Diterpenoids from Leaves of Cultivated Plectranthus ornatus

Two new diterpenoid derivatives 7 alpha ,12 beta ,17-triacetoxy-6 beta, 19-dihydroxy-13 beta ,16-spirocicloabiet-8-ene-11,14-dione ( 1 ) and 6 beta -acetoxy-3 beta ,7 alpha ,12 alpha -trihydroxy-13 beta ,16-spirocicloabiet-8-ene-11,14-dione ( 2 ) along with 11 ( 3 - 13 ) miscellaneous compounds were isolated from the leaves of Plectranthus ornatus Codd. Their structures were elucidated by spectroscopic analysis and gauge independent atomic orbitals (13) C NMR calculations. The isolated compounds were screened for their effects on intestinal motility using guinea-pig ileum and duodenum and by their cytotoxicity against 4 human cancer cell lines (HCT-116, SF-295, PC-3, and HL-60). Compounds 6 and 9 were moderately cytotoxic against HL-60, whereas 6 and 13 were more active on SF-295 and HCT-116.

Automated summary

Two new diterpenoid derivatives were isolated from the leaves of Plectranthus ornatus Codd, and their structures and biological activities were investigated. The compounds showed moderate cytotoxicity against human cancer cell lines.