Okabe T, Nomoto K, Tanaka N
J Antibiot (Tokyo). 1986 Jan;39(1):1-5. doi: 10.7164/antibiotics.39.1.
Streptomyces tanashiensis IM8442T was found to produce lactoquinomycin B, a novel antibiotic, together with lactoquinomycin A. Lactoquinomycin B was purified, and the physico-chemical and biological characteristics were studied. Lactoquinomycin B, C24H27NO9, mp 149-152 degrees C (dec), FD-MS m/z 473 (M+), is a basic substance, showing UV lambda MeOHmax (epsilon) 239 (15,100), 287 (3,450) and 369 nm (5,300), and IR nu CHCl3max 1790 (gamma-lactone), and 1700 and 1650 (quinone) cm-1. The structure of lactoquinomycin B was elucidated by 1H NMR and 13C NMR in comparison with those of lactoquinomycin A, indicating that B is a 4a,10a-epoxide derivative of A. Lactoquinomycin B displayed inhibitory activity against bacteria, particularly Gram-positive organisms, and cytotoxicity against human and murine tumor cell lines. LD50 for mice was ca. 40 mg/kg by iv route.
发现谷保链霉菌IM8442T可产生一种新型抗生素乳醌霉素B以及乳醌霉素A。对乳醌霉素B进行了纯化，并研究了其理化性质和生物学特性。乳醌霉素B，化学式为C24H27NO9，熔点149 - 152℃（分解），场解吸质谱m/z 473（M+），是一种碱性物质，其紫外光谱在甲醇中的最大吸收波长（ε）为239（15,100）、287（3,450）和369nm（5,300），红外光谱在氯仿中的最大吸收峰为1790（γ-内酯）、1700和1650（醌）cm-1。通过与乳醌霉素A的1H NMR和13C NMR对比，阐明了乳醌霉素B的结构，表明B是A的4a,10a-环氧化物衍生物。乳醌霉素B对细菌尤其是革兰氏阳性菌具有抑制活性，对人和小鼠肿瘤细胞系具有细胞毒性。小鼠静脉注射的半数致死量约为40mg/kg。
