Nocamycin is produced by Nocardiopsis syringae. It is recovered from the culture fluid by extraction with chloroform. The MW of the crystalline antibiotic is 503, its melting point is 147-149o, .**GRAPHIC**. = -50o (c 0.21, chloroform), .lambda.max 235 and 348 nm .**GRAPHIC**. = 150 and 420. The summation formula is C26H33NO9. The biological activity is 100,000 units/mg with respect to Bacillus mycoides. Nocamycin forms salts with alkali soluble in water. On hydrolysis with an alkali it forms carbonic acid having no ester bond and methoxylic group in the antibiotic molecule. Nocamycin is a new natural substance.