PESTICIDAL DRY POWDER FORMULATION ENRICHED IN AZADIRACHTIN UPTO 88%, AN EMULSIFIABLE CONCENTRATE ENRICHED UPTO 30% OF AZADIRACHTIN AND APROCESS FOR PREPARING SUCH FORMULATION ANDCONCENTRATE FROM NEEM SEED/KERNEL
The invention relates to a preparation of azadirachtin, in a dry solid powde r form, having a purity upto 88% ; an emulsion concentrate having upto 30% by weight of azadirachtin, and a process for preparing said azadirachtin dry powder from neem seeds/kernels, which comprising: (a) disintegrating th...
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Zusammenfassung: | The invention relates to a preparation of azadirachtin, in a dry solid powde r form, having a purity upto 88% ; an emulsion concentrate having upto 30% by weight of azadirachtin, and a process for preparing said azadirachtin dry powder from neem seeds/kernels, which comprising: (a) disintegrating the neem seeds/kernels into a powder; (b) subjecting the said powder to continuous extraction using methan ol or aqueous methanol or ethanol (rectified spirit) or aqueous ethanol at ambient temperature; (c) concentrating the extract and stirring the concentrate with petroleumether or hexane and phase separating by conventional methods; (d) stirring the denser phase containing major quantity of azadirachtin with a water immiscible organic solvent and water as required depending on the solvent us ed for extraction and phase separating by conventional methods; (e) concentrati ng the organic phase and gradually adding the concentrate to petroleumether or hexa ne under stirring at ambient temperature (f), filtering under suction and dryin g under vacuum at a temperature in the range of 25 - 65.degree.C. to obtain a neem seed/kernel extract as a powder having azadirachtin of 10-19% purity; (g) re~dissolving the product obtained in step (f) in a solvent and adding the solution to petroleumether or hexane at ambienttemperature gradually under stirring yielding a white solid, which after filtration and drying under vacuum at 65.degree.C. resulting in azadirachtin having 15-26% purity as a white powder (h), dissolving the azadirachtin (10- 19%) from step (e) in an organic solvent and subjecting to column chromatography (silicagel) by stepwise elution using different compositions of hexane/petroleumether and ethylacetate leading to solid azadirachtin powder upto 49% (i) dissolving the azadirachtin having upto 49% purity in methanol, ethanol or acetonitrile and subjecting it to HPLC (C18 column) to produce azadirachtin of purity upto 88% in a solid powder form, and (j) and stirring the product of step (i) with solvents and emulsifiers with or without synergist and UV stabilise r to obtain the emulsifiable concentrate. |
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