Sharma Vandana, Walia Suresh, Kumar Jitendra, Nair Muraleedharan G, Parmar Balraj S
Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi-110 012, India.
J Agric Food Chem. 2003 Jul 2;51(14):3966-72. doi: 10.1021/jf0342167.
Azadirachtin A enriched concentrate containing 60% active ingredient (a.i.) was prepared from the methanolic extract of the de-fatted neem (Azadirachta indica A. Juss) seed kernels. Azadirachtins A, B, and H, the three major bioactive constituents of neem seed kernel, were purified from this methanolic concentrate by employing reverse phase medium-pressure liquid chromatography (MPLC), using methanol-water solvent system as an eluant. The three pure azadirachtin congeners thus obtained were characterized by their unique mass spectral fragmentation, using electrospray probe in positive ion mode (ESI). All three azadirachtins exhibited nematicidal and antifungal activities. Azadirachtin B was the most effective against the reniform nematode Rotylenchulus reniformis (EC(50) 96.6 ppm), followed by Azadirachtin A (119.1 ppm) and H (141.2 ppm). At 200-ppm concentration, the test compounds caused 50-65% mortality of Caenorhabditis elegans nematode. Azadirachtin H showed the highest activity against the phytophagous fungi Rhizoctonia solani (EC(50) 63.7 ppm) and Sclerotium rolfsii (EC(50) 43.9 ppm), followed by B and A. The isolation of pure azadirachtins A, B, and H directly by MPLC purification from its concentrate and their characterization by ESIMS are unique and less time-consuming.
从脱脂印楝（Azadirachta indica A. Juss）种子仁的甲醇提取物中制备了含有60%活性成分（a.i.）的印楝素A富集浓缩物。印楝种子仁的三种主要生物活性成分印楝素A、B和H，通过使用甲醇-水溶剂系统作为洗脱剂的反相中压液相色谱（MPLC）从该甲醇浓缩物中纯化得到。由此获得的三种纯印楝素同系物通过在正离子模式（ESI）下使用电喷雾探针的独特质谱碎片进行表征。所有三种印楝素均表现出杀线虫和抗真菌活性。印楝素B对肾形线虫Rotylenchulus reniformis最有效（EC(50) 96.6 ppm），其次是印楝素A（119.1 ppm）和H（141.2 ppm）。在200 ppm浓度下，测试化合物导致秀丽隐杆线虫50 - 65%的死亡率。印楝素H对食草真菌立枯丝核菌（EC(50) 63.7 ppm）和齐整小核菌（EC(50) 43.9 ppm）表现出最高活性，其次是B和A。通过MPLC从其浓缩物中直接纯化纯印楝素A、B和H并通过ESIMS对其进行表征是独特且耗时较少的。
