A New Butyrolactone Charlesolide and Other Constituents from Roots of Geranium charlesii

A new butyrolactone that was called charlesolide and the known phenolic compounds gallic acid (3,4,5-trihydroxybenzoic acid) and its methyl gallate and ethyl gallate derivatives were isolated from roots of Geranium charlesii (Aitch. & Hemsl.) Vved. Their structures were elucidated using IR, UV, and NMR spectra and comparisons with those of standard samples. An X-ray crystal structure analysis established the absolute configuration of the chiral centers of charlesolide as 3S, 4S,7′S, 2″R, and 3″S.