ABSTRACT
Fifteen new isopimarane-type diterpenes, taichunins E-S (1-15), and a new 20-nor-isopimarane, taichunin T (16), together with four known compounds were isolated from Aspergillus taichungensis (IBT 19404). The structures of these new compounds were determined by NMR and mass spectroscopy, and their absolute configurations were analyzed by NOESY and TDDFT calculations of ECD spectra. Taichunins G, K, and N (3, 7, and 10) completely inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced formation of multinuclear osteoclasts in RAW264 cells at 5 µM, with 3 showing 92% inhibition at a concentration of 0.2 µM.
Subject(s)
Abietanes/pharmacology , Aspergillus/chemistry , Osteoclasts/drug effects , RANK Ligand , Abietanes/isolation & purification , Animals , Biological Products/isolation & purification , Biological Products/pharmacology , Mice , Molecular Structure , RAW 264.7 Cells , TaiwanABSTRACT
Four new norditerpenes, taichunins A-D (1-4), were isolated from the fungus Aspergillus taichungensis (IBT 19404). Compound 1 has a new carbon framework. The absolute configurations were determined by the calculated ECD spectral method. Compound 1 was cytotoxic against HeLa cells with an IC50 value of 4.5 µM, whereas 2-4 were nontoxic at 50 µM.
