Phoslactomycin F

Phoslactomycins A to F are new antifungal antibiotics produced by Streptomyces nigrescens SC-273. On the basis of physico-chemical properties and NMR studies, their structures have been determined as shown in Fig. 6. They are characterized by possessing alpha, beta-unsaturated delta-lactone, phosphate ester, conjugated diene and cyclohexane ring moieties. The structural difference between them is ascribed to a substituent bound to the cyclohexane ring.

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).