Purification, structure characterization and antioxidant activity of polysaccharides from Saposhnikovia divaricata / 中国天然药物

Polysaccharide from traditional Chinese herb, Saposhnikovia divaricata (Turcz.) Schischk. (SD) was extracted, fractionated and characterized in this work. Four fractions were prepared. Their molecular weight, monosaccharide compositions, linkage modes and structural properties were characterized with SEC-MALS-RI, HPAEC-PAD, GC-MS and NMR. SDP1 was assigned as a 1, 4-α-glucan with small amount of O-6 linked branches. SDP2 contained a big amount of the 1, 4-α-glucan and a small amount of arabinogalactan, while SDP3 possessed relatively lower amount of the 1, 4-α-glucan and a big amount of the arabinogalactan. SDP4 was defined as a pectic arabinogalactan. Four fractions showed antioxidant activities in both molecular and cellular levels and their activity was ranked as SDP4 ≈ SDP3>SDP2>SDP1. The 1, 4-α-glucan in SDP1 had the weakest, while SDP3 and SDP4 showed similar and the highest antioxidant activity. The arabinogalactan was the major component of both SDP3 and SDP4, which significantly contributed to the antioxidant activity of SDP.

Protective effects of Rabdosia japonica var. glaucocalyx extract on lipopolysaccharide-induced acute lung injury in mice / 中国天然药物

The present study was designed to evaluate the protective effects of ethanol extracts of Rabdosia japonica var. glaucocalyx (Maxim.) Hara (RJ) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and the possible underlying mechanisms of action. The mice were orally administrated with RJ extract (16, 32 or 64 mg(kg(-1)) daily for consecutive7 days before LPS challenge. The ung specimens and the bronchoalveolar lavage fluid (BALF) were collected for histopathological examinations and biochemical analyses. Pretreatment with RJ significantly enhanced superoxide dismutase (SOD) activity and reduced the wet-to-dry weight (W/D) ratio, the levels of nitric oxide (NO) and protein leakage, and myeloperoxidase (MPO) activity in mice with ALI, in a dose-dependent manner. RJ reduced complement deposition and significantly attenuated LPS-induced ALI by reducing productions of inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). The results demonstrated that RJ may attenuate LPS-induced ALI via reducing the production of pro-inflammatory mediators, and reducing complement deposition and radicals.

Chemical constituents of Rabdosia japonica var. glaucocalyx and their anti-complementary activity / 中国中药杂志

To study the chemical constituents of Rabdosia japonica var. glaucocalyx and their anti-complementary activity on the basis of preliminary studies. Target isolation guided by anti-complementary activity test, compounds in the chloroform and n-butanol fractions were isolated and purified by silica gel and Sephadex LH-20 column chromatographies, and preparative HPLC. The structures were identified by various spectroscopic data including ESI-MS, 1H-NMR and 13C-NMR data. The compounds were evaluated for anti-complementary activity in vitro. Eleven compounds were isolated from the chloroform and n-butanol soluble fractions and identified as stigmasterol (1), stigmas-9 (11) -en-3-ol (2), glaucocalyxin D (3), kamebakaurin (4), maslinic acid (5), corosolic acid (6), minheryins I (7), diosmetin (8), caffeic acid ethylene ester (9), caffeic acid (10) and vitexin (11). Isoquercetrin, rutin, quercetin, 3-methylquercetin, luteolin, 7-methylluteolin, and apigenin which were isolated from the preliminary studies together with compounds 9 and 10 showed inhibition of the complement system by the classical pathway. Compounds 2, 4, 6-9 and 11 were obtained from this plant for the first time. Caffeic acid (10) showed the strongest activity in vitro with a CH50 value of 0.041 g x L(-1).