نتایج جستجو برای: dynamic 1h nmr
تعداد نتایج: 482449 فیلتر نتایج به سال:
A combined theoretical and experimental study on the structure, infrared, UV-Vis and 1H NMR data of trans-2-(m-cyanostyryl)pyridine, trans-2-[3-methyl-(m-cyanostyryl)]pyridine and trans-4-(m-cyanostyryl)pyridine is presented. The synthesis was carried out with an efficient Knoevenagel condensation using green chemistry conditions. Theoretical geometry optimizations and their IR spectra were ca...
Cistanche deserticola (CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein, 1H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD. Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in ...
phytochemical investigation of the dichloromethane extract of the dried roots of ferula badrakema resulted in the identification of one new and six known compounds. known compounds were sesquiterpene coumarins: mogoltacin, feselol, badrakemin acetate, ferocaulidin, conferone and conferol acetate. the new compound was a sesquiterpene, named badrakemonin. the structures of these compounds were el...
conformational properties of n-aryl-1-azacyclooctan-5- ones with a p-methyl, m-methyl, and p-methoxy group as a substituent have been studied by 1h-nmr, 13c-nmr and ir spectroscopies. transannular interaction of the two functional groups have been examined from the ring inversion barriers and the carbonyl vibrational frequencies with reference to the corresponding data of the respective monofun...
Four new metabolites, including three new oblongolides named C1, P1, and X1 (1-3) and 6-hydroxyphomodiol (10), along with eight known compounds--oblongolides B (4), C (5), D (6), O (7), P (8) and U (9), (3R,4aR,5S,6R)-6-hydroxy-5-methylramulosin (11), and (3R)-5-methylmellein (12)--were isolated from the endophytic fungal strain Phomopsis sp. XZ-01 of Camptotheca acuminate. Their structures wer...
A new glutarimide antibiotic named actiketal was isolated from the culture fluid of the epiderstatin-producing streptomycete, Streptomyces pulveraceus subsp. epiderstagenes. The IC50 of the antibiotic for inhibition of the incorporation of [3H]thymidine into epidermal growth factor-stimulated Balb/MK cells was 14.5 microM. The structure of this compound was determined by 1H and 13C NMR spectros...
In this investigation, the structural, electronic properties, 13C and 1H NMR parameters and firsthyperpolarizability of Z-Ligustilide were explored. As well, the solvent effect on structural parameters, frontier orbital energies, electronic transitions, and 13C and 1H NMR parameters was illustrated based on Polarizable Continuum Model (PCM).These consequences specify that the polarity of solven...
1-substituted 1H-tetrazoles were efficiently synthesized under solvent-free conditions from the reaction of primary amines, triethylorthoformate, and sodium azide in the presence of Cu/C as a heterogeneous catalyst. Various amines including aromatic and heteroaromatic amines were used to afford the corresponding products in good to excellent yields. The characterization of corresponding product...
UNLABELLED BACKGROUND With the gaining popularity of commercially prepared decoctions of herbal medicines on the market, an objective and efficient way to reveal the authenticity of such products is urgently needed. Previous attempts to use chromatographic or spectroscopic methods to identify ginseng samples made use of components derived from methanol extracts of the herb. It was not establ...
Instrumentation: NMR spectra were recorded on Bruker Advance 400 (400.14 MHz for 1H and 100.62 MHz for 13C), Bruker Advance III plus 400 (400.34 MHz for 1H and 100.67 MHz for 13C), and Bruker Advance III 600 (600.13 MHz for 1H and 150.90 MHz for 13C) NMR spectrometers. All the collected spectra were referenced on residual solvent signal according to Nudelman and coworkers.[1] Mass spectra were ...
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