نتایج جستجو برای: 1h and 13c nmr calculations
تعداد نتایج: 16856055 فیلتر نتایج به سال:
Four new C-glucopyranosides of resveratrol oligomers, hemsleyanosides A-D, were isolated from the bark of Shorea hemsleyana. The structures were established on the basis of spectroscopic evidence, including 1H-1H and 1H-13C long-range couplings and nuclear Overhauser effect experiments in the NMR spectrum.
From hexanic extract of aerial parts of Peucedanum ruthenicum M. Bieb (Apiaceae) collected from Mazandaran province of Iran, four triterpenoids namely taraxasterol, y-taraxasterol, poriferasterol and b-sitosterol have been isolated by column chromatography, thin layer chromatography, and crystallization. Their structures were elucidated by spectroscopic methods (UV, IR, MS, 1H and 13C-N...
3-Arylhydrazono-2,4-dioxo-4-phenylbutanoateshave been prepared by the coupling of benzoylpyruvate with aryldiazonium chlorides.Reactions ofthe 3-arylhydrazono-2,4-dioxo-4-phenylbutanoateswith 1-aminoguanidine, semicarbazide, and thiosemicarbazidegave5-substituted 2-imino-6-azauracil (3a),6-azauracil (3b), and 2-thio-6-azauracil (3c), respectively. The analytical data of these compounds - IR, 1H...
in the present work, the quantum theoretical calculations of the molecular structure of the 1-(1, 3-benzothiazol-2-yl)-3-(thiophene-5-carbonyl) thiourea has been predicted and are evaluated using density functional theory (dft) in gas phase. the geometry of the title compound was optimized by b3lyp/6-311+g and b3lyp/6-311+g* methods and the experimental geometrical parameters of the title compo...
nano silica sulfuric acid catalyzed synthesis of 2-substituted aryl (indolyl) kojic acid derivatives
nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...
in this paper, new (2e, 2'e)-3, 3'-(((3- hydroxypropane-1, 2-diyl) bis (oxy)) bis (2, 1-phenylene)) bis (1-phenylprop-2-en-1-one) (2a) was prepared in good yield by condensation reaction of acetophenone with bisaldehyde (1a) in ethanolic naoh solutions at room temperature. the (2e, 2'e)-3, 3'-(((3- hydroxypropane-1, 2-diyl) bis (oxy)) bis (2, 1-phenylene)) bis (1-phenylprop-...
From methanolic extract of aerial parts of Peucedanum ruthenicum M. Bieb (Apiaceae) collected from Mazandaran province of Iran, four flavonoids namely Isorhamnetin 3-0-rutinoside 1, rutin 2, quercetin 3, morin 4 and two phenolic acids namely caffeic acid 5 and p-coumaric acid 6 have been isolated by Paper Chromatography (PC) and crystallization. Their structures were elucidated by MS, 1H, 13C N...
Phytochemical studies on Galanthus elwesii resulted in the isolation of five alkaloids: incartine, hordenine, hippeastrine, 8-O-demethylhomolycorine and lycorine. The NMR data given previously for incartine were revised and completed by two-dimensional 1H-1H and 1H-13C chemical shift correlation experiments. In vitro studies on the bioactivity of incartine were carried out.
Derivatization of aldehyde cyanohydrins as (R)- and (S)-MPA esters and comparison of the corresponding 1H- and 13C-NMR spectra allows the assignment of their absolute configuration.
Re-investigation of the methylene chloride extract of the roots of Ferula sinaica gave ferusinol, a new sesquiterpene coumarin with a rare carbon skeleton, and samarcandin diastereomer. The structures elucidation were determined by MS, 1H- 13C-1D and 2D NMR spectral data.
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