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.
Lipiarmycin, a new antibiotic from Actinoplanes. I. Description of the producer strain and fermentation studies.
The producer strain of the new antibiotic, lipiarmycin, is described. The colony morphology, the presence of globose sporangia bearing motile spores, the absence of aerial mycelium and the presence of meso-DAP in cell wall, ascribe this strain to the genus Actinoplanes. The pigmentation and morphological characteristics together with the cultural and physiological features distinguish this strain from all the described Actinoplanes species. It is considered to be a new species for which the name Actinoplanes deccanensis nov. sp. is proposed. Lipiarmycin is produced in an organic complex medium containing NaCl. Production occurs at the end of trophophase and continues, though at decreasing rate, during isophase.
Highly enantio- and diastereoselective synthesis of β-methyl-γ-monofluoromethyl-substituted alcohols.
Enanatiopure β-methyl-γ-monofluoromethyl alcohols were prepared from the allylic alkylation between fluorobis(phenylsulfonyl)methane with Morita-Baylis-Hillman carbonates. The reaction was catalyzed by using the Cinchona alkaloid derivative, (DHQD)(2)AQN. The origin of the stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed stereoselectivity.