 350: 118524 ​​(2022)).

[0039] Lavender is widely used in cosmetics, perfumes, food, and aromatherapy for its many benefits. Its chemical composition is dominated by oxygenated monoterpenes, with linalool and linalyl acetate being the main components (11.4–46.7% and 7.4–44.2%, respectively). Linalool has antibacterial, antiviral, anti-inflammatory, and anxiolytic properties (Nedeltcheva-Antonova et al., Plantes., 11: 3150 (2022)). Linalyl acetate exhibits antispasmodic, anti-inflammatory, and anti-hyperpigmentation properties (Moon et al., Molecules., 23: 1711 (2018)).

[0040] The alcohol functional group of linalool gives it polarity, making linalool highly soluble in organic solvents such as alcohol (Pereira et al., Colloids Surf. B., 171: 566-578 (2018)). Linalyl acetate, an ester formed by the condensation of linalool with acetic acid, is also polar and soluble in polar solvents such as ethanol (Dànilà et al., Ind Crops Prod., 122: 483-492 (2018)).

[0041] Palmarosa (Cymbopogon martini) is a herb known for its sweet, rose-like scent, rich in geraniol (over 60%). Geraniol is recognized for its numerous pharmacological and biological activities such as antifungal, antimicrobial, anthelmintic, and insect repellent (Thakker et al., Sustain. Chem. Eng., 6: 3215-3224 (2018)).

[0042] Geraniol is a primary alcohol with polar hydroxyl groups, which gives it some solubility in water and other polar solvents (Sharma et al., Sens. Actuators B: Chem, 219: 146-157 (2015)).

[0043] These plants also contain phenolic compounds (phenolic acids, flavonoids, and tannins), which are important phytochemicals with significant physiological and morphological properties, including antioxidant, antiallergic, antimicrobial, antiatherogenic, anti-inflammatory, cardioprotective, antithrombotic, and vasodilatory effects (Balasundram et al., Food Chem., 99: 191-203 (2006)).

[0044] The term "derivative" refers to plant material obtained by methods such as harvesting, chopping, and extraction with a solvent such as ethanol.

[0045] The term "organic" refers to a product obtained from natural resources without harmful chemicals.

[0046] The preparation of the ethano-terpene solvent according to this invention is based on the choice of plants rich in terpenes, aiming to obtain a solvent rich in terpenes which have a strong affinity for each molecule to be extracted and / or solubilized.

[0047] Ethanolic extraction is carried out from plant materials, such as leaves and stems, fresh or dried, of one or more plant species.

[0048] Plant material is reduced to small pieces for processing, for example by cutting, shredding, or grinding. The goal is to shred the plant or part of the plant and thus break the plant cell walls.

[0049] Ideally, the plant material is finely ground to expose a larger surface area to the ethanol.

[0050] In solvent embodiments, the purity of the ethanol is at least 92%, at least 96%, more preferably 99%.

[0051] In one embodiment, the step of bringing the plant material into contact with the ethanol is a maceration of the plant material with the solvent. It may also be a soaking, a spraying or any other technique known to those skilled in the art...

[0052] To facilitate the extraction step, the mixture is preferably stirred or agitated, while increasing the speed of the extraction process. This is conveniently achieved using magnetic stirring.

[0053] In a preferred embodiment, the liquid-solid ratio is preferably between 5 and 100 mL / g, ideally 10 mL / g.

[0054] Extraction begins to occur relatively quickly (within minutes) even at room temperature and is accelerated by heating.

[0055] The extraction temperature is not a critical parameter and it is easy to choose the operational temperature range using general knowledge and taking into account taking into account various factors such as material compatibility, possible degradation of active compounds and mixture composition, or extraction rate and boiling points.

[0056] In one embodiment, the extraction can be carried out at a temperature between room temperature and 120°C. However, for active compounds of plant origin, moderate temperatures are recommended so as not to alter the structure of these compounds. The temperature will then advantageously be between room temperature and 50°C.

[0057] Extraction time varies depending on the plant material, from 40 minutes to a few hours.

[0058] According to one embodiment, the solid-liquid extraction is carried out using ethanol in which the plant or at least part of the plant, possibly previously cut and / or ground, is brought into contact, then the liquid phase obtained is separated from the solid phase consisting of the plant material by filtration with or without pressure or by centrifugation during a separation step.

[0059] Residual plant matter is removed, for example by filtration, leaving the ethanol containing the dissolved extracts.

[0060] A single-step extraction may be sufficient. To increase extraction yield, the initial extraction may be followed by one or more re-extraction steps. A second extraction of the previously extracted plant material with fresh ethanol is performed to produce a final solution. The various conditions of time, temperature, and ethanol purity used are the same as for the first extraction step.

[0061] Mechanical grinding opens plant cells and unwanted co-extracted chemicals can enter the solution. Lignans, sugars, and pigments (chlorophylls, carotenoids, and flavonoids) are some of the co-extracted chemicals that can be found in extracts of ground plant material.

[0062] A disadvantage of ethanol is its affinity for water-soluble molecules, especially plant pigments, requiring additional purification after extraction.

[0063] In a preferred embodiment, the recovery of the ethano-terpene solvent involves the removal of plant pigments.

[0064] Pigment separation is preferably carried out by vacuum evaporation, generally in a rotary evaporator between 0 and 900 bar and 10 to 90°C.

[0065] In embodiments of the composition, what is provided by the present invention is a solution, a filtered solution, a colorless solution, a decolorized solution, produced by the method described above.

[0066] The invention also includes a plant ethanolic extract, obtained directly by means of the process as described above, characterized in that it comprises terpenes extracted from the plant.

[0067] It also relates to a peppermint extract characterized in that it comprises at least 35-60% menthol.

[0068] It also relates to a thyme extract characterized in that it comprises at least 10-64% thymol.

[0069] It also relates to a verbena extract characterized in that it comprises at least 14.8-45.5% citral.

[0070] It also relates to a rosemary extract characterized in that it comprises at least 15-55% eucalyptol.

[0071] It also relates to a caraway extract characterized in that it comprises at least 50-65% carvone.

[0072] It also relates to a lavender extract characterized in that it comprises at least 11.4-46.7% linalool.

[0073] It also relates to a palmarosa extract characterized in that it comprises more than 60% geraniol.

[0074] The ethanolic extracts obtained have aromatic and biological properties, with antioxidant properties.

[0075] An advantage of this invention is the use of pure ethanol as a solvent with GRAS (Generally Recognized as Safe) status, producing a clean green ethano-terpene solvent free from residual impurities, making it more suitable for sensitive applications such as food and pharmaceutical processing.

[0076] In addition to being clean, the ethano-terpene solvent represents a sustainable alternative to many conventional solvents derived from petroleum or other non-renewable sources, thanks to the renewable origin of ethanol and plants.

[0077] Advantageously, both ethanol and terpenes are biodegradable. This characteristic gives the ethano-terpene solvent the valuable property of decomposing naturally over time, thus reducing its environmental impact.

[0078] In addition, terpenes and phenolic compounds can provide the ethano-terpene solvent with specific properties such as aroma, flavor, improved solubilizing power and selectivity, as well as bioactive and pharmacological properties. The synergistic combination of ethanol and terpenes gives the solvent antioxidant and antimicrobial properties, thus increasing its effectiveness in pharmaceutical, cosmetic, disinfectant, and cleaning formulations.

[0079] The combination of pure ethanol and terpenes results in a versatile, tailor-made solvent, adapted to the specific needs of various industries and applications. The polarity of terpenes varies depending on the functional groups present in the terpene molecule. Choosing the terpene composition according to their polarity is crucial to improve the solubility of the substances to be extracted or solubilized in ethanol.

[0080] An advantage of this invention is the recovery of plant pigments such as chlorophylls, carotenoids, flavonoids and anthocyanins, from the decolorization phase of the ethano-terpene solvent, which can then be used as natural colorants in food and cosmetic applications, or as antioxidants and health-promoting agents in medicinal and therapeutic applications.

[0081] Furthermore, the synergy between ethanol and terpenes in the ethano-terpene solvent can be exploited as an alternative biodegradable fuel or as an additive in biodiesel production. This improves the properties of biodiesel, reduces greenhouse gas emissions, and decreases dependence on limited fossil resources.

[0082] The ethano-terpene solvent according to the invention can be used in the processes of extraction and / or solubilization of plant, animal or prokaryotic biological materials, as well as in synthesis and formulation in the food, pharmaceutical, cosmetic, chemical, perfume and fuel industries, and in cleaning and disinfection processes.

[0083] In another embodiment, the ethano-terpene solvent according to the invention can be used to specifically solubilize lipophilic or partially polar compounds in solid-liquid extraction operations.

[0084] The ethano-terpene solvent according to the invention can be used in conventional extraction operations, such as maceration (with or without mechanical agitation), percolation, leaching, as well as in extraction processes assisted by innovative technologies such as ultrasound and microwaves.

[0085] The ethano-terpene solvent according to the invention is easily recyclable after the eco-extraction process, thanks to its volatile nature. It can be reused in new extractions without the formation of oxidation compounds.

[0086] METHOD OF IMPLEMENTATION

[0087] According to a general concept of the invention, the ethano-terpene solvent is prepared from fresh plants by following the following steps: Recovery of fresh plants; Washing the plants with water, then draining to remove the wash water; Grinding the plants with ethanol at a plant / ethanol mass ratio of at least 1g per 5 mL (1:5), preferably 1:10; Separation of the liquid phase (colored extract) and residues; Decolorization by vacuum evaporation of the liquid phase to obtain a transparent solvent rich in terpenes and low in phenolic compounds.

[0088] According to a first aspect of the invention, the plants are chosen from fresh Magnoliophytes, rich in terpenes.

[0089] Preferably, for experimental purposes, the plants are chosen from the botanical genera Mentha, Rosmarinus, Thymus, Verbena, Carum, Cymbopogon and Lavandula, with a content of terpene compounds between 30 and 70% by weight of the extract material, preferably between 40 and 60%.

[0090] In one particular aspect, the plant is used in its entirety without prior selection. The stem, leaves, and flowers are all used for maximum yield.

[0091] According to a second aspect of the invention, the liquid obtained in the separation step undergoes a decolorization step by vacuum evaporation. This step is carried out at a temperature of at least 90°C in a rotary evaporator. At the end of this step, a transparent solvent composed mainly of terpenes with ethanol and a low content of phenolic compounds is recovered.

[0092] Preferably, the ethanol used in the various steps of the present process is bioethanol.

[0093] In a particular aspect, after the grinding step, the residues from the separation step are reused for maximum extraction. Ethanol is added at 50% of the volume of the residues, then maceration is carried out at a temperature of 50°C for half an hour under magnetic stirring.

[0094] The green ethano-terpenic solvent obtained according to the process of the invention is transparent, free of plant pigments and rich in terpenic compounds diluted in ethanol. It has a significant selective power thanks to its amphiphilic properties (polar and apolar), allowing a better affinity with the molecules to be extracted or solubilized.

[0095] Additionally, the green ethano-terpene solvent has a terpene recovery rate of between 81 and 98%.

[0096] Examples of processes for preparing the ethano-terpene solvents according to the invention, as well as test results demonstrating their effectiveness, are presented below.

[0097] EXAMPLES

[0098] Example 1: Preparation of the ethano-terpene solvent

[0099] Preparation of ethanolic plant extract

[0100] The plants studied were peppermint (Mentha), thyme (Thymus), rosemary (Rosmarinus), verbena (Verbena), caraway (Carum), palmarosa (Cymbopogon), and lavender (Lavandula). The plant material was collected from the wild.

[0101] The leaves and stems of the plant are collected fresh. 100 g of plant material are mixed with 99% ethanol, the solid-liquid ratio is 1:10 (1 g of plant material to 10 mL of ethanol), and the mixture is ground at room temperature in a high-speed mechanical mixer, which acts to cut the plant material into small fragments and mix them thoroughly with the ethanol. After a few minutes, the color of the ethanol begins to change, becoming colored, following the solvent extraction of the pigments and active ingredients from the plant material.

[0102] To maximize the extraction yield, maceration can be continued by maintaining the mixture at 50°C for 1 h with stirring. The plant residue separated from the first extraction cycle is extracted a second time, again for 30 min with 0.5 L of ethanol.

[0103] This extraction of the remaining material from the residue increased the overall terpene yield by 5 to 10%. The resulting mixture is conventionally filtered to remove plant residues, leaving a colored extract comprising ethanol with terpenes and dissolved solids extracted from the plant material.

[0104] Recovery of ethano-terpene solvent

[0105] The ethanolic plant extract from the previous step contains more plant pigments and is decolorized by removing them. The ethano-terpene solvent is separated from the plant pigments by vacuum evaporation at 90°C under a pressure of 0-900 bar.

[0106] Performance test

[0107] Each sample is shaken vigorously for 20 seconds and 5 g of each sample is aliquoted into 50 mL vials. They are placed on a hot plate and the ethanol extracts are evaporated at 50°C until completely dry. The vials are weighed using an analytical balance before and after aliquoting the samples, as well as after evaporation is complete. The sample yield is determined from a 5 g aliquot by calculating the weight after evaporation subtracted from the weight before evaporation.

[0108] Results

[0109] The terpene extraction yield mainly concerns the recovery rate of terpenes by the process of the invention. The recovery rate is defined as the ratio of the final weight after evaporation of the liquid part to the initial weight of the plant material (plant).

[0110] The following examples of recovery rates are for peppermint, thyme, verbena, rosemary, caraway, lavender and palmarosa.

[0111] 4.86 g of terpene-rich extract were obtained from peppermint (30 to 55% menthol). The extraction yield expressed on the dry weight of the plant is 97.2%.

[0112] From thyme (10 to 60% thymol), 4.17 g of terpene-rich extract were obtained. The extraction yield expressed on the dry weight of the plant is 83.4%.

[0113] From verbena (14.8 to 45.5% citral), 4.39 g of terpene-rich extract were obtained. The extraction yield expressed on the dry weight of the plant is 87.8%.

[0114] 4.69 g of terpene-rich extract was obtained from rosemary (15 to 55% eucalyptol). The extraction yield expressed on the dry weight of the plant is 93.8%.

[0115] From caraway (50 to 65% carvone), 4.63 g of terpene-rich extract were obtained. The extraction yield expressed on the dry weight of the plant is 92.6%.

[0116] From lavender (11.4 to 46.7% linalool), 4.87 g of terpene-rich extract were obtained. The extraction yield expressed on the dry weight of the plant is 97.4%.

[0117] From palmarosa (more than 60% geraniol), 4.89 g of terpene-rich extract were obtained. The extraction yield expressed on the dry weight of the plant is 97.8%.

[0118] Example 2: Test of the solubilizing power of the ethano-terpene solvent

[0119] Solubility of lutein in the solvent defined in the invention rich in menthol in comparison with the solubility of lutein in tetrahydrofuran

[0120] The solubility of lutein is compared in two solvents: in tetrahydrofuran, on the one hand, and in the solvent according to the invention rich in menthol (extracted from peppermint), on the other hand. For each solvent evaluated, an excess of lutein, analytical standard, was brought into contact with 1 mL of solvent. The mixture is stirred at a temperature of 30°C protected from light for one hour. The mixture is then centrifuged at 3000 g for 10 min to remove undissolved lutein. The solubility of lutein in the tested solvent was quantified at 445 nm by a UV-Vis spectrophotometer (Jasco V-730). The solubility of lutein in tetrahydrofuran is 8.1 mg / mL and the solubility of lutein in the solvent according to the invention is 8.2 mg / mL.

[0121] Solubility of ascorbic acid in the solvent defined in the invention rich in carvone in comparison with the solubility of ascorbic acid in water

[0122] The solubility of ascorbic acid is compared in two solvents: in water, on the one hand, and in the solvent according to the invention rich in carvone (extracted from caraway), on the other hand. For each solvent evaluated, an excess of ascorbic acid, of purity 99%, was brought into contact with 1 mL of solvent. The mixture is stirred at a temperature of 25 °C for two hours. The mixture is then passed through a 0.22 µm membrane to remove the ascorbic acid that was not solubilized in the tested solvent. The solubility of ascorbic acid was quantified at 243 nm by a UV-Vis spectrophotometer (Jasco V-730). The solubility of ascorbic acid in water is 328.5 mg / mL and the solubility of ascorbic acid in the solvent according to the invention is 328.12 mg / mL.

[0123] Solubility of curcumin in the solvent defined in the invention rich in geraniol in comparison with the solubility of curcumin in dimethyl sulfoxide (DMSO)

[0124] The solubility of curcumin is compared in two solvents: in DMSO, on the one hand, and in the solvent according to the invention rich in geraniol (extracted from palmarosa), on the other hand. For each solvent evaluated, an excess of curcumin, analytical standard, was added to 1 mL of solvent. The mixture is stirred at a temperature of 30°C protected from light for one hour. The mixture is then centrifuged at 5000 g for 10 min to remove undissolved curcumin. The solubility of curcumin in the tested solvent was quantified at 425 nm by a UV-Vis spectrophotometer (Jasco V-730). The solubility of curcumin in DMSO is 11 mg / mL and the solubility of curcumin in the solvent according to the invention is 12.6 mg / mL.

[0125] Solubility of caffeine in the solvent defined in the invention rich in linalool in comparison with the solubility of caffeine in chloroform

[0126] The solubility of caffeine is compared in two solvents: in chloroform, on the one hand, and in the solvent according to the invention rich in linalool (extracted from lavender), on the other hand. For each solvent evaluated, an excess of caffeine, with a purity of 99%, was added to 1 mL of solvent. The mixture is stirred at a temperature of 25 °C for one hour. The mixture is then passed through a 0.22 µm membrane to remove the caffeine that has not been solubilized in the tested solvent. The solubility of caffeine was quantified at 273 nm by a UV-Vis spectrophotometer (Jasco V-730). The solubility of caffeine in chloroform is 181.02 mg / mL and the solubility of caffeine in the solvent according to the invention is 180.74 mg / mL.

[0127] The solubilizing power and the intrinsic characteristics of the solvent are partly the result of its composition rich in terpene compounds and other phenolic compounds diluted in ethanol and having both a significant selective power thanks to its polar and apolar properties for a better affinity with the molecules to be extracted. The richness in terpenes is due in principle to the recovery rate of the latter by the process of the invention. A recovery rate which is between 81 and 98%. References cited in the description Aghamohammadi, A., Azadbakht, M,, & Hosseinimehr, SJ (2016). Quantification of thymol content in different extracts of Zataria multiflora by HPLC method. Pharmaceutical and Biomedical Research, 2(1), 8-13. Aziz, E., Batool, R., Akhtar, W., Shahzad, T., Malik, A., Shah, M. A., ... & Thiruvengadam, M. (2021). Rosemary species: a review of phytochemicals, bioactivities and industrial applications. South African Journal of Botany. Balasundram, N., Sundram, K., & Samman, S. (2006). Phenolic compounds in plants and agri-industrial by-products : Antioxidant activity, occurrence, and potential uses. Food chemistry, 99(1), 191-203. Bouyahya, A., Mechchate, H., Benali, T., Ghchime, R., Charfi, S., Balahbib, A., ... & Omari, N. E. (2021). Health benefits and pharmacological properties of carvone. Biomolecules, 11(12), 1803. Brahmi, F., Khodir, M., Mohamed, C., & Pierre, D. (2017). Chemical composition and biological activities of Mentha species. Aromatic and medicinal plants-Back to nature, 10, 47-79. da Cruz Francisco, J., Topgaard, D., Sivik, B., & Bergenstâhl, B. (2004). Phase behavior of the monoolein-water system: The effects of addition of the hydrocarbon 1, 8 -cineole and supercritical carbon dioxide. The Journal of Supercritical Fluids, 31(3), 263-271 . Dànilà, E., Moldovan, Z., Popa, M., Chifiriuc, M. C., Kaya, A. D., & Kaya, M. A. (2018). Chemical composition, antimicrobial and antibiofilm efficacy of C. Union and L. angustifolia EOs and of their mixtures against Staphylococcus epidermidis clinical strains. Industrial Crops and Products, 122, 483- 492. Ejaz, R., Malik, S., Ahmad, M., Ali, H., & Choudhry, S. (2020). Anti-biofilm potential of menthol purified from Mentha piperita L. (Mint). Biological and Clinical Sciences Research Journal, 2020(1). Erasto, P., & Viljoen, A. M, (2008). Limonene-a review: biosynthetic, ecological and pharmacological relevance. Natural Product Communications, 3(7), 1934578X0800300728. Formule Verte N°08 décembre 2011, pages 28-32. Hamidpour, R., Hamidpour, S., Hamidpour, M., & Shahlari, M. (2013). Camphor (Cinnamomum camphora), a traditional remedy with the history of treating several diseases. Int. J. Case Rep. Images, 4(2), 86-89. HÔferl M, Buchbauer G, Jirovetz L, Schmidt E, Stoyanova A, Denkova Z, Slavchev A, Geissler M (2009). Correlation of antimicrobial activities of various essential oils and their main aromatic volatile constituents. J. Essent. Oil Res.21:459-463. Jarvis, A. P., & Morgan, E. D. (1997). Isolation of plant products by supercritical- fluid extraction. Phytochemical Analysis: An International Journal of Plant Chemical and Biochemical Techniques, 8(5), 217-222. Kolassa N (2013) Menthol differs from other terpenic essential oil constituents. Regul Toxicol Pharmacol 65( 1 ): 115-118. Kubica, P., Szopa, A., Dominiak, J., Luczkiewicz, M., & Ekiert, II. (2020). Verbena officinalis (common vervain)-a review on the investigations of this medicinally important plant species. Planta medica, 86(17), 1241-1257. Lesnik, S., Furlan, V., & Bren, U. (2021). Rosemary (Rosmarinus officinalis L.): extraction techniques, analytical methods and health-promoting biological effects. Phytochemistry Reviews, 20(6), 1273- 1328. Lima, I, O., de Medeiros Nobrega, F., de Oliveira, W.A., de Oliveira Lima, E., Albuquerque Menezes, E., Afrânio Cunha, F., & de Fatima Formiga Melo Diniz, M. (2012). Anti-Candida albicans effectiveness of citral and investigation of mode of action. Pharmaceutical Biology, 50(12). 1536-1541. Moon, P.D., Han, N.R., Lee, J.S., Kim, H.M. and Jeong, H.J. (2018). Effects of linalyl acetate on thymic stromal lymphopoietin production in mast cells. Molecules, 23(7), 1711. Nedeltcheva-Antonova, D., Gechovska, K., Bozhanov, S., & Antonov. L. (2022). Exploring the Chemical Composition of Bulgarian Lavender Absolute (Lavandula Angustifolia Mill.) by GC / MS and GC-FID. Plantas, 11(22), 3150. Oualdi, I., Bralimi, F., Mokhtari, O., Abdellaoui, S., Tahani, A., & Oussaid, A. (2021). Rosmarinus officinalis from Morocco, Italy, and France: Insight into chemical compositions and biological properties. Materials Today: Proceedings, 45, 7706–7710. Pereira, L, Severino, P., Santos, A. C., Silva, A. M., & Souto, E. B. (2018). Linalool bioactive properties and potential applicability in drug delivery systems. Colloids and Surfaces B : Biointerfaces, 171, 566- 578. Perveen, S., & Al-Taweel, A. (Eds.). (2018). Terpenes and terpenoids. BoD-Books on Demand. Qin, Z., Cheng, H., Song, Z., Ji, L., Chen, L., & Qi, Z. (2022). Selection of deep eutectic solvents for extractive deterpenation of lemon essential oil. Journal of Molecular Liquids, 350, 118524. Riachi, L. G., & De Maria, C. A. (2015). Peppermint antioxidants revisited. Food chemistry, 176, 72- 81. Salehi, B., Mishra, A. P., Shukla, I., Sharifi- Rad, M., Contreras, M. D. M., Segura- Carretero, A., ... & Sharifi- Rad, J. (2018). Thymol, thyme, and other plant sources: Health and potential uses. Phytotherapy Research, 32(9), 1688-1706. Sharifi- Rad, M., Varoni, E. M., Iriti, M., Martorell, M., Setzer, W. N., del Mar Contreras, M., ... & Sharifi- Rad, J. (2018). Carvacrol and human health: A comprehensive review. Phytotherapy Research, 32(9), 1675-1687. Sharma, P., Ghosh, A., Tudu, B., Sabhapondit, S., Baruah, B. D., Tamuly, P., ... & Bandy opadhyay, R. (2015). Monitoring the fermentation process of black tea using QCM sensor based electronic nose. Sensors and Actuators B : Chemical, 219, 146-157. Sharma, S., Habib, S., Sahu, D., & Gupta, J. (2021). Chemical properties and therapeutic potential of citral, a monoterpene isolated from lemongrass. Medicinal Chemistry, 17(1), 2-12. Su. ¥. H., & Lin, J. Y. (2022). Menthone inhalation alleviates local and systemic allergie inflammation in ovalbumin-sensitized and challenged asthmatic mice. International Journal of Molecular' Sciences, 23(7), 4011. Thakker, M. R., Parikh, J. K., & Desai, M. A. (2018). Ultrasound assisted hydrotropic extraction: a greener approach for the isolation of geraniol from the leaves of Cymbopogon martinii. ACS Sustainable Chemistry & Engineering, 6(3), 3215-3224. Tian, H., Li, D., Xu, T., Hu, J., Rong, Y., & Zhao, B. (2017). Citral stabilization and characterization of nanoemulsions stabilized by a mixture of gelatin and Tween 20 in an acidic system. Journal of the Science of Food and Agriculture, 97(9), 2991-2998. TIgNEH, T. M., & BABU G, N. E. E. L. A. I. A. II. (2020). Variation in Chemical Composition and Antimicrobial Acti vities of Essential oil of Leaves of Knob Wood, Zanthoxylum chalybeum Collected from Three Different Places of Eastern Ethiopia. Oriental Journal of Chemistry, 36(3 ). Zeng, J., Wang, W., Lin, J., Zhang, Y., Li, H., Liu, J., ... & Wei, Y. (2022). Purification of menthone and menthol from Mentha haplocalyx by suspension particle assisted solvent sublation, neuroprotective effect in vitro and molecular' docking of menthol on amyloid ~p. Journal of Chromatography A, 1674, 463125. Zielihska, A., Ferreira, N. R., Durazzo, A., Lucarini, M., Cicero, N., Mamouni, S. E., ... & Souto, E. B. (2019). Development and optimization of alpha-pinene-loaded solid lipid nanoparticles (SLN) using experimental factorial design and dispersion analysis. Molecules, 24(15), 2683.

Claims

Claims 1. Transparent ecological ethano-terpenic solvent of plant origin, formed from a synergistic mixture of ethanol and terpenes from fresh plants, characterized in that it comprises between 81 and 98% of the terpenes of the original plant, with a low content of phenolic and volatile compounds of the plant, recyclable and usable in new processes without the formation of oxidation compounds.

2. Process for the preparation of ethano-terpene solvent according to claim 1, characterized in that it comprises the following steps: Recovery of fresh plants; Washing the said plants with water, then draining to remove the wash water; Grinding plants with ethanol; Removal of plant residues and recovery of the colored extract; Decolorization of the colored extract, by elimination of plant pigments; Recovery of transparent ethano-terpenic solvent.

3. Process for the preparation of ethano-terpene solvent according to claims 1 and 2, characterized in that the plant is chosen from the botanical branch Magnoliophyta.

4. Process for the preparation of ethano-terpene solvent according to claims 1 to 3, characterized in that the plant is chosen from the botanical classes Magnoliopsida and Liliopsida rich in oxygenated and / or hydrocarbon terpenes.

5. Process for the preparation of ethano-terpene solvent according to claims 1 to 4, characterized in that the plant can be chosen from plants belonging to the botanical genera Mentha, Thymus, Rosmarinus, Verbena, Carum, Cymbopogon and Lavandula.

6. Process for the preparation of ethano-terpene solvent according to claims 1 to 5, characterized in that the selection of the plant is based on the degree of polarity of their major terpenes, these terpenes being chosen to have the same degree of polarity and affinity with the molecule to be extracted and / or solubilized.

7. Process for the preparation of ethano-terpene solvent according to claims 1 to 6, characterized in that the selected plant comprises a terpene composition of between 30 and 70% by weight of the extract material, in particular between 40 and 60%.

8. Process for the preparation of ethano-terpene solvent according to claims 1 to 7, characterized in that the selected plant is used with all its components, including flowers, buds, stems, leaves, roots, fruits, bark or seeds.

9. Process for the preparation of ethano-terpene solvent according to claims 1 to 8, characterized in that the plant, ground in the form of a fine fragment, is macerated with ethanol (99%) in a plant / ethanol mass ratio of at least 1 g per 10 mL (1:10).

10. Process for the preparation of ethano-terpene solvent according to claims 1 to 9, characterized in that the maceration is carried out at a temperature of 50°C for 1 hour of stirring.

11. Process for the preparation of ethano-terpene solvent according to claims 1 to 10, characterized in that the step of decolorizing the colored extract is a step of evaporation under vacuum at a temperature less than or equal to 90°C and a pressure between 0 and 900 bar.

12. Ethano-terpene solvent according to claim 1, characterized in that it is selective and its selectivity is a function of the degree of polarity of its terpene composition, which is modified and selected for each molecule to be extracted and / or solubilized.

13. Ethano-terpene solvent according to claims 1 and 12, characterized in that its composition in terpenes and phenolic compounds gives it antioxidant, biological and aromatic properties.

14. Use of the ethano-terpene solvent according to claims 1 and 12, for the solubilization of lutein, with a solubility of 8.2 mg / mL compared to that in tetrahydrofuran of 8.1 mg / mL.

15. Use of the ethano-terpene solvent according to claims 1 and 12, for the solubilization of ascorbic acid, with a solubility of 328.12 mg / mL compared to that in water of 328.5 mg / mL.

16. Use of the ethano-terpene solvent according to claims 1 and 12, for the solubilization of curcumin, with a solubility of 12.6 mg / mL compared to that in DMSO of 11 mg / mL.

17. Use of the ethano-terpene solvent according to claims 1 and 12, for the solubilization of caffeine, with a solubility of 180.74 mg / mL compared to that in chloroform of 181.02 mg / mL.

18. Use of the ethano-terpene solvent according to claims 1, 12 and 13, in the processes of extraction and / or solubilization of plant and / or animal biological materials and / or prokaryotes, in the synthesis and formulation in the food, pharmaceutical, cosmetic, chemical, perfume and fuel industries, as well as in cleaning and disinfection processes.

Images