A chemotaxonomic study of the terverticillate penicillia based on high performance liquid chromatography of secondary metabolities

Abstract

Isolates of terverticillate Penicillium taxa were examined for production of secondary metabolites. The secondary metabolites were analysed by reversed phase HPLC with diode array detection (DAD) and each metabolite was characterized by its retention index (RI) and uv-VIS spectrum. Secondary metabolites with closely related uv-VIS spectra were placed in a chromophore family and a total of 216 different chromophore families was observed. The 279 objects times 216 binary variables matrix was analysed using average linkage clustering (UPGMA), using several different distance coefficients. The Yule coefficient and the Jaccard coefficient were found to be a very good combination of distance coefficients when analysing binary secondary metabolite data. Profiles of chromophore families of secondary metabolites allowed a clear separation of P. arenicola, P. lanosum, P. nalgiovense and P. oxalicum and the terverticillate taxa proposed earlier. A separation of P. commune and P. verrucosum into chemotypes as earlier suggested was not observed. Two new taxa should be described based on distinct profiles of chromophore families of secondary metabolites. Some taxa were shown to have a marginal position among the terverticillate penicillia. Other taxa clustered in groups indicating natural series.