Submitted to: Chemical and Pharmaceutical Bulletin
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2009
Publication Date: 11/19/2009
Citation: Xu, W., Jacob, M.R., Agarwal, A.K., Clark, A.M., Liang, Z., Li, X. 2009. ent-Kaurane Glycosides from Tricalysia okelensis. Chemical and Pharmaceutical Bulletin. 58:261-264. Interpretive Summary: This manuscript describes the isolation and structure elucidation of two new ent-kaurane glycosides from the roots of Tricalysia okelensis, a sample obtained from National Cancer Institute Open Repository.
Technical Abstract: Tricalysia is a genus of the plant family Rubiaceae, with approximately 50 species distributed in subtropical and tropical areas in Asia and Africa, some of these used as folk medicine.1,2) Extensive phytochemical studies on Tricalysia dubia led to the isolation of a number of structurally diverse diterpenoids (primarily with an ent-kaurane skeleton)3-6) and their glycosides 2,7,8) and alkaloids,9) while a bioassay-guided fractionation scheme identified the triterpenoids oleanolic acid and ursolic acid from Tricalysia niamniamensis that showed inhibitory activity against human ligase I.10) The organic extract of the roots of Tricalysia okelensis from the US National Cancer Institute Open Repository showed marginal antifungal activity but failed to produce enriched antifungal activity upon fractionation. A phytochemical investigation focusing on its diterpenoid constituents was thus conducted, leading to the identification of two new ent-kaurane glycosides, tricalysiosides V (1) and W (2). Herein we report the isolation and structure elucidation of the two compounds.