Isolation and purification of antifeedant and antioviposition substances against the diamondback moth from a tropical plant.

1994年，松材线虫丙酮提取物对小菜蛾1龄和4龄幼虫的拒食活性分别为60ppm和500ppm。这些提取物在125ppm处理的笼式甘蓝上也观察到了对DBM雌虫的产卵作用。1995年，在对DBM 4龄幼虫的非选择性生物测定试验指导下，对圆盘甘蓝地上部分进行了一系列分级，以分离正己烷、ETOAc、BuOH和水层。随后的生物测定表明，正己烷LayR是对DBM幼虫最有效的拒食剂。己烷层的进一步分馏得到7个馏分。组分5和6即使在减少剂量(50杯/叶圆盘)的情况下仍然有效。因此，随后对组分5进行分级，并获得5个亚组分(F5-1至F5-5)。其中F5-2是最有效的取食威慑剂，最低剂量为25µg/叶圆盘。通过制备性薄层层析，最终从F5-2中分离得到一个活性成分(F526)。将使用其他分析程序进行进一步的化学分析，以确定该活性化合物的化学结构。

In 1994, antifeedant activity of the acetone extract from A.paniculata against the 1st- and 4th-instar larvae of the diamondback moth (DBM), P.xylostella, was observed at 60 ppm and 500 ppm respectively. Antioviposition effect on the DBM females was also observed on caged cabbage treated with these extracts at 125 ppm.In 1995, a series of fractionation of the aerial parts of A.paniculata guided by a no-choice bioassay test on the 4th-instar larvae of the DBM was conducted for the isolation of the hexane, ETOAc, BuOH and water layrs. Subsequent bioassay tests showed that the hexane layr is the most potent antifeedant against the DBM larvae. Futher fractionation of the hexane layr yielded 7 fractions. Fractions 5 and 6 were still effective even at a reduced dose (50 mug/leaf disc). Thus, fraction 5 was subsequently fractionated and 5 sub-fractions (F5-1 to F5-5) were obtained. Among those F5-2 was the most effective feeding deterrent at a minimum dose of 25mug/leaf disc. Through preparative TLC,an active compound (F526) was finally purified and isolated from F5-2. Further chemical analysis using other analytical procedures will be done to determine the chemical structure of this active compound.