Kaushik Nutan
Bioresources and Biotechnology Division, TERI, Habitat Place, Lodhi Road, New Delhi 110 003, India.
Anal Bioanal Chem. 2002 Dec;374(7-8):1199-204. doi: 10.1007/s00216-002-1638-7. Epub 2002 Nov 12.
A simple and economical method has been developed to estimate the azadirachtin content and fatty acid composition of neem kernels. Neem kernels are crushed and soaked overnight in ethanol. The extract obtained is analysed by HPLC after filtering through a 0.22 micro m membrane. The peaks are separated using acetonitrile-water (40:60) 1 mL min(-1) as the mobile phase on an RP-18 column and monitored at 214 nm. For the determination of fatty acid composition, the fatty acids are directly transmethylated in the kernel powder by heating with methanol-acetyl chloride-benzene (20:1:4, v/v) for 1 h in a water bath. The fatty acid methyl esters (FAMEs) obtained are extracted in hexane and analysed using GLC. The separation of the FAMEs is achieved using an RH-Wax column using temperature programming, 170-200 degrees C at 2 degrees min(-1). The peaks are detected using an FID. Both the methods do not require any clean up or defatting of seeds. This results in faster, easier and more economical sample preparation.
已开发出一种简单且经济的方法来估算印楝籽仁中印楝素的含量和脂肪酸组成。将印楝籽仁碾碎并在乙醇中浸泡过夜。通过0.22微米的膜过滤后，用高效液相色谱法（HPLC）分析所得提取物。使用乙腈 - 水（40:60）1毫升/分钟作为流动相，在反相18柱上分离峰，并在214纳米处进行监测。为了测定脂肪酸组成，脂肪酸在籽仁粉中通过与甲醇 - 乙酰氯 - 苯（20:1:4，体积比）在水浴中加热1小时直接进行甲基化。所得脂肪酸甲酯（FAMEs）用己烷萃取并使用气相色谱法（GLC）进行分析。使用RH - Wax柱通过程序升温（170 - 200摄氏度，升温速率2摄氏度/分钟）实现FAMEs的分离。使用氢火焰离子化检测器（FID）检测峰。这两种方法都不需要对种子进行任何净化或脱脂处理。这使得样品制备更快、更简便且更经济。
