CONSTITUENTS OF HELIANTHUS-MOLLIS LAM AND THEIR ANTIFEEDANT ACTIVITY

Reinvestigation of the chloroform extract of aerial parts of Helianthu s mollis Lam. afforded, besides the already reported compounds, furthe r constituents: a mixture of diterpenoic acids and nevadensin. The mix ture of diterpenoic acids was quantitatively transformed into a mixtur e of methyl esters, which were separated by HPLC, and subsequently ide ntified by spectroscopic methods. The following esters were isolated: methyl-trachyloban-19-oate, methyl-kaur-16-en-19-oate, -19-oateandmeth yl-14-angeloxy-trachyloban-19-oate. The antifeedant activity of the mi xture of diterpenoic acids, the mixture of esters, individual esters, and desacetyleupaserrin was established against the storage pests Trib olium confusum Duv., Trogoderma granarium Ev. and Sitophilus granarius L.