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1.
郭慧然  廖学焜   《广西植物》1994,14(3):289-291
米面翁(BuckleyalanceolataMiq.)果实含油33.4%。经气相色谱分析.油中常见脂肪酸为棕榈酸2.6%,硬脂酸1.3%,棕榈油酸0.5%,油酸38.7%,亚油酸1.6%,亚麻酸7.9%;尚有3个不常见脂肪酸,通过分离和紫外光谱、红外光谱、核磁共振、色谱-质谱方法鉴定,以及臭氧化法证实油中含十八碳烯-反11-二块-7,9-酸.含量为39.4%,在植物中首次发现。另外两个未鉴定酸,含量分别为3.8%和4.2%。  相似文献   

2.
报道了缢蛏碱性磷酸酶(简称ALP)经不同浓度盐酸胍处理时酶的分子构象所发生的变化以及酶变化和失活的动力学过程。在胍中酶荧光发射峰强度下降,紫外差光谱在246nm和285nm处出现2个负峰,CD谱中酶的α螺旋度下降,且随浓度增大,变化程度也加大。动力学研究表明,酶在0.5mol/L、1.0mol/L、2.0mol/L3.0mol/L、4.0mol/L盐酸胍中的变性速度常数分别为3.21×10~(-4)s~(-1)、6.38×10~(-4)s~(-1)、2.17×10~(-3)s~(-1)、2.33×10~(-3)s~9-1)、5.17×10~(-3)s~(-1);而酶在相应盐酸胍中的失活速度常数分别为2.33×10~(-4)s~(-1)、3.57×10~(-4)s~(-1)、5.86×10~(-4)s~(-1)、1.14×10~(-3)s~(-1)、3.45×10~(-3)s~(-1);表现为失活与构象伸展变化基本平行。  相似文献   

3.
正常小鼠高频心电图时域值和功率谱的研究   总被引:4,自引:1,他引:4  
本文用南京新博公司生产的NHE-1000型心电高频信息检测分析仪研究了正常小鼠(昆明种)高频心电图(HF-ECG)的时域值和QRS波群的功率谱。主要结果如下(以正导为例,-X±SD):心率603±88次/min(n=74);P-R间期相对较长。为34.9±4.7ms(n=58),占心动周期的34.9±4.9%,这与人类有很大的不同;QRS波宽9.2±1.2ms,占心动周期的9.2±1.4%(n=74),这一结果与以前的文献报道相差较大。T波宽10.3±3.2ms,占心动周期的10.3±3.2%;Q-T间期19.4±3.2ms,占心动周期的19.5±3.6%;QRS波群峰-峰值(Vp-p)为1.456±0.480mV;T波高0.336±0.115mV;73只动物Ⅱ导联高频切迹总数只有3个,扭挫26个。Ⅱ导联QRS波群的功率谱特点:0—80Hz的相对能量为45.48±15.32%;80—200Hz为43.97±9.95%;200—300Hz为8.89±7.38%;300—1000Hz为1.66±2.74%。  相似文献   

4.
在637例临床拟诊与待排肺结核的细菌学检测中,加做结核菌L型(TB-L)检测,结果痰、胸水、支气管肺泡灌洗液(BALF)浓缩涂片及支刷的阳性率分别从23.3%、13.5%、33.3%、42.2%提高到34.2%、28.9%、53.3%及62.3%。痰、胸水和BALF液体培养阳性率分别从45.0%、26.9%、66.7%提高至57.9%、46.1%和82.2%。显著高于单纯结核菌细菌型(TB-B)检测(p<0.001),使常规方法检测不出的135例单独TB-L感染肺结核得到确诊。分析该组病例因临床和胸片表现不典型,PPD试验不敏感,漏诊和误诊率高达84.4%。且化疗效果差。  相似文献   

5.
多花含笑叶的挥发油成分研究   总被引:12,自引:0,他引:12  
运用气相色谱-质谱-计算机联用技术,结合标准谱库,对昆明产多花含笑叶的挥发油成分进行了研究,分离鉴定了42个化合物,其中单萜16个,倍半萜21个,分别占精油总含量的21=21%和49.08%,主要成分为γ-木罗烯(12.04%),十六碳三烯酸甲酸(7.45%),兰桉醇(7.38%),1,8-桉叶素(5.76%),α-愈创木烯(5.64%),香桧烯(4.26%),十六碳二烯酸甲酯(4.26%),β-槛香烯(3.76%),β-蒎烯(3.20%)等。  相似文献   

6.
光叶马鞍树根化学成分研究   总被引:3,自引:0,他引:3  
从光叶马鞍树(Maackia tenuifolia(Hemsl.)Hand-Mazz.)根乙醇浸膏的二氯甲烷捏溶部位分离得到13个成分,经光谱方法确定了它们的结构,其中化合物1-3为新化合物,分别为(2R,3R)-2’,4‘-dihydroxymaackiaflavanonol(1),maackiaphenone(2),4-(1,2-dimethyl-2-propenyl)-1,3-dihydro  相似文献   

7.
丹皮酚对心肌细胞自律性和延迟后除极的影响   总被引:8,自引:0,他引:8  
目的与方法:采用常规玻璃微电极技术研究丹皮酚对离体心肌细胞自律性(AM)、延迟后除极(DAD) 及触发活动(TA)的影响。结果:1.8×10-4mol/L丹皮酚灌流组,肾上腺素(Adr)的阈浓度空白对照组为(1.28±0.57)μmol/L,药后为(1.56±0.53)μmol/L(n=9,P>0.05);用(1.8×10- 3) mol/L丹皮酚(Pae)灌流组,Adr 浓度由空白对照组的(1.22 ±0.62)μmol/L升高到(6.22±2.11)μmol/L(n=9,P<0.01)。1.8×10-3mol/L的Pae 能明显抑制哇巴因(Oua)诱发的DAD的幅值,当基本刺激周长为500,400,300 和200 ms 时,其DAD幅值从(5.5±2.0)mV,(7.3±2.1)mV,(8.0 ±2.4)mV和(9.2±1.9)mV减小到(3.0±1.1)mV、(3.6±1.7)mV,(4.3±2.0) mV和(5.9 ±1.6) mV,P<0.01。当基本刺激周长为200 ms时,TA 数目由5.5±1.0 降至0.7±0.3(P<0.01)。结论:丹皮酚能抑制心肌细胞AM、DAD及TA,具有抗心律失常作用  相似文献   

8.
采用自制的壳聚糖为载体对单宁酶(TA)固定化,TA与壳聚糖配比1:2.5,30℃固定2h,活力回收达23.6%~33.1%;偶联效率为84.9%~88.0%。固定化单宁酶(ITA)的表观Km值(以没食子酸丙酯为底物)为22.2×10-6mol/L,TA的Km值(以没食子酸丙酯为底物)为10×10-6mol/L,TA和ITA的最适反应温度分别为40℃和50℃;60℃处理15min,残存活性分别为13.6%和60.3%。TA和ITA的最适pH值分别为5.8和6.4;TA在pH4.8~7.8活力稳定,而ITA活力稳定范围在pH4.8~6.8.ITA作用于EGCG的半衰期为78.7h,EGCG水解率达90.3%。对茶多酚提取物进行水解,其所含的酯型儿茶素EGCG和ECG水解率分别为96.4%和96.8%,非酯型儿茶素EGC和EC的含量显著增加。  相似文献   

9.
为了解乙型肝炎血源疫苗皮内接种的持久效果,选HBsAg、抗-HBs和抗-HBc均(-)的9~11岁儿童103名,随机分成4组,分别皮内接种1μg×4和3μg×4(均按0,1,2,5月程序)和肌肉接种10μg×3和30μg×3(各按0,1,2月程序)。首针后48月时,1μg、3μg、10μg和30μg组抗-HBs≥10mIU/mI者各为69.2%,80.0%、92.3%和81.8%;GMT则为14.5,79.0,44.8和70.9mIU/ml,3μg×4皮内免疫的近期和远期效果与肌肉组30μg×3相似,宜于某些人群采用  相似文献   

10.
观察血管紧张素Ⅱ(AngⅡ)对心肌肌浆网Ca2+,Mg2+-ATPase基因(SERCA2a)转录调节的影响,评价DMP811对此效应的干预作用.6周龄雄性SD大鼠随机分为3组,每组6只.组1:生理盐水输注;组2:AngⅡ输注+DMP811管饲(3mg·d-1·kg-1);组3:AngⅡ输注(200ng·min-1·kg-1.1周后称其体重,取心脏并称重,提取心脏总RNA后采用Northernblot的方法检测SER-CA2a的转录水平,采用RT-PCR检测AngⅡ1型受体(AT1)mRNA水平.实验后,组3心重(CW)、心重/体重(C/B)、AT1受体转录水平均高于组1(分别增加4.7±0.4%,4.9±0.9%和24.7±3.5%;P<0.01),而SERCA2a基因转录水平显著低于组1(降低20.1±3.0%,P<0.01),并且SERCA2amRNA水平与AT1受体mRNA水平呈负相关(r=-0.74,P<0.01).AngⅡ导致的上述改变能被DMP811完全阻断.AngⅡ通过其Ⅰ型受体的介导,诱导了SERCA2a的转录下调  相似文献   

11.
A crude synthetic preparation called crude "X-methyl" folate has previously been shown to function as a folate antagonist for rats and chicks. This product has been shown to contain two folate antagonists: 9-methyl folate, present as 6% by weight of the product and which has low activity as a folate antagonist for Streptococcus faecalis, and pyrrofolic acid, a compound present in small amounts (0.04%), but having high anti-folate biological activity for S. faecalis. These experiments deal with the antifolate activity of these two fractions for the rat as measured by their effects on histidine oxidation. Rats were fed a purified diet based on 20% vitamin-free casein and containing 1.0% sulfasuxidine. When this diet was supplemented with a marginal amount of folic acid (0.3 mg per kg diet), the addition of 4 g of crude antagonist decreased histidine oxidation and decreased liver folate levels. The addition of 240 mg of pure 9-methyl folic acid (amount of 9-methyl folic acid in 4 g of crude) produced similar decreases in histidine oxidation and liver folate levels. A concentrate of pyrrofolic acid (equivalent to 4 g of crude) free of 9-methyl folic acid produced no decrease in histidine oxidation and minimal changes in liver folate. This indicates that the folate antagonist activity observed previously with animals is probably due to the 9-methyl folic acid component rather than to the pyrrofolic acid activity.  相似文献   

12.
Positional isomers of hexadecenoic aud octadecenoic acids of human adipose tissue have been separated by gas-liquid chromatography and their amounts determined by oxidative cleavage (MnO(4) and IO(4)). The following isomeric octadecenoic acids were present: 7-octadecenoic acid (0.4%), 8- (1.9%), 9- (73.0%), 10- (2.5%), 11- (19.0%) and 12- (3.2%). The hexadecenoic acids have also been shown to be a mixture of positional isomers, in which the cis-9-isomer predominates. 10-Hexadecenoic and 12-octadecenoic acids could conceivably be precursors of linoleic acid. The following branched fatty acids have also been determined in human depot fat: 13-methyltetradecanoic, 12-methyltetradecanoic, 14-methylpentadecanoic, 14-methylhexadecanoic, and 16-methylheptadecanoic acid. They were present in percentages of 0.02-0.6% and their identification rests solely on comparison of their gas-liquid chromatographic retention times with those of synthetic compounds.  相似文献   

13.
Five fatty ester derivatives of podophyllotoxin have been prepared by reacting the corresponding fatty acids with the hydroxy group of podophyllotoxin in the presence of dimethylaminopyridine and N,N-dicyclohexylcarbodiimide. The fatty acids incorporated are: 9,12-epoxy-9,11-octadecadienoic acid, octadec-11E-en-9-ynoic acid, 11,12-E-epoxy-octadec-9-ynoic acid, octadeca-9Z,11E-dienoic acid and 9,10-dibromooctadecanoic acid. The average yield of esterification was >95% and the structures of the products were confirmed by a combination of nuclear magnetic resonance spectroscopic and mass spectrometric analyses.  相似文献   

14.
Several grams of labelled trans linoleic and linolenic acids with high chemical and isomeric purities (>97%) have been prepared for human metabolism studies. A total of 12.5 g of (9Z, 12E)-[1-(13)C]-octadeca-9,12-dienoic acid and 6.3 g of (9Z,12Z, 15E)-[1-(13)C]-octadeca-9,12,15-trienoic acid were obtained in, respectively, seven steps (7.8% overall yield) and 11 steps (7% overall yield) from 7-bromo-heptan-1-ol. The trans bromo precursors used for the labelling were synthesised by using copper-catalysed couplings. The trans fatty acids were then obtained via the nitrile derivatives. A total of 23.5 g of (9Z,12Z)-[1-(13)C]-octadeca-9, 12-dienoic acid and 10.4 g of (9Z,12Z,15Z)-[1-(13)C]-octadeca-9,12, 15-trienoic acid were prepared in five steps in, respectively, 32 and 18% overall yield. Large quantities of bromo and chloro precursors were synthesised from the commercially available acid according to Barton's procedure. In all cases, the main impurities (>0.5%) of each labelled fatty acid have been characterised.  相似文献   

15.
Summary We have studied the effects of Efamol evening primrose oil (EPO) on fatty acid-binding proteins (L-FABP) of rat liver. EPO contains 72% cis-linoleic acid and 9% cis-gamma linolenic acid. EPO has been clinically used for treatment of a number of diseases in humans and animals. EPO is also known to lower cholesterol level in humans and animals. Feeding of an EPO supplemented diet to rats (n = 9) for 2 months decreases the oleate binding capacity of purified L-FABP of rat liver whereas the palmitate binding activity was increased by 38%. However, EPO feeding did not alter the L-FABP concentrations significantly as measured by using the fluorescence fatty acid probe, dansylamino undecanoic acid. Endogenous fatty acid analysis of L-FABPs revealed significant qualititative and quantitative changes in fatty acid pattern after EPO feeding. EPO feeding decreased the endogenous palmitate level by 53% and oleate level by 64% in L-FABPs and also EPO feeding decreased the total endogenous fatty acid content from 62 nanomole per mg of protein to 42 nanomole per mg of L-FABP (n = 3).  相似文献   

16.
The acylneuraminic acid fraction, obtained on mild acid hydrolysis of glycoproteins from bovine submandibular glands, contains approximately 2% N-acety-9-O-L-lactylneuraminic acid. The compound has been isolated and purified by ion-exchange and cellulose column chromatography. The structure has been elucidated using thin-layer chromatography, colorimetry, gas-liquid chromatography/mass spectrometry, periodate oxidation and specific lactate dehydrogenases. An evaluation of the different analytical methods is given.  相似文献   

17.
Membranes of intact rabbit reticulocytes and rat liver mitochondrial membranes oxygenated by the pure reticulocyte lipoxygenase contain 13-keto-9Z,11E-octadecadienoic acid and 9-keto-10E,12Z-octadecadienoic acid. In mitochondrial membranes not treated with lipoxygenase and in rabbit erythrocyte membranes these products were not detected. The chemical structure of the compounds has been identified by cochromatography with authentic standards on various types of HPLC columns, by uv and ir spectroscopy and GC/MS. In the membranes of rabbit reticulocytes up to 2% of the linoleate residues are present as its 9- and 13-keto derivatives. Most of the keto compounds (up to 90%) are esterified in the membrane ester lipids, only about 10% were found in the free fatty acid fraction. It is proposed that the keto dienoic fatty acids are formed via decomposition of hydroperoxy polyenoic fatty acids originating from the oxygenation of the membrane lipids by the reticulocyte lipoxygenase.  相似文献   

18.
A general scheme for the purification of baculovirus-expressed cytochrome P450s (P450s) from the crude insect cell pastes has been designed which renders the P450s suitable for analysis by high-performance liquid chromatography (HPLC) electrospray ionization mass spectrometry (ESI-MS). An HPLC/ESI-MS procedure has been developed to analyze small amounts of intact purified P450 (P450s cam-HT, 1A1, 1A2, 2A6, 2B1, 2C9, 2C9 C175R, 3A4, 3A4-HT) and rat NADPH cytochrome P450 reductase (P450 reductase). The experimentally determined and predicted (based on the amino acid sequences) molecular masses (MMs) of the various proteins had identical rank orders. For each individual protein, the difference between the experimentally determined (+/-SD, based on experiments performed on at least 3 different days) and predicted MMs ranged from 0.002 to 0.035%. Each experimentally determined MM had a standard deviation of less than 0.09% (based on the charge state distribution). Application of this HPLC/ESI-MS technique made the detection of the covalent modification to P450 2C9 following mechanism-based inactivation by tienilic acid possible. In the absence of glutathione, three P450 2C9 species were detected that produced ESI mass spectra corresponding to native P450 2C9 and both a monoadduct and a diadduct of tienilic acid to P450 2C9. In the presence of glutathione, only native P450 2C9 and the monoadduct were detected. Based on the observed mass shifts for the P450 2C9/tienilic acid adducts, a mechanism for the inactivation of P450 2C9 by tienilic acid is proposed.  相似文献   

19.
The cell lipids of the zygomycete Absidia corymbifera F-965 extracted with isopropanol and CHCl3-MeOH mixtures at the exponential growth phase comprise 20+/-2% of mycelium dry wt. The lipids consist of: triacylglycerols (51% of the total lipids extracted), diacylglycerols (9%), monoacylglycerols (3%), ergosterol (5%), ergosterol peroxide (5alpha,8alpha-epidioxyergosta-6,22-diene-3beta-ol) (3%), fatty-acid esters of ergosterol (less than 0.5%), free fatty acids (4%), glucocerebroside (3%), and glycerophospholipids (22%). The main phospholipids are phosphatidylethanolamine (39% of the total phospholipids), phosphatidyl-myo-inositol (17%), diphosphatidylglycerol (12%), phosphatidic acid (7%), phosphatidylcholine (6%), phosphatidylglycerol (3%), and two unusual phospholipids reported earlier, N-acetylphosphatidylethanolamine (7%) and N-ethoxycarbonyl phosphatidylethanolamine (9%). In addition, two unknown acidic phospholipids are present in traces. Saturated fatty acids of the lipids are dominated by n-hexadecanoic acid and unsaturated ones by octadecenoic acid; octadecadienoic and octadecatrienoic acids are present in lesser amounts. Ergosterol peroxide as well as the above glucocerebroside which contains 9-methylsphinga-4(E),9(E)-dienine have first been revealed in zygomycetes.  相似文献   

20.
超临界CO_2萃取冬虫夏草子座挥发性成分的GC-MS研究   总被引:4,自引:0,他引:4  
报道冬虫夏草挥发性成分的组成,为其进一步的研究工作奠定基础。采用超临界CO2萃取法从冬虫夏草子座中提取挥发性成分,气相色谱-质谱联用技术对其化学成分进行分析。超临界流体萃取物共鉴定了39种组分,占总馏出组分的86.6%以上,占色谱总馏出峰面积的98.56%以上。已鉴定组分中,含量最高的为油酸,相对含量25.6%;其次为亚油酸,相对含量22.67%;再次为棕榈酸11.86%。超临界CO2萃取法能更真实、全面的反映药材中的化学成分,适合于珍稀中药材相关组分的测定。  相似文献   

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