Microbial Transformations of Natural Antitumor Agents XXII: Conversion of Bouvardin to O-Desmethylbouvardin and Bouvardin Catechol

Mass spectrometry of cyclic peptides

“…17) is a natural antitumor agent. Petroski et al characterized 0-desmethyl-Tyr3-bouvardin and bouvardin catechol (hydroxylation at Tyr3 meta position) as the major products of microbial transformations of bouvardin by use of EIMS combined with accurate mass measurements and FD in combination with NMR (180). Besidc NMR assignments the information of the low-mass ions generated by fragmentation of the modified Tyr3 were used to establish the structures.…”

Phylogenetic Analysis of Aspergillus Section Circumdati Based on Sequences of the Internal Transcribed Spacer Regions and the 5.8 S rRNA Gene

“…Isolates of A. ochraceus or A. sclerotiorum are useful for biochemical transformation of steroids, alkaloids, or phenazines (Chen et al, 1994;Petroski et al, 1983;Hill and Johnson, 1969). Some species, e.g., A. sclerotiorum and A. melleus, are important sources of proteolytic enzymes (Kundu et al, 1974;Luisetti et al, 1991) and other metabolites (Matsukuma et al, 1992;Lin et al, 1995), while sclerotia of several species contain anti-insectan compounds (Wicklow et al, 1994;Whyte et al, 1996;Ooike et al, 1997).…”