Morris Bruce D, Foster Stephen P, Grugel Sharon, Charlet Laurence D
Department of Entomology, North Dakota State University, Fargo, North Dakota 58105, USA.
J Chem Ecol. 2005 Jan;31(1):89-102. doi: 10.1007/s10886-005-0976-2.
Two diterpenoid alcohols, ent-kauran-16alpha-ol (1) and ent-atisan-16alpha-ol (2), were isolated from pre bloom (R3-R4 stage) sunflower heads as oviposition stimulants for the banded sunflower moth, Cochylis hospes. Fractionation of a sunflower head extract, by normal-phase flash column chromatography, resulted in an early eluting fraction exhibiting significant activity in an egg-laying bioassay. Compounds 1 and 2, along with ent-trachyloban-19-oic acid (3) and ent-kaur-16-en-19-oic acid (4), were isolated as the major components of this fraction and identified by their NMR and mass spectra. The purified compounds were individually tested for ovipositional activity in dose-response bioassays. In these bioassays, compounds 1 and 2 gave linear dose responses, with increasing numbers of eggs laid as the dosage of either increased. Compounds 3 and 4 failed to stimulate significant egglaying at any of the dosages tested. A factorial design bioassay, using compounds 1 and 2, showed that 1 was relatively more stimulatory than 2, and that there was no synergistic effect on oviposition when the two compounds were combined.
从处于开花前期（R3-R4阶段）的向日葵花盘中分离出两种二萜醇，对映贝壳杉烷-16α-醇（1）和对映阿替生烷-16α-醇（2），它们是向日葵螟Cochylis hospes的产卵刺激物。通过正相快速柱色谱法对向日葵花盘提取物进行分馏，得到一个在产卵生物测定中表现出显著活性的早期洗脱馏分。化合物1和2，连同对映曲石竹烷-19-酸（3）和对映贝壳杉-16-烯-19-酸（4），作为该馏分的主要成分被分离出来，并通过其核磁共振谱和质谱进行鉴定。在剂量-反应生物测定中对纯化后的化合物分别进行产卵活性测试。在这些生物测定中，化合物1和2呈现出线性剂量反应，随着任一种化合物剂量的增加，产卵数量也增加。化合物3和4在任何测试剂量下都未能刺激显著的产卵。使用化合物1和2进行的析因设计生物测定表明，1比2的刺激作用相对更强，并且当两种化合物组合时对产卵没有协同作用。
