Chemistry and biological activity of diterpenoid compounds from Croton oblongifolius Roxb

Abstract

Chemical modification of crotocembraneic acid (l) and necrotocembraneic acid (2) from Croton oblongifolius Roxb. Had been investigated. Both 1 and 2 were esterified by reacting with diazomethane. The methyl esters were reduced with LiAIH…to give the corresponding alcohols. The alcohols were oxidized with manganese dioxide to give the corresponding aldehydes, crotocembranal (lc), and neocretobembranal (2c). All compounds gave expected spectral data. Croton oblongifolius Roxb. From various locations in Thailand were subjected to chemical screeing using proton NMR. The crude heane extract of stem bark pointed out various types of chemical constituents. Plant specimens from selected locations were subjected to conventional extraction and isolation. Several diterpenoids were characterized including three new diterpenoids belonging to the halimane type. They were crotohalimaneic acid (7) , benzoyl crotohalimanolic acid (8) and crotohalimoneic acid (9) All compounds both natural and synthetic were subjected to biological activity tests. Many compounds exhibited cytotosicith against panel of six cell lines which were LS 929 (fibroblast), S102 (hepatoma), HEP-G2 (heptatoma), SW 620 (colon), chago (lung), Kato-3 (gastric) and BT 474 (breast). Morever, some diterpenoids were tested for cyclic AMP phosphodiesterase inhibition and it was forund that 1 and 2 exhibit the highest enzyme inhibition.