The biochemistry of aromatic amines. 10. Enzymic N-hydroxylation of arylamines and conversion of arylhydroxylamines into o-aminophenols.

The spectrum of the compound from V. sativa shows two bands, the more complex one, at higher field, is the AB portion of an ABX spectrum which has been further split by a single proton. The lower field band is the AB part of an ABX spectrum. The position and multiplicities of these bands in the observed spectrum are those expected of the 3and 5-protons of the proposed formula. The 2and 4proton signals are masked by the band arising from the few per cent of water in the commercial D20 used as solvent. The most prominent feature of the spectrum of the compound from L. tingitanus is the triplet at a shift of 2-18 p.p.m. This has been assigned to the 6-protons in formula (II): the triplet splitting, and the small upfield shift of this band compared with the corresponding band in the spectrum of the compound from V. 8ativa, is in agreement with the introduction of a -CH2grouping between the C-4 and C-5 of formula (I). Two other complex bands were observed in the spectrum of this compound and their positions and multiplicities are suitable for the 3and 5-protons of formula (II). Again the methine protons are masked by the solvent line. These spectra are in agreement with the chemical evidence and indicate that the compounds isolated from V. sativa and L. tingitanu8 are the lactones derived respectively from y-hydroxyarginine and y-hydroxyhomoarginine.