METABOLISM OF THE TOMATO SAPONIN ALPHA-TOMATINE BY GIBBERELLA-PULICARIS

The ascomycete Gibberella pulicaris is able to metabolize the saponin alpha-tomatine within 2 h by first removing the complete lycotetraose moiety leading to the aglycone tomatidine. This product is further con verted into 7 alpha-hydroxy-tomatidine and the corresponding Delta(5)- dehydro product 7 alpha-hydroxy-tomatidenol. Structural evidence for t he hydroxylated main metabolite as well as the unsaturated minor produ ct is based on MS and NMR measurements. The latter include the applica tion of modern soft pulse H-1 NMR techniques allowing the definitive l ocalization of the position of hydroxylation even for the few milligra m quantities that could be obtained. (C) 1998 Published by Elsevier Sc ience Ltd. All rights reserved.