Title of Invention

A PROCESS OF PREPARING A SOLUBLE DOUBLE METAL SALT OF GROUP IA AND IIA OF (-) HYDROXYCITRIC ACID

Abstract

A process for preparing a soluble double metal salt of group IA and IIA of (-)hydroxycitric acid of general formula I and more particularly formula II as given below: where x is IA group metal, where Y is IIA group metal. comprising Step 1-heating concentrated (-)hvdroxycitric acid under vacuo to evaporate water at 60-70 c and form syrup of (-)hydroxycitric acid lactone, Step 2-drying and desiccating the said syrup to obtain solid mass of (-) hydroxycitric acid lactone, step 3-neutralizing the said solid mass with group IA metal hydroxides. Step 4-partially displacing partially group IA metal ions in the above salt solutions by adding group IIA metal chlorides to form soluble double metal salt of group IA and IIA of (-)hydroxycitric acid, step 5-precipltating the said double metal salt of group IA & IIA metal salts of (-)hydroxycitric acid by adding aqueous polar solvent and spray drying, if desired.

Full Text

This invention relates to a process of preparing a new soluble double metal salt of group IA and IIA of (-) hydroxycitric acid from (-) hydroxycitric acid lactone. The product obtained by the process with . >98% purity can be used safely not only as a food supplement in various nutrieutical formulations and beverages but also for effecting obesitv control. BACKGROUND (-) Hydroxycitric acid (HCA) occurs in the fruit rind of Garcinia species (G. Cambogia, G. indica and G. atroviridis). The first two species grow abundantly in India and the third occurs mostly in South East Asian countries. The success of this natural food product derived from Garcinia fruit has been documented and been in use since several centuries BC. Also known as "Kokum", the extracts of the fruit have been used as a tart flavoring in meat and seafood dishes, turned into a refreshing beverage that serves as a unique flavor enhancer, gourmet spice and a digestive after a heavy meal. In Ayurveda, the traditional ancient system of herbal medicine in India, Garcinia is also considered to be one of the prime herbs that are beneficial for the heart. In more recent times, Garcinia has received worldwide attention as a nutriceutical for effective obesity control. Several scientists including at Hoffman-La Roche have established that HCA, the active ingredient in the fruit, prevents the conversion of excess carbohydrates to fat in animals. The energy released by the excess carbohydrate is converted into and stored as glycogen, a readily usable form of energy. Interestingly, it has been shown to inhibit ATP dependent citrate-lyase, a key enzyme in diverting carbohydrate to fatty acids and cholesterol synthesis. (Sullivan et al. Lipids, 9:121 and 129 (1973), Sergio, W„ Medical Hypothesis 27:39 (1988)). The age-old practice of consuming Garcinia rind as a food additive by inhabitants of Malabar and Konkan coast of the Indian peninsula has established the safety of HCA. The isolation and chemical nature of (-) hydroxycitric acid from Garcinia rind are described in the publication of Lewis Y.S., et al. (Methods in Enzymology, 13:613 (1967) and in the patents (Indian patents 160753 & 178298 and US patents 5536516 & 5656314). It is believed that consumption of HCA influences the body metabolism leading to the saturation of glycogen receptors in the liver and a consequent transmission of signals of satiation to brain. Even as a food supplement, (-) HCA helps a person to lose/control weight in a natural way without affecting normal physical activities. In view of its unique property, several health care formulations incorporating HCA are being sold across the counter in the Western markets. These include tablets, capsules, herbal teas, chocolate bars, milk shakes and other beverages. The active ingredient (HCA) from this insoluble HCA salt is released upon contact with hydrochloric acid in the stomach and absorbed through the intestine to exert its metabolic effect. There is prior art on the preparation of a soluble tri-potassium salt of (-) HCA (Lewis Y.S., et al (Methods in Enzymology, 13:613 (1967), International Patent WO 96/36585, US patent 08/440,968 filed). However, its alkaline nature and risks associated with the consumption of high potassium (-36%) makes this product unsuitable for HCA-based formulations. In our earlier patents (Indian patent No. 178298 & US patents 5536516, 5656314) which describes preparation of a concentrate of (-) hydroxycitric acid and its lactone in liquid form, comprising of several steps; like water extraction of Garcinia rind containing (-) hydroxycitric acid and its concentration, acetone refinement of this concentrated water extract, evaporation of acetone, loading thus obtained refined extract on ion-exchange columns containing an anion exchange resin followed by a cation exchange resin, and finally evaporation of the free acid liberated from the ion-exchange process to said concentration. This liquid form of (-) hydroxycitric acid has problems of stability and half-life. In addition, its highly acidic nature poses problems in formulating into beverage and various other food products without affecting their flavor and properties. The object of this invention is to overcome the above drawbacks by developing a process for the preparation of a new soluble double metal salt of (-) hydroxycitric acid from hydroxycitric acid lactone. To achieve the said objective, this invention provides a process for preparing a new soluble double metal salt of group IA and IIA of (-) hydroxycitric acid of general formula I and more particularly formula II as given below from (-) hydroxycitric acid lactone: precipitating the said solubilised group IIA metal salts of (-) hydroxycitric acid by adding aqueous polar solvent to get soluble IIA metal salt of (-) hydroxycitric acid. r The soluble metal salt of (-) hydroxycitric acid is obtained in powder form by spray drying prior to the solvent addition or spray drying water solubilised solvent precipitated material. The drying and desiccating the said syrup is carried out under vacuo for 4-5 hours, and the group IIA metal chloride solution was added drop wise with vigorous stirring. The free (-) hydroxycitric acid present in the step 2 is neutralized by three equivalents of group IA metal hydroxides. Partial displacement of group IA metal ion in step 3 is carried out with 3 equivalent of group IIA metal chloride. Group IA hydroxides used LiOH, NaOH, KOH, RbOH, CsOH and FrOH Group IIA metal chlorides BeCl2, MgCl2, CaCl2, SrCl2, BaCl2and RaC12 The said polar solvents are methanol, ethanol, propanol, isopropanol. The soluble double metal salt of group IA and IIA of (-) hydroxycitric acid is soluble sodium calcium salt of (-) hydroxycitric acid The invention will now be described with reference to the following example: EXAMPLE One hundred gm Garcinia Cambogia rind was extracted 4 times with 80% acetone in water (250 ml each time) for 4 hours. The combined extract (830-ml) was concentrated to 300 ml by heating \n vacuo at 56°C (500 millibar and filtered through cheese cloth to remove water,insoluble non polar substances. The filtrate (260-ml) containing 18 gm of hydroxycitric acid decolorized by addition of 2.6 gm of activated charcoal and filtered. The resultant clear solution was concentrated to 50 ml, and the free acid was converted into the sodium salt of hydroxycitric acid by the addition of 11 gm of sodium hydroxide pellets, were added. To this formed solution of sodium salt of (-) hydroxycitric acid 20 ml of solution containing 9 gm of calcium chloride was added drop wise with vigorous stirring. The soluble salt of hydroxycitric acid is then precipitated by addition of ethanol. The precipitated salt is filtered, washed with ethanol and dried to obtain 20.7 gm of the soluble calcium salt of hydroxycitric acid (yield 89.84%). We Claim: 1. A process for preparing a new soluble double metal salt of group IA and I1A of (-) hydroxycitric acid of general formula I and more particularly formula II as given below from (-) hydroxycitric acid lactone: where X is IA group metal: Li or Na or K or Rb or Cs or Fr where Y is IIA group metal: Be or Mg or Ca or Sr or Ba or Ra comprising: heating concentrated (-) hydroxycitric acid under vacuo to evaporate water at 60-70° C and form syrup of (-) hydroxycitric acid lactone, drying and desiccating the said syrup to obtain solid mass of (-) hydroxycitric acid lactone, neutralizing the filtrate with group IA metal hydroxides, displacing partially group IA metal ions in the above salt solutions by adding group IIA metal chlorides to form soluble double metal salt of group IA and IIA of (-) hydroxycitric acid, - precipitating the said solubilised group IIA metal salts of (-) hydroxycitric acid by adding aqueous polar solvent to get soluble IIA metal salt of (-) hydroxycitric acid. 2. A process as claimed in claim 1 wherein soluble metal salt bf hydroxycitric acid is obtained in powder form by spray drying prior to the solvent addition or spray drying water solubilised solvent precipitated material. 3. A process as claimed in claim 1 wherein the free (-) hydroxycitric acid present in step 2 is neutralized by three equivalents of group 1A metal hydroxides. 4. A process as claimed in claim 1 wherein partial displacement of group IA metal ion in step 3 is carried out with one equivalent of group IIA metal chloride. 5. A process as claimed in claim 1 wherein the drying and the desiccating the said syrup is carried out under vacuo for 4 to 5 hours and the group IIA metal chlorides solution was added drop wise with vigorous stirring. 6. A process as claimed in claim 1 wherein group IA metal hydroxides used are LiOH. NaOH, . RbOH. CsOH and FrOH and group IIA metal chlorides used are BeCl2, MgCl2 CaCl2, SrCl2, BaCl2 and . RaCl2. 7. A process as claimed in claim 1 wherein the said polar solvents are methanol, ethanol, propanol, isopropanol. 8. A process as claimed in claim 1 of the preceding claims wherein soluble group IIA metal salt of (-) hydroxycitric acid is soluble calcium salt of (-) hydroxycitric acid. 9. A process for preparing a new soluble double metal salt of group IA and HA of (-) hydroxycitric acid of general formula I and more particularly formula II substantially as herein described with reference to the forgoing example.

Documents:

1985-mas-1997 abstract.jpg

1985-mas-1997 abstract.pdf

1985-mas-1997 claims.pdf

1985-mas-1997 correspondnece-others.pdf

1985-mas-1997 correspondnece-po.pdf

1985-mas-1997 description (complete).pdf

1985-mas-1997 form-1.pdf

1985-mas-1997 form-26.pdf

1985-mas-1997 form-4.pdf

1985-mas-1997 form-6.pdf

1985-mas-1997 petition.pdf