厚朴叶中具血管舒张作用的化学成分研究

实验采用离体血管环灌流模型,观察厚朴叶正丁醇萃取部位对去甲肾上腺素预收缩的内皮完整和去除内皮的家兔离体血管环张力的影响。结果显示:厚朴叶正丁醇萃取部位对内皮完整和去除内皮的血管环在一定剂量内呈现浓度依赖性舒张作用,该作用可能与该部位大量成分———槲皮苷和芦丁有关。从该部位分离得到7个化合物,分别为槲皮苷(1),芦丁(2),紫丁香苷(3),丁香脂素-4,4’-双-O-β-D-葡萄糖苷(4),芥子醛-4-O-β-D-吡喃葡萄糖苷(5),松脂素-4-O-β-D-吡喃葡萄糖苷(6),丁香脂素-4-O-β-D-吡喃葡萄糖苷(7)。其中化合物4和6首次从该种植物中分离得到。     

Antioxidant flavonoids from leaves of Polygonum hydropiper L

Ten flavonoid compounds were isolated from the dried leaves of Polygonum hydropiper L. (Laksa leaves), and identified as 3-O-alpha-L-rhamnopyranosyloxy-3',4',5,7-tetrahydroxyflavone; 3-O-beta-D-glucopyranosyloxy-4',5,7-trihydroxyflavone; 6-hydroxyapigenin; 6"-O-(3,4,5-trihydroxybenzoyl) 3-O-beta-D-glucopyranosyloxy-3', 4', 5, 7-tetrahydroxyflavone; scutillarein; 6-hydroxyluteolin; 3',4',5,6,7-pentahydroxyflavone; 6-hydroxyluteolin-7-O-beta-D-glucopyranoside; quercetin 3-O-beta-D-glucuronide; 2"-O-(3,4,5-trihydroxybenzoyl) quercitrin; quercetin. Evaluation of the antioxidative activity, conducted in vitro, by using electron spin resonance (ESR) and ultraviolet visible (UV-vis) spectrophotometric assays, showed that these isolated flavonoids possess strong antioxidative capabilities. Measurement of the Trolox equivalent antioxidant capacity (TEAC) values, against ABTS (2,2'-azinobis(3-ethyl-benzo-thiazoline-6-sulphonic acid) radicals and phenyl-tert-butyl nitrone (PBN) azo initiator (AI) also showed strong anti-oxidative activity. The most powerful of the antioxidants was 2"-O-(3,4,5-trihydroxybenzoyl) quercitrin (galloyl quercitrin). A combination of two flavonoid compounds was tested for synergistic anti-oxidative capacity, but no significant improvement was observed.     

槲皮苷:一种抑制钙调蛋白磷酸酶(CN)的新型免疫抑制剂

目的 以钙调蛋白磷酸酶(CN)为靶酶,从中草药中寻找高效、低毒的免疫抑制剂.方法 以CN为靶点,筛选并分离能够抑制其活性的天然化合物.在细胞和动物水平评价该化合物的免疫抑制效果及毒副作用,并通过荧光猝灭、分子对接、免疫印迹、双荧光素酶报告基因、实时定量PCR等实验探究天然化合物与CN的作用机理及可能的免疫抑制作用机制....     

RP-HPLC法同时测定藏药珠芽蓼中牡荆素、槲皮苷和槲皮素的含量(英文)

采用RP-HPLC法建立了同时测定珠芽蓼中牡荆素、槲皮苷、槲皮素三种黄酮的方法,色谱柱为kromasilC18(250 mm×4.6 mm,5μm),以甲醇-水(含0.25%磷酸)为流动相梯度洗脱,流速1 mL/min,检测波长360 nm。结果表明,牡荆素、槲皮苷和槲皮素质量浓度在8～40、5～50μg/mL和5.33～52μg/mL范围内与色谱峰面积均呈良好的线形关系,平均回收率分别为100.3%、98.9%和100.4%,日内稳定性偏差分别为0.78%,0.51%和0.38%,日间稳定性偏差为2.6%,1.9%和2.1%。该方法简单、准确,可为珠芽蓼的质量控制提供科学依据。     

研究报告：槲皮苷： 一种抑制钙调蛋白磷酸酶（CN）的新型免疫抑制剂

目的以钙调蛋白磷酸酶(CN)为靶酶,从中草药中寻找高效、低毒的免疫抑制剂。方法以CN为靶点,筛选并分离能够抑制其活性的天然化合物。在细胞和动物水平评价该化合物的免疫抑制效果及毒副作用,并通过荧光猝灭、分子对接、免疫印迹、双荧光素酶报告基因、实时定量PCR等实验探究天然化合物与CN的作用机理及可能的免疫抑制作用机制。结果槲皮苷在体外和细胞内均能抑制CN的活性,并且能够有效抑制小鼠脾细胞的增殖,缓解小鼠迟发超敏反应。毒理研究结果显示,槲皮苷对实验小鼠无急性毒性,且毒副作用很小。荧光猝灭实验和分子对接分析表明,槲皮苷可能与CN上的两个位点相结合,并通过CN-NFAT通路参与调节免疫反应。结论通过筛选获得了新型CN抑制剂槲皮苷。槲皮苷具有成为新型低毒免疫抑制剂的潜在可能。     

马鞭草的化学成分研究(Ⅱ)

从马鞭草的乙醇提取物中分离得到7个化合物,经理化特征及波谱数据分析确定其结构分别为龙胆苦苷(1),槲皮苷(2),山柰酚(3),毛蕊花糖苷(4),桃叶珊瑚苷(5),β-谷甾醇(6)和熊果酸(7)。其中化合物1~3为首次从该植物中分离得到。     

不同生境鱼腥草形态特征及主要有效成分含量差异分析

以不同生境中的鱼腥草为研究对象,分析其形态特征及主要有效成分含量的差异。该文测定了不同生境下主要环境因子指标及鱼腥草的叶长、叶宽、株高、基径、生物量和含水量,用高效液相色谱法测定其各部分主要有效成分金丝桃苷、槲皮苷含量,并对测量结果进行单因素方差分析和相关性分析。结果表明:环境因子会对鱼腥草的形态建成及有效成分积累造成不同影响,适宜的光照强度有利于鱼腥草对有效成分的累积;鱼腥草中有效成分的含量表现出叶茎根的规律。适宜的遮阴处理,既可避免强光照对鱼腥草生长的抑制,又可显著提高有效成分的含量,从而整体增加对鱼腥草有效成分的收益。     

Studies on Extracellular Ribonuclease from Yeast

An extracellular ribonuclease of Rhodotorula glutinis was purified about 50-fold from the culture broth, by a procedure involving ammonium sulfate fractionation, DEAE-Sephadex column chromatography, acetone fractionation and Sephadex G-100 gel filtration. The purified enzyme was homogeneous when examined by the ultracentrifuge and disc electrophoresis. The molecular weight was calculated to be 58,900 and 56,000 by the sedimentation-diffusion method and the sedimentation equilibrium method, respectively.     

Differential apoptosis-inducing effect of quercetin and its glycosides in human promyeloleukemic HL-60 cells by alternative activation of the caspase 3 cascade

Flavonoids were demonstrated to possess several biological effects including antitumor, antioxidant, and anti-inflammatory activities in our previous studies. However, the effect of glycosylation on their biological functions is still undefined. In the present study, the apoptosis-inducing activities of three structure-related flavonoids including aglycone quercetin (QUE), and glycone rutin (RUT; QUE-3-O-rutinoside), and glycone quercitrin (QUI; QUE-3-O-rhamnoside) were studied. Both RUT and QUI are QUE glycosides, and possess rutinose and rhamnose at the C3 position of QUE, respectively. Results of the MTT assay showed that QUE, but not RUT and QUI, exhibits significant cytotoxic effect on HL-60 cells, accompanied by the dose- and time-dependent appearance of characteristics of apoptosis including an increase in DNA ladder intensity, morphological changes, apoptotic bodies, and an increase in hypodiploid cells by flow cytometry analysis. QUE, but not RUT or QUI, caused rapid and transient induction of caspase 3/CPP32 activity, but not caspase 1 activity, according to cleavage of caspase 3 substrates poly(ADP-ribose) polymerase (PARP) and D4-GDI proteins, and the appearance of cleaved caspase 3 fragments being detected in QUE- but not RUT- or QUI-treated HL-60 cells. A decrease in the anti-apoptotic protein, Mcl-1, was detected in QUE-treated HL-60 cells, whereas other Bcl-2 family proteins including Bax, Bcl-2, Bcl-XL, and Bag remained unchanged. The caspase 3 inhibitor, Ac-DEVD-FMK, but not the caspase 1 inhibitor, Ac-YVAD-FMK, attenuated QUE-induced cell death. Results of DCHF-DA assay indicate that no significant increase in intracellular peroxide level was found in QUE-treated cells, and QUE inhibited the H(2)O(2)-induced intracellular peroxide level. Free radical scavengers N-acetyl-cysteine (NAC) and catalase showed no prevention of QUE-induced apoptosis. In addition, QUE did not induce apoptosis in an mature monocytic cell line THP-1, as characterized by a lack of DNA ladders, caspase 3 activation, PARP cleavage, and an Mcl-1 decrease, compared with those in HL-60 cells. Our experiments provide evidence to indicate that the addition of rutinose or rhamnose attenuates the apoptosis-inducing activity of QUE, and that the caspase 3 cascade but not free radical production is involved.