藏药裸茎金腰挥发性化学成分研究

用毛细管气相色谱-质谱联用法,首次分析了藏药裸茎金腰(Chrysosplenium nudicaule Bunge)挥发性化学成分,经毛细管色谱分离出95个峰,共鉴定了其中78种成分。分析鉴定结果表明,裸茎金腰挥发性主要化学成分为二十烷、十六烷酸乙酯、邻苯二甲酸二丁酯、(Z,Z,Z)-9,12,15-十八烯酸乙酯、2,6-二叔丁基-对甲苯酚、5,6,7,7α-四氢-4,4,7α-三甲基-2,(4H)-苯并呋喃酮等。化合物类型以烃、烯烃、脂肪酸酯、酮、芳香类和芳香杂环化合物为主。     

长叶水麻挥发性化学成分研究

长叶水麻（Ｄｅｂｒｅｇｅａｓｉａ ｌｏｎｇｉｆｏｌｉａ （Ｂｕｒｍ．ｆ．）Ｗｅｄｄ．）是荨麻科植物,果可食,根入药,除风湿。本文彩毛细管气相色谱－质谱联用法对长叶水麻挥发性化学成分进行了研究,经毛细管色谱分离出１０８个峰,共确认了其中８３种成分。用气相色谱面积归一化法测定了各成分的相对百分含量,分析鉴定结果表明,长叶水麻挥发油主要化学成分为丁基化羟基甲苯、十五烷、邻苯二甲酸二丁酯、２,６－二甲基奈     

北艾蒿挥发油成分研究

采用水蒸气蒸馏法提取,运用毛细管气相色谱-质谱联用法对北艾蒿挥发性化学成分进行了分析,用气相色谱面积归一化法测定了各成分的相对百分含量。经毛细管色谱分离出26个峰,并鉴定出峰所对应的化合物。其主要化学成分为(Z,Z)-3,5-辛二烯(63.99%);2,5-辛二烯(10.08%);3,4,5-三甲基-1-己烯(3.55%);桉油醇(2.84%);长叶薄荷酮(2.36%);3-甲基-2-环己烯-1-酮(2.37%);樟脑(2.32%);十氢-1,1,7-三甲基-4-亚甲基-1H-奥(2.13%)等。     

燕子掌挥发油化学成分的研究

应用气象色谱-质谱联用技术对燕子掌挥发油化学成分进行了分析研究,共鉴定出66种组分与燕子掌主要挥发性化学成分以苯乙醇、2,6,6-三甲基-2,4-环庚二烯-1-酮、6,10,14-三甲基十五烷-2-酮、十六烷酸甲酯、十六烷酸乙酯、十八烷酸甲酯为主要成分,化合物类型以酮、酯、类等化合物为主,其中十六烷酸甲酯的含量最高,占挥发油总量的26．13％。     

木里柠檬叶精油化学成份的研究

用毛细管气相色谱-质谱-计算机数据联用技术、标准品叠加法和毛细管保留指数定性法分析了木里柠檬(Citrus Liilion(L.)Burm.f.)的叶精油化学成分。从水蒸汽蒸馏叶精油被分离的110多个色谱峰中鉴定了41种化合物,并测定了其相对含量。其主要成分是香叶醛(21.3058％)、橙花醛(13.9580)、d-柠檬烯(9.8359)、β-水芹烯(9.3297)、橙花醇(4.4657)、乙酸橙花酯(2.8162)、香茅醛(2.6338)、乙酸芳樟酯(2.2179)、α-水芹烯(2.0390)、香芹酮(2.0213)、6-甲基-5-庚烯-2-酮(1.7250)和乙酸香叶酯(1.6586)。被鉴定的成份占总成份的96.6652％     

藏药短管兔耳草挥发性化学成分的研究

采用毛细管气相色谱—质谱联用技术对藏药短管兔耳草挥发性化学成分进行了研究,经毛细管色谱分离出62个峰,共确定了其中41种化学成分,所鉴定的化合物含量占全挥发油的77．32％;用气相色谱面积归一化法测定了各化学成分的相对含量,其主要化学成分为：二苯胺(16．47％)、邻苯二甲酸丁基—8—甲基壬基酯(6．42％)、二十六碳烷(4．76％)、十六烷酸(3．66％)、二十四碳烷(3．40％)、邻苯二甲酸二丁酯(3．38％)、二十二碳烷(3．30％)、二十碳烷(3．26％)、十六烷酸乙酯(2．77％)、十八碳烷(2．76％)、戊酸(2．48％)、3—乙基环辛烯(2．05％)等。     

杉木叶醇提物中石油醚溶解组分的化学成分分析

采用气-质联用法对杉木(Cunningham ia lanceolataHook.)叶醇提物石油醚溶解组分的化学成分进行了研究,经毛细管色谱分析分离出38个峰,共确认出其中36种成分,鉴定出的化学成分质量占总量的98.06%以上。应用色谱峰面积归一法分析各成分的质量分数,含量较高的物质有:十八酸-1,3-甘油二酯(16.929%)、二十七烷(15.178%)、棕榈酸-2-(十八烷氧基)乙酯(11.038%)、油酸(6.531%)、三十七醇(6.877%)等。化合物的类型主要为饱和脂肪酸酯(33.834%)和烃类化合物(22.031%)。     

湿地蒿挥发油成分研究

目的:分析湿地蒿的化学成分. 方法:采用水蒸气蒸馏法提取,运用毛细管气相色谱-质谱联用法对湿地蒿挥发性化学成分进行了分析,用气相色谱面积归一化法测定了各成分的相对百分含量. 结果:经毛细管色谱分离了38个峰,并鉴定出峰所对应的化合物.其主要化学成分为7,11-二甲基-1,6,10-十二碳三烯(56.20%);IR-α-蒎烯(18.63%);3-(苯二甲酰亚氨甲基)-苯甲酸(4.8%);1-甲基-4-(1-甲基乙基)-1,4-环己二烯(3.46%);6,6-二甲基-2-亚甲基-[3,1,1]二环庚烷(1.41%);庚烷(1.28%)等.     

异叶青兰挥发性化学成分研究

采用毛细管气相色谱－质谱联用法对异叶青兰挥发性化学成分进行了研究,经毛细管色谱分离出１８４多个峰,共确认了其中１５４种成分,所鉴定化合物的含量占全油的８３．５２％。用气相色谱面积归一化法测定了各成分的相对百分含量,其主要化学成分为４－甲基噻唑、６,６－二甲基－二环「３,３,１」－庚－２－烯－２－甲醇,４－（１－甲基乙基）－苯甲醇、十六酸乙酯等。     

蝴蝶果茎挥发油的化学成分

采用水蒸汽蒸馏法从大戟科蝴蝶果茎中提取挥发油,用气相色谱-质谱联用技术对挥发油化学成分进行分析。分离出36个峰,鉴定出35种化合物,占总油量的98.34%,并应用面积归一化法测定各成分的相对百分含量。其主要成分为十六烷酸乙酯(13.19%)、正十六烷酸(11.11%)、十八碳烯酸乙酯(6.18%)、正十八烷(4.98%)、(Z,Z)-9,12-十八碳二烯酸(4.90%)及十八碳二烯酸乙酯(4.21%)。     

Simultaneous determination of 19 intracellular nucleotides and nucleotide sugars in Chinese Hamster ovary cells by capillary electrophoresis

Twelve nucleotides and seven nucleotide sugars in Chinese Hamster ovary (CHO) cells were determined by capillary electrophoresis (CE). The CE operating conditions of buffer pH value, ion strength, capillary temperature, polymer additive and cell extraction method were investigated. Optimum separation was achieved with 40 mM sodium tetraborate buffer (pH 9.5) containing 1% (w/v) polyethylene glycol (PEG) at a capillary temperature of 22 degrees C. Acetonitrile and chloroform were used for intracellular extraction. This method can be used to monitor intracellular carbohydrate metabolism.     

Determination of local variation of the thickness of the capillary basement membrane of the human placenta at term by a morphometric method

Material was taken from exactly determined sites on five placentas to determine local variation of the thickness of the capillary basement membrane in the normal human placenta at term. The thickness of the capillary basement membrane was determined in electron micrographs by a morphometric method and the resultant values were processed statistically. The results and the method are both discussed.     

Pitfalls of venous occlusion method for determination of capillary pressure in humans

We tested the method of estimating capillary pressure from venous pressure transients obtained after sudden venous clamping in a hydrodynamic model. The basic principles were confirmed in the model, but it was found that when occlusion was caused over a relatively wide distance or in a predistended vessel, capillary pressure was overrated. This problem was due to volume backflow from the occlusion site, since it could be eliminated by placing a one-way valve upstream from the occlusion site. Upstream from the valve, the venous pressure transient accurately followed capillary pressure. Downstream, however, the reading of capillary pressure was impaired by the backflow volume squeezed between valve and occlusion clamp, which caused an immediate large pressure elevation. We also tested the method recently advanced to estimate capillary pressure in humans from venous pressure curves obtained after rapid venous occlusion with an air-filled compression cuff. With the cuff around the upper arm, venous pressure was recorded at different levels along the forearm. The tracings obtained from the dorsum of the hand and halfway along the forearm did not show the initial rapid upstrokes that might indicate the capillary pressure. Tracings obtained slightly below or above the cubital fossa were similar to those seen downstream from the one-way valve in the model. Extrapolation to zero-time, using the distally recorded curves as a template, yielded values equal to venous pressure. We conclude that although the problem of backflow can be circumvented by pressure recording distal from venous valves, the method of venous occlusion by a circular upper-arm cuff may not be appropriate to estimate capillary pressure in humans.     

Determination of urinary succinylacetone by capillary electrophoresis for the diagnosis of tyrosinemia type I

The presence of succinylacetone in urine or blood or amniotic fluid is pathognomonic of an inherited metabolic disorder, named tyrosinemia type I. We developed a capillary electrophoretic method for the fast analysis of succinylacetone in urine samples. The separation was performed at reversed polarity mode using either a cationic surfactant as the buffer additive, or a capillary coated with a positively charged polyelectrolyte. Under these conditions, urine samples were directly injected to the capillary without any pretreatment step. The utility of the method was demonstrated by the identification of succinyacetone in urine from patients with hereditary tyrosinemia type I. For all patients, diagnostic peaks at the expected migration times were detected. The developed method is rapid, simple, inexpensive, and suitable for the determination of succinylacetone in clinical urine samples.     

Application of capillary zone electrophoresis to study the properties of rhodanese fromAcidithiobacillus ferrooxidans

A new capillary zone electrophoretic method was applied to the assay of enzymic activity of rhodanese from Acidithiobacillus ferroxidans. The enzyme activity determined by capillary zone electrophoresis was compared with that determined by discontinuous spectrophotometry, the values obtained being in good agreement. The method was also used to evaluate Michaelis constants of cyanide and thiocyanate as substrates; a new approach was developed to solve the problem with variable ionic strength of the samples. The pH and temperature optima for the enzyme were also determined.     

Optimization and validation of analytical conditions for bovine serum albumin using capillary electrophoresis.

A quick and reproducible capillary electrophoresis method was optimized and validated for the assay of bovine serum albumin (BSA). The effects of various parameters such as pH of buffer, concentration of buffer, capillary dimensions, use of coated capillaries, and additives such as surfactants and protein solubilizers were evaluated. The capillary coatings or additives did not give any advantage in reducing the surface adsorption of BSA on the capillary walls. The optimized conditions include use of borate buffer, pH 8.5 having a concentration of 150 mM in a 27 cm capillary with an aperture window of 100 x 200 microns for detection. The optimized method for the detection of BSA was validated. The interday and intraday coefficient of variation was not greater than 7.59% at BSA concentrations of 25-1000 micrograms/ml. The method developed was reproducible and accurate.     

Rapid quantification of DNA methylation through dNMP analysis following bisulfite-PCR

We report a novel method for rapid quantification of the degree of DNA methylation of a specific gene. Our method combined bisulfite-mediated PCR and quantification of deoxyribonucleoside monophosphate (dNMP) contents in the PCR product through capillary electrophoresis. A specific bisulfite-PCR product was enzymatically hydrolyzed to dNMP monomers which were quantitatively analyzed through subsequent capillary electrophoresis. PCR following bisulfite treatment converts unmethylated cytosines to thymines while leaving methyl-cytosines unchanged. Then the ratio of cytosine to thymine determined by capillary electrophoresis represents the ratio of methyl-cytosine to cytosine in genomic locus of interest. Pure oligonucleotides with known sequences were processed in parallel as standards for normalization of dNMP peaks in capillary electrophoresis. Sources of quantification uncertainty such as carryovers of dNTPs or primers and incomplete hydrolysis were examined and ruled out. When the method was applied to samples with known methylation levels (by bisulfite-mediated sequencing) as a validation, deviations were within ±5%. After bisulfite-PCR, the analytical procedure can be completed within 1.5 h.     

Quantitative changes of the capillary bed in aging human skin

The present study focuses on the quantitative changes of the capillary bed in aging human skin. Forty-five skin samples were excised from the anterior thoracic region of cadavers of caucasian origin in the age range 33-82 years. The immunohistochemical method with anti-human CD34 was used for the detection of the capillary endothelium. Morphometric analysis was done by Vision Assistant software. The capillary bed was quantified by two parameters: capillary area (CA) and intercapillary distance (ID) in 6 age groups. Results revealed no quantitative changes of the capillary bed up to the age of 60 years. In the papillary dermis a significant reduction of the capillary area was seen in the 7th, 8th and 9th decennium. A considerable decrease, by 33%, was determined in the 7th decennium. During the 8th and 9th decennium the capillary area was reduced by a further 19% and 13%. In total from the 4th till the 9th decennium, the capillary bed in the papillary dermis was diminished by 65%. The intercapillary distance in the papillary dermis singnificantly increased during the 8th decennium. On the basis of the mutual evaluation of both the observed parameters, CA and ICD, the authors supposed that the reduction of the capillary bed in the papillary dermis during the 7th decennium was probably caused only by the shortening of the capillary loops, which copied flattened dermal papillae, and during the 8th decennium also by the decreased number of the capillary loops. In the reticular dermis the capillary bed remained unchanged.     

An enzyme immobilized microassay in capillary electrophoresis for characterization and inhibition studies of alkaline phosphatases

A simple and fast dynamically coated capillary electrophoretic method was developed for the characterization and inhibition studies of alkaline phosphatases (EC 3.1.3.1). An inside capillary enzymatic reaction was performed, and hydrolysis of the substrate 4-nitrophenylphosphate to 4-nitrophenol was measured. Fused-silica capillary surface was dynamically modified with polycationic polybrene coating. By reversal of the electroosmotic flow (EOF), analysis time was reduced up to 3 min as the anionic analytes were migrated in the same direction as the EOF. Furthermore, the sensitivity of the method was increased using electroinjection through high-field amplified injection. The baseline separation of 4-nitrophenylphosphate and 4-nitrophenol was achieved by employing 50 mM sodium phosphate as the running buffer (pH 8.5), 0.0025% polybrene, and a constant voltage of −15 kV, and the products were detected at 322 nm. Under the optimized conditions, a good separation with high efficiency was achieved. The new method was applied to study enzyme kinetics and inhibitor screening. K_m and K_i values obtained with the new CE method were compared well with the standard spectrophotometric method. Dynamic coating of fused-silica capillary gave fast and reproducible separation of substrate and product. The method can be easily optimized for inhibition studies of other isozymes.