Multiple component quantitative analysis for the pattern recognition and quality evaluation of Kalopanacis Cortex using HPLC.

A quantitative and pattern recognition analyses were conducted for quality evaluation of Kalopanacis Cortex (KC) using HPLC. For quantitative analysis, four bioactive compounds, liriodendrin, pinoresinol O-ß-D-glucopyranoside, acanthoside B and kalopanaxin B, were determined. The analysis method was optimized and validated using ODS column with mobile phase of methanol and aqueous phosphoric acid. The validation gave acceptable linearities (r > 0.9995), recoveries (98.4% to 101.9%) and precisions (RSD < 2.20). The limit of detection of compounds ranged from 0.4 to 0.9 µg/mL. Among the four compounds, liriodendrin was recommended as a marker compound for the quality control of KC. The pattern analysis was successfully carried out by analyzing thirty two samples from four species, and the authentic KC samples were completely discriminated from other inauthentic species by linear discriminant analysis. The results indicated that the method was suitable for the quantitative analysis of liriodendrin and the quality evaluation of KC.

Protein tyrosine phosphatase 1B inhibitors isolated from Morus bombycis.

Bioassay-guided fractionation of the chloroform-soluble fraction of Morus bombycis, using an in vitro PTP1B inhibitory assay led to the identification of three 2-arylbenzofurans, albafuran A (1), mulberrofuran W (2) and mulberrofuran D (6), along with three chalcone-derived Diels-Alder products, kuwanon J (3), kuwanon R (4), and kuwanon V (5). Compounds 1-6 showed remarkable inhibitory activity against PTP1B with IC(50) values ranging from 2.7 to 13.8 microM. Inhibition kinetics were analyzed by Lineweaver-Burk plots, which suggested that compounds 1-6 inhibited PTP1B in a mixed-type manner. The present results indicate that the respective lipophilic and hydroxyl groups of 2-arylbenzofurans and chalcone-derived Diels-Alder products play an important role in inhibition of PTP1B.