Chemical constituents from Taraxacum officinale and their α-glucosidase inhibitory activities.

Three novel butyrolactones (1-3) and butanoates (4-6), namely taraxiroside A-F, were isolated from Taraxacum officinale along with twenty-two known compounds (7-28). Their chemical structures were elucidated by interpretation of spectroscopic data and comparison with those of literatures. All isolates were evaluated for their α-glucosidase inhibitory activities.

Rapid separation of cyanidin-3-glucoside and cyanidin-3-rutinoside from crude mulberry extract using high-performance countercurrent chromatography and establishment of a volumetric scale-up process.

This study describes the rapid separation of mulberry anthocyanins; namely, cyanidin-3-glucoside and cyanidin-3-rutinoside, using high-performance countercurrent chromatography, and the establishment of a volumetric scale-up process from semi-preparative to preparative-scale. To optimize the separation parameters, biphasic solvent systems composed of tert-butyl methyl ether/n-butanol/acetonitrile/0.01% trifluoroacetic acid, flow rate, sample amount and rotational speed were evaluated for the semi-preparative-scale high-performance countercurrent chromatography.

Two new phenolic glucosides from Lagerstroemia speciosa.

Two new phenolic glucosides, 1-O-benzyl-6-O-E-caffeoyl-β-d-glucopyranoside and 1-O-(7S,8R)-guaiacylglycerol-(6-O-E-caffeoyl)-β-d-glucopyranoside, were isolated from the aerial parts of Lagerstroemia speciosa, along with ten known compounds. The structures of the isolated compounds were determined based on 1D- and 2D-NMR, Q-TOF MS and optical rotation spectroscopic data. All of the compounds showed moderate inhibitory activities against nitric oxide production in lipopolysaccharide-treated RAW264.

Flavokawains B and C, melanogenesis inhibitors, isolated from the root of Piper methysticum and synthesis of analogs.

The ethanolic extract of the root of Piper methysticum was found to inhibit melanogenesis in MSH-activated B16 melanoma cells. Flavokawains B and C were isolated from this extract based on their anti-melanogenesis activity and found to inhibit melanogenesis with IC50 values of 7.7μM and 6.

Flavonoids from Symplocos racemosa.

A novel isoflavone glycoside, peseudobatigenin 7-O-[β-d-apiofuranosyl-(1''''→5''')-O-β-d-apiofuranosyl-(1'''→6'')]-β-d-glucopyranoside, namely sympracemoside (1), was isolated from the aerial parts of Symplocos racemosa along with 15 known flavonoids (2-16). Their structures were characterized by Q-TOF mass, optical rotation, UV, 1D and 2D-NMR spectroscopic data. Compounds 3, 9, 16 showed moderate inhibitory activities against NO production with IC50 value of 88.

Application of high-performance countercurrent chromatography for the isolation of steroidal saponins from Liriope plathyphylla.

High-performance countercurrent chromatography (HPCCC) with electrospray light-scattering detection was applied for the first time to isolate a spirostanol and a novel furostanol saponin from Liriope platyphylla. Due to the large differences in KD values between the two compounds, a two-step HPCCC method was applied in this study. The primary HPCCC employed methylene chloride/methanol/isopropanol/water (9:6:1:4 v/v, 4 mL/min, normal-phase mode) conditions to yield a spirostanol saponin (1).

Separation of five oligostilbenes from Vitis amurensis by flow-rate gradient high-performance counter-current chromatography.

A rapid and efficient high-performance counter-current chromatography (HPCCC) method was developed to separate five oligostilbenes from the roots of Vitis amurensis. An n-hexane/ethyl acetate/methanol/water system (4:8:4:10, v/v/v/v) was selected as an optimal two-phase solvent system of which the upper phase was used as the stationary phase and the lower phase was used as the mobile one. Partition coefficient values for the target compounds under these optimized conditions were 0.

Application of high-speed countercurrent chromatography-evaporative light scattering detection for the separation of seven steroidal saponins from Dioscorea villosa.

Introduction: Steroidal saponins in Dioscorea species are chemically characterised as spirostanol and furostanol saponins, and have been used as standard marker compounds due to their chemotaxonomical significance and their important biological activities.

Objective: To design a simple, rapid and efficient method for the separation of steroidal saponins with a high degree of purity using high-speed countercurrent chromatography (HSCCC) coupled with evaporative light scattering detection (ELSD).

Methodology: In the first step, reversed-phase mode HSCCC (flow rate: 1.