枸骨的化学成分

从枸骨(Ilex cornuta Lindl,ex paxt.)中分离得到20个化合物,鉴定了16个,分别为：枸骨甙1(Gougusidel,V)即坡摸酸3-β-O-O-L吡喃阿拉伯糖甙;枸骨甙2(Gouguside 2,Ⅵ)即3-β-O-D-吡喃葡萄糖基坡摸酸-β-28-O-D吡喃葡萄糖酯;枸骨甙3(Gouguside 3,Ⅶ)即3-β-O-(β-D-吡喃葡萄糖基)-α-L吡喃葡萄糖基坡摸酸-β-28-O-D-吡喃葡萄糖酯的类似物;枸骨甙4(Gouguside 5,ⅩⅦ)即3-β-O-(β-D-吡喃葡萄糖基)-α-L-吡喃葡萄糖基坡摸酸-β-28-O-D-吡喃葡萄糖酯;枸骨甙5(Gouguside 5,ⅩⅧ)即坡摸酸3-β-O-α-L-2’-乙酰氧基吡喃阿拉伯糖基-28-O-β-D-吡喃葡萄糖酯,枸骨甙6(Gouguside 6,ⅩⅪ)即3-β-O-(β-D-吡喃葡萄糖基)-α-L-4-乙酰氧基吡喃阿拉伯糖基坡摸酸-β-28-O-D-吡喃葡萄糖酯;枸骨甙7(Gouguside 7,ⅩⅩ)即3-β-O-α-L-吡喃阿拉伯糖基-28-O-β-D-吡喃葡萄糖酯;胡萝卜甙(daucostorol Ⅷ);2,4-二羟基苯甲酸(2,4-dihydroxybenzoicacid I);3,4-二羟基桂皮酸(3,4-dihyroxycinnamunic acid Ⅱ,Ⅳ);长链脂肪酸或醇5个(Longchain fatty acid Ⅲ,Ⅵ,Ⅶ,Ⅷ,ⅩⅣ)。在鉴定的16个化合物中,枸骨甙1、枸骨甙2、枸骨甙6和枸骨甙7为首次从枸骨中分离得到,枸骨甙3和枸骨甙4为新化合物。     

安心酮对心血管系统作用的实验研究

目的研究安心酮（麻黄苯丙酮,Ｏｘｙｆｅｄｒｉｎｅ）对心脏血流动力学、冠脉流量和急性心肌缺血的药理效应方法观察药物对大鼠离体灌流心脏和在体狗心脏血流动力学、冠脉流量和心肌缺血的影响结果安心酮在一定的剂量范围内明显地增强心肌收缩力和对抗戊巴比妥所致的心力衰竭。但是,高剂量的安心酮可导致心功能抑制,使心肌收缩力和血压降低,β受体阻断剂可阻断其对心脏的激动作用,而安心酮又可拮抗异丙肾上腺素对心脏的兴奋作用。因此认为,本品可能是一种β受体部分激动剂。此外,安心酮可明显增加冠脉流量,减轻结扎冠状动脉引起的心肌梗死,以及拮抗高剂量的脑垂体后叶素所致的急性心肌缺血,这些作用可能是激动血管β２受体、选择性扩张冠脉和降低心肌耗氧量的结果结论安心酮明显地增强心肌收缩力、增加冠脉流量和改善心肌缺血。     

缩醛基毛冬青提取化合物R4对缺血缺氧心肌的保护作用

目的：研究缩醛基毛冬青提取化合物R4对缺血缺氧心肌的保护作用,以便为缩醛基毛冬青提取化合物R4的临床新用途提供实验依据。方法：采用小鼠常压耐缺氧实验、夹闭气管小鼠心电消失时间、垂体后叶素所致大鼠心肌缺血模型及大鼠冠脉结扎所致的心肌缺血模型,观察缩醛基毛冬青提取化合物R4对缺血缺氧心肌的保护作用。结果：缩醛基毛冬青提取化合物R4（1.0、2.0、4.0 mg/kg）均能显著延长小鼠常压耐缺氧条件下的存活时间,延长夹闭气管小鼠心电消失时间,缩醛基毛冬青提取化合物R4（0.75、1.5和3.0 mg/kg）能拮抗垂体后叶素引起的心电图变化,并能明显降低结扎冠脉所致大鼠的心肌梗塞范围。结论：缩醛基毛冬青提取化合物R4对缺血缺氧心肌具有明显保护作用,其效应与剂量呈相关性,其机制可能是通过扩张冠脉,增加心肌的供血供氧而发挥抗心肌缺血的作用。     

缩醛基毛冬青提取化合物R4对缺血缺氧心肌的保护作用

目的:研究缩醛基毛冬青提取化合物R4对缺血缺氧心肌的保护作用,以便为缩醛基毛冬青提取化合物R4的临床新用途提供实验依据。方法:采用小鼠常压耐缺氧实验、夹闭气管小鼠心电消失时间、垂体后叶素所致大鼠心肌缺血模型及大鼠冠脉结扎所致的心肌缺血模型,观察缩醛基毛冬青提取化合物R4对缺血缺氧心肌的保护作用。结果:缩醛基毛冬青提取化合物R4(1.0、2.0、4.0 mg/kg)均能显著延长小鼠常压耐缺氧条件下的存活时间,延长夹闭气管小鼠心电消失时间,缩醛基毛冬青提取化合物R4(0.75、1.5和3.0 mg/kg)能拮抗垂体后叶素引起的心电图变化,并能明显降低结扎冠脉所致大鼠的心肌梗塞范围。结论:缩醛基毛冬青提取化合物R4对缺血缺氧心肌具有明显保护作用,其效应与剂量呈相关性,其机制可能是通过扩张冠脉,增加心肌的供血供氧而发挥抗心肌缺血的作用。     

枫香脂和苏合香的心血管药理学研究

本文比较了苏合香及枫香脂生药、精制枫香脂、枫香脂挥发油的毒性及其对心血管系统的药理作用。结果表明 ,枫香脂毒性小于苏合香。 4种样品均能提高小鼠常压下的心肌耐缺氧能力 ,其中精制枫香脂及枫香脂挥发油的作用最强 ;均可显著降低氯仿诱导的小鼠室颤发生率 ,其中精制枫香脂作用最强 ;对体外血栓干重的抑制率 ,精制枫香脂的作用强于苏合香 ;均可提高冠脉流量 ,其中精制枫香脂及枫香脂挥发油的作用强度及作用维持时间均优于苏合香 ;对离体豚鼠心功能的影响基本相似。提示以精制枫香脂取代苏合香应用于心血管疾病是可能的。     

白藜芦醇甙对大鼠心脏缺血/再灌注损伤的保护作用

本文利用冠脉结扎/放松方法和Langendorff灌注技术,建立在体和离体大鼠心脏缺血/再灌注(ischemia/reperfusion,I/R)损伤模型,探讨白藜芦醇甙(polydatin)对大鼠I/R心肌损伤的保护作用及其机制.观察白藜芦醇甙对缺血和再灌注心律失常、心肌梗死面积、心脏收缩功能、心肌超氧化物歧化酶(superoxide dismutase,SOD)活性、丙二醛(malondialdehyde,MDA)含量、NO含量以及一氧化氮合酶(nitric oxide synthase,NOS)活性的影响.结果显示:与对照组相比,白藜芦醇甙组大鼠缺血和再灌注心律失常明显降低(P<0.05,P<0.01);心肌梗死面积显著减少(P相似文献   

雌激素对去卵巢大鼠离体心脏缺血／再灌注损伤的保护作用

目的：探讨雌激素对去卵巢大鼠离体心脏缺血／再灌注损伤的保护作用。方法：成年SD雌鼠,随机分为假手术组（Sham）,双侧卵巢切除组（Ovx）和双侧卵巢切除后补充17β-雌二醇组（Ovx＋E2）。各组离体心脏再随机分为不同时间的缺血再灌注亚组。测量的指标包括冠脉流出液中LDH及CK含量、心室肌细胞存活率及产率、基础状态和异丙肾上腺素（ISO）刺激状态下收缩幅度。结果：30min缺血及其各复灌纽均显著增加冠脉流出液中LDH、CK的释放量。Ovx组LDH、CK漏出在30min缺血及再灌注条件下,显著高于正常灌注组,而Ovx＋E2组可减轻心肌损伤,减少LDH、CK的释放。10min和20min缺血对心肌细胞存活率、产率及冠脉流出液中LDH、CK含量影响均不明显。Sham、Ovx、Ovx＋E2各组心肌细胞基础收缩幅度在正常和10minⅠ＋30minR灌注条件下无显著差异。Ovx显著增加其他各组心肌细胞基础收缩和ISO刺激收缩幅度,Ovx＋E2可使其降至Sham水平。结论：雌激素对去卵巢大鼠心肌缺血／再灌注损伤具有保护作用。     

Phytosterols accumulation in the seeds of Linum usitatissimum L.

A comparative study was performed to determine the free sterols content and composition during the development of three varieties of linseed (H52, O116 and P129). Seed samples were collected at regular intervals from 7 to 60 days after flowering (DAF). Ten compounds were identified: cholesterol, campesterol, brassicasterol, stigmasterol, β-sitosterol, Δ5-avenasterol, cycloartenol; 24-methylene cycloartanol, obtusifoliol, citrostadienol. The maximum level of 4-desmethylsterols (1515 mg/100 g oil) was reached at 7 DAF in P129 variety. H52 had the highest level of 4-4 dimethylsterols (355 mg/100 g oil) at 28 DAF. The greatest amount of 4-monomethylsterols (35 mg/100 g oil) was detected in H52 at 14 DAF. During linseed development, β sitosterol (830 mg/100 g oil) was the major 4-desmethylsterols, followed by campesterol (564 mg/100 g oil) and stigmasterol (265 mg/100 g oil). Some of these compounds followed nearly the same accumulation pattern during linseed maturation.     

gamma-Glutamyltranspeptidase-dependent metabolism of 4-hydroxynonenal-glutathione conjugate.

A major pathway for detoxification of the highly reactive lipid peroxidation product, 4-hydroxy-2,3-trans-nonenal (HNE) is through the conjugation with glutathione (GSH). We have studied the metabolism of GS-HNE conjugate by the enzyme gamma-glutamyltranspeptidase (GGT) using its purified form, as well as a GGT-overexpressing fibroblast cell line (V79 GGT). Using mass spectrometry analysis we identified for the first time cysteinylglycine-HNE (CysGly-HNE) as the GGT metabolite of GS-HNE. Furthermore, the GGT-dependent metabolism of GS-HNE in the V79 GGT cell line was associated with a considerable increase of cytotoxicity as compared to a control cell line which does not express GGT (V79 Cl). The cytotoxic effect was dose- and time-dependent (100% cellular death at 200 microM GS-HNE after 24 h incubation) in V79 GGT cells, whereas no decrease of viability was observed in V79 Cl cells. A similar cytotoxic effect was obtained when cells were incubated directly with CysGly-HNE, demonstrating that this GGT-dependent metabolite unlike GS-HNE, exhibits cytotoxic properties.     

Liver-microsome-mediated formation of alkylating agents from vinyl bromide and vinyl chloride.

When a mixture of vinyl chloride/oxygen or vinyl bromide/air was passed through a mouse-liver microsomal system, volatile alkylating metabolites were trapped by reaction with excess 4-(4-nitrobenzyl)pyridine. The absorption spectra of the adducts, either from vinyl bromide or vinyl chloride, were identical with that obtained by reaction of chloroethylene oxide with 4-(4-nitrobenzyl) pyridine. Chloroethylene oxide decomposes in aqueous solution with a half-life of 1.6 minutes. After reaction of chloroethylene oxide and 2-chloroacetaldehyde with adenosine and Sephadex chromatography the binding products were compared with those formed in the presence of vinyl chloride, mouse-liver microsomes and adenosine. A common product of these reactions was tentatively characterized as 3-β-ribofuranosyl-imidazo-[2,1-i]purine.     

Lacipirellula parvula gen. nov., sp. nov., representing a lineage of planctomycetes widespread in low-oxygen habitats,description of the family Lacipirellulaceae fam. nov. and proposal of the orders Pirellulales ord. nov., Gemmatales ord. nov. and Isosphaerales ord. nov.

Pirellula-like planctomycetes are ubiquitous aquatic bacteria, which are often detected in anoxic or micro-oxic habitats. By contrast, the taxonomically described representatives of these bacteria, with very few exceptions, are strict aerobes. Here, we report the isolation and characterization of the facultatively anaerobic planctomycete, strain PX69^T, which was isolated from a boreal lake. Its 16S rRNA gene sequence is affiliated with the Pirellula-related Pir4 clade, which is dominated by environmental sequences retrieved from a variety of low-oxygen habitats. Strain PX69^T was represented by ellipsoidal cells that multiplied by budding and grew on sugars, some polysaccharides and glycerol. Anaerobic growth occurred by means of fermentation. Strain PX69^T grew at pH 5.5–7.5 and at temperatures between 10 and 30 °C. The major fatty acids were C18:1ω9c, C16:0 and C16:1ω7c; the major intact polar lipid was dimethylphosphatidylethanolamine. The complete genome of strain PX69^T was 6.92 Mb in size; DNA G + C content was 61.7 mol%. Among characterized planctomycetes, the highest 16S rRNA gene similarity (90.4%) was observed with ‘Bythopirellula goksoyri’ Pr1d, a planctomycete from deep-sea sediments. We propose to classify PX69^T as a novel genus and species, Lacipirellula parvula gen. nov., sp. nov.; the type strain is strain PX69^T (=KCTC 72398^T = CECT 9826^T = VKM B-3335^T). This genus is placed in a novel family, Lacipirellulaceae fam. nov., which belongs to the order Pirellulales ord. nov. Based on the results of comparative genome analysis, we also suggest establishment of the orders Gemmatales ord. nov. and Isosphaerales ord. nov. as well as an emendation of the order Planctomycetales.     

Dental pulp collagenase: initial demonstration and characterization.

A collagenase, active against native helical collagen, was initially found in the explant medium of bovine dental pulp. In contrast to the collagenases from other oral tissues, all the pulp enzyme released was in a latent form which was activated by trypsin treatment, 4-aminophenylmercuric acetate, and some chaotropic agents. The activated enzyme was inhibited by low concentrations of EDTA and calf serum. The molecular weight of activated enzyme was tentatively estimated at 45,000 daltons by gel filtration. The enzyme attacked undenatured collagen in solution at 20°C producing characteristic products $\text{α}{}^{\mathrm{A}}\text{(}\text{3}\text{4}\text{)}$ and $\text{α}{}^{\mathrm{B}}\text{(}\text{1}\text{4}\text{)}$.     

GST-Exendin-4在大肠杆菌中的可溶性表达和纯化

为了制备GST-Exendin-4融合蛋白,以本实验室构建好的pET22b-Exendin-4为模板,通过PCR扩增出Exendin-4基因,酶切克隆入pGEX-4T-1,构建重组表达质粒pGEX-4T-1-Exendin-4.经DNA测序证实插入序列与设计完全一致后,将重组质粒转化大肠杆菌BL21(DE3),在不同浓度的IPTG和不同温度诱导下,经SDS-PAGE分析鉴定,表达出Mr约为30 kD的目的蛋白,灰度扫描显示目的蛋白占菌体总蛋白的29.9%,超声裂解后的上清通过Sepharose 4B亲和层析纯化、透析、除盐及冷冻干燥得到高纯度的目的蛋白.本研究成功制备了高纯度的GST-Exendin-4融合蛋白,为下一步进行目的蛋白大规模的生产打下了良好的基础.     

Potent inhibition of thrombin by the newly synthesized arginine derivative No. 805. The importance of stereo-structure of its hydrophobic carboxamide portion

Four stereoisomers of 4-methyl-1-[N²-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulfonyl)-L-arginyl]-2-piperidinecarboxylic acid were synthesized and examined for the inhibitory effect on thrombin. The inhibitory potency varied largely with the stereo-configuration of the 4-methyl-2-piperidinecarboxylic acid portion. The (2R, 4R)-isomer was the most potent inhibitor with a Ki of 0.019 μM, while the (2R, 4S) and (2S, 4R)-isomers showed the values of Ki 0.24 and 1.9 μM, respectively. The least potent inhibitor, (2S, 4S)-isomer, showed a Ki of 280 μM which is approximately 15,000 times that of (2R, 4R)-isomer.     

Affinity labeling of E. coli RNA polymerase with substrate and template analogues

Irradiation of E.coli RNA polymerase at 330–360 nm in the presence of either 4-thiouridine triphosphate or polydeoxy-4-thiothymidylic acid leads to covalent substitution by substrate or template analogue and causes irreversible inactivation of the enzyme. Evidence for specific inactivation was obtained from kinetic experiments. The sites of chemical modification of RNA polymerase were shown to be exclusively the subunits β′ and β.     

Control of catabolism of mitochondria in oncogenesis. I. Increase of hepatic mitochondrial population during feeding inactive or marginally active amino azo dyes: absence of de novo biosynthesis

The mechanism of the well established phenomenon that the number of liver mitochondria increases during administration of 2-methyl-4-dimethylaminoazobenzene (2-Me-DAB) has been investigated. Fed to rats, both 2-Me-DAB (0.06%) and 4-diethylaminoazobenzene (4-DEAB) (0.0635 %) increase the amount of liver mitochondria by 47% and 31%, respectively. It was established that this is not due to de novo mitochondriogenesis. The increase in the amount of mitochondria correlates with an ~ 10% decrease of total liver protein per g of tissue. Mitochondrial ATP synthesis, which is a prerequisite of any anabolic situation, is drastically impaired following feeding of 2-Me-DAB beyond 1 week as indicated by a very substantial decrease of State 3 respiration, the respiratory control index, and the $\text{ADP}\text{O}$ ratio. Determination of the polysome profile and polysome/monosome ratio at intervals during 2-Me-DAB administration showed no change, despite the fact that mitochondrial components are coded for in both nuclear and mitochondrial DNA. During 4-DEAB administration there was, however, a small but definite rise of the polysome/monosome ratio. Administration of 2-Me-DAB up to 42 days brought about drastic inhibition of the incorporation of [³H]thymidine into both DNA's (approx. 59% with mitochondrial DNA and approx. 77% with nuclear DNA), indicating that these templates could not possibly be involved in the substantial increase of the mitochondrial population. The data suggest that the increase results from a steady accumulation due to increase of the half-life of mitochondria, owing possibly to an inhibition of lysosomal catabolic enzymes.