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A pathway via condensation of a four-carbon unit from the tricarboxylic acid (TCA) cycle with a three-carbon unit, possibly phosphoenol pyruvate, was gleaned from the biosynthesis of 4-hydroxy-3-nitrosobenzamide in Streptomyces murayamaensis mutants MC2 and MC3 and therefore, of 3-amino-4-hydroxybenzoic acid. 3-Amino-4-hydroxy(5-2H)benzoic acid was readily incorporated into the ferrous chelate of 4-hydroxy-3-nitrosobenzamide by S. murayamaensis in the isolation of 4-hydroxy-3-nitrosobenzamide and its ferrous chelate from S. murayamaensis. The involvement of the TCA cycle and the orientation of the four-carbon intermediate was confirmed.

3-Amino-4-hydroxybenzoic acid (4) had been identified as a specific precursor of 4-hydroxy-3-nitrosobenzamide, an iron-chelating metabolite isolated from Streptomyces murayamaensis. This suggests that 4 might be a proximate precursor for the mC7N unit of the manumycin antibiotics. Results of experiments conducted to verify this hypothesis showed that 4 is a precursor of the mC7N moiety of asukamycin, an antibiotic of the manumycin family.

Structural analysis of kinamycin antibiotics, initially isolated from Streptomyces murayamaensis and characterized as benzo(b)carbazoloquinone cyanamides, provides revised structures for them, establishing them as 5-diazobenzo(b)fluorenes. Prekinamycin is a diazo compound. Kinamycin biosynthesis may involve 5, or 12-deoxy-10 or 7-O-dimethyl-9 as intermediates.

Reports on the biosynthesis of 4-hydroxy-3-nitrosobenzamide in Streptomyces murayamaensis mutants MC2 and MC using sodium [1,2-13C2]- and [1-13C,18O2]acetate, sodium [2,3-13C2]succinate, [1,2-13C2]glutamic acid, [4,13C]aspartic acid, and sodium [1-13C]- and [2,3-13C2]pyruvate. Subsequent specific incorporations of acids.