摘要
从我国特有的高效杀虫植物闹羊花RhododendronmolleG .Don中分离提纯了 1 4个活性化合物 ,并研究了这些化合物对斜纹夜蛾Spodopteralitura幼虫表皮成分的影响及构效关系 ,为揭示闹羊花素类化合物的作用机制、优化结构及确定先导化合物提供了参考。通过IR ,UV ,NMR ,MS等光谱鉴定了 3个新化合物黄杜鹃素A ,B ,C (rhodomolinA ,B ,C)。结果表明 :闹羊花素Ⅲ (rhodojaponinⅢ ) ,黄杜鹃素A ,羊踯躅素Ⅰ (rhodomolleinⅠ ) ,黄杜鹃素B ,黄杜鹃素C ,羊踯躅素ⅩⅧ (rhodomolleinⅩⅧ ) ,木藜芦素Ⅲ (grayantoxinⅢ )和对照药剂印楝素 (azadirachtin)的生长发育抑制活性明显高于其他化合物 ,以 5 0mg L浓度浸渍叶碟饲喂斜纹夜蛾 4龄幼虫后 ,虫重、蛹重以及羽化率均显著低于空白对照。处理后 1 2 0h ,各化合物处理和空白对照试虫表皮几丁质相对含量为 2 8 1 5 %～ 35 1 8% ,差异不显著。闹羊花素Ⅲ ,黄杜鹃素A ,B ,C ,羊踯躅素ⅩⅧ和印楝素处理显著降低试虫表皮总蛋白的相对含量 ,提高了表皮总脂肪的相对含量。进一步研究发现 ,闹羊花素Ⅲ和印楝素处理后 ,试虫表皮水溶性蛋白、氢键结合蛋白和共价键结合蛋白相对含量显著降低 ,弱键结合蛋白相对含量显著提高 ,而对电价键结合蛋白相对含量无明显影响。
The effects of fourteen active compounds previously isolated from Rhododendron molle G. Don on the cuticle components of Spodoptera litura larvae and their structure-activity relationship were studied to illustrate the mode of action and optimize rhodojaponins structure. The structures of three new compounds, rhodomolin A, B and C, were elucidated based on IR,UV,NMR and MS spectroscopic data. When the fourth instar larvae of S. litura were treated with 50 (mg/L) of compounds rhodojaponin Ⅲ,rhodomolin A,rhodomollein Ⅰ,rhodomolin B,rhodomolin C,rhodomollein \{ⅩⅧ\},grayantoxin Ⅲ and azadirachtin, an known botanical insect growth regulator, respectively, the weight of larvae and pupae and the emergence rate were significantly less than CK, which showed greater insect growth inhibition activities than other tested compounds from R. molle. After 120 h treatment, all the cuticle chitin contents of larvae, both treated with compounds and CK, were 28.15%-35.18%, which show no significant difference. When treated with compounds rhodojaponin Ⅲ, rhodomolin A, rhodomolin B, rhodomolin C, rhodomollein \{ⅩⅧ\} and azadirachtin, however, the contents of total protein of larvae cuticle significantly increased and those of total fats decreased than those of CK, respectively. Furthermore, the contents of water soluble protein, hydrogen bond combined protein and covalent bond combined protein in the cuticle decreased significantly, while the content of weak bond combined protein increased significantly and the content of electrovalence bond combined protein was not significantly different from that of CK when larvae were treated with compound rhodojaponin Ⅲ and azadirachtin. It was inferred that the action mode of insect growth inhibition in rhodojaponins is not to inhibit chitin syntheses, but to disturb internal secretion, and significantly decreasing the content of water soluble protein in cuticle would be one important mechanism. Preliminary analysis of their structure-activity relationship showed that substitute group structures of C-2,3-epoxy, C-6, C-10 and C-14 were most important to these grayanoid diterpenids with insect growth inhibition activity. The difference of model of inhibition action between rhodojaponins and azadirachtin was also discussed.
出处
《昆虫学报》
CAS
CSCD
北大核心
2004年第6期705-714,共10页
Acta Entomologica Sinica
基金
国家自然科学基金资助项目 (30 2 70 886 )
广东省自然科学基金资助项目 (0 1 0 30 1 )
关键词
闹羊花素
斜纹夜蛾
表皮成分
构效关系
Rhodojaponins
Spodoptera litura
cuticle component
structure-activity relationship
