D77, one benzoic acid derivative, functions as a novel anti-HIV-1 inhibitor targeting the interaction between integrase and cellular LEDGF/p75

Integration of viral-DNA into host chromosome mediated by the viral protein HIV-1 integrase (IN) is an essential step in the HIV-1 life cycle. In this process, Lens epithelium-derived growth factor (LEDGF/p75) is discovered to function as a cellular co-fa

Relationship between the allelopathic activity and molecular structure of hydroxyl derivatives of benzoic acid and their effects on cyanobacterium Microcystis aeruginosa

The antialgal activities of benzoic acid, 2-hydroxybenzoic acid (salicylic acid), 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid (gallic acid) were studied on the growth of two strains of Microcystis aeruginosa (toxic FACHB 942 and non-toxic 469). The results showed that the sequence of 50% growth inhibition concentration (ErC50) of 6- compounds for both strains of M. aeruginosa followed the same order: gallic acid > 3,5-dihydroxybenzoic acid > 4-hydroxybenzoic acid > salicylic acid > 3-hydroxybenzoic acid > benzoic acid. The position and the numbers of hydroxy groups between the hydroxy group and carboxyl influenced the antialgal effects of phenolic acids. We also investigated the joint effects of benzoic acid, 4-hydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid on the growth of M. aeruginosa ( toxic FACHB 942). The mixture of phenolic allelochemicals showed the synergistic effects.

Catalytic ring hydrogenation of benzoic acid with supported transition metal catalysts in scCO(2)

The ring hydrogenation of benzoic acid to cyclohexanecarboxylic acid over charcoal-supported transition metal catalysts in supercritical CO2 medium has been studied in the present work. The cyclohexanecarboxylic acid can be produced efficiently in supercritical CO2 at the low reaction temperature of 323 K. The presence of CO2 increases the reaction rate and several parameters have been discussed.

In situ synthesis of terbium-benzoic acid complex in sol-gel derived silica by a two-step sol-gel method

Terbium complexes with benzoic acid and its derivatives o-hydroxybenzoic acid and p-hydroxybenzoic acid were in situ synthesized in sol-gel derived silica matrix via a two-step sol-gel process. The formation process of the complex was characterized by fluorescence spectra, absorption spectra and IR spectra. The gels that contain in situ synthesized complexes exhibit the characteristic emission bands of terbium ion. The fluorescence lifetimes of Tb3+ in the silica gels are longer than those in the pure complexes and in the solutions that contain the corresponding complexes. (C) 2000 Elsevier Science Ltd. All rights reserved.

A new sesquiterpene-substituted benzoic acid from the brown alga Dictyopteris divaricata.

A new sesquiterpene-substituted benzoic acid has been isolated from the brown Alga Dictyopteris divaricata Okam.. Its structure was elucidated as 3-[(2-hydroxy-2,5,5,8a-tetramethyldecahydro-1-naphthalenyl)methyl]-4-hydroxybenzoic acid, named dictyvaric acid on the basis of spectroscopic methods including IR, HRFABMS, 1D and 2D NMR techniques.

Preparation and characterization of novel luminescent sol-gel films containing a RE3+ carboxylic acid complex

RE3+ (Eu3+, Tb3+) complexes with carboxylic acid (salicylic acid and benzoic acid) were introduced into the sol, which was prepared by the hydrolysis of tetraethoxysilane (TEOS). A sol-gel luminescent thin film (SG-LTF) was then prepared by dispersing the sol onto a silica substrate by a spin coating method. Multi-layer luminescent thin films were prepared by repeating the same process. The luminescent spectra, fluorescence lifetime and thermal stability of the SG-LTFs were investigated. For the reason of comparison polyvinylbutyral (PVB) was added into a N,N-dimethylformamide (DMF) solution in which the comparative RE3+ carboxylic acid complexes were previously dissolved to form the DMF/PVB solution and the PVB luminescent thin film (PVB-LTF) was prepared. The results show that a broad excitation band indicates the formation of RE complexes in the solid SG-LTFs. RE ions, which are restrained in the silica matrix, present longer lifetimes and higher thermal stability than that in the PVB-LTF containing the corresponding pure complexes. The different doping concentration of RE (III) complexes in the SG-LTFs and the different change of the emission intensities with the heat treatment temperature in the sol-gel thin film and the sol-gel bulk gel were also discussed in this paper.

CHEMICAL-IONIZATION MASS-SPECTROMETRY OF BENZOYL PEROXIDE - A RADICAL AROMATIC-SUBSTITUTION RESULTING IN BIPHENYLCARBOXYLIC ACID IN THE GAS-PHASE

A radical aromatic substitution resulting in biphenylcarboxylic acid is inferred for the decomposition of benzoyl peroxide from the chemical ionization and collision-induced dissociation mass spectra. The thermolysis of benzoyl peroxide gives rise to a benzoyloxy radical, which undergoes rapid decarboxylation and hydrogen abstraction leading to phenyl radical and benzoic acid, respectively. Attack of the resulting phenyl radical on the benzoic acid results in bipbenylcarboxylic acid. On the other hand, the phenyl radical abstracts a hydrogen atom to yield benzene, which is then subjected to the attack of a benzoyloxy radical, affording phenyl benzoate. This substitution reaction rather than the recombination of benzoyloxy and phenyl radicals is found to be responsible for the formation of phenyl benzoate under the present conditions.

Macrocyclic polyamine-modified poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith for capillary electrochromatography

1,4,10,13,16-Pentaazatricycloheneicosane-9,17-dione (macrocyclic polyamine)-modified polymer-based monolithic column for CEC was prepared by ring opening reaction of epoxide groups from poly(glycidyl methacrylate-co-ethylene dimethacrylate) (GMA-co-EDMA) monolith with macrocyclic polyamine. Conditions such as reaction time and concentration of macrocyclic polyamine for the modification reaction were optimized to generate substantial EOF and enough chromatographic interactions. Anodic EOF was observed in the pH range of 2.0-8.0 studied due to the protonation of macrcyclic polyamine at the surface of the monolith. Morphology of the monolithic column was examined by SEM and the incorporation of macrocyclic polyamine to the poly(GMA-co-EDMA) monolith was characterized by infrared (IR) spectra. Successful separation of inorganic anions, isomeric benzenediols, and benzoic acid derivatives on the monolithic column was achieved for CEC. In addition to hydrophobic interaction, hydrogen bonding and electrostatic interaction played a significant role in the separation process.

西藏胡黄连和鸡矢藤的化学成分及黄芪多糖的提取工艺研究

本论文由四部分组成，前三部分为实验论文，第四部分为文献综述。第一、二部分分别报道了中药西藏胡黄连和鸡矢藤的化学成分研究结果。从两种药用植物中共分离和鉴定了32个化学成分，其中3个为新化合物。第三部分为黄芪多糖的提取工艺研究。第四部分概述了近年来植物多糖的研究进展。 第一章为西藏胡黄连化学成分研究。通过正、反相硅胶柱层析等分离方法从药用植物西藏胡黄连（Picrorhiza scrophulariiflora Pennell）的根茎中共分离纯化出7个化合物。运用MS、1H-NMR、13C-NMR、DEPT、HSQC和HMBC等现代谱学方法，结合理化分析对这些化合物的结构进行了分析鉴定。7个化合物中有两个是酚性的葡萄糖苷类成分：西藏胡黄连酚苷D (1)、4-O-β-D-(6-O-vanilloyl glucopyranosyl) vanillic acid (6)；四个苯乙基苷类化合物：plantamajoside (2)、plantainoside D (3)、西藏胡黄连苷A (4) 和西藏胡黄连苷F (5)；一个苯基小分子化合物：香豆酸甲酯 (7)。其中化合物1和5未见文献报道，确定为新化合物；化合物3为首次从该种植物中分到。 第二章为鸡矢藤化学成分研究。从鸡矢藤（Paederia scandense (Lour) Merrill）全草中分离出25个化合物，通过理化常数和波谱数据鉴定了它们的结构。25个化合物中包括一个蒽醌类成分：茜根定-1-甲醚 (1)；两个香豆素：异东莨菪香豆素 (2)和5-羟基-8-甲氧基吡喃香豆素 (3)；两个香豆素-木脂素化合物：臭矢菜素 B (4)和臭矢菜素 D (5)；一个木脂素：异落叶松树脂醇 (6)；两个黄酮：diadzein (7)和蒙花苷 (8)；三个三萜类化合物：齐墩果酸 (9)、乌苏酸 (10)和 3-O-β-D-吡喃葡萄糖基乌苏烷 (11)；三个甾体及其糖苷：b-谷甾醇 (12)、胡萝卜苷 (13)和(24R)-豆甾-4-烯-3-酮 (14)；六个小分子化合物：对羟基苯甲酸 (15)，咖啡酸 (16)，香豆酸 (17)，丁烯二酸 (18)，3,5-二甲氧基-4-羟基苯甲酸(19)，咖啡酸-4-O-β-D-吡喃葡萄糖苷(20)；五个环烯醚萜类化合物：鸡矢藤苷 (21)，鸡矢藤酸 (22)，鸡矢藤酸甲酯 (23)，saprosmoside E (24)和paederoside B (25)。其中化合物25未见文献报道，为新化合物。化合物1～8、11、14、15～20为首次从该化合物中分离得到。同时对鸡矢藤中环烯醚萜类化合物做了高效液相-串联质谱(HPLC-MSn)分析，探讨了这类化合物的质谱裂解规律。 第三章为黄芪多糖的提取工艺研究。首先确定了黄芪多糖含量的测定方法，并进行了方法学验证；其次探讨了黄芪中黄芪多糖的提取工艺，确定以酶法-Sevag法联用来去除黄芪多糖中的蛋白质，可使其提取物中黄芪多糖总含量达到70％以上。 第四章为近年来植物多糖的研究进展。主要包括植物多糖的提取纯化、多糖的定性定量检测方法、多糖的结构分析和多糖的药理活性。 This dissertation consists of four parts. The first and second parts reports the studies on the chemical constituents of medicinal plants of Picrorhiza Scrophulariiflora and Paederia scandens. The third part is about the extract technique of Astragalan Polysaccharide (APS). The last part reviews the progress of the studies on plant polysaccharides. 　 The first chapter is about the chemical constituents of P. Scrophulariiflora which is widely used as an important medicine to treat various immune-related diseases. A new phenyl glycoside, scrophenoside D (1) and a new phenylethyl glycoside, scroside F (5), together with five known compounds, plantamajoside (2), plantainoside D (3), scroside A (4), 4-O-β-D-(6-O-vanilloylglucopyranosyl) vanillic acid (6); and methyl-p-coumarate (7) were isolated from the stems of P. scrophulariiflora. Their structures were elucidated by spectroscopic and chemical methods. The second chapter is about the chemical constituents of medicinal herb of P. scandens. Twenty-five compounds were isolated and purified by normal and reversed phase silica gel column chromatography. By physicochemical properties and spectral analysis, their structures were identified as rubiadin-1-methylether (1), isoscopoletin (2), 5-hydroxyl-8-methoxyl-coumarin (3), cleomiscosin B (4), cleomiscosin D (5), isolariciresinol (6), diadzein (7), linarin (8), oleanolic acid (9), ursolic acid (10), 3-O-β-D-glucopyranosyloxyl-ursane (11), b-sitosterol (12), b-daucosterol (13), (24R)-stigmast-4-ene-3-one (14), p-hydroxyl-benzoic acid (15), caffic acid (16), coumaric acid (17), trans-butenedioic acid (18), 3,5-dimethoxyl-4-hydroxylbenzoic acid (19), caffeic acid 4-O-β-D-glucopyranoside (20), paederoside (21), paederosidic acid (22), paederosidic acid methyl ester (23), saprosmoside E (24), paederoside B (25). Among them, compound 25 is a new compound. Compounds 1～8、11、14、15～20 were isolated from this plant for the first time. Futhermore, we studied the HPLC-MSn analysis and investigation of fragmentation behavior of the sulfur-containing iridoid glucosides. The third chapter is about the extracting process of Astragalan Polysaccharide (APS). The method of the content determination is built. The optimum condition of extraction of polysaccharides from Radix Astragali is defined and the more effective way to remove protein is combined enzyme method with Sevag method, by which the content of polysaccharides extract can be up to 70%. The last part is a review of the research progress of the plant polysaccharides, which includes its extraction, isolation, purification, determination, structure analysis, and pharmacology.

钮子瓜和袋花忍冬的化学成分研究

钮子瓜（Zehneria maysorensis Arn.）是一种常用的中草药，其性味苦、凉，主要功效为清热利湿、散风止痛，主治膀胱炎、头痛。体外活性筛选实验表明，袋花忍冬（Lonicera saccata Rehd.）95%乙醇提取物的乙酸乙酯部分对血管紧张素转化酶显示较强的抑制活性。为明确钮子瓜的药用物质基础和袋花忍冬中具有ACE抑制活性的成分，首次对两个植物的成分进行了研究。 1. 从钮子瓜95%乙醇提取物中主要通过色谱方法首次分离了14个化合物，通过波谱方法鉴定为(2S,3S,4R,10E)-2-[(2R)-2-羟基二十四烷酰基氨基]-10-十八烷-1,3,4-三醇（1）、(2S,3S,4R)-2-二十四烷酰基氨基-十八烷-1,3,4-三醇 （2）、胡萝卜苷（3）、swertish （4）、苯甲酸（5）、水杨酸（6）、loliolide （7）、胸腺嘧啶（8）、尿嘧啶（9）、(23Z)-9,19-环阿尔廷-23-烯-3β,25-二醇（10）、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇（11）、十六烷酸 1-甘油酯（12）、大豆脑苷Ⅰ（13）和(22E,24S)-24-甲基-5α-胆甾-7,22-二烯-3β,5α,6β-三醇（14）。其中化合物4为一黄酮碳苷，具有旋转异构现象，有止痛作用；化合物6具有抗炎、镇痛、减热的活性，它们可能是钮子瓜药用物质基础的一部分。 2. 从袋花忍冬95%乙醇提取物中首次分离并鉴定了16个已知化合物：胡萝卜苷（3）、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇（11）、十六烷酸 1-甘油酯（12）、E-p-coumaryl behenate (15)、谷甾醇（16）、2,6-dihydroxyhumula-3(12), 7(13),9(E)-triene (17)、环阿尔廷-25-烯-3β,24ξ-二醇 (18)、二十四烷酸 (19)、2,4-二羟基-3,6-二甲基苯甲酸甲酯 (20)、乌苏酸 (21)、柚皮素 (22)、木犀草素 (23)、柏双黄酮（24）咖啡酸 (25)、洋芹素（26）和木犀草素-7-O-β-D-葡萄糖苷 (27)。其中木犀草素（23）和咖啡酸（25）含量较高，它们为抑制ACE活性的成分。 3．综述了黄酮碳苷的旋转异构现象。 Zehneria maysorensis is a folk medicine for the treatment of cystitis and headache. The ethyl acetate soluble fraction of the 95% ethanol extract of Lonicera saccata showed obvious ACE inhibitory activity in vitro. To reveal their active constitutents, they were subjected to chemically study. From the 95% ethanol extract of the whole plants of Zehneria maysroensis fourteen compounds were isolated for the first time. On the basis of spectral data and/or by comparison with authentic samples, they were characterized to be (2S,3S,4R,10E)-2-[(2R)-2-hydroxytetracosanoylamino]-10-octadecene-1,3,4-triol (1), (2S,3S,4R)-2-tetracosanoylamino-1,3,4-octadecanetriol (2), daucosterol (3), swertish (4), benzoic acid (5), salicylic acid (6), loliolide (7), thymine (8), uracil (9), (23Z)-9,19-cycloart-23-ene-3β,25-diol (10), (20S,22E,24R)-5α,8α-epidioxy-ergosta- 6,22-diene-3β-ol (11), 2,3-dihydroxypropyl hexadecoate (12), soya-cerebroside (13) and (22E,24S)-24-methyl-5α-cholesta-7,22-diene-3β,5α,6β-triol (14). Compound 4, a C-glycosylflavone, showed a very interesting rotational isomerism. Compounds 4 and 6 may be the active constituents of Zehneria maysorensis considering their sedative and anti-inflammation activity, respectively. From the whole plants of Lonicera saccata, sixteen compounds were isolated for the first time. On the basis of spectral data and/or by comparison with authentic samples, they were identified to be daucosterol (3), (20S,22E,24R)-5α,8α-epidioxy- ergosta-6,22-diene-3β-ol (11), 2,3-dihydroxypropyl hexadecoate (12), E-p-coumaryl behenate (15), β-sitosterol (16), 2,6-dihydroxyhumula-3(12),7(13),9(E)-triene (17), cycloart-25-ene-3β,24ξ-diol (18), tetracosanoic acid (19), methyl 2,4-dihydroxy- 3,6-dimethylbenzoate (20), ursolic acid (21), naringenin (22), luteolin (23), cupressuflavone (24), caffeic acid (25), apigenin (26) and luteolin-7-O-β-D- glucopyranoside (27). Luteolin (23) and caffeic acid (25) were the ACE inhibitory active constituents. Rotational isomerism for C-glycosylflavonoid was reviewed.

Determination of photochemically produced hydroxyl radicals in seawater and freshwater

A variety of short-lived, reactive chemical species (i.e. free radicals and excited state species) are known to be photochemically produced in natural waters. Some of these transients may strongly affect chemical and biological processes, and they have been implicated in the degradation of organic pollutants and natural organic compounds in aqueous environments. Previous studies demonstrated that the highly reactive hydroxyl radical (OH) is photochemically formed in seawater. However, the quantitative importance of this key species in the sea has not been previously studied because of past analytical limitations. By using a highly sensitive probe based on α-H atom abstraction from methanol, we were able to measure production rates and steady-state concentrations of photochemically produced OH radicals in coastal and open ocean seawater and freshwaters. The validity of the method was tested by intercalibrating with an independent, OH-specific reaction, hydroxylation of benzoic acid, and also by competition kinetics experiments. Our OH production rates and steady-state concentrations for freshwaters are in excellent agreement with those measured by previous investigators for similar waters. In contrast, for seawater, the values we measured are 1–3 orders of magnitude higher than previously predicted by models, indicating that there is a major unknown photochemical OH source (s) in seawater.

Novel hybrid periodic mesoporous organosilica material grafting with Tb complex: Synthesis, characterization and photoluminescence property

A novel periodic mesoporous organosilica (PMO) material was synthesized through one-step co-condensation of 1,2-bis(triethoxysilyl)ethane (BTESE) and benzoic acid-functionalized organosilane (BA-Si) using cetyltrimethylammonium bromide (CTAB) as a structure-directing agent under basic conditions. The materials were fully characterized by FTIR, XRD, N-2 adsorption-desorption isotherms and FESEM. FTIR spectra proved that BA-Si was successfully incorporated into the PMO materials (PMOs) via benzyl group as a linker. XRD and N-2 adsorption-desorption isotherms revealed the characteristic mesoporous structure with highly uniform pore size distributions. FESEM confirmed that the morphology of the PMOs was significantly dependent cri the molar ratio of two organosilica precursors.