Fdr 50p freeze dryer

Crude R. palmatum extract powder was obtained from Sun Ten Pharmaceutical Co., Ltd. For each tested extract, 1 g of powder was dissolved in 40 ml methanol or distilled water and gently shaken overnight at room temperature. Solution samples were filtered with Whatman No. 1 filter paper, lyophilized in an IWAKI FDR-50P freeze dryer, then sterilized by a 0.44 μm syringe filter and stored at −80 °C until used (100 % stock solution). Also, filtered extract was injected directly into the HPLC instrument with C-18 reverse phase column. Separation was conducted with gradient elution using acetonitrile and 0.1 % phosphoric acid at a flow rate of 1 ml/min, eluent detected at 250 nm. Chrysophanol, rhein, emodin, aloe-emodin, and physcion were purchased from Sigma Chemical Co. of St. Louis, serving as external standards for comparing chromatographic peaks of methanol and water extracts with the retention time of these marker compounds.

Dried stems of Sambucus Formosana Nakai (Supplemental Fig. 1A) were purchased from the medicinal herb pharmacy in Taichung, and identified as described in Flora of Taiwan (Yang and Chiu, 1998 ). Dried stem slices (Supplemental Fig. 1B) were soaked in 95% ethanol with the sonication for 2 h; the stem ethanol extract was filtered by Whatman No. 1 paper, then lyophilized in an IWAKI FDR-50 P freeze dryer, as described in our previous study (Wang et al., 2012 ). The powder of Sambucus Formosana Nakai stem ethanol extract was kept in the sterile bottle; the stock solution of 10 mg/ml in dimethyl sulfoxide was prepared and stored in −20 °C freezer and the test solutions of the stem extract were diluted by the media. The phenolic acid constituents such caffeic acid, chlorogenic acid, coumaric acid, ferulic acid, and gallic acid, were purchased from Sigma-Aldrich company.