planar structures of 1 and 2 were identified by a combination of NMR, MS, and UV spectroscopic analyses. The absolute configurations were assigned based on chemical and chromatographic methods as well as ECD calculations. A new chromatography-based experimental method for determining the configurations of stereogenic centers β to nitrogen atoms in macrolactams was established and successfully applied in
链霉菌的培养。从家蚕的肠中分离出的
SD53菌株产生了两种大内酰胺类
天然产物,
青霉素(1)和孟买霉素C(2)。1和2的平面结构通过NMR,MS和UV光谱分析的组合进行鉴定。绝对构型是根据
化学和色谱方法以及
ECD计算指定的。建立了一种基于色谱的实验方法,用于确定大内酰胺中立体异构中心β到氮原子的构型,并成功应用于本报告。这些化合物对桑蚕昆虫病原体苏云
金芽孢杆菌和各种人类病原体以及人类癌
细胞系表现出显着的
生物活性。尤其是,
青霉素能有效抑制肠炎沙门氏菌和变形杆菌,MIC值分别为0.083μg/ mL和0.025μg/ mL。讨论了在
青霉素中涉及形成
环戊烯酮部分的
生物合成途径。