Secondary metabolites by chemical screening. I. Calcium 3-hydroxyquinoline-2-carboxylate from a Streptomyces

Streptomyces griseoflavus subsp. (Gö 3592) was investigated by chemical screening methods. The mycelium contained gilvocarcin V (1). The culture filtrate contained the calcium salt of 3-hydroxyquinoline-2-carboxylic acid (2) confirmed by spectroscopic methods and by a 5-step partial synthesis of the free acid (3).