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Benzoyl
Terms modified by Benzoyl Selected AbstractsX-Ray Structure Analyses of syn/anti -Conformers of N -Furfuroyl-, N -Benzoyl-, and N -Picolinoyl-Substituted (2R)-Bornane-10,2-sultam DerivativesHELVETICA CHIMICA ACTA, Issue 8 2008Karolina Koszewska Abstract The synthesis and the X-ray structure of the three new N -(arylcarbonyl)-substituted derivatives 2a,2c of (2R)-bornane-10,2-sultam are presented and discussed. Direct comparison of the solid-state analyses shows that the dipole-directed SO2/CO anti- /syn- conformations may be very sensitive to weak electronic/electrostatic repulsions of the heteroatom lone pairs. The optimum interactions are reached when the lone pair of the , -positioned heteroatom is oriented in the O(3)C(11)N(1) plane. Such rare syn -conformations may be observed with at least up to 1.8,kcal/mol higher energy as compared to their ground states. Additionally, these anti/syn- conformations are also very sensitive to external influences such as, for example, the crystal-packing forces. [source] Synthesis of phosphorylated 1,3,5-oxadiazines via N -acyltrifluoroacetimidoylphosphonatesHETEROATOM CHEMISTRY, Issue 1 2002Petro P. Onys'ko N -Benzoyl- and N -methoxycarbonyltrifluoroacetimidoylphosphonates react with dimethylcyanamide in a [4+2]-cycloaddition to give 4-phosphorylated 1,3,5-oxadiazines. The structures of the products were confirmed by NMR (1H, 13C, 19F, 31P) and IR spectra and by XRD analysis. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:22,26, 2002; DOI 10.1002/hc.1102 [source] Benzoyl peroxide-initiated copolymerization of citronellol and vinyl acetateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2002Prachi Pandey Abstract The radical copolymerization of citronellol with vinyl acetate (VA) in xylene at 60 ± 0.1 °C for 90 min in the presence of benzoyl peroxide follows ideal kinetics and results in the formation of an alternating copolymer as demonstrated by the values of the reactivity ratios [r1 (VA) = 0.02 and r2 (citronellol) = 0.0002], which have been calculated with the Kelen,Tüdos method. The overall activation energy is computed to be 75 kJ/mol. The IR spectrum of the copolymer shows the presence of bands at 3400 cm,1 due to an alcoholic group and 1750 cm,1 due to a ,CO group. The values of the Mark,Houwink constants for this copolymer system have been determined with gel permeation chromatography to be , = 0.375 and K = 2.4 × 10,4. The glass-transition temperature, determined with differential scanning calorimetry, is 68.32 °C. The mechanism has been elucidated. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1243,1252, 2002 [source] Total Synthesis of Auripyrone,A Using a Tandem Non-Aldol Aldol/Paterson Aldol Process as a Key Step,ANGEWANDTE CHEMIE, Issue 46 2009Michael Als Reindiastereomer entsteht das Polypropionat 3 mit der Titelreaktion aus dem Epoxyalkohol 1 und dem Keton 2. Das Keton wurde für eine effiziente Synthese von Auripyron,A genutzt, wobei die Schlüsselschritte eine hoch regioselektive Halbketalisierung eines Ketodiols und eine späte Spiroketalisierung an einem stabilen Halbketal sind. TBDPS = tert -Butyldiphenylsilyl, Bz = Benzoyl, TES = Trietyhlsilyl. [source] Synthesis and Pharmacological Activity of N-[,-(para-Substituted Benzoyl)ethyl]isoleucine and -methionine.CHEMINFORM, Issue 50 2005A. G. Agababyan Abstract For Abstract see ChemInform Abstract in Full Text. [source] Benzoyl and/or Benzyl Substituted 1,2,3-Triazoles as Potassium Channel Activators.CHEMINFORM, Issue 42 2005Part 8. Abstract For Abstract see ChemInform Abstract in Full Text. [source] Palladium-Catalyzed C2 or C5 Direct Arylation of 3-Formylthiophene Derivatives with Aryl BromidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2010Jia Jia Dong Abstract The system Pd(OAc)2/dppb was found to be an efficient catalyst precursor for the direct arylation of 3-formylthiophene derivatives. When using 3-formylthiophene, the 2-arylated thiophenes were obtained with regioselectivities of 76,86,%, whereas the arylation of 3-formylthiophene diethyl acetal gave the 5-arylated thiophenes with regioselectivities of 64,88,%. These reactions were performed by using only 0.1 mol-% of the catalyst. Moreover, this procedure has been found to be tolerant to a variety of functional groups on the aryl bromide such as formyl, propionyl, benzoyl, nitrile, or nitro. [source] Regioselective C-6 Hydrolysis of Methyl O -Benzoyl-pyranosides Catalysed by Candida Rugosa LipaseEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 10 2009Aslan Esmurziev Abstract Hydrolysis of six methyl O -benzoyl-pyranosides has been investigated using Candida rugosa lipase in dioxane/buffer mixtures. The lipase catalysed the hydrolysis of all substrates in a regiospecific manner at C-6. The rate of reaction was dependent on pyranoside structure, reaction temperature and scale, dioxane concentration and agitation speed. Starting from their C-6 O -benzoyl precursors, the methyl 2,3,4-tri- O -benzoyl-pyranosides of ,- D -galactose, ,- D -galactose, ,- D -glucose, and methyl 2,3-di- O -benzoyl-,- D -galactopyranoside could be isolated in 85,96,% yield. In hydrolysis of methyl 2,3,4,6-tetra- O -benzoyl-,- D -glucopyranoside and methyl 2,3,4,6-tetra- O -benzoyl-,- D -galactopyranoside substrate inhibition were observed, which in part could be overcome by increasing the reaction volume. Methyl 2,3,4,6-tetra- O -benzoyl-,- D -glucopyranoside and methyl 2,3,4,6-tetra- O -benzoyl-,- D -mannopyranoside were poor substrates for Candida rugosa lipase and low degree of conversion towards products were obtained under all conditions. No acyl migration was detected in any of the products.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] C-Glycosidations of a 2-Ketohexosyl Bromide with Electrophilic, Radical, and Nucleophilic Anomeric CarbonsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2003Frieder W. Lichtenthaler Abstract The susceptibility of acylated 2-ketohexosyl halides to C-homologation is demonstrated with the easily accessible tri- O -benzoyl-,- D - arabino -hexos-ulosyl bromide 1 as the model compound. C-Glycosidation with an electrophilic anomeric carbon requires prior carbonyl protection, to avoid carbonyl addition by the C-nucleophile, for example, as the cyanohydrin. Silver triflate-promoted reaction with the silylenol ether of acetophenone then efficiently yields the ,-phenacyl product. With thermal (AIBN) or photochemical induction, 1 smoothly generates an anomeric radical , comparatively electrophilic, due to its capto-dative substitution , which exclusively traps hydrogen in the presence of tributyltin and electron-deficient alkenes. With allyltributylstannanes, however, it reacts with high stereoselectivity to afford ,- C -allyl glycosiduloses. The ,-bromoketone functionality in ulosyl bromide 1 is susceptible to Reformatsky conditions: treatment with zinc-copper couple readily generates the 1,2-enolate, a most simple anomeric nucleophile, which effectively adds to aldehydes to give ,- C -hydroxyalkyl glycosiduloses or ,- C -disaccharides (with sugar aldehydes) with a high degree of double stereoselection. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Isolation and X-Ray Structures of Reactive Intermediates of Organocatalysis with Diphenylprolinol Ethers and with ImidazolidinonesHELVETICA CHIMICA ACTA, Issue 11 20085-Repulsion, A Survey, Comparison with Computed Structures, the Geminal-Diaryl Effect at Work, with 1-Acyl-imidazolidinones: The Abstract Reaction of 2-phenylacetaldehyde with the Me3Si ether of diphenyl-prolinol, with removal of H2O, gives a crystalline enamine (1). The HBF4 salts of the MePh2Si ether of diphenyl-prolinol and of 2-(tert -butyl)-3-methyl- and 5-benzyl-2,2,3-trimethyl-1,3-imidazolidin-4-one react with cinnamaldehyde to give crystalline iminium salts 2, 3, and 4. Single crystals of the enamine and of two iminium salts, 2 and 3, were subjected to X-ray structure analysis (Figs.,1, 2, and 6), and a 2D-NMR spectrum of the third iminium salt was recorded (Fig.,7). The crystal and NMR structures confirm the commonly accepted, general structures of the two types of reactive intermediates in organocatalysis with the five-membered heterocycles, i.e., D, E (Scheme,2). Fine details of the crystal structures are discussed in view of the observed stereoselectivities of the corresponding reactions with electrophiles and nucleophiles. The structures 1 and 2 are compared with those of other diphenyl-prolinol derivatives (from the Cambridge File CSD; Table,1) and discussed in connection with other reagents and ligands, containing geminal diaryl groups and being used in enantioselective synthesis (Fig.,4). The iminium ions 3 and 4 are compared with N -acylated imidazolidinones F and G (Figs.,9, 12, and 13, and Table,3), and common structural aspects such as minimalization of 1,5-repulsion (the ,A1,3 -effect'), are discussed. The crystal structures of the simple diphenyl-prolinol,HBF4 salt (Fig.,3) and of Boc- and benzoyl-(tert -butyl)methyl-imidazolidinone (Boc-BMI and Bz-BMI, resp.; Figs.,10 and 11) are also reported. Finally, the crystal structures are compared with previously published theoretical structures, which were obtained from high-level-of-theory DFT calculations (Figs.,5 and 8, and Table,2). Delicate details including pyramidalization of trigonal N-atoms, distortions around iminium CN bonds, shielding of diastereotopic faces, and the , -interaction between a benzene ring and a Me group match so well with, and were actually predicting the experimental results that the question may seem appropriate, whether one will soon start considering to carry out such calculations before going to the laboratory for experimental optimizations. [source] Kinetics and mechanism for the formation of o -carboxy(N -methyl)-benzohydroxamic acid in the cleavage of ethyl N -[o -(N -methyl- N -hydroxycarbamoyl)-benzoyl]carbamate in N -methylhydroxylamine, acetate, and phosphate buffersINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 9 2003M. Niyaz Khan The rate of cleavage of ethyl N -[o -(N -methyl- N -hydroxycarbamoyl)benzoyl]- carbamate (ENMBC) in the buffer solutions containing N -methylhydroxylamine, acetate + N -methylhydroxylamine, and phosphate + N -methylhydroxylamine followed an irreversible consecutive reaction path: ENMBC where A and B represent N -hydroxyl group cyclized product of ENMBC and o -(N -methyl- N -hydroxycarbamoyl)benzoic acid, respectively. Both rate constants k1 obs and k2 obs showed the presence of buffer catalysis, but buffer catalysis turned out to be weak in the presence N -methylhydroxylamine buffer, while it was strong in the presence of acetate and phosphate ones. Buffer-independent rate constants k10 and k20 increased linearly with the increase in aOH with definite intercepts. The values of molar absorption coefficient of A, obtained under varying total buffer concentrations at a constant pH, showed the presence of a fast equilibrium: A + CH3NHOH , C, where C represents N -[o -(N -methyl- N -hydroxycarbamoyl)methyl]benzohydroxamic acid. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 427,437, 2003 [source] Kinetic evidence for the occurrence of kinetically detectable intermediates in the cleavage of N -ethoxycarbonylphthalimide under N -methylhydroxylamine buffersINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 2 2002M. Niyaz Khan The kinetics of the aqueous cleavage of N -ethoxycarbonylphthalimide (NCPH) in CH3NHOH buffers of different pH reveals that the cleavage follows the general irreversible consecutive reaction path NCPH ENMBC AB, where ENMBC, A, and B represent ethyl N -[o -(N -methyl- N -hydroxycarbamoyl)benzoyl]carbamate, N -hydroxyl group cyclized product of ENMBC, and o -(N -methyl- N -hydroxycarbamoyl)benzoic acid, respectively. The rate constant k1 obs at a constant pH, obeys the relationship k1 obs = kw + knapp [Am]T + kb[Am]T2, where [Am]T is the total concentration of CH3NHOH buffer and kw is first-order rate constant for pH-independent hydrolysis of NCPH. Buffer-dependent rate constant kb shows the presence of both general base and general acid catalysis. Both the rate constants k2 obs and k3 obs are independent of [Am]T (within the [Am]T range of present study) at a constant pH and increase linearly with the increase in aOH with definite intercepts. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 95,103, 2002 [source] Synthesis and biological evaluation of 9-thia-5,10-dideazafolic acidJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2002Mark Wall The folate analogue, 9-thia-5,10-dideazafolic acid (3b), was obtained in an efficient two-step procedure in an overall yield of 60%. The previously unknown intermediate dimethyl-thiocarbamic acid S-(2-amino-3,4-dihydo-4-oxo-pyrido[2,3- d]pyrimidin-6-yl) ester (5) was prepared via the condensation of 2,6-diamino-3H -pyrimidin-4-one and S-(2-malonaldehyde)-1,1,3,3-tetramethylthiouronium bromide (4). Compound 5, in a one pot procedure, was deprotected using sodium hydroxide and then coupled to diethyl N -[(4-chloromethyl)benzoyl]-L-glutamate, followed by saponification of the ethyl esters to give the 9-thia-5,10-dideazafolic acid (3b). Compound 3b was a potent inhibitor of human 5-aminoimidazole-4-carboxamide ribonucleotide transformylase (Ki of 8 ± 5 ,M) and showed no inhibition of human glycinamide ribonu-cleotide transformylase at concentrations as high as 50 ,M. Compound 3b was screened by the National Cancer Institute Developmental Therapeutics Program against 60 human tumors and was found to be active against a leukemia RPMI-8226 cell line where the LC50 was 1 ,M. [source] C, -hydroxymethyl methionine: synthesis, optical resolution and crystal structure of its (+)- N, -benzoyl derivativeJOURNAL OF PEPTIDE SCIENCE, Issue 12 2001Renata Witkowska Abstract (R,S)-Methionine was transformed into C, -hydroxymethyl methionine by a route involving C, -hydroxymethylation of 2-phenyl-4-methylthioethyl-5-oxo-4,5-dihydro-1,3-oxazole. The absolute configuration of (,)- C, -hydroxymethyl methionine was elucidated to be (S) by chemical correlation with (S) (,)- C, -ethyl serine. Absolute structure determination (by single crystal X-ray diffraction) on N, -benzoyl- C, -hydroxymethyl methionine confirmed the (R)-configuration for the (+)-enantiomer. In addition, the X-ray diffraction analysis showed that the C,,, -disubstituted glycyl residue adopts the fully extended (C5) conformation. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd. [source] PNA synthesis using a novel Boc/acyl protecting group strategyJOURNAL OF PEPTIDE SCIENCE, Issue 8 2001Thomas Kofoed Abstract The synthesis of novel Boc/acyl protected monomers for the synthesis of peptide nucleic acid (PNA) is described. The oligomerization protocol using these new monomers has been optimized with regard to coupling reagents. The use of base-labile acyl protecting groups at the exocyclic amines of the heterocyclic bases (isobutyryl for guanine and benzoyl for adenine and cytosine) and a PAM-linked solid support offers an attractive alternative to the present procedures used in PNA synthesis. This strategy has been applied for the synthesis of a test 17mer PNA on both control pore glass (CPG) and a polystyrene MBHA support and was used in the preparation of PNA,DNA chimeras. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd. [source] Synthesis, properties, and solvatochromism of 1,3-dimethyl-5-{(thien-2-yl)-[4-(1-piperidyl) phenyl]methylidene}-(1H,3H)-pyrimidine-2,4,6-trioneJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 4 2007Mohamed El-Sayed Abstract A new merocyanine dye, 1,3-Dimethyl-5-{(thien-2-yl)-[4-(1-piperidyl)phenyl]methylidene}- (1H, 3H)-pyrimidine-2,4,6-trione 3, has been synthesized by condensation of 2-[4-(piperidyl)benzoyl]thiophene 1 with N,N, -dimethyl barbituric acid 2. The solvatochromic response of 3 dissolved in 26 solvents of different polarity has been measured. The solvent-dependent long-wavelength UV/Vis spectroscopic absorption maxima, vmax, are analyzed using the empirical Kamlet,Taft solvent parameters ,* (dipolarity/polarizability), , (hydrogen-bond donating capacity), and , (hydrogen-bond accepting ability) in terms of the well-established linear solvation energy relationship (LSER): (1) The solvent independent coefficients s, a, and b and (vmax)0 have been determined. The McRae equation and the empirical solvent polarity index, ET(30) have been also used to study the solvatochromism of 3. Copyright © 2007 John Wiley & Sons, Ltd. [source] Polysulfone ionomers functionalized with benzoyl(difluoromethylenephosphonic acid) side chains for proton-conducting fuel-cell membranesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 2 2007Benoīt Lafitte Abstract Polysulfones carrying benzoyl(difluoromethylenephosphonic acid) side chains were prepared and investigated for use as proton-conducting fuel-cell membranes. In the first step, polysulfones were lithiated and reacted with methyl iodobenzoates to prepare p - and o -iodobenzoyl polysulfones. Next, the phosphonated polysulfones were prepared via CuBr-mediated cross-coupling reactions between the iodinated polymer and [(diethoxyphosphinyl)difluoromethyl]zinc bromide. Finally, dealkylation with bromotrimethylsilane afforded highly acidic CF2PO3H2 derivatives. The replacement of the iodine atoms by CF2PO3Et2 units was almost quantitative in the case of o -iodobenzoyl polysulfone. Membranes based on ionomers having 0.90 mmol of phosphonic acid units/g of dry polymer took up 6 wt % water when immersed at room temperature, and conductivities up to 5 mS cm,1 at 100 °C were recorded. This level of conductivity was comparable to that reached by a membrane based on a sulfonated polysulfone having 0.86 mmol of sulfonic acid/g of dry polymer. Thermogravimetry revealed that the arylCF2PO3H2 arrangement decomposed at approximately 230 °C via cleavage of the CP bond. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 269,283, 2007. [source] Preparation of oligoamide-ended poly(ethylene glycol) and hydrogen-bonding-assisted formation of aggregates and nanoscale fibersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2005Fengjun Hua Abstract An oligoamide-ended poly(ethylene glycol) (PEG) with a PEG weight-average molecular weight of 5000 (PEG-5000-oligoamide), with 3,5-bis-[2-(5-acetylamino-2-isobutoxy-benzoylamino)-acetylamino]-benzoyl as the oligoamide, was synthesized. PEG-5000-oligoamide aggregated in chloroform or toluene via hydrogen-bonding interactions among the oligoamide strands as a core and PEG, which was soluble in the solvents, as a shell. When a chloroform solution of PEG-5000-oligoamide at a concentration of approximately 0.06 g/L was cast onto a silicon wafer or a mica plate, rapid solvent evaporation induced its self reassembly as nanofibers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1119,1128, 2005 [source] Extended application of a chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid to the resolution of N -(substituted benzoyl)-,-amino acid amidesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2006Guanghui Tan Abstract A chiral stationary phase (CSP 1) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was applied to the resolution of N -(substituted benzoyl)-,-amino acid amides and esters. N -(Substituted benzoyl)-,-amino acid amides were well resolved using a mixture of acetic acid-triethylamine-acetonitrile (0.01 : 0.05 : 100, v/v/v) as an optimum mobile phase while N -(substituted benzoyl)-,-amino acid esters were not resolved at all. In contrast, both N -(substituted benzoyl)-,-amino acid amides and esters were not resolved at all or resolved very poorly on another CSP (CSP 2), which lacks the two N,H hydrogens of the amide tethers of CSP 1. Among the substituents on the benzoyl group of analytes, the nitro group was the best for good resolution of analytes on CSP 1. From these results, the two N,H hydrogens of the amide tethers of CSP 1, the carbonyl oxygen of the amide group of analytes, and the nitro group on the benzoyl group of analytes were concluded to play significant roles in chiral recognition. In addition, various N -(3,5-dinitrobenzoyl)leucine amides with different lengths of N -alkylamide chains were resolved on CSP 1 and N -(3,5-dinitrobenzoyl)leucine N -propylamide was found to show the best chiral recognition in terms of the separation (, = 1.30) and the resolution factor (RS = 3.17). [source] Changes in inhibitory activity and secondary conformation of soybean trypsin inhibitors induced by tea polyphenol complexationJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2009Huihua Huang Abstract BACKGROUND: Tea polyphenol (TP) is a new food additive for antioxidant application, while soybean is an important resource for food and feed processing. It is therefore of rational and practical significance to investigate the influence of TP on soybean trypsin inhibitors (TIs). The aim of this study was to determine the effects of TP on the inhibitory activity of Kunitz (KTI) and Bowman,Birk (BBTI) TIs and to reveal the relationship between the inhibitory activity and conformation of KTI and BBTI by measurement of circular dichroism (CD) spectra. RESULTS: KTI and BBTI were found to be partially deactivated by TP. BBTI exhibited stronger resistance than KTI to TP deactivation. The unchanged KM value of trypsin for benzoyl- DL -arginine- p -nitroanilide hydrolysis indicated that KTI and BBTI inhibited trypsin in a non-competitive pattern when complexed with TP. As the TP/TI ratio was increased and the inhibitory activity of KTI and BBTI decreased, the conformation of KTI and BBTI showed relevant changes and the major CD negative bands shifted progressively towards the near-UV region. CONCLUSION: These results show the deactivation effects of TP on KTI and BBTI and reveal preliminarily the relationship between the inhibitory activity and secondary structure of KTI and BBTI. Copyright © 2009 Society of Chemical Industry [source] Effects of tea polyphenols on the activities of soybean trypsin inhibitors and trypsinJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2004Huihua Huang Abstract Tea polyphenols (TPs) and other materials were extracted from Chinese green tea, and their effects on trypsin inhibitors and trypsin were analysed. TPs were found to have a deactivation effect on both Kunitz trypsin inhibitor (KTI) and Bowman,Birk trypsin inhibitor (BBTI). KTI was more easily deactivated than BBTI by complexing with TPs. The deactivation effect of TPs on KTI and BBTI reached a maximum at a TP/KTI ratio of 25 and a TP/BBTI ratio of 16. However, the deactivation effect of TPs on KTI and BBTI was reduced dramatically when KTI and BBTI were already complexed with trypsin. TPs were also found to inhibit trypsin. The inhibitory activity of TPs, KTI and BBTI on trypsin was found to decrease in the order BBTI > gtTI > gtPs. Complete inhibition of trypsin by TPs could not be achieved. When the TP concentration was increased to about 17 µg ml,1, the residual activity of trypsin was maintained at 400 TU mg,1, equivalent to 32% of the initial trypsin activity. In TP inhibition the KM value for trypsin remained unchanged at 5.88 × 10,4 mol l,1 and Vmax decreased when benzoyl- DL -arginine- p -nitroanilide (BAPNA) was used as substrate. The pattern of trypsin inhibition by TPs is non-competitive. Copyright © 2004 Society of Chemical Industry [source] Fatty acid synthase inhibitory activity of dibenzocyclooctadiene lignans isolated from Schisandra chinensisPHYTOTHERAPY RESEARCH, Issue S2 2010MinKyun Na Abstract Inhibition of fatty acid synthase (FAS) has been proposed to be a new therapeutic target for the treatment of cancer and obesity. In our preliminary screening study on the FAS inhibitory activity, a n -hexane soluble fraction prepared from the fruit of Schisandra chinensis (Schisandraceae) was found to inhibit FAS activity at 100,,g/mL. Nine dibenzocyclooctadiene lignans were isolated from the active fraction and were evaluated for their inhibitory effect on FAS for the first time. The compounds possessing a benzoyl or tigloyl group in the dibenzocyclooctadiene skeleton entirely inhibited the FAS activity in a dose dependent manner. The findings may be partially related to the anticancer effect of the medicinal plant, suggesting a further study on the anticancer potential of dibenzocyclooctadiene derivatives. Copyright © 2010 John Wiley & Sons, Ltd. [source] Formation of b1 -1 and the corresponding a1 -1 product ions in the mass spectra of N- {para -(ferrocenyl)benzoyl} dipeptide estersRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 15 2008Alok Goel First page of article [source] Probing the shapes of chiral bis-(o -naphthalimidobenzoyl) systems using X-ray and circular dichroism methodsACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2009Urszula Rychlewska CD (circular dichroism) and X-ray investigations have been carried out in order to identify the prevalent conformations and define the forces that determine the molecular and supramolecular organization of the alkyl-bridged bichromophoric [NAB, ortho -(1,8-naphthalimido)benzoyl] units, each consisting of the benzoyl substituted in the ortho position with the 1,8-naphthalimide group. The results reveal that NAB bichromophores incorporated into the same molecule exist in a variety of conformation/helicity combinations. The molecular structures are largely stabilized by local 1,3-CH/CO dipole,dipole interactions, while the crystal packing besides dispersive H...H interactions is mostly governed by multiple C,H...O(=C) and C,H..., interactions. The relatively small contribution of ,..., interactions comes from a pairwise off-face stacking between naphthalimide rings or from pairwise carbonyl..., interactions. All these types of intermolecular interactions have been summarized quantitatively by means of a Hirshfeld surface analysis. [source] Two modes of O,H...O hydrogen bonding utilized in dimorphs of racemic 6- O -acryloyl-2- O -benzoyl- myo -inositol 1,3,5-orthoformateACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009Shobhana Krishnaswamy The title compound, C17H16O8, yields conformational dimorphs [forms (I) and (II)] at room temperature, separately or concomitantly, depending on the solvent of crystallization. The yield of crystals of form (I) is always much more than that of crystals of form (II). The molecule has one donor ,OH group that can make intermolecular O,H...O hydrogen bonds with one of the two acceptor C=O groups, as well as with the hydroxyl O atom; interestingly, each of the options is utilized separately in the dimorphs. The crystal structure of form (I) contains one molecule in the asymmetric unit and is organized as a planar sheet of centrosymmetric dimers via O,H...O hydrogen bonds involving the OH group and the carbonyl O atom of the acryloyl group. In the crystal structure of form (II), which contains two independent molecules in the asymmetric unit, two different O,H...O hydrogen bonds, viz. hydroxyl,hydroxyl and hydroxyl,carbonyl (benzoyl), connect the molecules in a layered arrangement. Another notable feature is the transformation of form (II) to form (I) via melt crystallization upon heating to 411,K. The higher yield of form (I) during crystallization and the thermal transition of form (II) to form (I) suggest that the association in form (I) is more highly favoured than that in form (II), which is valuable in understanding the priorities of molecular aggregation during nucleation of various polymorphs. [source] Intramolecular hydrogen-bond-directed coordination: trans -bis(N -benzoyl- N,-propylthiourea-,S)diiodoplatinum(II) and trans -bis(N -benzoyl- N,-propylthiourea-,S)dibromoplatinum(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2004Arjan N. Westra In the title compounds, trans -[PtI2(C11H14N2OS)2], (I), and trans -[PtBr2(C11H14N2OS)2], (II), respectively, intramolecular N,H,O (propylamine side) hydrogen bonds in the potentially bidentate thiourea ligands lock the carbonyl O atoms into six-membered rings, determining the S -monodentate mode of coordination of these ligands. Intramolecular N,H,X (X is I or Br) interactions (benzoylamine side) lead to slight distortions of the PtII coordination spheres from ideal square-planar geometry. The PtII ion is located on an inversion centre in both structures. [source] Pyrazolo[3,4- d]pyrimidine Derivatives as COX-2 Selective Inhibitors: Synthesis and Molecular Modelling StudiesARCHIV DER PHARMAZIE, Issue 6 2009Demetrio Raffa Abstract The pyrazolo[3,4- d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4- d]pyrimidin-4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5-benzamido-1H -pyrazolo[3,4- d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5-aminopyrazole-4(N -benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a,d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological results. [source] Pharmacokinetics and pharmacodynamics of TF-505, a novel nonsteroidal 5,-reductase inhibitor, in normal subjects treated with single or multiple dosesBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 3 2002Tomoe Fujita Aims To assess the tolerability, pharmacokinetics and pharmacodynamics of a novel nonsteroidal,, and,, noncompetitive,, inhibitor,, of,, type,, I,, and,, type,, II,, 5,-reductases, (,)-(S)-4-[1-[4-[1-(4-isobutylphenyl) butoxy]benzoyl]indolizin-3-yl]butyric acid (TF-505), after single and multiple oral doses in healthy volunteers. Methods In the single-dose study, six young adult males in each dose group received 25 mg or 50 mg of TF-505, and six older males (, 40 years) in each dose group received 75 mg or 100 mg of TF-505. The subjects were given the drug in ascending dose and in the fasting state. Six subjects also received 50 mg of TF-505 after breakfast in a two-period crossover manner. In the multiple-dose study, six older males in each dose group received 12.5 mg or 25 mg TF-505 after breakfast daily for 7 days. Plasma concentrations of TF-505, dihydrotestosterone (DHT) and testosterone were measured. The pharmacokinetics of TF-505 were analysed by a compartment model with first-order absorption, first-order elimination and a lag time. Pharmacokinetic and pharmacodynamic relationships were evaluated by indirect response modelling with inhibition of input. Results Maximum plasma concentration (Cmax) and the area under the concentration,time curve (AUC) increased proportionately after the single dose up to 50 mg and with the multiple doses. Linearity was not detected between 75 and 100 mg of TF-505. Dose dependency was also noted for the effect of TF-505 on DHT concentrations following single doses up to 50 mg and multiple doses. Plasma DHT concentrations decreased maximally to 58.2, 49.5, 54.2 and 49.8% of basal values at 8,12 h after single administration of 25, 50, 75 and 100 mg TF-505, respectively, and to 60.5 and 49.4% at the 7th and 5th dose following multiple doses of 12.5 and 25 mg TF-505, respectively. The predicted effect curves matched the observed data when the indirect response model was applied to the time course of the suppressant effect of TF-505 on plasma DHT concentrations after both the single and multiple studies. Fifty percent inhibitory concentrations (IC50) of 0.82, 1.48, 1.31 and 0.88 µ g ml,1, zero-order rate constants for the onset of plasma DHT concentration changes (kin) of 17.8, 17.4, 17.0 and 10.7% h,1 and first-order rate constants,, for,, increase,, in,, plasma,, DHT,, concentrations,, to,, basal,, values,, (kout),, of,, 0.17,,, 0.16,,, 0.17,, and,, 0.10 h,1,, for,, the,, single,, study,, at,, doses,, of,, 25,,, 50,,, 75,, and 100 mg, respectively, were attained. In the multiple-dose study, IC50s were 1.74 and 1.49 µg ml,1 for the 12.5 and 25 mg doses, respectively. No serious adverse events related to TF-505 were observed. Conclusions TF-505 was well tolerated in healthy male volunteers. Accumulation of TF-505 in plasma was not observed during multiple dosing. The indirect response model described the relationships between pharmacokinetics and pharmacodynamics of TF-505. Such modelling is expected to yield an appropriate dosage regimen in subsequent clinical trials. [source] X-ray and 13C solid-state NMR studies of N -benzoyl-phenylalanineCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2000M.J. Potrzebowski Abstract: A crystalline sample of N -benzoyl- dl -phenylalanine 1 and a polycrystalline sample of N -benzoyl- l -phenylalanine 2 were studied using 13C high-resolution solid-state NMR spectroscopy. The X-ray structure of the dl form was established. Sample 1 crystallizes in a monoclinic form with a P21/c space group, a = 11.338(1) Å, b = 9.185(1) Å, c = 14.096(2) Å, ,,= 107.53(3)°, V = 1400(3) Å3, Z = 4 and R = 0.053. The principal elements of the 13C chemical shift tensors ,ii for 1 and 2, selectively 13C (99%) labeled at the carboxyl groups were calculated. On the basis of 13C ,ii analysis the hydrogen bonding pattern for sample 2 was deduced. Enriched samples were used to establish the intermolecular distance between chemically equivalent nuclei for 1 and spatial proximity in heterogeneous domain for 2, employing the ODESSA pulse sequence. The consistence of the complementary approach covering X-ray data, analysis of the 13C ,ii parameters and ODESSA results is revealed. [source] ChemInform Abstract: Synthesis and Evaluation of the ,-Glucosidase Inhibitory Activity of 3-[4-(Phenylsulfonamido)benzoyl]-2H-1-benzopyran-2-one Derivatives.CHEMINFORM, Issue 28 2010Shaojie Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] | ||||||||||||||||||||||||||||||||||