Flavanols from the Camellia sinensis var.assamica and their hypoglycemic and hypolipidemic activities

α-Glucosidase and lipase inhibitors play important roles in the treatment of hyperglycaemia and dyslipidemia. To identify novel naturally occurring inhibitors, a bioactivity-guided phytochemical research was performed on the pu-erh tea. One new flavanol, named(–)-epicatechin-3-O-(Z)-coumarate(1), and 16 known analogs(2–17) were isolated from the aqueous extract of the pu-erh tea. Their structures were determined by spectroscopic and chemical methods. Furthermore, the water extract of pu-erh tea and its fractions exhibited inhibitory activities against α-glucosidases and lipases in vitro;compound 15 showed moderate inhibitory effect against sucrase with an IC_(50) value of 32.5 μmol/L and significant inhibitory effect against maltase with an IC_(50) value of 1.3 μmol/L. Compounds 8, 10, 11 and15 displayed moderate activity against a lipase with IC_(50) values of 16.0, 13.6, 19.8, and 13.3 μmol/L,respectively.

Formal semantic description standard family for Chinese KOS(Ⅱ): Research and implementation of Classification Scheme Sharing Service System

In the context of globalization of network information, it is an urgent need to consider networked development and sharing for classification schemes. Since 2000, the international mainstream classification schemes have published their Web versions one after another, while there is still a lack of an integrated, reusable and Semantic-Web-oriented solution for classification schemes and classification-like knowledge organization systems. By using computer programs to automatically analyze the source files of the classification schemes in the MARC or HTML format, this paper adopts CNKOS to produce the semantic description of the classification schemes. On account of this, this paper employs international advanced open-source technologies, takeing the representative domestic CLC as an example, to construct the CLSS prototype system. It is proved that this solution can be put into practical use and can facilitate the quick deployment of other classification-like Chinese knowledge organization systems. The successful implementation of the system verifies the scientificity and practicality of CNKOS, and it plays a demonstrating and promoting role and provides a reusable solution for other domestic classification schemes and classification-like knowledge organization systems. The solution can serve as a reference for similar international knowledge organization systems in realizing their Semantic Web style sharing services.