Title:Alkaline Methanolysis and Octylamine Addition Products of Dehydrocostus
Lactone Isolated from Echinops kebericho Root
Volume: 20
Issue: 5
Author(s): Minbale Gashu*
Affiliation:
- Department of Chemistry, Debre Berhan University, Debre Berhan, Ethiopia
Keywords:
Dehydrocostus lactone, methanolysis, michael addition, Echinops kebericho root, Saussurea lappa, alkaline.
Abstract: Dehydrocostus lactone is biosynthesized in Saussurea lappa (commonly known as costus),
Echinops kebericho, and E. amplexicaulis. Since reports described the compound as a bioactive metabolite,
many analogues were synthesized to evaluate the structure-activity relationship. In this study,
two new analogues of the active principle were synthesized to compare their mycelial growth inhibition
potential against two plant pathogens, namely, Fusarium species causing root rot/wilt of faba
bean and Phytophthora infestans triggering potato late blight in Ethiopia. Structural changes at the
lactone ring of the synthesized compounds led to a decrease in growth inhibition diameter, which describes
the role of the α-methylene-γ-lactone moiety in determining the observed bioactivity. The
chemical structures of the two new compounds are elucidated using spectroscopic analysis and reported
for the first time.
