Research for utilization of unused natural resources

点击翻译按钮获取中文摘要

1) A new anthracycline-derived pentacyclic metabolite, seragakinone A, and new peptides, dictyonamides A and B, were isolated from a marine-derived fungus Cocodinium sp., and the structures were determined on the basis of combination of NMR analyses, X-ray analysis, and degradation experiments. Seragakinone A showed antimicrobial activity, while dictyonamide A exhibited inhibitory activity against CDK-4.2) Three new lycopodium alkaloids, seratezomines A 〜 C, with seco-seratinine-type, a seratenine-type, and a lycodoline-type skeletons, respectively, were isolated from the club moss Lycopodium serratum var. serratum. On the other hand, three new alkaloids, complanadine A, lyconadine A, 11-hydroxy lycodine, were isolated from lycopodium complanatum.3) Fifteen new Daphniphyllum alkaloids, daphnezomines A 〜 G and daphnicyclidins A 〜 H were isolated from Daphniphyllum humile and D. teijsmanni. Daphnezomines A and B are novel alkaloids with aza-adamantane core, while daphnezomines F and G have a 1-azaobicyclo[5.2.2]undecene ring system. Daphnicyclidins A 〜 H possess unque fused hexa- or pentacyclic skeletons.4) Three new bicyclic peptides, celogentins A 〜 C, were isolated together with moroidin from the seeds of Celosia argentea. Celogentins A 〜 C and moroidin inhibited the polymerization of tubulin. Structure-activity relationship study using four moroidin derivatives as well as Celogentins A 〜 C and moroidin indicated that the bicyclic ring system including non-peptide connections among β^S-Leu, Trp, and His residues with ring size and conformations suitable for interaction with tubulin would be important for their activity.