Siddiqui Bina Shaheen, Ali Syed Kashif, Ali Syed Tariq, Naqvi Syed Naeem ul Hassan, Tariq Rajput Muhammad
H.E.J. Research Institute of Chemistry, International Center for Chemical & Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
Nat Prod Commun. 2009 Apr;4(4):473-6.
The azadirachtin, salannin, nimbin, deacetylnimbin, azadiradione and epoxyazadiradione contents were determined by HPLC in the fractions prepared from the kernel of neem fruits (Azadirachta indica) collected at different ripening stages. The fully mature fruit (yellow fruits) kernels contained the highest concentration of azadirachtin, nimbin and salannin, whereas the concentration of azadiradione (NC) and epoxyazadiradione (NL) was high in the unripe green berries. The toxicity of the fractions (KEA-1 to KEA-5) obtained from the kernels collected at successive intervals, as well as of the pure limonoids referred to above was evaluated against 3rd instar larvae of Aedes aegypti L. (wild strain). It was observed that the toxicity of these fractions increased with the maturity of the fruits. An interesting observation was that the toxicities of KEA-3 to KEA-5 are comparable and the concentration of all the major limonoids is optimum in KEA-3, which suggested that these exert a joint effect against Aedes aegypti.
采用高效液相色谱法测定了从不同成熟阶段采集的印楝果实（印楝）种子中制备的各馏分中印楝素、印楝宁、尼姆宾、去乙酰尼姆宾、印楝二酮和环氧印楝二酮的含量。完全成熟的果实（黄色果实）种子中印楝素、尼姆宾和印楝宁的浓度最高，而未成熟的绿色浆果中印楝二酮（NC）和环氧印楝二酮（NL）的浓度较高。对从连续间隔采集的种子中获得的馏分（KEA - 1至KEA - 5）以及上述纯柠檬苦素类化合物对埃及伊蚊（野生品系）三龄幼虫的毒性进行了评估。观察到这些馏分的毒性随着果实成熟度的增加而增加。一个有趣的观察结果是，KEA - 3至KEA - 5的毒性相当，并且所有主要柠檬苦素类化合物在KEA - 3中的浓度最佳，这表明它们对埃及伊蚊发挥联合作用。
