Three New Chlorinated Cyclopentenols, Palmaenols A and B and Palmaetriol, from the Discomycete Lachnum palmae.

The new chlorinated cyclopentenols, palmaenol A (1) and palmaetriol (3), were isolated from the culture broth of the discomycete Lachnum palmae (NBRC- 106495). In addition, a new chlorinated cyclopentenol, palmaenol B (2), a geometric isomer of 1, was also obtained from the culture broth containing KCl. The structures of 1-3 were elucidated from spectroscopic data. Compounds 1-3 are cyclopentenols containing three or two chlorines; 1 and 2 are also reduced forms of palmaenones A (4) and B (5), which have been isolated from the same discomycete, respectively. Compounds 4 and 5 had potent antimicrobial activity, while compounds 1-3 showed no such activity. Thus, it is suggested that the unsaturated carbonyl group at C-6 has an important role for the antimicrobial activity.