Biotransformation of phthalazine by Fusarium moniliforme and Cunninghamella elegans

Abstract

Fusarium moniliforme and Cunninghamella elegans were grown in fluid Sabouraud medium at 28 C. They were dosed with 6.2 mM phthalazine and then incubated for 3 d with shaking at 125 rpm. After extraction with ethyl acetate, the metabolites were purified by HPLC and identified by the UV/visible, mass, and NMR spectra. The results show that F. moniliforme oxidized about 42% of the phthalazine to 1 (2/H)-phthalazinone (= 1-hydroxyphthalazine) and that C. elegans oxidized about 6% of the phthalazine to a novel metabolite, phthalazine N-oxide (= phthalazine 2-oxide).

Key Words:

• azaarenes
• heterocyclic compounds
• N-oxides
• phthalazinone