Determination of tannic acid and its phenolic metabolites in biological fluids by high-performance liquid chromatography.

A method for the identification and determination of tannic acid and its phenolic metabolites in biological fluids by high-performance liquid chromatography was developed. Tannic acid and four phenolic compounds, namely gallic acid, pyrogallol, 4-O-methylgallic acid and ellagic acid, were successfully extracted from the biological fluids by using ethyl acetate at acidic conditions. Gallic acid, pyrogallol and 4-O-methylgallic acid were found in the sheep urine, gallic acid, 4-O-methylgallic acid and ellagic acid in plasma, and gallic acid and ellagic acid in abomasal fluid after abomasal dosing of tannic acid. Tannic acid was found in the plasma apart from the abomasal fluid into which it was administered. The concentrations of tannic acid, gallic acid, pyrogallol, 4-O-methylgallic acid and ellagic acid in plasma, abomasal fluid and urine were measured. This method could be applied to measurement of other hydrolysable tannins and their phenolic metabolites in biological materials.     

淋洗液自动发生-离子色谱法同时测定食品中的21种有机酸

建立了一种利用离子色谱法同时测定样品中奎尼酸、乙酸、丙酮酸、草酰乙酸、甘露酸、乳酸、琥珀酸、苹果酸、酒石酸、草酸、富马酸、抗坏血酸、α-酮戊二酸、肉桂酸、水杨酸、柠檬酸、异柠檬酸、阿魏酸、顺乌头酸、反乌头酸、β-香豆酸等21种有机酸的方法。样品经提取、脱色、过滤后用IonPac AS11分离柱分离,以EG40自动淋洗液发生器生成的5~34 mmol/L KOH为淋洗液洗脱,抑制电导检测器检测。21种有机酸的浓度与其峰面积在一定的范围内呈良好的线性关系,检出限均低于0.188 mg/L,加标回收率为91.5%~101.8%。该法用于多种食物样品中有机酸的测定,结果令人满意。     

离子排斥色谱法同时测定果汁中11种有机酸

 用离子排斥色谱法实现了对果汁中 11种有机酸 (草酸、柠檬酸、酒石酸、苹果酸、抗坏血酸、乳酸、琥珀酸、甲酸、乙酸、戊二酸、富马酸 )的分离测定。以 17mmol/L硫酸为淋洗液 ,样品在ICE ION 30 0离子排斥柱上分离后 ,用紫外检测器在 2 10nm处测定其中的有机酸。各组分质量浓度测定的相对标准偏差在 1.5 %～ 9.8% (n =10 )。     

Use of complexing ligands in the determination of antimony and tin by atomic-absorption spectrometry

The atomic-absorption spectrophotometric determination of antimony is best achieved in the presence of either an ammonium fluoride, hydrochloric acid, nitric acid mixture, or one of the following complexing agents: tartaric acid, citric acid, oxalic acid, 2-mercaptopropanoic acid. The interference of the 29 metals tested is least in the ammonium fluoride-hydrochloric acid-nitric acid mixture and is similar in tartaric acid, citric acid and 2-mercaptopropanoic acid media. However, the interference is pronounced in oxalic acid. Tin can be determined if any of the complexing agents or 6M hydrochloric acid is present.     

紫锥花种属中酚类化合物的HPLC分析

本文报道了一种测定紫锥花草药中咖啡酸、对羟基苯甲酸、对-香豆酸、原儿茶酸、丁香酸、阿魏酸、香草酸、咖啡奎尼酸、洋蓟酸、菊苣酸和紫锥花苷等11种酚类化合物的高效液相色谱分析方法。本法可应用于各种紫锥花草药中酚类化合物的测定。结果表明,在紫锥菊种属中含量最多的酚类化合物是菊苣酸、咖啡奎尼酸和紫锥花苷;在狭叶紫锥菊种属中含量较丰的是紫锥花苷和菊苣酸;而在白花紫锥菊种属中则以紫锥花苷以含量较多。     

Electrolysis of Nitric Acid by Using a Glassy Carbon Fiber Column Electrode System

The electrochemical redox behavior of nitric acid was studied using a glassy carbon fiber column electrode system, and its reaction mechanism was suggested and confirmed in several ways. Electrochemical reactions in less than 2.0M nitric acid was not observed. However, in more than 2.0M nitric acid, the reduction of nitric acid to nitrous acid occurred and the reduction rate was slow so that the nitric acid solution had to be in contact with an electrode for a period of time long enough for an apparent reduction current of nitric acid to nitrous acid to be observed. The nitrous acid generated in more than 2.0M nitric acid was rapidly and easily reduced to nitric oxide by an autocatalytic reaction. Sulfamic acid was confirmed to be effective to destroy the nitrous acid. At least 0.05M sulfamic acid was necessary to scavenge the nitrous acid generated in 3.5M nitric acid.     

Darstellung einiger perfluorbenzol-di-, tri- und tetrasulfonsäuren

1,2,3,4-Tetrafluorbenzenesulfonic acid, 1,2,4,5-tetrafluorobenzenesulfonic acid, 1,2,3,5-tetrafluorobenzenedisulfonic acid, 1,3,5-trifluorobenzene-2,4-disulfonic acid and 1,3,5-trifluorobenzenetrisulfonic acid are obtained by sulfonation of the three isomeric tetrafluorobenzenes, and of 1,3,5-trifluorobenzene, with stabilized SO₃ at normal pressure. Starting from dilithium 1,2,3,4-tetrafluorobenzenedisulphinate 1,2,3,4-tetrafluorobenzenedisulfonic acid can be prepared via oxidation with hydrogen peroxide. Fluorine displacement reactions lead to 1-thiol-2,3,5-trifluorobenzenedisulfonic acid, 1-thiol-2,3,6-trifluorobenzenedisulfonic acid, 1-thiol-2,4,5-trifluorobenzenedisulfonic acid, 1-thiol-2,5-difluorobenzenetrisulfonic acid and 1-thiol-3,5-difluorobenzenetrisulfonic acid, which can be converted into 1,2,4-trifluorobenzenetrisulfonic acid, 1,3-difluorobenzenetetrasulfonic acid and 1,4-difluorobenzenetetrasulfonic acid by oxidation procedures. N.m.r. parameters of the new compounds are described.     

Synthesis of natural pulvinic acids based on a ‘[3+2] cyclization-Suzuki cross-coupling’ strategy

A number of pulvinic acid natural products were prepared based on Suzuki cross coupling reactions of α-hydroxy-γ-alkylidenebutenolides which are readily available by cyclization of 1,3-bis-silyl enol ethers with oxalyl chloride. The formal total synthesis of pulvinic acid, atromentic acid, gomphidic acid and of 4-hydroxypulvinic acid, 4′-hydroxypulvinic acid and iso-gomphidic acid are reported. In addition, total syntheses of pinastric acid, xerocomic acid and variegatic acid were accomplished.     

OH-radical induced degradation of hydroxybenzoic- and hydroxycinnamic acids and formation of aromatic products—A gamma radiolysis study

The OH-radical induced degradation of hydroxybenzoic acids (HBA), hydroxycinnamic acids (HCiA) and methoxylated derivatives, as well as of chlorogenic acid and rosmarinic acid was studied by gamma radiolysis in aerated aqueous solutions. Primary aromatic products resulting from an OH-radical attachment to the ring (hydroxylation), to the position occupied by the methoxyl group (replacement –OCH₃ by ?OH) as well as to the propenoic acid side chain of the cinnamic acids (benzaldehyde formations) were analysed by HPLC–UV and LC–ESI–MS. A comparison of the extent of these processes is given for 3,4-dihydroxybenzoic acid, vanillic acid, isovanillic acid, syringic acid, cinnamic acid, 4-hydroxycinnamic acid, caffeic acid, ferulic acid, isoferulic acid, chlorogenic acid, and rosmarinic acid. For all cinnamic acids and derivatives benzaldehydes were significant oxidation products. With the release of caffeic acid from chlorogenic acid the cleavage of a phenolic glycoside could be demonstrated. Reaction mechanisms are discussed.     

非抑制型电导检测离子排斥色谱法分析有机酸

本文以对甲苯磺，酸加硼酸作为淋洗液，采用非抑制型电导检测，研究了离子排斥色谱法分离和检测苹果酸，抗坏血酸，乳酸，琥珀酸，甲酸，乙酸，丙酸等有机酸的色谱条件，并进行了实际样品的分析。     

Plain Thin-layer Chromatography of Some Herbicides and Related Compounds on Admixture of Barium Sulfate and Calcium Sulphate in Mixed Solvents

Abstract

Some carboxylic herbicides and plant growth regulators such as benzoic acid, 4-chlorophenoxyacetic acid, cinnamic acid, 2,4-D, indole-3-acetic acid, indolepropionic acid, α-naphthalleneacetic acid, β-naphthal eneacetic acid, β-naphthoxyacetic acid, phenoxyacetic acid, TCA and 2,4,5-T have been separated on BaSO₄-CaSO₄ (1:1) coatings in mixed solvent systems.

Quantitative separations of indole-3-acetic acid (100 μg) from 50–100 μg of benzoic acid, α-naphthaleneacetic acid and 2,4,5-T have been carried out successfully.     

芳香胺氰乙基化催化反应的研究进展

从催化剂的应用角度,总结了酸、路易斯酸、固体酸性氧化物、强酸性阳离子交换树脂、无机碱、有机碱以及由酸/路易斯酸、路易斯酸/路易斯酸、路易斯酸/路易斯碱等催化体系在催化芳香胺的氰乙基化反应中的应用进展,阐述了芳香胺的氰乙基化反应的酸催化和碱催化机理,并对芳香胺的氰乙基化反应的今后发展方向进行了展望。     

三乙醇胺交联聚硅氧烷树脂对羧酸吸附性能研究

本文研究了甲酸、乙酸、丙酸和戊酸在三乙醇胺交联聚硅氧烷树脂上的吸附行为。通过其吸附速度、吸附等温线的研究,得出甲酸和乙酸在该树脂上以单分子吸附为主,丙酸和戊酸以多分子吸附为主,而且吸附的强弱与羧酸的解离有关,解离越强吸附越弱,反之,吸附越强。     

Preparation of 2‐, 4‐, 5‐, and 6‐aminonicotinic acid tert‐butyl esters

Procedures are reported to prepare the tert‐butyl esters of 2‐aminonicotinic acid, 4‐aminonicotinic acid, 5‐aminonicotinic acid, and 6‐aminonicotinic acid from 2‐chloronicotinic acid, 4‐chloronicotinic acid, 5‐bromonicotinic acid, and 6‐chloronicotinic acid, respectively, without need for purification of intermediates. J. Heterocyclic Chem., (2012).     

GC/MS法分析奶油中的脂肪酸

利用气相色谱/质谱/计算机联用技术分析人造奶油、天然奶油和新西兰奶油中的脂肪酸,从中鉴定出7种酸:棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸、亚麻油酸及花生酸。人造奶油含亚油酸比天然奶油含的高。     

钨酸催化氧化环己烯合成己二酸

以钨酸/有机酸性添加剂为催化体系, 在无有机溶剂、相转移剂的情况下, 催化30%过氧化氢氧化环己烯合成己二酸. 当钨酸∶有机酸性添加剂∶环己烯∶过氧化氢＝1∶1∶40∶176(摩尔比, 钨酸用量为2.5 mmol)时, 使用有机酸性添加剂考察钨酸的催化性能, 结果表明以钨酸/间苯二酚催化氧化环己烯的催化效果最优, 反应8 h时己二酸分离产率达90.9%、纯度为～100%; 而不使用有机酸性添加剂时, 己二酸分离产率只有72.1%, 产品纯度为96.2%. 当使用磺酸水杨酸、草酸、水杨酸为有机酸性添加剂时, 随反应时间的增加, 己二酸分离产率均升高, 但反应6 h以后, 己二酸分离产率随时间的变化不明显. 当磺酸水杨酸用量为2.5 mmol时, 己二酸分离产率和纯度均较高. 钨酸-磺酸水杨酸催化体系重复使用五次后, 己二酸分离产率仍可达到80.5%.     

添加剂对乙二胺湿法烟气脱硫的影响

采用自主设计的鼓泡吸收装置,以乙二胺溶液为脱硫剂,研究了盐酸、硫酸、磷酸、柠檬酸和硼酸作为添加剂对湿法烟气脱硫的影响。实验结果表明,加入酸添加剂后,提高了吸收液的有效吸收容量。其中,乙二胺/硼酸和乙二胺/磷酸的有效吸收容量较高,分别为266 mg/L和269 mg/L,pH值缓冲效果最佳。同时发现,乙二胺溶液的脱硫率随时间的延长而迅速减小;加入添加剂后,吸收液能在较长时间内保持较高脱硫率。10次吸收-解吸循环实验结果显示,乙二胺/硼酸、乙二胺/磷酸和乙二胺/柠檬酸的平均脱硫率均达99%,SO2解吸顺序为乙二胺/硼酸乙二胺/磷酸乙二胺/柠檬酸。硼酸和磷酸可强化乙二胺湿法烟气脱硫过程,是具有开发前景的添加剂。     

Energetics and structural properties, in the gas phase, of trans-hydroxycinnamic acids

We have studied the energetics and structural properties of trans-cinnamic acid (CA), o-, m-, and p-coumaric acids (2-, 3-, and 4-hydroxycinnamic acids), caffeic acid (3,4-dihydroxycinnamic acid), ferulic acid (4-hydroxy-3-methoxycinnamic acid), iso-ferulic acid (3-hydroxy-4-methoxycinnamic acid), and sinapic acid (3,5-dimethoxy-4-hydroxycinnamic acid). The experimental values of Δ(f)H(m)°(g), determined (in kJ·mol(-1)) for CA (-229.8 ± 1.9), p-coumaric acid (-408.0 ± 4.4), caffeic acid (-580.0 ± 5.9), and ferulic acid (-566.4 ± 5.7), allowed us to derive Δ(f)H(m)°(g) of o-coumaric acid (-405.6 ± 4.4), m-coumaric acid (-406.4 ± 4.4), iso-ferulic acid (-565.2 ± 5.7), and sinapic acid (-698.8 ± 4.1). From these values and by use of isodesmic/homodesmotic reactions, we studied the energetic effects of π-donor substituents (-OH and -OCH(3)) in cinnamic acid derivatives and in the respective benzene analogues. Our results indicate that the interaction between -OCH(3) and/or -OH groups in hydroxycinnamic acids takes place without significant influence of the propenoic fragment.     

Fatty Acid Composition of Pistachio Nuts in Turkey

In this study oil yields and fatty acid compositions in the kernels of two varieties (Uzun and Siirt) of pistachio grown in different region of Turkey were investigated. Kernel oils were obtained by Soxhlet extraction using petroleum ether. The yields were found to be 57.1-58.9% and 56.1-62.6 respectively for the Uzun and Siirt varieties, on a moisture-free basis. Fatty acid composition of oils were analysed by GC/MS in the methyl ester form. Fourteen fatty acid components representing about 99% of the total oils were characterised. Oleic acid (55.4-62.6% and 60.7-65.5%, respectively) was the main fatty acid component in both varieties. Pentadecanoic acid, (Z)-7-hexadecenoic acid, margaric acid, Z-7-octadecenoic acid, arachidic acid, 11-eicosenoic acid, and behenic acid were detected in both varieties for the first time.     

Cytotoxic triterpenes from a Chinese medicine, Goreishi

Bioactivity-guided fractionation of the methanol extract of Goreishi (the feces of Trogopterus xanthipes Milne-Edwards) afforded one new and three known cytotoxic triterpenes, namely, 3-O-cis-p-coumaroyltormentic acid, pomolic acid, 2 alpha-hydroxyursolic acid, and jacoumaric acid. In the course of this investigation, six additional compounds having no cytotoxic activity were isolated, namely, maslinic acid, 3-O-trans-p-coumaroylmaslinic acid, ursolic acid, tormentic acid, euscaphic acid, and a new triterpene, 3-O-trans-p-coumaroyltormentic acid. The structures of the new compounds were established on the basis of X-nucleus-proton correlation with fixed evolution time (XCORFE) and other spectroscopic evidence.