New phenylpropane and anti-inflammatory diterpene derivatives from Amentotaxus formosana.

One new diterpene, 8(14),15-sandaracopimaradiene-2alpha,3beta,18-triol (1), two new phenylpropane derivatives, i.e., (E)-methyl 2-(3,4-methylene-dioxyphenyl)-3-methoxypropenoate (2) and (E)-2-(3,4-methylene-dioxyphenyl)-3-methoxypropenoic acid (3), and two known diterpenes, ent-8(14),15-sandaracopimaradiene-2alpha,18-diol (4) and 8(14),15-sandaracopimaradiene-2alpha,18,19-triol (5), were isolated from the heartwoods and barks of Amentotaxus formosana, respectively. The anti-inflammatory activity of the diterpenes 1, 4, and 5 was assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, macrophages, and microglial cells. Compounds 1, 4, and 5 showed significant concentration-dependent inhibitory effects on the release of beta-glucuronidase from rat neutrophils in response to formyl-Met-Leu-Phe/cytochalasin B (fMLP/CB) with IC50 values of 5.5 +/- 1.8, 8.4 +/- 2.9 and 19.2 +/- 3.3 microM, respectively. Compounds 1 and 5 also showed significant concentration-dependent inhibitory effects on superoxide anion generation in rat neutrophils stimulated with fMLP/CB and phorbol 12-myristate 13-acetate (PMA) with IC50 values of 12.6 +/- 1.2 and 9.4 +/- 1.7, and 10.7 +/- 3.3 and 12.9 +/- 0.9 microM, respectively.