华中五味子挥发性成份的研究

华中五味子有收敛、止咳、止汗、止泻、活血和健胃等作用。近年来已分离到约15种非挥发性成份,但关于它的挥发性成份迄今未见报道。我们用毛细管气相色谱法分离出     

Development of a quality evaluation method for Fructus schisandrae by pressurized capillary electrochromatography

A pressurized CEC (pCEC) method with postcolumn detection cell had been developed for quantifying the lignans from Fructus schisandrae extracts. The effects of different experimental conditions, such as the ACN content of the mobile phase, the concentration and pH of the buffer, the applied voltage, and the supplementary pressure were studied. Five lignans (schisandrin, gomisin A, schisantherin C, deoxyschizandrin, schisandrin B) were baseline separated using a mobile phase of ACN-phosphate buffer (pH 5.4; 5 mM) (40:60 v/v) under -4 kV applied voltage. The method showed the satisfactory retention time and peak area repeatability. The calibration curves were linear in the range 50.0-1000.0 microg/mL for schisandrin, 20.0-500.0 microg/mL for gomisin A, 10.0-200.0 microg/mL for schisantherin C, 20.0-500.0 microg/mL for deoxyschizandrin, and 20.0-500.0 microg/mL for schisandrin B. The correlation coefficients were between 0.9978 and 0.9989. With this pCEC system, fingerprints of F. schisandrae were preliminarily established to distinguish two members S. chinensis (Turcz.) Baill. and S. sphenanthera Rehd. Et Wils. of F. schisandrae by characteristic peaks, and evaluate the quality of various sources of raw materials by determining the contents of the five lignans.     

藏药柳茶叶乙醇水提取物中化学成分的鉴定

采用多种色谱分离技术对藏药柳茶叶80%乙醇提取物进行分离纯化,得到了9个化合物。 根据其理化性质与NMR谱数据对化合物进行了结构鉴定,分别为金丝桃苷（hyperoside,Ⅰ）、槲皮素（quercetin,Ⅱ）、芸香苷（rutin,Ⅲ）、槲皮素3-O-β-D-吡喃葡萄糖苷（quercetin-3-O-β-D-glucopyranoside,Ⅳ）、儿茶素（catechin,Ⅴ）、香草酸（vanillic acid,Ⅵ）、熊果苷（arbutin,Ⅶ）、异阿魏酸（isoferulic acid,Ⅷ）和胡萝卜苷（daucosterol,Ⅸ）。 化合物中除Ⅳ、Ⅷ和Ⅸ外,其余6个化合物为首次从该属植物中分离鉴别。     

A new phenolic compound with antioxidant activity from the branches and leaves of Pyrus pashia

The branches and leaves of Pyrus pashia are used to cure abdominal pain and diarrhoea in Chinese folk medicine. A new phenilic compound, 4-O-β-d-glucopyranosylbenzyl-benzoate ester (1), along with 21 known ones (2–22) were isolated from the branches and leaves of this plant. Compounds 2 and 3 displayed remarkable antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl radical (IC₅₀ = 13.26 ± 0.04 μM, 13.28 ± 0.11 μM, respectively), which were at the same grade as positive control rutin. The caffeoyl group in compounds 2 and 3 was supposed to play an important role in the antioxidant activities.     

Enhanced Extraction Efficiency of Flavonoids from Pyrus ussuriensis Leaves with Deep Eutectic Solvents

In this study, deep eutectic solvents (DESs) were synthesized using different ratios of choline chloride (CC) and dicarboxylic acids, and their eutectic temperatures were determined. The DES synthesized using CC and glutaric acid (GA), which showed a higher extraction efficiency than conventional solvents, was used for the extraction of flavonoid components from Pyrus ussuriensis leaves (PUL), and the extraction efficiency was evaluated using the response surface methodology. The flavonoid components rutin, hyperoside, and isoquercitrin were identified through high-performance liquid chromatography (HPLC), equipped with a Waters 2996 PDA detector, and HPLC mass spectrometry (LC-MS/MS) analyses. The optimum extraction was achieved at a temperature of 30 °C using DES in a concentration of 30.85 wt.% at a stirring speed of 1113 rpm and an extraction time of 1 h. The corresponding flavonoid content was 217.56 μg/mL. The results were verified by performing three reproducibility experiments, and a high significance, with a confidence range of 95%, was achieved. In addition, the PUL extracts exhibited appreciable antioxidant activity. The results showed that the extraction process using the DES based on CC and GA in a 1:1 molar ratio could effectively improve the yield of flavonoids from PUL.     

库尔勒香梨(Pyrus bretschneideri Rehd)在不同温度条件下的呼吸和乙烯释放速率的变化

本文对不同温度条件下香梨果实的呼吸及乙烯释放速率进行了研究.实验结果表明,不同温度下香梨的呼吸及乙烯释放速率具有明显的差异;呼吸跃变的发生与乙烯释放速率的增加有密切关系;低温能有效地抑制香梨的呼吸作用,延迟跃变发生的时间,从而延长果实的贮藏寿命.     

Variation of the Lignan Content of Schisandra chinensis (Turcz.) Baill. and Schisandra sphenanthera Rehd. et Wils.

A rapid and convenient extraction technique followed by HPLC analysis has been developed for determination of lignans in Schisandra chinensis (Turcz.) Baill. and Schisandra sphenanthera Rehd. et Wils. Under the optimized conditions the lignans schisandrin, schisantherin, deoxyschisandrin, and γ-schisandrin were extracted from ten samples collected from different regions in China and then quantified by HPLC. The lignan content of the ten samples is different. S. sphenanthera Rehd. et Wils. is richer in deoxyschisandrin but there is less schisandrin and γ-schisandrin is not found. S. chinensis (Turcz.) Baill. is usually richer in γ-schisandrin, the maximum amount being 4.263 mg g⁻¹, although one sample contained none. This method is simple, rapid, sensitive, and repeatable, and is suitable for identification and differentiation of samples from different regions of China.     

凹叶厚朴各部位挥发油成分比较研究

采用顶空固相微萃取(HS-SPME)提取凹叶厚朴不同部位的挥发油成分,气相色谱-质谱(GC-MS)分析其组成.结果显示:根鉴定出19个化合物,其中4(14),11-桉叶二烯(26.04％),(1S-顺)-1,4-二甲基-7-(1-甲基亚乙基)-奠(24.94％),石竹烯(9.41％),β-桉叶醇(7.28％)为主要成分...     

Optimization of the ultrasound‐assisted extraction of antioxidant phloridzin from Lithocarpus polystachyus Rehd. using response surface methodology

The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box–Behnken design was used to analyze the effects of ethanol concentration, liquid–solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high‐performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1‐,diphenyl‐2‐picrylhydrazyl, hydroxyl radical scavenging test and reduction force). The optimal parameters obtained by response surface methodology were a volume fraction of ethanol of 64%, a liquid–solid ratio of 37:1, a soaking time of 35 h and a sonication time of 38 min. The proportion of the extraction of phloridzin from L. polystachyus under these industrial process conditions was 3.83%. According to the obtained results, response surface methodology could be suggested as an adequate model for optimizing the extraction process of phloridzin from L. polystachyus . Ultrasound extraction significantly increased the extraction rate of phloridzin, which could be used as an antioxidant in pharmaceutical and food products.     

苹果梨叶片中IAA氧化酶的测定

本文介绍了用紫外分光光度计测定苹果梨花芽分化各时期叶征中IAA氧化酶活性的方法。该方法使用的样品量少,操作简单,灵敏度高。经回收和重复性实验表明,方法的准确度和精密度均符合要求。