Yonghua Su

Combined application of macroporous resin and high speed counter‐current chromatography for preparative separation of three flavonoid triglycosides from the leaves of Actinidia valvata Dunn

In this paper, the combined techniques of macroporous resin column chromatography and high speed counter-current chromatography were applied for preparative separation of flavonoid triglycosides from the leaves of Actinidia valvata Dunn, a famous Chinese medicinal herb. Twelve kinds of macroporous resins were investigated by adsorption and desorption tests. HPD-300 resin showed the maximum effectiveness and thus was selected for the first cleaning-up, in which 20% ethanol was used to remove the undesired constituents and 60% ethanol to elute the targets. The crude extract was then purified by high speed counter-current chromatography with the solvent system composed of ethyl acetate-n-butanol-water (2:1:3 and 4:1:5, v/v). Three flavonoid triglycosides, namely, kaempferol 3-O-α-L-rhamnopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→6)-β-D-galactopyranoside, kaempferol 3-O-α-L-rhamnopyranosyl-(1→3)-(4-O-acetyl-α-L-rhamnopyranosyl)-(1→6)-β-D-galactopyranoside and kaempferol 3-O-α-L-rhamnopyranosyl-(1→3)-(2,4-di-O-acetyl-α-L-rhamnopyranosyl)-(1→6)-β-D-galactopyranoside, were obtained. The purities of the separated compounds were all over 95% as determined by HPLC area normalization method. Their chemical structures were confirmed by UV, MS, NMR, and the standards.

Titanate-silica mesostructured nanocables: synthesis, structural analysis and biomedical applications

1D hierarchical composite mesostructures of titanate and silica were synthesized via an interfacial surfactant templating approach. Such mesostructures have complex core-shell architectures consisting of single-crystalline H(2)Ti(3)O(7) nanobelts inside the ordered mesoporous SiO(2) shell, which are nontoxic and highly biocompatible. The overall diameter of as-prepared 1D hierarchical composite mesostructures is only approx. 34.2 nm with a length over 500 nm on average. A model to explain the formation mechanism of these mesostructures has been proposed; the negatively charged surface of H(2)Ti(3)O(7) nanobelts controls the formation of the octadecyltrimethylammonium bromide (C(18)TAB) bilayer, which in turn regulates the cooperative self-assembly of silica and C(18)TAB complex micelles on the interface to produce a mesoporous silica shell. More importantly, the application of synthesized mesostructured nanocables as anticancer drug reservoirs has also been explored, which indicates that the membranes containing these mesoporous nanocables have a great potential to be used as transdermal drug delivery systems.

Hepatoprotective Activity of the Total Saponins from Actinidia valvata Dunn Root against Carbon Tetrachloride-Induced Liver Damage in Mice

The protective activity of the total saponins from Actinidia valvata Dunn root (TSAV) was studied against carbon-tetrachloride- (CCl4-) induced acute liver injury in mice. Mice were orally administered TSAV (50, 100, and 200 mg/kg) for five days and then given CCl4. TSAV pretreatment significantly prevented the CCl4-induced hepatic damage as indicated by the serum marker enzymes (AST, ALT, and ALP). Parallel to these changes, TSAV also prevented CCl4-induced oxidative stress by inhibiting lipid peroxidation (MDA) and restoring the levels of antioxidant enzymes (SOD, CAT, GR, and GPX), GSH and GSSG. In addition, TSAV attenuated the serum TNF-α and IL-6 levels and inhibited the serum iNOS and NO levels. Liver histopathology indicated that TSAV alleviated CCl4-induced inflammatory infiltration and focal necrosis. TSAV (200 mg/kg) also significantly decreased Bak, Bax mRNA and Fas, FasL, p53, and NF-κB p65 protein expressions and increased Bcl-2 mRNA and protein expressions. Meanwhile, TSAV significantly downregulated caspase-3 and caspase-8 activities and prevented CCl4-induced hepatic cell apoptosis. In addition, TSAV exhibited antioxidant activity through scavenging hydroxyl and DPPH free radicals in vitro. These results indicated that TSAV could protect mice against CCl4-induced acute liver damage possibly through antioxidant, anti-inflammatory activities and regulating apoptotic-related genes.

Novel flavonoids from the leaves of Actinidia valvata Dunn: structural elucidation and antioxidant activity.

Two novel flavonoids, kaempferol 3- O- α-L-rhamnopyranosyl (1-3) (2,4-di- O-acetyl-α-L-rhamnopyranosyl) (1-6) β-D-galactopyranoside (1) and kaempferol 3- O-α-L-rhamnopyranosyl (1-3) (4-O-acetyl-α-L-rhamnopyranosyl) (1-6) β-D-galactopyranoside (2), along with three known ones, kaempferol-3- O-β-D-galactopyranoside (3), kaempferol (4), and 7-hydroxychromone (5), have been isolated from the leaves of Actinidia valvata Dunn, and their structures were elucidated based on spectroscopic methods. Compounds 1-3 exhibited dose-dependent activity in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, superoxide anion radicals, and hydroxyl radicals, and inhibited lipid peroxidation of mouse liver homogenate IN VITRO.

New Triterpenoids with Cytotoxic Activity from Actinidia Valvata

Two new triterpenoids, 30-O-β-d-glucopyranosyloxy-2α,3α,24-trihydroxyurs-12, 18-diene-28-oic acid O-β-d-glucopyranosyl ester (1) and 2α,3β,3,30-tetrahydroxyurs-12, 18-diene-28-oic acid O-β-d-glucopyranosyl ester (2) were isolated from roots of Actinidia valvata Dunn. Their structures were elucidated by means of extensive spectroscopic studies. Both these two new compounds showed moderate cytotoxic activity in vitro against BEL-7402 and SMMC-7721 tumor cell line.