Abietane and C20-norabietane diterpenes from the stem bark of Fraxinus sieboldiana and their biological activities.
Lin S, Zhang Y, Liu M, Yang S, Gan M, Zi J, Song W, Fan X, Wang S, Liu Y, Yang Y, Chen X, Guo Y, Wang W, Shi J.
Fourteen new abietane (1-14) and seven new C(20)-norabietane (15-21) diterpenes, together with five known analogues, have been isolated from the stem bark of Fraxinus sieboldiana. Their structures were elucidated by spectroscopic data analysis. In the in vitro assays, at 10(-5) M, compounds 8, 16, and 22 showed inhibitory activity against the release of β-glucuronidase in rat polymorphonuclear leukocytes induced by platelet-activating factor, with 59.7 ± 4.8%, 56.1 ± 5.6%, and 65.9 ± 3.1% inhibition, respectively. Compound 23 was active against H5N1 avian influenza virus with an IC(50) value of 4.8 μM. Compounds 3 and 5 exhibited selective cytotoxic activities against A2780 (IC(50) 1.7 μM) and A549 (IC(50) 6.0 μM), respectively.