In vitro oxygenation of N,N'-diphenylguanidines.

1. The enzymic C-oxygenation of N,N'-diphenylguanidine (DPG) to N-(4-hydroxyphenyl)-N'-phenylguanidine (4HPG) and the N-oxygenation of N,N'-bis-(pentafluorophenyl)-guanidine (BPG) to N"-hydroxy-N,N"-bis-(pentafluorophenyl)-guanidine (HBPG) is reported. 2. The metabolites were identified by t.l.c. and mass spectral analysis using synthetic reference compounds. 3. Rat and rabbit liver homogenates (9000 g supernatant and microsomes) were used as enzyme source. 4. The enzymic oxygenations were both O2 and NADPH dependent. NADPH could not be replaced by hydrogen peroxide. 5. 15N-n.m.r. spectroscopy was used to elucidate structure and tautomerism of BPG and HBPG.