Title of Invention

A PROCESS FOR EXTRACTION OF CURCUMINOIDS FORM CURCUMA SPECIES.

Abstract

A process for the extraction of Curcuminoids from Curcuma species: This invention provides is an extraction process with an organic solvent for recovery of curcuminoids from the aqueous solution of hydrotrope after dilution of the hydrotrope solution with water or without dilution at a particular temperature range. The organic solvent selected for the extraction may be immiscible with water such as a group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons, ketones, ethers, esters, alcohols, amides and a mixtures thereof.

Full Text

The present invention relates to a process for extraction of curcuminoids from curcuma species. The present invention particularly relates to a process for extraction of curcuminoids from Curcuma species such as Curcuma longa, Curcuma aromatica, Curcuma amada, Curcuma zedoariai, Curcuma xanthorrhiza, Curcuma caesia, Curcuma aerugiosa, Curcuma angustifolia, Curcuma leucorrhiza, Curcuma pierreana, Curcuma domestica, and Curcuma mangga. The concentration of curcuminoids is about 0.1% to 6% in different Curcuma species This method is particularly related to the extraction of curcuminoids using aqueous hydrotrope solutions for the first time. Curcumin, (C21H20O6), a major constituent of turmeric (Curcuma longa) is present with two related compounds viz. demethoxycurcumin and bisdemethoxycurcumin together known as curcuminoids. Curcuminoids are used extensively as a food-coloring agent, natural antioxidant, spice, and condiment and for medicinal purposes. It has shown potent anticancer activity [Kuttan, Ramadasan; et. al., Cancer Lett. (Shannon I rel.) 1985, 29(2), 197-202], Curcuminoids also has potential as an antiviral agent. It has been proven a modest inhibitor of HIV-1 and HIV-2 proteases [Sui, Z; et. al,. Biorg. Med. Chem. 1993, 6, 415-422] Sastry B. S. [Res. Ind. 1970, 15, (4), 258-60] described an extraction process for the extraction of curcuminoids from turmeric wherein the curcuminoids were extracted with acetone followed by petroleum ether. Other solvents used for extraction are ethanol, ethyl acetate and benzene. The extraction of curcuminoids into these organic solvents was not very selective, as other compounds like oleoresins were extracted reducing the purity of curcuminoids. This makes post-extraction processing cumbersome. Myagi, Hisashige et al (Jpn. Kokai Tokyo Koho JP 06,69,479 [9409,479] (CL. C07C49/255), 18 Jan 1994, Appl. 92/169,647, 26 Jun 1992; 5pp.) patented a process for extraction of curcuminoids using supercritical carbon dioxide. The supercritical carbon dioxide was actually used for extracting essential oils and then curcuminoids were extracted from Curcuma longa using mixture of ethanol and water. This process using supercritical fluid extraction is not economical and curcuminoids extracted is then converted to a water soluble curcumin cyclodextrin complex. Chassagnez, A; et al [Cienc. Technol. Aliment. 1997, 17 (4), 399-404], carried out a pretreatment on Curcuma longa material before extraction, using supercritical carbon dioxide and determined that the curcuminoids extraction largely depends on this pretreatment. Ran, Qiliang; and Zhou, Xianrong [Shipin Kexue (Beijing) 1988, 101, 12-15], extracted curcuminoids from Curcuma with alkaline water (pH~9). The curcuminoids was recovered by precipitation at pH 3-4. The product contained 82.5% curcuminoids. However, the curcuminoids were unstable in alkaline conditions and the degradation rale rapidly increases from pH 7.45 to a maximum at about 10.2.[Price Lisa C; and Buescher. R. W; J. FoodSci. 1997, 62 (2), 267-269]. Most of these prior art processes relate to the extraction of Curcuma longa oleoresin containing curcuminoids and other volatile oils. Curcuminoids containing oleoresin is then solvent extracted and recrystallised to obtain 'pure curcuminoids. These conventional processes are carried out using a number of steps that often present difficult operating conditions and result in a high cost of production. The main object of the present invantion is to provide a process for the extraction of curcuminoids from Curcuma species. Another objective of the present invention is to provide a cost-effective process for the extraction of curcuminoids from Curcuma species in a substantially pure form using the phenomena of hydrotropy. The approach was to find a suitable hydrotrope for selective extraction of curcuminoids from Curcuma species followed by dilution of the extract phase to precipitate curcuminoids in pure form. In this process of invention the selective extraction of phytochemicals like curcuminoids is conducted in a simple two step process which successfully exploits the ability of hydrotropes to dissolve the otherwise water insoluble organic compounds in aqueous solution. The first step involves the selective extraction of curcuminoids from Curcuma species and its solubilization in the aqueous hydrotrope solution. The second step involves the recovery of curcuminoids by simple dilution with water as most of the curcuminoids precipitates out. In another embodiment of the invention the extracted curcuminoids is recovered from the aqueous hydrotiope solution by extraction with an organic solvent followed by de solventisation. Another object of the present invention is to provide a process for the extraction of curcuminoids from Curcuma longa in the first step without using an organic solvent or excessive temperature to retain the purity of curcuminoids. The curcumin of Formula 1, de-methoxy curcumin of Formula 2 and bis (de-methoxy) curcumin of Formula 3 together known as curcuminoids have been extracted from the rhizomes of Curcuma species Formula 1 :- (Formula Removed) Formula 2 :- de-Methoxy curcumin (Formula Removed) Formula 3 :- Bis de-methoxy curcumin (Formula Removed) Accordingly the present invention provides a process for the extraction of curcuminoids from Curcuma species which comprises : I. contacting the Curcuma species with an aqueous hydrotrope solution at a temperature in the range of 0-100°C for preferential extraction of curcuminoids from the Curcuma species and separating the solution obtained from the solid, II. recovering the curcuminoids from the solution obtained at the end of step (I) by known methods. In an embodiment of the invention the curcuminoids are recovered from the aqueous solution of hydrotrope obtained in step (I), after dilution with water or without dilution, by extraction with organic solvent selected from a group of aromatic and aliphatic hydrocarbons such as benzene, alkyllated benzene, heptane, hexane, octane, cyclohexane, halogenated hydrocarbones such as CHC13, CC14, CH2C12, ketones such as(CH3)2CO,methyl isobutyl ketone, esters such as ethylacetate, propylacetate, ethers such as diethyl ether, diisopropyl ether, dibutyl ether, alcohols such as butanol, hexanol, amides such as phosphoamides, trioctyl phosphene, and a mixtures thereof. The rhizomes of Curcuma species such as Curcuma longa and Curcuma aromatica in pulverized form, preferably in the mesh size of 5 to 300 are brought in intimate contact with an aqueous solution of hydrotrope in the form of a slurry in a stirred vessel. In the process of invention when the contacting is done in the stirred vessel the Curcuma species powder is added to the aqueous hydrotrope solution of concentration in the range of 0.1 1gmol/lit to 5.0gmol/lit. After the aforementioned components are brought together in the mixture usually in the form of slurry the mixture is agitated for a period sufficient for the extraction of curcuminoids to take place. A typical mixing time is in the range of 15 minutes to 24 hours depending upon the concentration of hydrotrope and the speed of agitation. The mixing is conducted at a selected temperature from 0°C -100°C preferably at room temperature of 30°C and atmospheric pressure. The Curcuma species for the extraction of curcuminoids may be such as Curcuma longa, Curcuma aromatica, Curcuma amada, Curcuma zedoariai, Curcuma xanthorrhiza, Curcuma caesia, Curcuma aerugiosa, Curcuma angustifolia, Curcuma leucorrhiza, Curcuma pierreana, Curcuma domestica, and Curcuma mangga. The term "hydrotrope" indicates short alkyl chain water soluble ampiphillic compounds. The hydrotrope is selected from the group consisting of sodium, potassium, calcium, ammonium, magnesium salts of alkyl benzene sulfonates, such as benzene sulfonate, toluene sulfonate, xylene sulfonate, ethyl benzene sulfonate, styrene sulfonate, pseudocumene sulfonate, mesitylene sulfonate, propyl benzene sulfonate and butyl benzene sulfonate, alkyl polyglycol sulfates phosphates such as methy cellosolve sulfate, ethyl cellosolve sulfate, propyl cellosolve sulfate, butyl cellosolve sulfate, pentyl cellosolve sulfate, hexyl cellosolve sulfate and the corresponding phosphates with sodium, potassium, and calcium counterions; methyl diglycol sulfates, ethyl diglycol sulfates, propyl diglycol sulfates, butyl diglycol sulfates, pentyl diglycol sulfates, hexyl diglycol sulfates and phosphates salts with of sodium, potassium, calcium and ammonium counterions; substituted aromatic carboxylates such as hydroxybenzotaes, toluates, chlorobenzoates, nitrobenzoates, alkyl benzene carboxylates with sodium, potassium, calcium and ammonium counterions; substituted phenates, such as hydroxyphenates, chlorophenates, alkyl phenates, naphthols; naphthalene carboxylates; substituted naphthalene carboxylates such as hydroxy naphthalene carboxylates and alkaU metal saccharine such as sodium saccharine. After the mixing the solid residue is separated from the solution by decantation or filtration or by centrifugation. The separated residue is washed with water and the washing is combined with filtrate or the filtrate is used as such for the recovery of curcuminoids. The filtrate is diluted with water to bring the concentration of hydrotrope to low enough to precipitate curcuminoids from the solution. The dilution is done at a temperature at a range 0-80 °C preferably in the range 20-30 0C. The precipitated curcuminoids are separated from the solution by decantation or filtration or centrifugation. The curcuminoids are washed with water and dried. The hydrotrope solution recovered during this step is concentrated and recycled. In another embodiment of this invention the filtrate obtained after the step(I) is subjected to extraction with an organic solvent for recovery of curcuminoids from the aqueous solution of hydrotrope after dilution of the hydrotrope solution with water or without dilution. The organic solvent selected for the extraction may be immiscible with water such as a group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons, ketones, ethers, esters, alcohols, amides and a mixtures thereof. The objects of the invention, its advantages and means of attaining the same are disclosed hereunder in greater detail with reference to the nonlimiting exemplary embodiments of the same. The examples are by way of illustration only and in no way restrict the scope of the invention. Chemicals used Curcuma longa (rhizomes of turmeric) Curcuma aromatica (rhizomes of Curcuma aromatica) Sodium butyl glycol sulphate (50 % aqueous solution, Hulls Germany) Sodium salicylate (IP grade) para-Toluene sulfonic acid (AR grade) Sodium cumene sulfonate (AR grade) Sccharine sodium (AR grade) Dichloromethane (AR grade) Toluene (AR grade) Chloroform (AR grade) Ethanol (AR grade) Acetic Acid Glacial (AR grade) Method of Analysis: High Performance Thin Layer Chromatography with E Merck HPTLC silica plates as stationary phase Example 1 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml sodium butyl glycol sulfatel.O gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(100 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 25.46% (74 mg.) based on the amount of .curcuminoids present in the rhizomes with a purity of 94.0%. Example 2 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml sodium butyl glycol sulfatel.5 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(200 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 28.74% (84 mg.) based on the amount of .curcuminoids present in the rhizomes with a purity of 93.0%. Example 3 5 gms of pulverized Curcuma longa powder of mesh size # 22 was added to 100 ml sodium butyl glycol sulfatel.5 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(200 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 43.35% (127 mg.) based on the amount of .curcuminoids present in the rhizomes with a purity of 92.8%. Example 4 5 gms of pulverized Curcuma longa powder of mesh size # 85 was added to 100 ml sodium butyl glycol sulfatel.5 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(200 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 36.34% (106 mg.) based on-the amount of .curcuminoids present in the rhizomes with a purity of 93.4%. Example 5 5 gms of pulverized Curcuma longa powder of mesh size # 22 was added to 100 ml sodium butyl glycol sulfatel.5 gmol/lit concentration and stirred vigorously for 8.0 hours at 50°C. The solution was filtered at 50°C and then diluted by addition of water(200 ml) 30°C. The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 51.50% (150 mg.) based on the amount of .curcuminoids present in the rhizomes with a purity of 97%. Example 6 5 gms of pulverized Curcuma longa powder of mesh size # 22 was added to 100 ml sodium butyl glycol sulfatel.5 gmol/lit concentration and stirred vigorously for 8.0 hours at 50°C. The solution was filtered at 50°C and diluted by addition of water(200 ml) at 30°C. The precipitated curcuminoids were dried and analyzed for purity. The supernatent solution is then extracted with 300 ml of toluene three times. The recovered curcuminoids was analysed for purity The total recovery of curcuminoids were 64.76 % (189 mg) based on the amount of .curcuminoids present in the rhizomes with a purity of 94.97% Example 7 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml sodium salicylate 3.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(400 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 50.79% (148 mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 89.2%. Example 8 5 gms of pulverized Curcuma longa powder of mesh size # 22 was added to 100 ml sodium salicylate 3.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(400 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 48.11% (140 mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 90.1%. Example 9 5 gms of pulverized Curcuma longa powder of mesh size # 85 was added to 100 ml sodium salicylate 3.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(400 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 49.79% (145 mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 92.7%. Example 10 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml sodium salicylate 3.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 40°C. The solution was filtered and then diluted by addition of water(400 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 48.67% (142 mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 82.2%. Example 11 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml para-toluene sulfonic acid 2.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(1900 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 13.79% (40 mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 79.3%. Example 12 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml sodium cumene sulfonate 2.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(3900 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 38.56% (113mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 90.7%. Example 13 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml sodium cumene sulfonate 2.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30 C. The solution was filtered and then extracted with 200 ml. dichloromethane five times. The recovered curcuminoids was analysed for purity. The recovery of curcuminoids was 28.45% (83mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 98.2%. Example 14 5 gms of pulverized Curcuma longa powder of mesh size # 6 was added to 100 ml saccharine sodium 2.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then extracted with 200 ml. dichloromethane five times. The recovered curcuminoids was analysed for purity. The recovery of curcuminoids was 17.5% (51mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 96.3%. Example 15 5 gms of pulverized Curcuma aromatica powder of mesh size # 6 was added to 100 ml sodium cumene sulfonate 2.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(3900 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 46.7% (13mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 86.1%. Example 16 5 gms of pulverized Curcuma aromatica powder of mesh size # 6 was added to 100 ml para-toluene sulfonic acid 2.0 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then diluted by addition of water(1900 ml). The precipitated curcuminoids were dried and analyzed for purity. The recovery of curcuminoids was 19.49% (5 mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 61.1%. Example 17 5 gms of pulverized Curcuma aromatica powder of mesh size # 6 was added to 100 ml sodium cumene sulfonate 2.0 gmol/lit concentration and .stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then extracted with 200 ml. dichloromethane five times. The recovered curcuminoids was analysed for purity. The recovery of curcuminoids was 42.88% (12mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 97.9%. Example 18 5 gms of pulverized Curcuma aromatica powder of mesh size # 22 was added to 100 ml sodium butyl glycol sulfate 1.5 gmol/lit concentration and stirred vigorously for 8.0 hours at 30°C. The solution was filtered and then extracted with 200 ml. dichloromethane five times. The recovered curcuminoids was analysed for purity. The recovery of curcuminoids was89.12% (24mg.) based on the amount of curcuminoids present in the rhizomes with a purity of 96.4%. The main advantages of the present invention are : 1. A simple practically viable method has been provided for the extraction of curcuminoids. 2. The number of steps required for extraction have been reduced and simple operating conditions are provided which can reduce the cost of production. 3. The hydrotrope solution can be recycled with or without the concentration step for further extraction which reduces the cost of chemicals. 4. The process of the present invention is carried out preferentially at modarate temperature which is an improvement over the prior art as it does not degrade curcuminoids and other chemicals. 5. The first step of the process of the present invention is carried out without the use of any organic solvent which retains the purity of curcuminoids and is an improvement over the prior art. We claim : 1. A process for extraction of curcuminoids from Curcuma species which comprises : I. contacting the Curcuma species with an aqueous hydrotrope solution at a temperature in the range of 0-100° C for preferential extraction of curcuminoids from the Curcuma species and separating the solution obtained from the solid residue. II. recovering the curcuminoids from the solution obtained at the end of step (I) by known methods. 2. A process as claimed in claim 1 wherein the Curcuma species used in the step(I) is Curcuma longa and Curcuma aromatica. 3. A process as claimed in claims 1 - 2 wherein the hydrotrope used in the step (I) is alkyl benzene sulfonates, alkyl poly glycol sulfate or phosphate, substituted benzene carboxylates, substituted phenates, substituted naphthonates and substituted naphthalene carboxylates and alkali metal saccharines. .4. A process as claimed in claims 1-3 wherein the concentration of hydrotrope used in the range of of 0.1 gmol/lit to 5.0 gmol/lit. 5. A process as claimed in claims 1 -4 wherein the known methods used for recovery of curcuminoids are such as dilution method, extraction method. 6. A process as claimed in claims 5 wherein the dilution of mixture is carried at by water and extraction is carried out by water immicsible organic solvent such as aromatic and aliphatic hydrocarbons, such as benzene, alkyllated benzene, heptane, hexane, octane, cyclohexane, halogenated hydrocarbones CHC13, CC14, CH2C12, ketones such as (CH3)2CO, methyl isobutyl ketone, esters such as ethylacetate, propylacetate, ethers such as diethyl ether, diisopropyl ether, dibutyl ether, alcohols such as butanol, hexanol, amides such as phosphoamides, trioctyl phosphene, and a mixtures thereof. 7. A process for the extraction of Curcuminoids from Curcuma species as herein 8. described with reference to the examples accompanying this specification.

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