Multi-stage countercurrent extraction method for azadirachtin

A tank-type countercurrent extraction method technology, which is applied in the field of tank-type countercurrent extraction of azadirachtin, can solve the problems of increased processing time and cost, increased degradation rate of azadirachtin, and poor thermal stability of azadirachtin. Good economic and social benefits, simplified raw material pretreatment, and shortened extraction cycle

Inactive Publication Date: 2010-10-13
INST OF GEOCHEM CHINESE ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Contain 20%~30% oil in the neem seed, direct mechanical pulverization is difficult to finely crushed, influences the leaching of azadirachtin, its raw material pretreatment mode mostly adopts shelling, pressing degreasing at present (as Chinese patent CN1158928C, CN1184222C, CN1362020A, CN1423938A, CN1423939A, CN1524858A, CN101440099A), but the thermostability of azadirachtin is poor, and the degradation rate of azadirachtin significantly increases when greater than 35 DEG C, and the degradation rate of azadirachtin is the largest during 65 DEG C, so in the degreasing process of pressing because of high temperature promptly has About 40% of azadirachtin is degraded, causing the yield of azadirachtin to decline; there are also solvents or supercritical CO degreasing (such as Chinese patents CN1049091C, CN1199980C, CN101029276A, ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Take a single tank as a group, take neem seed powder 1500g and put it in the extraction tank, set the extraction temperature to 32°C, pump 5 times of methanol into the dynamic countercurrent circulation for extraction for 49min, the solvent consumption is 1:5W / V, collect the extract in Concentrate under reduced pressure at 45°C, recover methanol to obtain a yellow-green solid extract containing 10.89% azadirachtin (determined by high performance liquid chromatography), and the yield of azadirachtin is 0.304%.

Embodiment 2

[0022] Take 3 cans as a group, put 1500g of neem seed powder in each can, set the extraction temperature at 32°C, use 5 times methanol dynamic countercurrent circulation to extract for 39 minutes in the first can, and supplement 3 times methanol dynamic with the extract of the previous unit in the second can Countercurrent circulation extraction for 39 minutes, the third tank was supplemented with 2 times of methanol from the previous unit extract, dynamic countercurrent circulation extraction for 39 minutes, the solvent dosage was 1:3.33W / V, the collected extract was concentrated under reduced pressure at 45°C, and methanol was recovered to obtain 10.46% Indian The yellow-green solid extract of nimbin (determined by high performance liquid chromatography), the yield of azadirachtin is 0.331%.

Embodiment 3

[0024] Take 4 cans as a group, put 1500g of neem seed powder in each can, set the extraction temperature at 32°C, use 5 times methanol dynamic countercurrent circulation to extract for 34min in the first can, and supplement 2.5 times methanol dynamic with the previous unit extract in the second can Countercurrent circulation extraction for 34 minutes, the third tank was supplemented with 1.5 times methanol dynamic countercurrent circulation extraction for 34 minutes, and the fourth tank was supplemented with 1 times methanol dynamic countercurrent circulation extraction for 34 minutes. The solvent dosage was 1:2.5W / V , the extract was collected and concentrated under reduced pressure at 45° C., and methanol was recovered to obtain a yellow-green solid extract containing 10.62% azadirachtin (as determined by high performance liquid chromatography), and the yield of azadirachtin was 0.386%.

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PUM

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Abstract

The invention provides a multi-stage countercurrent extraction method for azadirachtin, which is characterized in that: coarsely crushed neem seeds are put into a multi-stage countercurrent extraction device, and a solvent is pumped into the multi-stage countercurrent extraction device for dynamic countercurrent extraction at normal temperature or by heating properly; and the extracting solution is concentrated to prepare a solid extract containing 10 to 20 percent of azadirachtin, and the solid extract is used for preparing azadirachtin pesticides. The method has the advantages of short process flow, high extraction speed, high yield of azadirachtin, energy and solvent conservation, low production cost, easy industrial production and the like.

Description

technical field [0001] The invention relates to a method for extracting insecticides from plants, in particular to a method for extracting azadirachtin from neem seeds in a tank group countercurrent manner. Background technique [0002] Azadirachtin insecticides have the characteristics of broad spectrum, high efficiency, low toxicity, no residue, no toxic and side effects on humans and animals, safe to natural enemies of pests, and not easy to produce drug resistance. They are currently one of the most widely researched and used biological pesticides at home and abroad. 1. It has been listed as a pollution-free pesticide recommended by the Green Food Office of the State Council. [0003] Extracting azadirachtin from neem seeds is the first step and an important operation unit in the production of azadirachtin insecticides. The content of azadirachtin in neem seeds is very low (generally 0.3% to 0.4%, high up to 0.6%), and the extraction of azadirachtin is relatively diffic...

Claims

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Application Information

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IPC IPC(8): C07D519/00A01P7/00
Inventor 杨军余德顺罗喜荣田弋夫莫彬彬
Owner INST OF GEOCHEM CHINESE ACADEMY OF SCI
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