Industrial large scale extracting method for nimbin dry powder

Abstract

The invention discloses a method for industrially extracting azadirachtin dry powder in great amount, which is used for solving the problem of industrially extracting the azadirachtin dry powder as a raw material of pesticide in great amount. The azadirachtin dry powder comprises a neem methanol crude extract, and is prepared by the following steps: preparing a phase separation solution by an ammonium sulphate solution, and preparing an extraction liquid by ethyl acetate and methylene dichloride; removing clotted oil residual and lower separated liquid phase; collecting oil phase; concentrating by a film evaporator and a condenser; reversely extracting and degreasing by n-hexane and petroleum ether; collecting an organic solvent; centrifugalizing a target product; drying and crushing; and the like. The method saves the solvent; the yield for extracting azadirachtin once reaches 82 percent, and reaches over 96 percent if extraction is repeated once with purity reaching 23 to 26 percent; industrialized production yield and purity are high; the method is simple; furthermore, amino acid, protein, nucleic acid, polysaccharide, alcohols, aldehydes, alkaloid, organic acid and other organic materials can be effectively separated with improved stability. The azadirachtin dry powder can be used as powder, suspension, tablet and other advanced preparation formulations. The method does not have high requirement on equipment, and is convenient for large-scale manufacture.

Description

technical field [0001] The invention relates to a process for extracting azadirachtin used in pesticides, in particular to a method for industrially extracting a large amount of dry powder of azadirachtin. Background technique [0002] Neem (Azadirachta indica A.Juss) is an arbor of the family Meliaceae, widely planted in tropical and subtropical regions. Originated in Myanmar and India, it is distributed and planted in more than 70 countries, with the largest output in Asian countries such as India. Active substances are contained in neem fruit, seeds, seed cores, branches, leaves, bark and sap, but especially in seeds. So far, more than 100 compounds have been found in neem, at least 70 compounds have biological activity, they are diterpenes, triterpenoids, pentatriterpenoids and non-terpenoids. It is mainly azadirachtin, azadirachtriol and azadirachtin, etc. These extracts have the functions of repelling insects, interfering with oviposition, interfering with insect var...

AI Technical Summary

Problems solved by technology

[0006] 1. Water and methanol are used as the liquid phase, in which amino acids, proteins, nucleic acids, polysaccharides, alcohols, aldehydes, alkaloids, organic acids and other organic substances are difficult to separate, which affects the purity

Not only poor stability, complex components pollute the environment, but also difficult to make advanced dosage forms such as powder, dry suspension, tablet, etc.

[0007] 2. Separating the dry powder of azadirachtin by layer washing column, the purity can be improved through repeated elution of normal phase column and reverse phase column, but, due to the constant change of washing solvent, the process is cumbersome and complicated, the separation speed is very slow, and the amount of solvent is large

[0008] 3. A single solvent is used as the extraction phase and the back extraction phase. The amount of solvent is too large, which requires a large amount of solvent and huge equipment. The investment and energy consumption in solvent recovery increase, and the cost rises!

[0009] 4. The high-content samples extracted from azadirachtin are mainly obtained in the laboratory at present, and there are no mature reports on the large-scale operation of real application in production