OBJECTIVE: There exists a close relationship between drying of a fresh herb and its preservation and extraction of efficient components. In order to investigate the influences of different drying methods on extraction and separation of ginsenosides, three drying processes, such as drying in the sun, drying in oven and microwave drying, were used to dry fresh ginsengs. METHODS: The ginsenosides of the dry ginsengs were extracted by poaching and microwave heating, and were separated by foam separation. The concentrations of ginsenosides were measured. RESULTS: Microwave drying saved both time and labor, and was favorable for release of ginsenosides. The ginsenosides could be extracted from the dry ginsengs in a shorter time by microwave heating than poaching. The ginsenosides Rb1, Rb2, Rd could be observably concentrated by foam separation. CONCLUSION: Microwave drying and microwave assisted extraction are efficient and economic methods with a high recovery yield of ginsenosides.

In the present study, the prokaryotic expression of glutathione transferase (GST) gene from Taenia solium and its immunological properties were investigated by means of biological informatics methods. The GST gene from T.solium was screened from the cDNA plasmid library of the adult worms. This gene was cloned into prokaryotic expression plasmid pET28a(+) and then expressed in E.coli BL21(DE3) after double enzyme digestion, PCR identification and IPTG induction. The expressed product was identified by SDS-PAGE and the recombinant protein was purified through purification column of His-Ni~(2+) protein. Meanwhile, the immunoreactivity of the purified protein was analyzed by Western blot assay. In these ways, the recombinants were successfully constructed and the highly purified proteins were obtained. It was demonstrated that these proteins could be recognized by sera of patients infected with T.asitica and T.rhynchus saginatus. From these observations, it is evident that highly efficient expression of GST of Taenia solium with definite immunoreactivity can be demonstrated in the prokaryotic expression system.