STRUCTURE AND BIOLOGICAL ACTIVITY OF LIPIARMYCIN
Actinoplanes deccanensis ATCC21983, the producer of antibiotics lipiarmycin A3 and A4, furnished also a related antibiotic designated lipiarmycin B, active against Gram-positive bacteria, including anaerobes, and against Neisseria. The structures of the two major components, B3 and B4, were elucidated from their physico-chemical properties, XHand 13C NMRspectra and fast atom bombardmentmass spectra data in comparison with lipiarmycins A3andA4.
Structure elucidation of the macrocyclic antibiotic lipiarmycin
By a combination of chemical degradations and 1H and 13C n.m.r. studies, the structure of the antibiotic lipiarmycin, produced by Actinoplanes deccanensis, has been elucidated. The molecule contains two glycosyl moieties, namely 2-O-methyl-4-O-homodichloro-orsellinate-β-D-rhamnose and 4-O-isobutyrate-5-methyl-β-rhamnose, attached to a 18-membered unsaturated lactone ring.
STUDIES ON JUVENIMICIN, A NEW ANTIBIOTIC. I
An actinomycete, strain No. T-1124, was found to produce new macrolide antibiotics, juvenimicins. Based on the results of taxonomic studies, the strain was considered to be a new variety of Micromonospora chalcea and the name Micromonospora chalcea var. izumensis is proposed. This strain also produced everninomicin. The production of juvenimicins was stimulated by addition of ferrous sulfate and magnesium sulfate in the fermentation medium. Among juvenimicins, juvenimicin A3 exhibited the most potent antimicrobial activities against gram-positive bacteria and furthermore was active against gram-negative bacteria.