25.

The First Occurrence of A Mallotus 3,4-Seco-Taraxerane Triterpenoid from Mallotus barbatus

Phan Minh Giang, Vu Minh Trang, Phan Tong Son, Katsuyoshi Matsunami and Hideaki Otsuka

Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong Street, Hanoi, Vietnam

Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan

Abstract: The first occurrence of a 3,4-seco-taraxerane triterpenoid in Mallotus species (Euphorbiaceae) is reported. The triterpenoid was isolated from the leaves of the Vietnamese medicinal plant Mallotus barbatus ( Wall.) Muell.-Arg. and its structure was determined to be 3,4-seco-taraxer-14-en-3-oic acid on the basis of HR-MS and NMR spectroscopic methods. For the first time, the 1 H and 13C NMR data and stereochemistry of this compound were fully established on the basis of the 1H- 1H COSY, NOESY, HSQC, and HMBC spectroscopic data.

Keywords: Mallotus barbatus ; Euphorbiaceae; triterpenoid; 3,4-seco-taraxerane.