SU726095A1 - Method of preparing myricetin - Google Patents

Description

I

Their distillation refers to an improved method for the production of myricetin.

Myricetin (3,5,7,3,4 b-hexaoxyflavone) belongs to the class of natural polyphenolic compounds - flavonols, which have a broad spectrum of biological effect. Myricetin has P-vitamin activity.

A method of obtaining myricetin is obtained by extracting the roots of a kermek with a petroleum chloroform mixture, then with methanol, followed by tanning the methanol extract to dry, water treatment, dissolving in methanol, evaporating the extract and treating it with ether and butanol and purifying the butanol fraction on cellulose ij.

The disadvantage of the known method is a comparatively low yield of miriditin (0.9%), the presence of impurities (yield of myricitrium W 1.55%, ramoglucoside myritin O, 43%, monomethyl ether of myrhetia, 0.85%), complexity and duration of the multistep process.

The purpose of the invention is to increase the yield and purity of the target product and to simplify the technology of PFC.

This goal is achieved by extracting the roots of the kerame with ethanol and, after evaporation of the extract to 20-25% of its initial volume, hydrolyzes it with a 2-6% solution of sulfuric acid at 90-95 ° C, followed by purification of the resulting precipitate successively with water and

0 ether.

This method differs from the known one in that ethanol is used as an alcohol; the extract is evaporated up to 20-25% of its original

5 volumes, then the distillation extract is hydrolyzed with a 2-6% solution of sulfuric acid at 9 ° -95 ° C and the resulting precipitate is successively treated with water and ether,

I When the concentration of sulfuric acid is less than 2%, the time of hydrolysis increases, and when the concentration of sulfuric acid is more than 6% and the increase in the volume of sulfuric acid, the yield of mirrycetin due to pacTBoi is increased in acid and the yield of oxidation byproducts that impede the purification of myrsetin increases.

At 90-95 ° C, the hydrolysis proceeds under mild conditions without the formation of oxidation products. With a decrease in temperature, the time of hydrolysis increases, and with an increase, the reaction products become resinified.

When hydrolysis of the extract is evaporated less than 75-80%, the yield of mirvdeliny decreases due to its dissolution in excess of alcohol. When the more concentrated extract is hydrolyzed to 15% of the initial volume (the extract is a resinous mass), it is difficult for the hydrolysis and purification of myricetine to be carried out uniformly from related substances.

P - meer 1,

3 kg of crushed carmek roots (dry) pour 5 liters of 9O% ethanol and infuse for two days at room temperature. The extract is filtered, evaporated under vacuum (water jet pump) in a water bath to 20% of the original volume (1.25 l, or 25%, and hydrolyzed with 4% sulfuric acid in a volume ratio between the extract. (1.25 l) and sulfuric acid (0.31 L). The hydrolysis is carried out at 90-95 ° C in a water bath for 1.5 hours. A yellow crystalline precipitate forms (the sum of flavonol aglycones). The precipitate is filtered, thoroughly washed with hot water to remove carbohydrates, phenols, tannins and acids, I view for 3 hours and process with ether. miritsetiyu boiling materials (resins, paraffins kver-

cetin, isorammetin, etc.). After processing and drying at 150 ° C, 69 g of myricetin are obtained. Output 2.3% by weight of dry.

raw materials. M.p. 358-359 ° C.

EXAMPLE 2 The experiment was carried out as in Example 1, but the extract was evaporated to 25% of the initial volume and hydrolyzed with 2% sulfuric acid. 54 g of myricetin are obtained. Output 1.8% by weight of dry raw materials. .

EXAMPLE 3. It is carried out as in Example 1, but the extract is evaporated to 25% of the initial volume and hydrolyzed with 6% sulfuric acid. 11 get 60 g of myrcetin. Output 2% by weight of dry raw materials.

Found,%: With 56.42; 56,44; And 3.01; 3.24.

 -gCalculated,%: C 56.54; And 3.14.

Paper chromatography in the boot acetic acid – water system (1: 4: 5) R 0.43; 15% acetic acid, O8

UV spectrum: D max. 255,

380 nm.

H-spectrum: 3300, 3400, 1660, 159. NMR spectrum: singlet at 2 H with /, 35 ppm. (N-: 2.6), two doublets cj 2.5Gi at 6.42 ppm (H-8) and 6, 15 ppm (Hb). The analytical data obtained allow us to consider the isolated product as an individual compound of Mirvdetin.

The proposed method allows for a significant yield (2.3%) and purity of the target product.

The increase in the yield of myricetin is due to the hydrolysis of glycosides of myricetin and its monomethyl ether.

Pa diagrams 1 and 2 show the extraction of myricetin from the roots of Kermec in a known and suggested way.

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about "

"According to the above schemes, the proposed method differs from the known absence of the extraction stages of the petro-chloroforming mixture, reducing to dryness, extraction with butanol and separation on cellulose. After the concentration of the extract, the proposed method is followed by acid hydrolysis of the substances accompanying myritsetin: mirchrin, myrhetin ramoglucoside and myrsetin monomethyl ether, which leads to a succession of myrsetin. Thus, this method of producing myricetin differs from the previously known method by simple technology and allows increasing the yield of the target product 2.6 times. In addition, the mother liquor remaining after the production of miriatina is effective as a fleet of reagent for enrichment of lead-zinc ores and has a similar effect on shale flotation as used in the kero-syn + OPSB industry. 5 3 about b Formula et al. A method of obtaining myritsetin by extruding the root of the Kerme with alcohol, evaporation of the extract and subsequent cleaning of myrsetin with the use of a water and ether treatment, characterized in that, in order to increase the yield and purity of the target product and simplification of the process; ethanol is used as an alcohol, evaporation of the extract is carried out to 20-25% of the initial volume, then the extract is hydrolyzed with a 2-6% solution of sulfuric acid at 90-95 ° C and the resulting precipitate is successively treated with water and eff. Sources of information taken into account during the examination 1. Chumbalov G. Ch. Chemical study of tannic and related substances of some plants of Kazakhstan. Abstract, diss. Tashkent, 1966, p. 24 (prototype).

Claims (1)

Claim A method of producing myricetin by extraction of Kermec roots with alcohol, evaporation of the extract and subsequent purification of myricetin using water and ether treatment, characterized in that, in order to increase the yield and purity of the target product and simplify the process technology, ethanol is used as alcohol, the extract is evaporated to 20-25% of the initial volume, then the extract is hydrolyzed with a 2-6% solution of sulfuric acid at 90-95 Q and the resulting precipitate is successively treated with water and ether.