Generation by mutasynthesis of potential neuroprotectant derivatives of the bipyridyl collismycin A

Abstract

Collismycin A is a member of the 2,2'-bipyridyl family of natural products and structurally belongs to the hybrid polyketides-nonribosomal peptides. A gene coding for a lysine 2-aminotransferase of Streptomyces sp. CS40 (collismycin A producer) was inactivated by gene replacement. The mutant was unable of synthesizing collismycin A but it recovered this capability when picolinic acid was added to the culture medium. By feeding different picolinic acid analogs to this mutant, two new collismycin A derivatives were obtained with a methyl group at the 4 and 6 position of the first pyridine ring of collismycin A, respectively. The two compounds showed effective neuroprotective action against an oxidative stress inducer in a zebra fish model, one of them showing higher neuroprotectant activity than that of collismycin A and that of the control lipoic acid.

Keywords: Nonribosomal peptide; Polyketide; Streptomyces.