The title compound Fe(CH4N2S)2Cl22(C11H6N2O) (Mr = 643.35) has been prepared and its crystal structure was determined by X-ray diffraction method with the following data: triclinic, space group P1, a = 7.3742(10), b =...The title compound Fe(CH4N2S)2Cl22(C11H6N2O) (Mr = 643.35) has been prepared and its crystal structure was determined by X-ray diffraction method with the following data: triclinic, space group P1, a = 7.3742(10), b = 13.0427(12), c = 15.215(2) , a = 88.969(12), b = 78.004(12), g = 79.689(11)o, V = 1408.1(3) 3, Z = 2, Dx = 1.517 g/cm3, m = 0.912 mm-1 and F(000) = 656. The final R = 0.030 and wR = 0.078 for 4070 observed reflections (I > 2s(I)), and R = 0.064 and wR = 0.091 for 5516 independent ones. The crystal consists of tetrahedral Fe(II) complex and hydrogen bonded 4,5-diazafluoren-9-one (dafone). The carbonyl bridge in dafone distorts the bipyridine moiety and results in the longer N…N separation of 3.071(3) and 3.061(3) ? There exists an extensive intermolecular hydrogen bond network in the crystal, and p-p stacking is observed between the neighboring dafone rings.展开更多
Electrocatalytic oxidation of thiosulfate at the 2,7-BFEFMCPE occurs at a potential about 460 mV less positive than that unmodified carbon paste electrode.The diffusion coefficient(=5.6×10^-5)cm^2 s^-1),the ki...Electrocatalytic oxidation of thiosulfate at the 2,7-BFEFMCPE occurs at a potential about 460 mV less positive than that unmodified carbon paste electrode.The diffusion coefficient(=5.6×10^-5)cm^2 s^-1),the kinetic parameters such as electron transfer coefficient,(=0.5) and kh(=1.21×10^-3 cm s^-1) of thiosulfate oxidation at the surface of,2,7-BFEFMCPE were determined.The electrocatalytic oxidation peak current of thiosulfate showed two linear dynamic ranges(0.0006-0.009 mmol/L and 0.009- 0.900 mmol/L) and a detection limit of 0.00015 mmol/L.This method was also examined as a new electrochemical sensor for the determination of thiosulfate in real sample.展开更多
Concise and efficient three-component domino [4+ 1 + 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cy...Concise and efficient three-component domino [4+ 1 + 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cyanation and aryl amination residing in fluoren-9-one framework were achieved in a one-pot operation. The reaction proceeds at fast rates and can be finished within 30 min, which makes workup convenient to give good to excellent chemical yields.展开更多
In search for new antioxidant agents derived from 6-azauracil, the spiro-5-(flurin-9’-yl)-6-azauracil <strong>3</strong> and their <em>N</em>,<em>N</em>-disubstituted-6-azauracils ...In search for new antioxidant agents derived from 6-azauracil, the spiro-5-(flurin-9’-yl)-6-azauracil <strong>3</strong> and their <em>N</em>,<em>N</em>-disubstituted-6-azauracils <strong>4</strong> - <strong>17</strong> have been synthesized using various methods and reaction conditions. Structure of the new synthesized compounds was deduced from elemental analysis and spectral measurements, for example IR, 1H/13C NMR and mass spectroscopy. The antioxidant evaluation of the new targets showed that the activity increases in the order of <strong>8</strong> > <strong>10</strong> > <strong>6</strong> > <strong>7</strong> > <strong>9</strong> in comparison with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ascorbic acid as standards.展开更多
A study was conducted to improve 9-methoxycanthin-6-one productivity (potential anti-tumour compound) from callus cultures of Emycorna longifolia (Tongkat All). Several factors affecting 9-methoxycanthin-6-one pro...A study was conducted to improve 9-methoxycanthin-6-one productivity (potential anti-tumour compound) from callus cultures of Emycorna longifolia (Tongkat All). Several factors affecting 9-methoxycanthin-6-one production in callus cultures such as different medium compositions and physical factors were investigated and analyzed. Results show that a higher production of 9-methoxycanthin-6-one (3.84 mg-g-1 DW (Dry Weight)) is obtained from callus cultured in 1/4 MS basal media. At fructose of 2% (w/v), the production of 9-methoxycanthin-6-one (4.59 mgg-1DW) is promoted to gain the highest yield, compared to other carbon sources tested. The addition of 2.0-mg·L^-1 dicamba also increases 9-methoxycanthin-6-one production (12.3 mg·g^-1 DW). Higher production of 9-methoxycanthin-6-one was obtained at pH 5.5 (1.53 mg·g^-1 DW). Production of 9-methoxycanthin-6-one (2.34 mg-g^-1 DW) in callus cultures is also increased when the medium is added with 1×10 ^-1μM phenylalanine. This study suggests that the successful production of 9-methoxycanthin-6-one in vitro cultures has a potential in large-scale production using bioreactor technology.展开更多
Photocyclisation of substituted (E)-3-hydroxy-2-(V-methyl-2'-phenylvinyl)-4-oxo-4H-1-benzopyrans to yield linear novel tricyclic 9H-furo[3,2-b]chromen-9-ones and angular fused tetracyclic xanthenones is described.
Crystals of the title compound C22H12N62HCl?H2O (DAA稨Cl) were obtained from a HCl aqueous solution of 4, 5-diazafluorene-9-one azine. The crystal belongs to monoclinic, space group P21/c with a = 5.203(3), b = 8.991(...Crystals of the title compound C22H12N62HCl?H2O (DAA稨Cl) were obtained from a HCl aqueous solution of 4, 5-diazafluorene-9-one azine. The crystal belongs to monoclinic, space group P21/c with a = 5.203(3), b = 8.991(3), c = 22.17(1) , b = 92.13(4), V = 1036.2(9) 3, Z = 2, C22H18N6O2Cl2, Mr = 468.1, Dc = 1.503 g/cm3, F(000) = 484, m(MoKa) = 0.344 mm-1, R = 0.052 and wR = 0.056 for 755 observed reflections. The Cl…N(2) distance of 2.999(6) ?and Cl…HN(2) angle of 160.8(8)o imply the existence of a stronger H-bond between Cl and DAA. And both the rather longer ClH distance of 1.814(2) ?and the unexpected shorter N(2)H distance of 1.236(6) ?suggest the protonation of DAA molecule and explain the weak coordination ability of DAA to a metal center in the acidic solution.展开更多
The esterifications of 9-(hydroxyimino)-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one (4) with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as t...The esterifications of 9-(hydroxyimino)-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one (4) with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger, whereas the reactions gave unexpected 8-substituted products N-(8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-yl)amides (5a-c) and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates (6d-e) by using excessive acid chlorides. The structures of 10 new compounds were determined by 1H NMR, 13C NMR, MS and HRMS, and the possible mechanism for the formation of unexpected products 5a--c and 6d-e was also proposed.展开更多
A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions o...A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.展开更多
目的:寻找番石榴叶乙酸乙酯萃取物中具有降糖活性的功能成分。方法:采用硅胶、羟丙基葡聚糖凝胶柱层析与溶剂重结晶法进行单体分离纯化;通过分析化合物的理化性质、核磁共振谱(nuclear magnetic resonance spectrum,NMR)、质谱(mass spe...目的:寻找番石榴叶乙酸乙酯萃取物中具有降糖活性的功能成分。方法:采用硅胶、羟丙基葡聚糖凝胶柱层析与溶剂重结晶法进行单体分离纯化;通过分析化合物的理化性质、核磁共振谱(nuclear magnetic resonance spectrum,NMR)、质谱(mass spectrum,MS)数据进行结构鉴定;建立降糖脂肪细胞模型评价主要单体的降糖活性。结果:从番石榴叶乙酸乙酯萃取物中共分得14个单体化合物,分别鉴定为:金丝桃苷(化合物1)、异槲皮苷(化合物2)、槲皮素-3-O-β-D-木糖苷(化合物3)、广寄生苷(化合物4)、番石榴苷(化合物5),槲皮素-3-O-(2’’-O-没食子酰基)-α-L-阿拉伯吡喃糖苷(化合物6),槲皮素(化合物7)、没食子酸乙酯(化合物8)、齐墩果酸(化合物9)、β-谷甾醇(化合物10)、isocaryolan-9-one(化合物11)、(-)-epiglobulol(化合物12)、t-cadinol(化合物13)和muurola-4,10(14)-dien-1-ol(化合物14)。降糖脂肪细胞模型测定结果表明,5种主要黄酮苷均具有降糖活性,其中以番石榴苷和广寄生苷降糖效果最好,40μmol/L浓度下促葡萄糖摄取值分别达到了(1.74±0.076)、(1.81±0.029)mmol/L。结论:化合物6、8、11~14为首次从该植物中分得,化合物11为一新的天然产物;番石榴苷和广寄生苷可能为番石榴叶主要降糖活性成分。展开更多
The polymorphic isomer [Cu(dafone)2(H2O)2](Hphth)2 1 (dafone = 4,5- diazafluoren-9-one, phth = 1,2-benzenedicarboxyl) has been synthesized and the structure was determined by single-crystal X-ray diffraction. Crystal ...The polymorphic isomer [Cu(dafone)2(H2O)2](Hphth)2 1 (dafone = 4,5- diazafluoren-9-one, phth = 1,2-benzenedicarboxyl) has been synthesized and the structure was determined by single-crystal X-ray diffraction. Crystal data: C38H26CuN4O12, monoclinic, space group P21/a with a = 11.5863(18), b = 25.512(4), c = 11.878(2) ?, β = 111.696(3)o, V = 3262.1(9) ?3, Mr = 794.17, Z = 4, Dc = 1.617 g/cm3, F(000) = 1628, μ = 0.748 mm-1, R = 0.0603 and wR = 0.1132 for 6878 observed reflections with I > 2σ(I). 1 consists of one [Cu(dafone)2(H2O)2]2+ cation and two monoprotonated 1,2-benzenedicarboxyl (Hphth) anions and forms a two-dimensional hydrogen bond network via intermolecular hydrogen bond interactions between the coordinated water molecules and carboxylato-oxygen atoms from monoprotonated benzenedicarboxyl anions.展开更多
Two new sterol have been isolated from the South China Sea marine organism. Compound 1 was isolated from the sponge Polymastia sobustia and compound 2 was obtained from the soft coral Sinularia inexplicata. Their stru...Two new sterol have been isolated from the South China Sea marine organism. Compound 1 was isolated from the sponge Polymastia sobustia and compound 2 was obtained from the soft coral Sinularia inexplicata. Their structures were established as 3 beta-hydroxy-stigmast-5en-7-one and 24-methylene cholestan -3 beta, 6 beta, 9 alpha, 19-tetrol by variety of spectral analysis such as IR, EIMS, 1DNMR, H-1-H-1 COSY, HMQC, HMBC, NOESY.展开更多
Two new aristolane sesquiterpenes, namely, aristolan-10-ol-9-one and aristolan-8-en-1-one, were isolated from the red alga Laurencia similis. Their structures were established on the basis of various NMR spectroscopic...Two new aristolane sesquiterpenes, namely, aristolan-10-ol-9-one and aristolan-8-en-1-one, were isolated from the red alga Laurencia similis. Their structures were established on the basis of various NMR spectroscopic analyses, including 2D NMR techniques ((1)H–(1)H COSY, HMQC, HMBC, and NOESY) and HR-FAB-MS.展开更多
An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-...An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-pot condensation method is described. The synthesized compounds are screened for further biological activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Bacillus using cut plate method and disc diffusion method.展开更多
3-Arylisothiazolo[5,4-b]quinolin-4(9H)-ones and 3-arylisoxazolo[5,4-b]quinolin-4(9H)-ones were synthesized and assayed for affinity for the benzodiazepine binding site of the GABAA receptors. While the 3-arylisothiazo...3-Arylisothiazolo[5,4-b]quinolin-4(9H)-ones and 3-arylisoxazolo[5,4-b]quinolin-4(9H)-ones were synthesized and assayed for affinity for the benzodiazepine binding site of the GABAA receptors. While the 3-arylisothiazoloquinolin-4-ones were found to be potent ligands, with affinities (expressed as the affinity Ki value) down to 1 nM, the 3-arylisoxazoloquinolin-4-ones are less potent. This is suggested to depend on sterical repulsive interaction of the 3-arylisoxazoloquinolin-4-ones with the receptor essential volume of the binding site, and a higher electron density at the nitrogen in the azole ring (N-2) as well as the carbonyl oxygen in the isothiazoloquinolin-4-ones enabling them to interact stronger with hydrogen bond donor sites at the binding site.展开更多
基金This work was supported by the National Natural Science Foundation of China (29973036)
文摘The title compound Fe(CH4N2S)2Cl22(C11H6N2O) (Mr = 643.35) has been prepared and its crystal structure was determined by X-ray diffraction method with the following data: triclinic, space group P1, a = 7.3742(10), b = 13.0427(12), c = 15.215(2) , a = 88.969(12), b = 78.004(12), g = 79.689(11)o, V = 1408.1(3) 3, Z = 2, Dx = 1.517 g/cm3, m = 0.912 mm-1 and F(000) = 656. The final R = 0.030 and wR = 0.078 for 4070 observed reflections (I > 2s(I)), and R = 0.064 and wR = 0.091 for 5516 independent ones. The crystal consists of tetrahedral Fe(II) complex and hydrogen bonded 4,5-diazafluoren-9-one (dafone). The carbonyl bridge in dafone distorts the bipyridine moiety and results in the longer N…N separation of 3.071(3) and 3.061(3) ? There exists an extensive intermolecular hydrogen bond network in the crystal, and p-p stacking is observed between the neighboring dafone rings.
文摘Electrocatalytic oxidation of thiosulfate at the 2,7-BFEFMCPE occurs at a potential about 460 mV less positive than that unmodified carbon paste electrode.The diffusion coefficient(=5.6×10^-5)cm^2 s^-1),the kinetic parameters such as electron transfer coefficient,(=0.5) and kh(=1.21×10^-3 cm s^-1) of thiosulfate oxidation at the surface of,2,7-BFEFMCPE were determined.The electrocatalytic oxidation peak current of thiosulfate showed two linear dynamic ranges(0.0006-0.009 mmol/L and 0.009- 0.900 mmol/L) and a detection limit of 0.00015 mmol/L.This method was also examined as a new electrochemical sensor for the determination of thiosulfate in real sample.
文摘Concise and efficient three-component domino [4+ 1 + 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cyanation and aryl amination residing in fluoren-9-one framework were achieved in a one-pot operation. The reaction proceeds at fast rates and can be finished within 30 min, which makes workup convenient to give good to excellent chemical yields.
文摘In search for new antioxidant agents derived from 6-azauracil, the spiro-5-(flurin-9’-yl)-6-azauracil <strong>3</strong> and their <em>N</em>,<em>N</em>-disubstituted-6-azauracils <strong>4</strong> - <strong>17</strong> have been synthesized using various methods and reaction conditions. Structure of the new synthesized compounds was deduced from elemental analysis and spectral measurements, for example IR, 1H/13C NMR and mass spectroscopy. The antioxidant evaluation of the new targets showed that the activity increases in the order of <strong>8</strong> > <strong>10</strong> > <strong>6</strong> > <strong>7</strong> > <strong>9</strong> in comparison with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ascorbic acid as standards.
基金supported by IRPA grant MMBPP-FRIM-03-02-04.(Under Malaysia-Massachucetts of Technology USA,MIT Biotechnology Partnership Program)
文摘A study was conducted to improve 9-methoxycanthin-6-one productivity (potential anti-tumour compound) from callus cultures of Emycorna longifolia (Tongkat All). Several factors affecting 9-methoxycanthin-6-one production in callus cultures such as different medium compositions and physical factors were investigated and analyzed. Results show that a higher production of 9-methoxycanthin-6-one (3.84 mg-g-1 DW (Dry Weight)) is obtained from callus cultured in 1/4 MS basal media. At fructose of 2% (w/v), the production of 9-methoxycanthin-6-one (4.59 mgg-1DW) is promoted to gain the highest yield, compared to other carbon sources tested. The addition of 2.0-mg·L^-1 dicamba also increases 9-methoxycanthin-6-one production (12.3 mg·g^-1 DW). Higher production of 9-methoxycanthin-6-one was obtained at pH 5.5 (1.53 mg·g^-1 DW). Production of 9-methoxycanthin-6-one (2.34 mg-g^-1 DW) in callus cultures is also increased when the medium is added with 1×10 ^-1μM phenylalanine. This study suggests that the successful production of 9-methoxycanthin-6-one in vitro cultures has a potential in large-scale production using bioreactor technology.
文摘Photocyclisation of substituted (E)-3-hydroxy-2-(V-methyl-2'-phenylvinyl)-4-oxo-4H-1-benzopyrans to yield linear novel tricyclic 9H-furo[3,2-b]chromen-9-ones and angular fused tetracyclic xanthenones is described.
基金The project was supported by the National Natural Science Foundation (29973036) of China
文摘Crystals of the title compound C22H12N62HCl?H2O (DAA稨Cl) were obtained from a HCl aqueous solution of 4, 5-diazafluorene-9-one azine. The crystal belongs to monoclinic, space group P21/c with a = 5.203(3), b = 8.991(3), c = 22.17(1) , b = 92.13(4), V = 1036.2(9) 3, Z = 2, C22H18N6O2Cl2, Mr = 468.1, Dc = 1.503 g/cm3, F(000) = 484, m(MoKa) = 0.344 mm-1, R = 0.052 and wR = 0.056 for 755 observed reflections. The Cl…N(2) distance of 2.999(6) ?and Cl…HN(2) angle of 160.8(8)o imply the existence of a stronger H-bond between Cl and DAA. And both the rather longer ClH distance of 1.814(2) ?and the unexpected shorter N(2)H distance of 1.236(6) ?suggest the protonation of DAA molecule and explain the weak coordination ability of DAA to a metal center in the acidic solution.
基金grants from the National Natural Science Foundation of China (No.20272010 and 20672022)
文摘The esterifications of 9-(hydroxyimino)-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one (4) with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger, whereas the reactions gave unexpected 8-substituted products N-(8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-yl)amides (5a-c) and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates (6d-e) by using excessive acid chlorides. The structures of 10 new compounds were determined by 1H NMR, 13C NMR, MS and HRMS, and the possible mechanism for the formation of unexpected products 5a--c and 6d-e was also proposed.
文摘A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.
文摘目的:寻找番石榴叶乙酸乙酯萃取物中具有降糖活性的功能成分。方法:采用硅胶、羟丙基葡聚糖凝胶柱层析与溶剂重结晶法进行单体分离纯化;通过分析化合物的理化性质、核磁共振谱(nuclear magnetic resonance spectrum,NMR)、质谱(mass spectrum,MS)数据进行结构鉴定;建立降糖脂肪细胞模型评价主要单体的降糖活性。结果:从番石榴叶乙酸乙酯萃取物中共分得14个单体化合物,分别鉴定为:金丝桃苷(化合物1)、异槲皮苷(化合物2)、槲皮素-3-O-β-D-木糖苷(化合物3)、广寄生苷(化合物4)、番石榴苷(化合物5),槲皮素-3-O-(2’’-O-没食子酰基)-α-L-阿拉伯吡喃糖苷(化合物6),槲皮素(化合物7)、没食子酸乙酯(化合物8)、齐墩果酸(化合物9)、β-谷甾醇(化合物10)、isocaryolan-9-one(化合物11)、(-)-epiglobulol(化合物12)、t-cadinol(化合物13)和muurola-4,10(14)-dien-1-ol(化合物14)。降糖脂肪细胞模型测定结果表明,5种主要黄酮苷均具有降糖活性,其中以番石榴苷和广寄生苷降糖效果最好,40μmol/L浓度下促葡萄糖摄取值分别达到了(1.74±0.076)、(1.81±0.029)mmol/L。结论:化合物6、8、11~14为首次从该植物中分得,化合物11为一新的天然产物;番石榴苷和广寄生苷可能为番石榴叶主要降糖活性成分。
基金This work was supported by the Natural Science Foundation of University of Jiangsu Province (No. 03KJB150118) and the Funds of Key Laboratory of Organic Synthesis of Jiangsu Province.
文摘The polymorphic isomer [Cu(dafone)2(H2O)2](Hphth)2 1 (dafone = 4,5- diazafluoren-9-one, phth = 1,2-benzenedicarboxyl) has been synthesized and the structure was determined by single-crystal X-ray diffraction. Crystal data: C38H26CuN4O12, monoclinic, space group P21/a with a = 11.5863(18), b = 25.512(4), c = 11.878(2) ?, β = 111.696(3)o, V = 3262.1(9) ?3, Mr = 794.17, Z = 4, Dc = 1.617 g/cm3, F(000) = 1628, μ = 0.748 mm-1, R = 0.0603 and wR = 0.1132 for 6878 observed reflections with I > 2σ(I). 1 consists of one [Cu(dafone)2(H2O)2]2+ cation and two monoprotonated 1,2-benzenedicarboxyl (Hphth) anions and forms a two-dimensional hydrogen bond network via intermolecular hydrogen bond interactions between the coordinated water molecules and carboxylato-oxygen atoms from monoprotonated benzenedicarboxyl anions.
文摘Two new sterol have been isolated from the South China Sea marine organism. Compound 1 was isolated from the sponge Polymastia sobustia and compound 2 was obtained from the soft coral Sinularia inexplicata. Their structures were established as 3 beta-hydroxy-stigmast-5en-7-one and 24-methylene cholestan -3 beta, 6 beta, 9 alpha, 19-tetrol by variety of spectral analysis such as IR, EIMS, 1DNMR, H-1-H-1 COSY, HMQC, HMBC, NOESY.
文摘Two new aristolane sesquiterpenes, namely, aristolan-10-ol-9-one and aristolan-8-en-1-one, were isolated from the red alga Laurencia similis. Their structures were established on the basis of various NMR spectroscopic analyses, including 2D NMR techniques ((1)H–(1)H COSY, HMQC, HMBC, and NOESY) and HR-FAB-MS.
文摘An efficient greener one pot synthesis of dimethyl-dihydro-7H-chromeno[3, 2-h]quinolin-8(9H)-one derivatives has been synthesized through cyclization of aromatic aldehyde, dimidone and 8-hydroxy-quinoline through one-pot condensation method is described. The synthesized compounds are screened for further biological activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Bacillus using cut plate method and disc diffusion method.
基金Financial support from the Swedish Board for Scientific Research(VR),the Knut and Alice Wallenberg Foundation,the Research School for Pharmaceutical Sciences at Lund University,Carlsberg Foundation,Denmark,and the NeuroScience PharmaBiotec Research Center,Den-mark,is gratefully acknowledged.
文摘3-Arylisothiazolo[5,4-b]quinolin-4(9H)-ones and 3-arylisoxazolo[5,4-b]quinolin-4(9H)-ones were synthesized and assayed for affinity for the benzodiazepine binding site of the GABAA receptors. While the 3-arylisothiazoloquinolin-4-ones were found to be potent ligands, with affinities (expressed as the affinity Ki value) down to 1 nM, the 3-arylisoxazoloquinolin-4-ones are less potent. This is suggested to depend on sterical repulsive interaction of the 3-arylisoxazoloquinolin-4-ones with the receptor essential volume of the binding site, and a higher electron density at the nitrogen in the azole ring (N-2) as well as the carbonyl oxygen in the isothiazoloquinolin-4-ones enabling them to interact stronger with hydrogen bond donor sites at the binding site.