SU149358A1 - Method for isolating alkaloid paravalallarin - Google Patents

Description

This invention relates to methods for isolating paravalallar alkaloid from vegetable raw materials.

Methods are known for isolating paravalalline alkaloid from vegetable — by grinding a plant, treating it with a weak alkaline solution, filtering it, extracting it with immiscible solvent, and then precipitating the alkaloid from the extract with acid and chromatographic separation in a benzene solution on alumina.

The proposed method for the isolation of the alkaloid paravalallin compared with the known methods involves, according to the invention, the use of the plant Paravallaris microphylla Pitara as a raw material. When using the plant Paravallaris microphylla Pitara, they use not only the leaves, but also the stems, as well as the roots of this plant. The average yield of the technical alkaloid is 0.35% for the leaves of the plant, 0.5% for the stems and 0.55% for the roots.

The method can be carried out in the following way.

Example 1. The selection of technical alkaloids. The powdered leaves of the plant Paravallaris microphylla Pitara are shifted in the amount of 200 g with a 10% ammonia solution and subjected to "ext. No. 149358-2 to a jerky extraction in a Soxhlet Tiaa apparatus. The ether solution, subjected to extraction, is concentrated by distillation to a volume of 200 cm, after which it is mixed three times with 100 cm of a 5% aqueous solution of hydrochloric acid and twice with 100 cm of a 1% hydrochloric acid solution. The acidic solutions that have been pooled are washed with ether (200 cm) and then, by adding ammonia, neutralized at pH-9. The precipitated alkaloids are extracted with methylene chloride in three doses of 200 cm at each intake. The organic solutions, merged together again, are washed with water in an amount of 200 cm, then distilled, dried on sodium sulfate and subjected to dry distillation. As a result, technical alkaloids are obtained in the form of a light brown semi-solid mass in the amount of 770 mg. The yield of alkaloids is 0.35% by weight of the leaves.

Example 2. Another selection of alkaloids.

200 g of crushed plant roots are mixed with 100 cm of 5% sodium carbonate solution and subjected to continuous cold recovery by leaching with methylene chloride until the sample of the solution used for extraction no longer contains alkaloids. The liquid used for recovery in a volume of from 1 to 3 liters is concentrated to 200 cm. Following this, the solution is shaken several times with 5% (by weight) aqueous solution of sulfuric acid, namely: three times with 200 cm and twice with 100 cm of solution. The acidic solutions that have been poured together are washed with benzene and then neutralized with soda until pH-9 is reached, while avoiding heating of the solution. The precipitated alkaloids are extracted in three steps with chloroform in an amount of 250 cm in each step. From their chloroform solutions, after their decantation, washing in 200 cm of water, dry calcium chloride and distillation, technical alkaloids are obtained in the form of a semi-solid mass of 1 g in weight, slightly brown. The yield of the finished product is 0.5% by weight of the roots of the plant.

Example 3. The separation of crystallized paravalallin.

5 g of technical al.caloids obtained from the roots of a plant are dissolved in 250 cm of boiling benzene. After cooling the solution, it is filtered and subjected to chromatographic processing using 150 g of alumina with an activity coefficient of 1.

After 1 liter of benzene was passed, the elution was continued with 5 l of pure etheroxyethyl and 5 l of a mixture of 95 parts of etheroxyethyl and 5 parts of methanol, the bulk parts being meant. The ether and ether-methanol solutions are distilled to obtain a dry precipitate, which is dissolved in 25 cm of boiling acetone. The acetone solution is filtered, cooled and 850 kg of pure paraallarin are isolated as prismatic crystals.

The alkaloid paravallarin isolated by the proposed method has a structure like 18-20-lactone D5-3p-M-methyl I1Ho-20-hydroxypregnenoic acid 18; it melts at a temperature of 178 ° (in a piece) and at a temperature of 18G (in a capillary) and can be used to obtain its derivatives by known methods, for example: paravallarin chloridate; N-methyl paravalallin; N-acetyl paravalalline; paravalarinol; triastechylparallarinol; methyl ester, N-acetyl paravallaric acid; dehydrated paravalallin derivative.

Prev Invention

The method for separating the alkaloid paravalalline from the plant raw material by grinding the plant, treating it with a weakly alkaline solution, filtering, extracting with solvents not displacing with water, followed by precipitating the alkaloids from the extract with acid and chromatographic separation in benzene solution on alumina, As the outcome of the raw material, the plant used is Paravallaris microphylla Pitara.

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