Mycotoxin contamination of dietary and medicinal wild plants in the Eastern Cape Province of South Africa

Nineteen dietary and 30 medicinal wild plants used by residents of the Eastern Cape Province of South Africa were investigated for the presence of fumonisin B-1 and aflatoxin B-1. The plants were extracted in water, and cleanup was undertaken on immunoaffinity cartridges; analysis was by HPLC using fluorescence detection. None of the plant extracts contained detectable levels of aflatoxin B-1; however, eight plants, four dietary and four medicinal, were positive for fumonisin B-1 at levels ranging from 34 to 524 mu g/kg and from 8 to 1553 mu g/kg, respectively. The presence of fumonisin B-1 was confirmed by LC-MS/MS using positive ion electrospray ionization. Fumonisin B-1 provided characteristic fragment ions at m/z 704, 686, 546, 528, 370, and 352 corresponding to sequential loss of H2O and tricarboxylic acid moieties from the alkyl backbone. These results indicate that exposure to fumonisin B-1 is much more widespread than initially thought and is the first report of mycotoxin contamination in South African medicinal and dietary wild plants.