[Structural characterization of a glucan isolated from Gastrodia elata].

OBJECTIVE: To study a glucan (GB II) isolated from Gastrodia elata. METHODS: The glucan was obtained with water extraction, alcohol precipitate, DEAE-Sepharose Fast Flow column and Sepharose CL-6B column chromatography; sugar composition analysis, IR and NMR were used to determine the structural feature. RESULTS: The molecular weight of the glucan was 4 300 dalton estimated by HPGPC; it contained 27 glucose residues, which mainly composed of alpha-D-(1-->4)-glucose with little glucuronic acid and branch O-6 points. CONCLUSION: The glucan was a new glucan for the first report from Gastrodia elata.

Optimization of extraction and purification of active fractions from Schisandra chinensis (Turcz.) and its osteoblastic proliferation stimulating activity.

Extraction and purification conditions of lignans from the fruits and seeds of Schisandra chinensis (Turcz.) were investigated through an orthogonal design of L(9)(3(4)) assay and macroporous resin technology. The extraction was optimized using 95% ethanol. For purification, the extract was dissolved in 30% ethanol, then adsorbed on a AB-8 macroporous resin and eluted with 30% ethanol and 70% ethanol successively, the latter resulting in a residue containing 65.2% of lignans. By HPLC analysis schisandrin, deoxyschisandrin and gamma-schisandrin were quantitatively determined. UMR 106 cells were used to examine the stimulatory activity of the lignans on osteoblasts in vitro. The lignans stimulated the proliferation of and the activity of alkaline phosphatase in the osteoblasts indicating their potential activity against osteoporosis.

[Determination of stachydrine and leonurine in Herba Leonuri by ion- pair reversed-phase high-performance liquid chromatography].

OBJECTIVE: To establish a high-performance liquid chromatography (HPLC) for determining stachydrine and leonurine contents in the crude drug of Yimu Cao, a Chinese motherwort herb(Herba Leonuri, the aerial part of Leonurus japonicus). METHODS: The sample was obtained from the crude drug by ultrasonic extraction with ethanol after decolorization with ethyl acetate. YMC-Park CN column (250.0 mm x 4.6 mm) was used with the mobile phase for stachydrine of 0.00125 mol/L SDS:C2H5CN (90:10) at the flow rate of 1.5 ml/min with the wavelength for detection of 201.7 nm, and that for leonurine of 0.00125 mol/L SDS (containing 0.05% HClO4):CH4OH(90:10) at the flow rate of 1 ml/min with the wavelength for detection of 282 nm. The sensitivity was 0.1 AUFs and the column temperature was 20 degrees Celsius;. RESULTS: With the injection amount (mg) as the abscissa and the peak area as the ordinate, the regression equation of the calibration curve for stachydrine was Y=1,187.542 3X-168.9822, and that for leonurine was Y=5,202.654X-221.141 (r=0.9998) with the linearity scope of 2.5-12.5 mg, detective limit of 0.15 mg, and recovery of (99.03+/-2.744) %. The analysis of extracted drug samples from 18 regions indicated that the alkaloids contents in Yimu Cao varied significantly, i.e. stachydrine within a range of 0.1%-0.2% while leonurine content, which was much lower, within 0.01%-0.05%. In general, the alkaloid contents were higher in the drug produced in northern China than in those produced in southern China. L. japonicus and the variant L. japonicus albiflorus had total alkaloid contents around 0.3%, which was higher than the contents of other species. CONCLUSION: As a convenient and feasible means for determining the alkaloid contents in Yimu Cao, HPLC produces accurate and reliable results and can be more effective than the formerly used methods.