Linearmycin A is novel linear polyene antibiotic isolated from mycelial extracts of Streptomyces sp. Linearmycin A and B have similar, long linear structures terminating with amino and carboxylic acid groups. The carboxylic acid terminal of linearmycin A links to a tetraenone, whereas linearmycin B links to a pentaenone. Linearmycin A has antifungal activity against Candida albicans. Linearmycin A has antibacterial activity, causing cellular lysis and colony degradation of the Gram-positive bacterium Bacillus subtilis acting directly on the cytoplasmic membrane.