苦参提取物体外抗菌实验研究

目的：探讨苦参总生物碱、总黄酮提取物及其混合物的体外抗菌效果。方法：采用液体二倍稀释法分析苦参总生物碱、苦参总黄酮提取物及其混合物对金黄色葡萄球菌、大肠埃希菌、福氏志贺菌、乙型副伤寒杆菌、铜绿假单胞菌、白色葡萄球菌、痢疾杆菌和柠檬色葡萄球菌的抗菌作用,并测定最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。结果：苦参总生物碱对以上菌株的MIC分别为：9.00、3.38、8.25、9.00、4.50、13.50、6.75、7.13mg.mL-1,MBC分别为：13.50、14.25、8.25、9.00、14.25、14.25、13.13、14.25mg.mL-1;苦参总黄酮对以上菌株的MIC分别为3.00、2.63、3.56、3.38、1.50、2.44、3.56、2.35mg.mL-1,MBC分别为14.25、12.75、7.13、13.50、13.50、12.75、12.75、13.13mg.mL-1;苦参总生物碱与总黄酮混合物对以上菌株的MIC分别为：2.25、2.07、3.28、3.94、1.22、2.44、2.07、1.97mg.mL-1,MBC分别为9.00、13.13、6.75、6.38、13.88、7.50、6.38、7.13mg.mL-1。结论：苦参总生物碱和总黄酮提取物对上述菌株存在体外抑菌和杀菌活性,混合物呈现一定协同作用。     

微波辅助提取麦冬黄酮的工艺研究

目的:研究微波辅助法提取麦冬黄酮的工艺条件。方法:采用单因素试验,探讨料液比、微波处理时间、微波强度以及乙醇体积分数对麦冬黄酮提取量的影响,并与传统回流法进行比较。结果:微波提取优化工艺条件为:乙醇体积分数为90%,料液比为1:14(g/ml),微波功率为中档,微波提取时间4min。微波处理后再进行回流提取较不经微波处理得到提取物的黄酮含量高出39.7%。结论:微波辅助法是一种提取麦冬黄酮的有效方法。     

藏药独一味叶中黄酮类化合物的研究

从藏药独一味叶中提取分离出五种黄酮类化合物,经化学试验,层析方法和光谱鉴定,分别定为木犀草素,木犀草甙,槲皮素,萹蓄甙和芹菜素-7-O-β-新橙皮糖甙。这些黄酮类化合物在独一味属中均为首次发现。     

狭叶香蒲花粉(蒲黄)黄酮类成分的研究

自香蒲科(Typhaceae)植物狭叶香蒲(Typha augustifolia L.)的干燥花粉中分离到五个黄酮醇甙,包括两个黄酮醇-3-三糖甙(Ⅰ,Ⅱ)和三个黄酮醇-3-双糖甙(Ⅲ,Ⅳ,Ⅴ)。其中,化合物Ⅰ是一个新的黄酮醇甙,为本植物的主要成分,经光谱分析(UV,IR.MS;¹HNMR和¹³CNMR)和水解试验确定为异鼠李素-3-0-(2_G-α-L-鼠李糖基)-α-L-鼠李糖(1→6)-β-D-葡萄糖甙,命名为香蒲新甙(typhaneoside,Ⅰ)。其它四种为已知成分。Ⅱ从本属植物中首次发现。     

Correlations between polyphenolic composition and antioxidant activity of Venetian propolis

Four propolis samples have been picked up in the Venetian region, from different orography and habitative density areas with the purpose to: (i) evaluate propolis’ antioxidant activity, measured by inhibition of lipid peroxidation; (ii) determine the polyphenolic components – flavonoids and caffeic acid derivatives – which give antioxidant activity to propolis; (iii) verify the potential correlations between antioxidant activity, polyphenolic content, that has been determined by Folin–Ciocalteu, enzymatic, DPPH quenching, TEAC-like assays, and spectroscopic characteristics of propolis and (iv) correlate chemical structure and antioxidant efficacy of each of the major components. The possible localization of the lipophylic components of propolis into the phospholipidic bilayer by thermal analysis (DSC) and spin label EPR techniques has also been investigated.     

Vane’s blood-bathed organ technique adapted to examine the endothelial effects of cardiovascular drugs in vivo

This study describes a modification of Vane’s blood-bathed organ technique (BBOT). This new technique consisted of replacing the cascade of contractile smooth muscle organs within the traditional BBOT by a single collagen strip cut from a rabbit’s hind leg tendon. Utilizing the extracorporeal circulation of an anesthetized heparinized mongrel cat or Wistar rat, arterial blood was dripped (1–3 ml min^–1) over a collagen strip. This resulted in a gain in weight of the strip, which was due to the deposition of platelet aggregates and a few blood cells trapped over the strip. Arterial blood that had been used for the superfusion was pumped back into the animal’s venous system. However, when this technique is adapted to human volunteers, the superfusing blood should be discarded. In animal experiments, intravenous injections of a variety of classic fibrinolytic agents (e.g., streptokinase) promoted the formation of platelet thrombi. Nitric oxide donors (e.g., SIN-1) at non-hypotensive doses hardly affected the mass of platelet thrombi deposited over the collagen strip, whereas endogenous prostacyclin (e.g., released from vascular endothelium by bradykinin) or exogenous prostacyclin and its stable analogues (e.g., iloprost) dissipated platelet thrombi as measured by a loss in the weight of the blood superfused collagen strip. This model allowed us to assay numerous drugs for their releasing properties of endogenous prostacyclin from vascular endothelium. These drugs included lipophilic angiotensin converting enzyme inhibitors (ACE-Is), which act in vivo as bradykinin potentiating factors (BPF). Other PGI₂-releasers included statins (e.g., atorvastatin and simvastatin), thienopyridines (e.g., ticlopidine and clopidogrel), a number of thromboxane synthase inhibitors, flavonoids, bradykinin itself, cholinergic M receptor agonists and nicotinic acid derivatives. The thrombolytic actions of lipophilic ACE-Is (e.g., quinapril and perindopril) were prevented by pretreatment with either bradykinin B₂ receptor antagonists (e.g., icatibant) or with endothelial COX-2 inhibitors (e.g., rofecoxib, celecoxib and high dose aspirin). The inhibition of endothelial nitric oxide synthetase (eNOS) by L-NAME hardly blunted the thrombolytic response to ACE-Is. Hence, it can be concluded that many recognized cardiovascular drugs apart from their known basic mechanisms of action, may also behave as releasers of endogenous endothelial prostacyclin. Furthermore, in many instances, this effect may be the primary mechanism of their therapeutic efficacy.     

基于FTIR的鸡骨草药材化学成分整体分析与评价

目的 研究鸡骨草的红外光谱特征及其不同部位化学成分的差异.方法 采集鸡骨草和毛鸡骨草药材整株和观察其不同部位的傅里叶变换红外光谱(FTIR)图,运用二阶导数谱和半定量分析研究不同谱图间的差异.结果 ①鸡骨草含挥发油、三萜类、氨基酸、黄酮、皂苷、多糖类等化学成分.②鸡骨草不同部位红外"指纹"区的特征光谱显示:鸡骨草根部的黄酮类少于茎部,而皂苷类和多糖类成分较高于茎部.结论 红外光谱技术可以快速鉴别出鸡骨草的化学成分,从整体上评价药材质量的优劣,为规范化种植鸡骨草药材提供了一种检测方法.     

一年生黄芩总黄酮含量的动态变化研究

目的：分析一年生黄芩在生殖生长期间，不同部位黄酮含量的动态变化，探讨黄芩的生长特性，为黄芩规范化栽培及开发利用提供依据。方法：应用分光光度法测定不同发育阶段黄芩不同部位总黄酮含量。结果：黄芩不同时期各部位总黄酮含量由高到低的排列顺序是：繁殖部位〉根〉叶〉茎。结论：繁殖部位不同器官总黄酮含量变化趋势基本一致；叶状苞片总黄酮的含量高于叶的含量；茎和花枝总黄酮的含量变化趋势基本一致。     

Luteolin,quercetin and ursolic acid are potent inhibitors of proliferation and inducers of apoptosis in both KRAS and BRAF mutated human colorectal cancer cells

KRAS and BRAF mutations are frequent in colorectal carcinoma (CRC) and have the potential to activate proliferation and survival through MAPK/ERK and/or PI3K signalling pathways. Because diet is one of the most important determinants of CRC incidence and progression, we studied the effects of the dietary phytochemicals quercetin (Q), luteolin (L) and ursolic acid (UA) on cell proliferation and apoptosis in two human CRC derived cell lines, HCT15 and CO115, harboring KRAS and BRAF activating mutations, respectively. In KRAS mutated HCT15 cells, Q and L significantly decreased ERK phosphorylation, whereas in BRAF mutated CO115 cells the three compounds decreased Akt phosphorylation but had no effect on phospho-ERK. Our findings show that these natural compounds have antiproliferative and proapoptotic effects and simultaneously seem to act on KRAS and PI3K but not on BRAF. These results shed light on the molecular mechanisms of action of Q, L and UA and emphasize the potential of dietary choices for the control of CRC progression.     

杨梅素糖苷衍生物的合成及其抗菌活性研究

摘要：目的 设计合成杨梅素类糖苷衍生物,并进行抗菌活性研究。方法 以天然产物杨梅苷为起始原料,经过保护基策略、糖苷化反应、酯化反应制备得到一系列新型半乳糖苷衍生物,对杨梅素类衍生物进行了抑菌活性研究。结果 以杨梅苷为原料,设计合成了14个杨梅素类衍生物,其中包含有8个未见文献报道的新型糖苷化合物,其结构经核磁、ESI-MS进行了确证。体外抗菌活性结果显示,8个杨梅素衍生物具有较杨梅素和杨梅苷更强的抗菌活性,其中,化合物9a-1~9a-4对金黄色葡萄球菌和表皮葡萄球菌的抗菌活性MIC值为1~8 μg/mL。结论 本研究首次以杨梅苷作为原料,设计了新的合成路线,并对合成中的关键反应条件进行了优化,构建了一条高效快捷的杨梅素衍生物的制备方法。化合物的初步活性结果显示,黄酮醇3位羟基半乳糖修饰可以显著提高杨梅素的抗菌活性,为杨梅素的进一步抗菌化合物的寻找提供了新的线索。