Twelve benzene derivatives from Clausena excavata.

A new phenethanol, (2'R)-4-(2', 3'-dihydroxy-3'-methyl-butanoxy)-phenethanol (1), along with other eleven known benzene derivatives (2-12) were isolated from the roots, stems and leaves of Clausena excavata (Rutaceae). Compounds 3 and 4 are new natural products, and compounds 5-8, 10-12 were isolated from C. excavata for the first time. Their structures were elucidated on the basis of MS, 1D and 2D NMR spectroscopic analyses including HSQC, COSY and HMBC experiments. 1 was tested for its cytotoxicities against A549, HeLa and BGC-823 cancer cell lines, and antimicrobial activities against Candida albicans and Staphylococcus aureus. The results showed that 1 did not exhibit cytotoxic and antimicrobial activities.