Synthesis and Structure Assignment of 2-(4-Methoxybenzyl)cyclohexyl β-D-Glucopyranoside Enantiomers

2006 ◽  
Vol 71 (10) ◽  
pp. 1470-1483 ◽  
Author(s):  
David Šaman ◽  
Pavel Kratina ◽  
Jitka Moravcová ◽  
Martina Wimmerová ◽  
Zdeněk Wimmer
Keyword(s):  
Analytical Data ◽  
Chiral Hplc ◽  
Nmr Analysis ◽  
Target Structure ◽  
Enantiomerically Pure ◽  
Whole Cells ◽  
H Nmr ◽  
Structure Assignment ◽  
Related Compounds ◽  
C Nmr

Glucosylation of the cis- and trans-isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a/1b, 2a/2b, 1a or 2a) was performed to prepare the corresponding alkyl β-D-glucopyranosides, mainly to get analytical data of pure enantiomers of the glucosides (3a-6b), required for subsequent investigations of related compounds with biological activity. One of the employed modifications of the Koenigs-Knorr synthesis resulted in achieving 85-95% yields of pure β-anomers 3a/3b, 4a/4b, 3a or 4a of protected intermediates, with several promoters and toluene as solvent, yielding finally the deprotected products 5a/5b, 6a/6b, 5a or 6a as pure β-anomers. To obtain enantiomerically pure β-anomers of the target structure (3a, 4a, 5a and 6a) for unambiguous structure assignment, an enzymic reduction of 2-(4-methoxybenzyl)cyclohexan-1-one by Saccharomyces cerevisiae whole cells was performed to get (1S,2S)- and (1S,2R)-enantiomers (1a and 2a) of 2-(4-methoxybenzyl)cyclohexan-1-ol. The opposite enantiomers of alkyl β-D-glucopyranosides (5b and 6b) were obtained by separation of the diastereoisomeric mixtures 5a/5b and 6a/6b by chiral HPLC. All stereoisomers of the products (3a-6b) were subjected to a detailed 1H NMR and 13C NMR analysis.

scholarly journals Synthesis of compounds related to the anti-migraine drug eletriptan hydrobromide

2012 ◽  
Vol 8 ◽  
pp. 1400-1405 ◽  
Author(s):  
Suri Babu Madasu ◽  
Nagaji Ambabhai Vekariya ◽  
M N V D Hari Kiran ◽  
Badarinadh Gupta ◽  
Aminul Islam ◽  
...  
Keyword(s):  
Mass Spectroscopy ◽  
Acute Treatment ◽  
Selective Serotonin ◽  
Spectroscopic Techniques ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
H Nmr ◽  
Related Compounds ◽  
C Nmr ◽  
Anti Migraine Drug

Eletriptan hydrobromide (1) is a selective serotonin (5-HT1) agonist, used for the acute treatment of the headache phase of migraine attacks. During the manufacture of eletriptan hydrobromide the formation of various impurities were observed and identified by LC–MS. To control the formation of these impurities during the preparation of active pharmaceutical ingredients, the structure of the impurities must be known. Major impurities of the eletriptan hydrobromide synthesis were prepared and characterized by using various spectroscopic techniques, i.e., mass spectroscopy, FTIR , 1H NMR, 13C NMR/DEPT, and further confirmed by co-injection in HPLC. The present study will be of great help in the synthesis of highly pure eletriptan hydrobromide related compounds.

Synthesis of Several Hydroxylated 23-(Benzimidazol-2-yl-, Benzoxazol-2-yl and Benzothiazol-2-yl)norcholanes and Some Related Compounds

1995 ◽  
Vol 60 (2) ◽  
pp. 257-275 ◽  
Author(s):  
Thi Thu Huong Nguyen ◽  
Jiří Urban ◽  
Eva Klinotová ◽  
Jan Sejbal ◽  
Jiří Protiva ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Succinic Anhydride ◽  
Benzimidazole Derivative ◽  
Acid Chlorides ◽  
H Nmr ◽  
Hydroxy Compounds ◽  
Related Compounds ◽  
Anti Hiv ◽  
C Nmr

The bile acids Ia - Id (lithocholic, chenodeoxycholic, deoxycholic, cholic) and their derivatives (O-acetylated acids and O-acetylated acid chlorides) reacted under various conditions with 1,2-diaminobenzene, 2-aminophenol and 2-aminothiophenol and afforded the title benzimidazoles II and VII, benzoxazoles V and benzothiazoles VI. Alkylation of the benzimidazole derivative IIa with 2-dimethylaminoethyl chloride resulted in 3α-hydroxy-23-[1-(2-dimethylaminoethyl)ben zimidazol-2-yl]- norcholane (IVa). The use of 1,2-diamino-4-methylbenzene enabled the preparation of 3α-acetoxy-23-[5(6)-methylbenzimidazol-2-y l]norcholane (VIII). Reactions of the 3α-hydroxy compounds IVa, Va and VIa with succinic anhydride resulted in the hemisuccinates IVi - VIi. The boric acid mediated condensation of O-acetyllithocholic acid (Ie) with 3,4-diaminopyridine gave compound X which was transformed to 3α-acetoxy-23-[1H-imidazo(4,5- c)pyridin-2-yl]norcholane (IX). The structure of the products was corroborated by the mass, IR, 1H NMR and 13C NMR spectra. Some of the compounds were tested for antileukemic and for the anti-HIV activity in vitro.

1,2-Bis(1-aryl-3-alkyltriazen-3-yl)ethanes and related compounds

1998 ◽  
Vol 76 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Donald L Hooper ◽  
Ian R Pottie ◽  
Marc Vacheresse ◽  
Keith Vaughan
Keyword(s):  
Nmr Spectroscopy ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Ir And Nmr Spectroscopy ◽  
Diazonium Coupling ◽  
Significant Line ◽  
Related Compounds ◽  
C Nmr

A series of novel bistriazenes, the 1,2-bis(1-aryl-3-methyltriazen-3-yl)ethanes, Ar-N T N-NMe-CH2CH2-NMe-N T N-Ar, have been synthesized by diazonium coupling with N,N'-dimethylethylenediamine. These bistriazenes are stable crystalline compounds and have been unequivocally characterized by IR and NMR spectroscopy (1H and 13C), and elemental analysis. The structures of two compounds in the series have been confirmed by X-ray crystallography. The 1H NMR spectra show significant line broadening of the N-methyl resonances arising from the restricted rotation around the N2-N3 bond of the triazene units. The presence of strongly electron-withdrawing groups on the aryl ring restricts the rotation to the point where the N-methyl signals of the rotamers are distinct even at room temperature; four resonances of the N-methyl signal are clearly evident and these can be assigned to the anti-anti, syn-syn, and syn-anti conformations of the bistriazene. Diazonium coupling with N,N'-diethylethylenediamine affords the N,N'-diethyl homologues of the bistriazenes, which have been similarly characterized. As model compounds to assist in spectroscopic analysis, a series of related triazenes, the 1-(1-aryl-3-methyltriazen-3-yl)-N,N-dimethyl-2-ethanamines, were prepared by diazonium coupling with N,N,N'-trimethylethylenediamine. These dialkyltriazenes exist mainly as oils, but characterization was achieved by IR, 1H NMR, and 13C NMR spectroscopy, also showing the presence of two rotamers in solution when strongly electron-withdrawing substituents are bonded to the aryl moiety.Key words: triazene, bistriazene, diazonium, ethylenediamine, molecular dynamics, NMR.

The reaction of chloro(triphenylphosphine)gold(I) with 1-methylthymine

1987 ◽  
Vol 65 (7) ◽  
pp. 1568-1575 ◽  
Author(s):  
R. Faggiani ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock ◽  
M. A. Turner
Keyword(s):  
Aqueous Methanol ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Cell Dimensions ◽  
Cell Data ◽  
Unit Cell Data ◽  
Related Compounds ◽  
C Nmr

1-Methylthyminato-N3-triphenylphosphinegold(I) was prepared by reacting chloro(triphenylphosphine)gold(I) with 1-methylthymine in aqueous methanol at pH 11. The product was examined by X-ray crystallography and was found to have the orthorhombic space group C2221 (no. 20) with cell dimensions a = 12.760(7) Å, b = 11.530(2) Å, c = 31.893(5) Å, and eight formula units in the unit cell. Data were collected with use of MoKα radiation and a Syntex P21, diffractometer. The crystal structure was determined by standard methods and refined to R = 0.112 and Rw = 0.076 on the basis of 4760 unique reflections. Bond lengths and bond angles are normal. Packing in the crystal lattice is dominated by the triphenylphosphine rings which arrange roughly as blades of a propellor and are the source of the crystal's chirality. The title and related compounds were also examined by 1H nmr, 13C nmr, and vibrational spectroscopy.

CYTOTOXIC COMPOUND FROM ETHYL ACETATE FRACTION OF Brucea javanica (L.) Merr FRUIT AGAINST HeLa CELL LINE

2015 ◽  
Vol 11 (1) ◽  
pp. 58
Author(s):  
Nurlina Nurlina ◽  
Ari Widiyantoro
Keyword(s):  
Ethyl Acetate ◽  
Amorphous Solid ◽  
Ethyl Acetate Fraction ◽  
Assay Method ◽  
Pure Compound ◽  
Brucea Javanica ◽  
H Nmr ◽  
Cytotoxic Compound ◽  
Related Compounds ◽  
C Nmr

<p>The pure compound relatively (85 mg) was isolated from 4.5 kg <em>Brucea javanica</em> (L.) Merr. fruits sample. It was obtained from ethyl acetate fraction as a red-brownish amorphous solid of melting point 202-206 <sup>o</sup>C. Phytochemical screening of isolate showed positive result of terpenoid group. Based on analysis by UV, IR,<sup>1</sup>H-NMR and <sup>13</sup>C-NMR spectroscopy and by comparison with known related compounds, indicated that isolate is quassinoid compound named Picras 3- en- 21- oat acid, 15-(acetyloxy)-13,20- epoxy-3-(ß-D- glucopyranosyloxy)-11, 12- dihydroxy -2, 16- dioxo -, methyl ester. Cytotoxic test using MTT assay method showed that compound have IC<sub>50</sub> 9,7 µg/mL.</p>

NMR Analysis of Oxidative Alkaline Extraction Stage Lignins

Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 623-631 ◽  
Author(s):  
Troy M. Runge ◽  
Arthur J. Ragauskas
Keyword(s):  
Chlorine Dioxide ◽  
Alkali Treatment ◽  
Alkaline Extraction ◽  
Nmr Analysis ◽  
Carboxyl Content ◽  
H Nmr ◽  
Structural Differences ◽  
Extraction Stage ◽  
C Nmr

Summary Chlorine dioxide delignified pulp was subjected to various oxidative alkaline extraction stages (EAr, E, EO, EP, and EPO) from which the residual and effluent lignins were isolated and characterized by 1H and 13C NMR. Results of the NMR analyses indicate an increase in unconjugated carboxyl content of the lignins with the alkali treatment; a decrease in phenolic and formyl groups with oxidant reinforcement, especially oxygen; and an enrichment in aromatic methoxyl groups with increasing amount of oxidant reinforcement. The alkaline extracted pulps were further treated to a second chlorine dioxide stage from which the residual lignins were extracted and analyzed by 1H NMR. Significant structural differences were noted between the various oxidative E stage and D1 stage lignins.

scholarly journals Physicochemical Properties of Extracellular Polymeric Substances Produced by Three Bacterial Isolates From Biofouled Reverse Osmosis Membranes

2021 ◽  
Vol 12 ◽  
Author(s):  
Zahid Ur Rehman ◽  
Johannes S. Vrouwenvelder ◽  
Pascal Saikaly
Keyword(s):  
Molecular Weight ◽  
Physicochemical Properties ◽  
Reverse Osmosis ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Nmr Analysis ◽  
Bacterial Strains ◽  
H Nmr ◽  
Ro Membrane ◽  
C Nmr

This work describes the chemical composition of extracellular polymeric substances (EPS) produced by three bacteria (RO1, RO2, and RO3) isolated from a biofouled reverse osmosis (RO) membrane. We isolated pure cultures of three bacterial strains from a 7-year-old biofouled RO module that was used in a full-scale seawater treatment plant. All the bacterial strains showed similar growth rates, biofilm formation, and produced similar quantities of proteins and polysaccharides. The gel permeation chromatography showed that the EPS produced by all the strains has a high molecular weight; however, the EPS produced by strains RO1 and RO3 showed the highest molecular weight. Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance (1H NMR), and Carbon NMR (13C NMR) were used for a detailed characterization of the EPS. These physicochemical analyses allowed us to identify features of EPS that are important for biofilm formation. FTIR analysis indicated the presence of α-1,4 glycosidic linkages (920 cm–1) and amide II (1,550 cm–1) in the EPS, the presence of which has been correlated with the fouling potential of bacteria. The presence of α-glycoside linkages was further confirmed by 13C NMR analysis. The 13C NMR analysis also showed that the EPS produced by these bacteria is chemically similar to foulants obtained from biofouled RO membranes in previous studies. Therefore, our results support the hypothesis that the majority of substances that cause fouling on RO membranes originate from bacteria. Investigation using 1H NMR showed that the EPS contained a high abundance of hydrophobic compounds, and these compounds can lead to flux decline in the membrane processes. Genome sequencing of the isolates showed that they represent novel species of bacteria belonging to the genus Bacillus. Examination of genomes showed that these bacteria carry carbohydrates-active enzymes that play a role in the production of polysaccharides. Further genomic studies allowed us to identify proteins involved in the biosynthesis of EPS and flagella involved in biofilm formation. These analyses provide a glimpse into the physicochemical properties of EPS found on the RO membrane. This knowledge can be useful in the rational design of biofilm control treatments for the RO membrane.

Synthesis and Structure Assignment of 2-(4-Methoxybenzyl)cyclohexyl β-D-Galactopyranoside Stereoisomers

2006 ◽  
Vol 71 (8) ◽  
pp. 1186-1198 ◽  
Author(s):  
David Šaman ◽  
Martina Wimmerová ◽  
Zdeněk Wimmer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nmr Analysis ◽  
Enantiomerically Pure ◽  
Structure Assignment

Several promoters were used in the Koenigs-Knorr synthesis of the title alkyl β-D-galactopyranosides, both in their diastereoisomeric forms (5a/5b and 6a/6b), resulting from the synthesis performed with the respective racemic cis and trans isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol, and in their enantiomerically pure forms 5a and 6a, starting only from the (1S,2S)- and (1S,2R)-enantiomers of 2-(4-methoxybenzyl)cyclohexan-1-ol. The aim of the study was to find convenient modification(s) of the Koenigs-Knorr synthesis of alkyl β-D-galactopyranosides from more hindered and more complex 2-substituted cycloalkanols. Separation of the diastereoisomeric compounds using HPLC on a chiral Nucleodex-β-OH column was used to obtain small quantities of all possibly existing enantiomerically pure products for unambiguous structure assignment by NMR analysis. The (1S,2S)- and (1S,2R)- enantiomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a and 2a) were prepared by a reduction of 2-(4-methoxybenzyl)cyclohexan-1-one with Saccharomyces cerevisiae in enantiomeric purities: ee = 98.5% ((1S,2S)-enantiomer (1a)), and ee ≥ 99% ((1S,2R)-enantiomer (2a)).

Phenol sulfate esters: ultraviolet, infrared, 1H and 13C nuclear magnetic resonance spectroscopic investigation

1978 ◽  
Vol 56 (20) ◽  
pp. 2681-2685 ◽  
Author(s):  
Mark A. Ragan
Keyword(s):  
Spectroscopic Investigation ◽  
Spectroscopic Properties ◽  
Synthetic Methods ◽  
Sulfate Ester ◽  
H Nmr ◽  
Naturally Occurring ◽  
13C Nuclear Magnetic Resonance ◽  
Supplementary Material ◽  
Related Compounds ◽  
C Nmr

Renewed interest in naturally occurring phenol sulfate ester salts has necessitated modem spectroscopic investigation of these compounds. Synthetic methods, plus spectroscopic (uv, ir, 1H nmr, 13C nmr), chromatographic, and electrophoretic properties are given for the potassium salts of phenyl sulfate (1), pyrocatechol disulfate (2), resorcinol disulfate (3), hydroquinone disulfate (4), phloroglucinol mono- (5), di- (6), and tri- (7) sulfates, and for the 2-sulfate (8) and 2,5-disulfate (9) of 1,2,3,5-tetrahydroxybenzene (10). 13C nmr chemical shift effects resulting from the replacement of phenolic —OH with —OSO3K are reported. Spectroscopic properties of the related compounds 1,2,3-tribenzyloxybenzene (11), 2,6-dibenzyloxy-1,4-benzoquinone (12), 2,6-dimethoxy-1,4-benzoquinone (13), 1,3-dibenzyloxy-2,5-dihydroxybenzene (14), and of a tentatively identified 1,3-dibenzyloxy-2,5-dihydroxybenzene monoethyl ether (15) are available as supplementary material.

scholarly journals The effect of ortho and para substituents on the formation of the E and Z isomers of the arylhydrazones obtained from diazonium coupling with methyl 3-aminocrotonate and 3-aminocrotononitrile

1996 ◽  
Vol 74 (2) ◽  
pp. 254-262 ◽  
Author(s):  
Jason V. Jollimore ◽  
Marc Vacheresse ◽  
Keith Vaughan ◽  
Donald L. Hooper
Keyword(s):  
Nmr Spectra ◽  
Single Species ◽  
Intramolecular Hydrogen Bonding ◽  
Diazonium Salts ◽  
H Nmr ◽  
Diazonium Coupling ◽  
E And Z Isomers ◽  
Intramolecular Hydrogen ◽  
Structure Assignment ◽  
C Nmr

Reaction of arene diazonium salts with 3-aminocrotononitrile or methyl 3-aminocrotonate affords the 2-aryl-hydrazono-3-oxobutanenitrile (1 or 3 and 3′) or the methyl 2-arylhydrazono-3-oxobutanoate (2 and 2′ or 4 and 4′). A series of these hydrazones has been prepared with a range of electron-withdrawing and -donating substituents in the ortho or para position of the aryl moiety. The hydrazones have been characterized by spectroscopic methods, with emphasis on the 1H NMR spectra, which have been used to determine the configuration of the hydrazones as E or Z or a mixture of the two. The para-substituted hydrazononitriles (1) are formed as a single species, namely the Z isomer, whereas the ortho isomers are formed as a mixture of E and Z configurations (3 and 3′). The hydrazonobutanoates (2 and 2′ or 4 and 4′) are formed as E/Z mixtures regardless of the position of the substituent in the aryl moiety. Complete assignments of all signals in the 1H NMR spectra have been made on the basis of the ability of the various substituents to participate in intramolecular hydrogen bonding and a mechanism is proposed to account for the variations in the proportions of E and Z isomers and the effect of the nature of the substituent on this ratio. 13C NMR spectra of selected hydrazones have been recorded as an aid to structure assignment. Key words: hydrazone, diazonium, NMR spectroscopy, E/Z isomers, crotonic acid derivatives.

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