Duramycins B and C, two new lanthionine containing antibiotics as inhibitors of phospholipase A2. Structural revision of duramycin and cinnamycin.

Duramycins B and C, two new lanthionine containing antibiotics, have been isolated from Streptoverticillium strain R2075 and Streptomyces griseoluteus (R2107). The known antibiotics duramycin and cinnamycin were reisolated from Streptoverticillium hachijoense (DSM 40114) and Streptomyces longisporoflavus (DSM 40165). The structures of these latter two compounds should be revised by changing amino acid residue 3 to glutamine and 17 to asparagine, respectively. Cinnamycin therefore seems to be identical to Ro 09-0198. Leucopeptin has been shown to be identical to duramycin. Physico-chemical data of these compounds provide evidence for a similar structure for all duramycin antibiotics. All compounds of this group inhibit human phospholipase A2 at a concentration of 10(-6) molar.