Studies on new phosphate ester antifungal antibiotics phoslactomycins. I. Taxonomy, fermentation, purification and biological activities.

New antibiotics phoslactomycins A, B, C, D, E and F, which contain alpha, beta-unsaturated delta-lactone, phosphate ester, conjugated diene and cyclohexane ring moieties, were isolated from the culture broth of a soil isolate actinomycete. Morphological, cultural and physiological studies revealed that the isolate is a strain of Streptomyces nigrescens. Phoslactomycins were obtained by butanol extraction, gel filtration and reverse phase chromatography. The antibiotics show strong activity against various fungi, particularly phytopathogenic fungi (Botrytis cinerea and Alternaria kikuchiana).