Qizhen Du

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Although Laggera pterodonta, a folk medicine has been widely used for several centuries as an antiviral agent, there have been no studies to identify its antiviral components. A bioassay-guided phytochemical examination of L. pterodonta disclosed that its aqueous extract, which was made up of three dicaffeoylquinic acids showed significant inhibitory(More)
The Chinese phytomedicinal formulation Sanqi Zongdai Pian, traditionally prepared from crude extracts from roots of Panax notoginseng (Araliaceae), contains highly polar dammarane saponins which were separated at a preparative scale using high-speed counter-current chromatography (HSCCC). In each operation, 283 mg methanolic extract of five tablets was(More)
Polysaccharides from a crude extract of Auricularia polytricha were separated by high-speed countercurrent chromatography (HSCCC). The separation was performed with an aqueous two-phase system of PEG1000-K2HPO4-KH2PO4-H2O (0.5:1.25:1.25:7.0, w/w). The crude sample (2.0 g) was successfully separated into three polysaccharide components of AAPS-1 (192 mg),(More)
Hydrophilic antioxidant constituents in the fruits of the vegetable Luffa cylindrica (L.) Roem (sponge gourds) were separated by an antioxidant-guided assay to yield eight compounds: p-coumaric acid (1), 1-O-feruloyl-beta-D-glucose (2), 1-O-p-coumaroyl-beta-D-glucose (3), 1-O-caffeoyl-beta-D-glucose (4), 1-O-(4-hydroxybenzoyl)glucose (5),(More)
Purification of (+)-dihydromyricetin from an extract (16 g) of leaves of Ampelopsis grossedentata was performed using a preparative triple-column countercurrent chromatograph. With a solvent system composed of n-hexane-ethyl acetate-methanol-water (1:3:2:4, v/v) 11.3 g of (+)-dihydromyricetin was obtained at a high purity of over 99% by HPLC at 254 nm in 9(More)
Two new tetrasaccharide glyceroglycolipids were obtained from pumpkin. The structures of the two compounds were determined using chemical methods and spectroscopic analysis. Both compounds demonstrated significant glucose-lowering effects in streptozotocin- and high-fat-diet-induced diabetic mice.
Salicin in the bark extract of Salix alba and amygdalin in the fruit extract of Semen armeniacae were each separated by slow rotary counter-current chromatography (SRCCC). The apparatus was equipped with a 40-L column made of 17 mm i.d. convoluted Teflon tubing. A 500g amount of crude extract containing salicin at 13.5% was separated yielding 63.5 g of(More)
High-speed counter-current chromatography (HSCCC) was used for the separation of anthocyanins on a preparative scale from bilberry fruit crude extract (Vaccinium myrtillus, Ericaceae) with a biphasic solvent system composed of methyl tert-butyl ether-n-butanol-acetonitrile-water-trifluoroacetic acid (1:4:1:5:0.01, v/v). Each injection of 500 mg crude(More)
Icariin was purified from the extract of Epimedium segittatum by high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-n-butanol-methanol-water (1:4:2:6, v/v). We used two multilayer coil planet centrifuges with different capacities. A 300 mg amount of the extract was separated using a semipreparative instrument(More)