CHEMICAL BASIS FOR ASPILIA LEAF-SWALLOWING BY CHIMPANZEES - A REANALYSIS

Thiarubrine A, an antimicrobial and nematocidal 1,2-dithiin polyyne ha s been reported to be a constituent of Aspilia leaves swallowed whole by chimpanzees. Aspilia samples were analyzed for the presence of thia rubrine A and other sulfur-containing polyynes using high-performance liquid chromatography (HPLC) and an antifungal bioassay. Thiarubrines A, B, D, and E and their corresponding thiophenes were not present in the leaves of three Aspilia species including A. mossambicensis and A. rudis, which are swallowed by chimpanzees at Mahale Mountains Nationa l Park and Gombe National Park, Tanzania. Antifungal activity, indicat ive of the presence of thiarubrines, was not detected in Aspilia leaf samples. Small amounts of thiarubrines A and B, and thiophenes A and B were found in A. mossambicensis roots. Analysis of three North Americ an taxa found high concentrations of thiarubrines and thiophenes in th e roots of Eriophyllum lanatum and Chaenactis douglasii, and the roots and leaves of Ambrosia chamissonis.