Isolation and identification of 7,8-didemethyl-8-hydroxy-5-deazariboflavin, an unusual cosynthetic factor in streptomycetes, from Streptomyces lincolnensis.

A study of complementing lincomycin nonproducing mutants of Streptomyces lincolnensis resulted in the discovery of a low molecular weight compound that functions as a catalytic agent, lincomycin cosynthetic factor (LCF), in the biosynthesis of propylproline.^ This note reports the isolation and identification of LCF and its detection in fermentation broths of many actinomycetes. For the purification of LCF, 5. lincolnensis mutant NTG-5 fermentation broth was adjusted to pH 3.0, filtered, passed over an Diaion HP-20 chromatography column and eluted with a H2O MeOHgradient. Active fractions, identified by bioassay,1} were pooled, adjusted to pH 9.0, absorbed to Amberlite IRA 458 (OH") resin, and eluted with H2O1 m AcOH. The Diaion HP-20 column chromatography and later steps were also followed by TLC (silica plates developed with methyl ethyl ketoneacetone-water, 71 :19:10, Rf 0.41) with long