Lanostane triterpene glycosides from the flowers of Lyonia ovalifolia var. hebecarpa and their antiproliferative activities

Abstract

Sixteen lanostane-type triterpene glycosides including eight new ones, named lyonicarposides A-H (1-8), were isolated from the flowers of Lyonia ovalifolia var. hebecarpa (Franch. ex F.B. Forbes & Hemsl.) Chun (Ericaceae). The chemical structures of the new compounds were elucidated by the comprehensive spectroscopic techniques and chemical methods. The Mo₂(OAc)₄-induced electronic circular dichroism method was used to determine the absolute configurations of C-24 in lyonicarposides A (1), C (3), and E (5). This is the first phytochemical study on the flowers of L. ovalifolia var. hebecarpa. All the isolates were evaluated for their antiproliferative activities against SMMC-7721, HL-60, SW480, MCF-7, and A-549 cell lines. Lyonicarposides A (1) and B (2) showed moderate antiproliferative activities against five cancer cell lines with IC₅₀ values ranging from 12.39 to 28.71 μM. Lyonicarposides C (3) and G (7) and lyonifoloside M (12) selectively inhibited the proliferation of HL-60 and MCF-7 cell lines with IC₅₀ values ranging from 13.03 to 17.71 μM. Interestingly, lyonifoloside L (13) selectively inhibited the proliferation of MCF-7 cell line with an IC₅₀ value of 16.27 μM. Their structure-activity-relationships were discussed.

Keywords: Antiproliferative activity; Chemical methods; Lanostane triterpene glycosides; Lyonia ovalifolia var. hebecarpa (Franch. ex F.B. Forbes & Hemsl.) Chun (Ericaceae); Mo(2)(OAc)(4)−induced electronic circular dichroism.