A new ent-clerodane diterpene from Detarium microcarpum Guill. & Perr. and its protective potential for osteoporosis.

A new clerodane diterpene, named 6α-hydroxy-3,13E-clerodien-15-oic acid (1), together with a known clerodane diterpene (2), four known labdane diterpenes (3-6), a triterpenoid (7), a known steroid (8), and two benzenoid compounds (9 and 10) were isolated from Detarium microcarpum Guill. & Perr. The structures of all obtained compounds were determined by chemical properties and spectroscopic evidence, accompanied by comparisons with data in the literature. Electronic circular dichroism (ECD) was performed for compounds 1-4 to confirm the absolute configuration. Compounds 1-3 and 8-10 were evaluated for the protective effect on osteoblasts. Compound 1 was observed to increase the proliferation of dexamethasone (DEX)-treated MC3T3-E1 cells significantly at 1 µM, which was comparable with the positive control geniposide at 10 µM. The results were further confirmed by flow cytometry analysis. In addition, compound 1 increased the level of alkaline phosphatase (ALP) and mineralization in osteoblasts inhibited by DEX. Moreover, Compound 9 (vanillic acid) showed a pronounced inhibition (IC50 6.5 ± 0.6 µM) on reactive oxygen species (ROS) production, and 10 (4-O-methyl gallic acid) showed a good inhibition with IC50 as 103.3 ± 2.2 µM, compared with the standard drug ibuprofen (IC50 54.2 ± 9.2 µM). Besides, compounds 1-3 and 8-10 were non-cytotoxic against MCF-7, NCI-H460, Hela, and BJ cell lines.

Lipoxygenase inhibitory constituents from Periploca aphylla.

Bisflavan-3-ols 1 and 2 and norterpenoid 3 have been isolated from the methanolic extract of the whole plant of Periploca aphylla. Their structures have been assigned on the basis of spectroscopic analysis including 1D and 2D NMR techniques. In addition, o-phthalic acid bis(2-ethylnonyl) ester (4), 1,3,6-trihydroxy-2,5-dimethoxyxanthone (5), and (+)-lyoniresinol (6) have been reported for the first time from this species. Compounds 1-3 displayed evident inhibitory potential against the enzyme lipoxygenase in a concentration-dependent fashion with IC(50) values 19.7, 13.5, and 150.1 microM, respectively.