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941.
Changlun Shao Zhiyong Guo Hong Peng Guangtian Peng Zhongjing Huang Zhigang She Yongcheng Lin Shining Zhou 《Chemistry of Natural Compounds》2007,43(4):377-380
A new isoprenyl phenyl ether, 3-hydroxy-4-(3-methylbut-2-enyloxy)benzoic acid methyl ester (1), together with 4-hydroxybenzoic acid (2), 2-hydroxy-6-methylbenzoic acid (3), and 4-hydroxy-3-methoxybenzoic acid (4) were isolated from Mangrove fungus (No. B60) from the South China Sea. The structures of the compounds were established
on the basis of NMR spectroscopic and mass spectrometric data. In the preliminary bioassay, compound 1 exhibited antibacterial and antifungal activities. Compound 1 also inhibited cytotoxicity to the hepG2 cell line with an IC50 value of 10.0 μg/mL.
Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 313–314, July–August, 2007. 相似文献
942.
Tomislav Došlić 《Journal of mathematical chemistry》2007,41(3):217-229
A global forcing set in a simple connected graph G with a perfect matching is any subset S of E(G) such that the restriction of the characteristic function of perfect matchings of G on S is an injection. The number of edges in a global forcing set of the smallest cardinality is called the global forcing number
of G. In this paper we prove several results concerning global forcing sets and numbers of benzenoid graphs. In particular, we
prove that all catacondensed benzenoids and catafused coronoids with n hexagons have the global forcing number equal to n, and that for pericondensed benzenoids the global forcing number is always strictly smaller than the number of hexagons. 相似文献
943.
Antonilêni F. D. Medeiros Ana Flávia O. Santos F. S. de Souza I. D. B. Júnior J. Valdilânio J. V. V. Procópio D. P. de Santana R. O. Macêdo 《Journal of Thermal Analysis and Calorimetry》2007,89(3):775-781
Compatibility studies between active drugs and excipients are substantial in the pharmaceutical technology. The objective
of the present work was to develop pre-formulated mixtures of metronidazole (MT) obtained by spray drying (SPDR) and their
thermoanalytical characterization. Dynamic and isothermal TG, conventional DSC and DSC coupled to a photovisual system were
used. DSC experiments with both techniques confirmed the homogeneity of the conventional and pre-formulated mixtures. The
TG data made possible the comparison the thermal stability of the different mixtures. Similar thermal stabilities were found
of the conventional and pre-formulated mixtures, with slower particles sizes of MT. 相似文献
944.
Ju Tao LIU Xiao Hong WANG Jing Fu LIU Faculty of Chemistry Northeast Normal University Changchun 《中国化学快报》2004,15(7):859-862
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pi, a = 8. 4960 (17), b = 10.447 (2), c = 11.299 (2) A, α= 68. 82 (3)°,β= 87.35 (3)°, γ = 66.97(3)°. V = 855. 3(3) A3, Z = 8, R1 = 0. 0857, wR2=0. 2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid. 相似文献
945.
Sham M. Sondhi Shefali Rajvanshi Nirupma Singh Shubhi Jain Anand M. Lahoti 《Central European Journal of Chemistry》2004,2(1):141-187
Non steroidal anti-inflammatory drugs are the most widely used medicines for relief of pain. These drugs have some side effects,
particularly toxicity in the gastrointestinal tract and kidneys. Various approaches have been used for obtaining safer anti-inflammatory
drugs. In this review we have summarized the recent developments in the following areas; (i) mode of action of NSAIDs (ii)
Role of COX-1 & COX-2 in inflammation, (iii) Different approaches used to improve gastric tolerance i.e. chemical manipulation,
formulation & co-administration, development of non specific (COX-1 & COX-2 inhibitors) and specific (COX-2 inhibitors) inflammation
inhibitors, and development of inflammation inhibitors having a mode of action other than COX-1 & COX-2 inhibition. We have
also focused on the safety of COX-2 inhibitors and the synthesis of heterocyclic compounds and their role as inflammation
inhibitors. 相似文献
946.
The goal of the present study is to test the hypothesis that LPA induces proliferation of astrocytes in hippocampus in vivo via phosphorylation of ERK 1/2. We first characterized the expression of GFAP, a special marker fiber protein of astrocytes,
in brain slices after direct injection of LPA into hippocampus by immunohistochemistry, and found that LPA induced a remarkable
proliferation of astrocytes. Then double-lablled immunofluorescence was used to detect GFAP and phosphorylation ERK 1/2 (p-ERK
1/2), LPA induced an immediate (10 min) and transient (<30 min) phosphorylation of ERK 1/2, and sequence sustained activation
of ERK 1/2 was observed, which last for at least 3 weeks after injection of LPA. Reactions are inhibited by U0126, a specific
pharmacological mitogen-activated protein kinase (MEK) inhibitor. Laser confocal scanning was used to study spatial relationship
of p-ERK and astrocytes. Amazingly, the early (<7 days) phosphorylation of ERK 1/2 is not expressed in astrocytes but in area
where neurons and/or in other cell type(s) occupied, expression of p-ERK 1/2 in astrocytes is not detected until 14 days after
LPA injection and lasts for at least 3 weeks. Taken together, these data suggest that LPA play an important role in proliferation
of astrocytes through phosphorylation of ERK 1/2 in hippocampus. It provides further proof for the functions of LPA in CNS
injury, and may contribute to clinical therapy for relative diseases. 相似文献
947.
An efficient palladium-catalyzed amination of aromatic bromides with hindered N-alkyl-substituted anilines is described, either using the combination of Pd(OAc)(2) and P(t-Bu)(3) or a palladium(I) tri-tert-butylphosphine bromide dimer, [Pd(mu-Br)(t-Bu(3)P)](2), a new, commercially available, and easily handled catalyst. 相似文献
948.
A high-performance capillary electrophoretic (CE) method with electrochemical detection (ED) has been developed for determination of the pharmacologically active flavonoids in Ginkgo biloba L. and phytopharmaceuticals containing its extract. Epicatechin, catechin, rutin, apigenin, luteolin, and quercetin are important flavonoids in this plant. Operated in a wall-jet configuration, a 300 micro m diameter carbon-disk electrode was used as working electrode with good response to the six analytes at +1000 mV (relative to the SCE). Under the optimum conditions, the analytes were separated within 22 min in a borax buffer (pH 9.0). Excellent linearity was obtained over two orders of magnitude and detection limits (S/N=3) ranged from 1.4 x 10(-7) to 5.0 x 10(-7) g mL(-1) for all six analytes. The method was successfully used for assay of Ginkgo biloba L. and its phytopharmaceuticals after a relatively simple extraction procedure; the results obtained were satisfactory. 相似文献
949.
Robert Weis Reto Brun Robert Saf Werner Seebacher 《Monatshefte für Chemie / Chemical Monthly》2003,134(7):1019-1026
Summary. 4-Aminobicyclo[2.2.2]octanones which were prepared in one-pot-reactions from benzylidene acetone and dialkylammonium rhodanides
were reduced stereoselectively to their corresponding alcohols. The activities of the bicyclic compounds against causative
organisms of tropical deseases were examined. The 4-aminobicyclo[2.2.2]octan-2-ols were in general more active against Trypanosoma b. rhodesiense and Plasmodium falciparum than the corresponding keto compounds.
Corresponding author. E-mail: robert.weis@uni-graz.at
Received November 27, 2002; accepted December 2, 2002
Published online May 2, 2003 相似文献
950.
WO3 and WO3:P (5 mol% H3PO4) thin films were prepared using the sol-gel route and the electrochromic properties of the films were investigated using
in situ spectroelectrochemical methods. The measurements were performed in propylene carbonate solution with 0.1 M LiClO4 as electrolyte. During the cathodic polarization at –0.8 V a blue coloration is observed with a reversible variation between
14% and 84% of the transmittance at λ=633 nm. The kinetics for the bleaching process is faster for the WO3:P film than for the undoped WO3 film.
Electronic Publication 相似文献