Minor secoiridoid aglycones from the low-polarity part of the traditional Chinese herb: Swertia mileensis

Abstract

Eleven new secoiridoid aglycones involving unusual C9-skeleton: swerimilegenins A-F (1–6); bis-C9-skeleton: swerimilegenin G (7); and C10-skeleton: swerimilegenins H-K (8–11), as well as six known ones, were isolated from the low-polarity part of the traditional Chinese herb medicine Swertia mileensis. Their structures were determined by extensive spectroscopic data and X-ray diffraction. Biogenetically, swerimilegenin A (1) belonged to 10-nor-secoiridoid, and swerimilegenins B-F (2–6) were 1-nor-secoiridoids. Erythrocentaurin (12) and gentiogenal (15) showed moderate anti-HBV activity on HepG 2.2.15 cell line in vitro. [Figure not available: see fulltext.].