Novel microbial metabolites of the phoslactomycins family induce production of colony-stimulating factors by bone marrow stromal cells. II. Isolation, physico-chemical properties and structure determination.

Leustroducsins (LSNs) A, B and C, novel inducers of colony-stimulating factors (CSFs), were isolated from culture broth of Streptomyces platensis SANK 60191 mainly by ethyl acetate extraction and preparative reverse-phase HPLC. The molecular weights and molecular formulae of LSNs A, B and C are 641: C32H52O10NP, 669: C34H56O10NP and 669: C34H56O10NP, respectively. The structure elucidation revealed that they belong to the phoslactomycin group antibiotics, and their structures contain an alpha,beta-unsaturated delta-lactone, an amino group, a phosphate ester and a cyclohexane ring moiety. The structures differ only at the substituent bound to the cyclohexane ring.