Chemical and antibacterial constituents of Skimmia anquetelia.

Investigation of the leaves of Skimmia anquetelia (Rutaceae) led to the isolation of a new coumarin glucoside 7,8-dihdroxy-6-[3'-beta- D-glucopyranosyloxy-2'(xi)-hydroxy-3'-methylbutyl]-coumarin ( 1) together with five known coumarins: 6-(2,3-dihydroxy-3-methylbutyl)-7-methoxycoumarin ( 2), skimmin ( 3), osthol ( 4), esculetin ( 5) and scopuletin ( 6). The antibacterial activity of compounds 1 and 3 was also investigated against the plant bacterial pathogens Agrobacterium tumifaciens, Pseudomonas syringae and Pactobacterium carotovorum. Structures were determined on the basis of analyses of spectral evidence including 1D, 2 D NMR (COSY, HMQC, HMBC and NOESY) and mass spectroscopy.