Isolation of borrelidin from Streptomyces californicus—An Indian soil isolate

In a screening programme for search of antibiotics active against clinical resistant strains of infectious bacteria, a potent antibiotic producer from soil capable of acting on vancomycin and methicillin resistant strains was isolated. The taxonomic and biochemical studies revealed that the culture was a strain of Streptomyces californicus. The fermentation schedule was determined in starch casein agar medium and was found to produce maximum antibiotic on 3 d. The biological activities of the crude extract revealed that the active compound has both antibacterial and antifungal activity. The cytotoxic studies on HBL 100 cancer cells revealed weak activity of the compound in comparison to doxorubicin. The active compound was further found to inhibit the neoangiogenesis in fertile eggs. The active compound was extracted from culture filtrates by ethyl acetate and purified by column chromatography using silica gel. Mass and H and C NMR spectral information of the active compound were obtained. Finally, the active compound was identified as borrelidin, being reported as new compound from S. californicus.