ESTABLISHING STYRYLPYRONE SYNTHASE ACTIVITY IN CELL-FREE-EXTRACTS OBTAINED FROM GAMETOPHYTES OF EQUISETUM-ARVENSE L BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY TANDEM MASS-SPECTROMETRY

Styrylpyrone synthase is a polyketide synthase, catalyzing the formati on of styrylpyrones from hydroxycinnamoyl-CoA precursors and malonyl-C oA, After incubation of cell free extracts obtained from Equisetum arv ense L, gametophytes with p-coumaroyl-CoA or caffeoyl-CoA, high perfor mance liquid chromatography atmospheric pressure chemical ionization-t andem mass spectrometry (HPLC-APCI-MS) led to the identification of bi snoryangonin and hispidin, respectively, as metabolites, These finding s enabled the development of an assay for styrylpyrone synthase activi ty based on HPLC analysis of the reaction products, The technique coul d also be useful for product identification in related polyketide synt hase reactions. (C) 1997 by John Wiley & Sons, Ltd.