Five new pyrrolizidine alkaloids,bohemamines J—N(1-5),were isolated from Streptomyces sp.CPCC 200497.Their structures were assigned based on detailed spectroscopic analysis and semisynthesis.Bohemamine J(1)possesses ...Five new pyrrolizidine alkaloids,bohemamines J—N(1-5),were isolated from Streptomyces sp.CPCC 200497.Their structures were assigned based on detailed spectroscopic analysis and semisynthesis.Bohemamine J(1)possesses a new chimeric skeleton derived from bohemamine A(6)and phenylacetaldehyde.Inspired by the nonenzymatic formation mechanism of the methylene-bridged dimers isolated from this strain,we synthesized a series of chimeric derivatives(8,9,and 12-23)through natural product chimera strategy.Compounds 13,15,19,and 21 showed significant antioxidant activity.展开更多
基金the National Natural Science Foundation of China(41806086,U1906213,41876172)。
文摘Five new pyrrolizidine alkaloids,bohemamines J—N(1-5),were isolated from Streptomyces sp.CPCC 200497.Their structures were assigned based on detailed spectroscopic analysis and semisynthesis.Bohemamine J(1)possesses a new chimeric skeleton derived from bohemamine A(6)and phenylacetaldehyde.Inspired by the nonenzymatic formation mechanism of the methylene-bridged dimers isolated from this strain,we synthesized a series of chimeric derivatives(8,9,and 12-23)through natural product chimera strategy.Compounds 13,15,19,and 21 showed significant antioxidant activity.