ENRIZENRIZ] ricardoricardo] danieldaniel]
Structure-Antifeedant Activity Relationship of Clerodane Diterpenoids. Comparative Study with Withanolides and Azadirachtin
ENRIZENRIZ] R.D.; H.A.BALDONI; M.ZAMORA; E.A.JAUREGUI; M.E.SOSA; C.TONN; J.LUCO; M.GORDALIZA
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
AMER CHEMICAL SOC
Lugar: Washington; Año: 2000 vol. 48 p. 1384 - 1384
A structure-antifeedant activity relationship (SAR) study of clerodane diterpenoids was carried out. Attention was focused on the feeding-deterrent activities exhibited toward Tenebrio molitor by clerodane diterpenoids and withanolides. Azadirachtin was chosen as a reference compound. SAR studies on the clerodane compounds indicate that the stereoelectronic factors are more important than the hydrophobic aspects as determinants of antifeedant activity. A furan ring in the side chain and a carbonyl R,â-unsaturated (or spiro-epoxide) group appear to be indispensable for the biological response. A conformational study indicate that the optimum interatomic distance between these moieties is a range between 9.5 and 10.5 Å. In addition, a similar stereoelectronic response was found among withanolides and azadirachtin. On the basis of these results it is reasonable to imagine a closely related chemical mechanism for these compounds.