NMR data

Ten new chromone derivatives were synthesized from the original 2-4-6- trihydroxyacetophenone using microwave irradiation. The product's structures were confirmed by FT-IR, 1H-NMR, and 13C-NMR spectra data. The anti-microbial activities of the obtained compounds were tested by the disc diffusion method. The results showed that most chromones have significant biological activities against Candida albicans.

10p viambani 18-06-2024 1 0   Download

Garcinia multiflora belonging to the Clusiaceae family is one of the medicinal plant species native to Viet Nam and southern China and its use is an ethno-medicinal remedy to treat acne, scabies, constipation, and inflammation. In this paper, the chemical investigation on the fruits of Garcinia multiflora growing in the north of Vietnam was reported.

9p viamancio 04-06-2024 1 0   Download

Seven known compounds, including two neolignans, four lignans, and one flavane were isolated from the methanol extract of Pandanus tonkinenis fruits. Their structures were determined to be ficusal, vladinol F, medioresinol, syringaresinol, lariciresinol, secoisolariciresinol, and luteoliflavan by analysis of MS and NMR data as well as by comparison of their spectral data with those reported in the literature.

7p dianmotminh02 03-05-2024 3 1   Download

From propolis of Lepidotrigona ventralis stingless bee collected in Tuyen Quang province, eight compounds were isolated and determined as lantanolic acid, moronic acid, (+)-eudesmin, (+)-yangambin, (+)-syringaresinol, (+)-pinoresinol, dihydroconiferyl alcohol and vanillin using NMR and MS spectral data. Compounds 1 and 2 showed significant cytotoxicity against HepG-2 cancer cell line with IC50 values of 25.84±0.48 and 39.92±1.14 ug/mL, respectively.

6p dianmotminh02 03-05-2024 2 1   Download

Phytochemical study of Knema pachycarpa leaves led to the isolation of ten compounds. Their chemical structures were determined as (7''R, 8''R)-hydnocarpin D, (7''R, 8''R)-hydnocarpin, sinaicitin, (-)-globulol, β-caryolanol, phytol, biochanin A, chrysoeriol, tanoside II and astragalin using NMR and MS spectral data. Among the isolates, (7''R, 8''R)-hydnocarpin showed good cytotoxic activity against KB, HepG-2, Lu and MCF-7 cancer cell lines with IC50 values from 13.99±0.62 ug/mL to 30.65±1.44 ug/mL.

6p dianmotminh02 03-05-2024 1 1   Download

From CHCl3-soluble extract of the leaves of Taxus wallichiana (Taxaceae), collected in Lam Dong Province, five compounds were isolated and identified as sciadopitysin, ginkgetin, (S)-(+)-rhododenol, (+)-erythro-N-benzoyl3-phenylisoserine methyl ester, and (−)-α-conidendrin (5). Their chemical structures were determined by 1D and 2D NMR spectra and comparison with published data. Except for (−)-α-conidendrin, these remaining compounds were first reported of Taxus wallichiana.

6p dianmotminh02 03-05-2024 4 3   Download

One new sesquiterpene, (4S,7R,10S)-2-oxo-4,10,11-trihydroxyguaia-1(5)-ene, and five lignans, kadsuralignan J, isovaleroylbinankadsurin A, schizandrin O, futokakadsurin C and arisantetralone were isolated from the roots of Kadsura induta. Their chemical structures were revealed by MS, 1D and 2D NMR spectra in comparison with the reported data. The absolute configuration of compound 1 was determined by calculation of its theoretical ECD spectra and compared with the experimental results.

9p dianmotminh02 03-05-2024 4 2   Download

wo germacranolide sesquiterpenes, 9β-acetoxy-3-epi-nobilium, zoapatanolide B and four benzoate ester derivatives, benzyl 2-O-β-D-glucopyranosyl-6-methoxybenzoate, benzyl 2-O-β-D-glucopyranosyl-6- hydroxybenzoate, methyl 2-O-β-D-glucopyranosylbenzoate, ficuside G were isolated from aerial part of Sigesbeckia orientalis. Structural elucidation of the isolated compounds was done using a combination of HR-ESI-MS, one-dimensional and two-dimensional NMR spectral methods, and comparison their spectral data with the previous literature.

7p dianmotminh02 03-05-2024 4 2   Download

Ebook "Computer-based structure elucidation from spectral data: The art of solving problems" is composed of three parts. Part I contains a concise description of the ACD/Structure Elucidator flow diagram, its knowledgebase, and the fundamental concepts making up the theoretical basis of CASE (Chap. 1). Different strategies regarding the application of the system depending on the specific features of the problem being solved are discussed in Chap. 2.

458p tudohanhtau1006 29-03-2024 3 1   Download

Ebook "Novel sampling approaches in higher dimensional NMR" presents a discussion of some of the most popular sampling schemes used in “fast” approaches to high-dimensional NMR. Novel ideas, regarding both experimental (sampling) schemes and processing algorithms, keep coming up. In particular, the novel sampling approaches are being integrating with automated assignment, structure determination, and beyond.

166p coduathanh1122 27-03-2024 2 1   Download

Phytochemical study of Knema saxatilis stems led to the isolation of six known compounds. Their chemical structures were determined as 8-hydroxy eriodictyol (1), (2S)-7-hydroxy-3′,4′-methylenedioxideflavan (2), sitostenone (3), protocatechuic acid (4), 4-hydroxybenzoic acid (5) and vanillin (6) using NMR and MS spectral data. Among the isolated compounds, compounds 1 and 3-6 were reported for the first time from the genus Knema.

7p vibego 02-02-2024 5 0   Download

Ebook "Protein NMR: Methods and protocols" covers state-of-the-art applications of solid-state and solution nuclear magnetic resonance( NMR) spectroscopy to study protein structure, dynamics and interactions. Chapters detail various aspects of data acquisition and processing, determination of the structure, multi-timescale dynamics of entities ranging from individual proteins to large macromolecular complexes to intact viral assemblies.

448p lucchinguyen 28-12-2023 9 2   Download

Three compounds were isolated from the butanol extract of Impatiens claviger’s leaves and twigs collected in Me Linh, Ha Noi. Their structures were elucidated by the mass, NMR spectroscopy and comparison with published data as two phenolic glucosides and one triterpene glycoside. One of them has been found for the first time in Impatiens genus.

4p vifalcon 18-05-2023 2 2   Download

A phytochemical investigation on the ethanolic (EtOH) extract of the Vietnamese Curcuma longa (C. longa) rhizomes has led to the isolation of four curcuminoids including curcumin (1), demethoxycurcumin (2), bisdemethoxycurcumin (3), and cyclocurcumin (4). The chemical structure of compounds 1-4 was elucidated by Nuclear magnetic resonance (NMR) and Mass spectrometry (MS) spectral data.

5p vimalfoy 08-02-2023 5 2   Download

Ten novel 2-aryl-5-(arylsulfonyl)-1,3,4-oxadiazoles were produced and assessed for their in vitro antibacterial and antioxidant activities. Diverse spectroscopic methods like 1 H NMR, 13C NMR, IR, and LCMS were used for the characterization of the prepared samples and all the data was in good agreement with the anticipated structures.

41p lyhuyenthu 31-01-2023 4 2   Download

Eriobotrya angustissima Hook.F. (Son tra hep) belongs to the family Rosaceae. Its leaves were collected at National Garden Bi Dup in Lam dong province. The research showed that, many triterpenes are very difficult to be separated from each other so that they can be obtained only as acetylated products.

3p vilexus 30-09-2022 6 3   Download

Three flavones (1-3) were isolated from the aerial part of Tithonia diversifolia (Hemsl.) A. Gray growing in Hoa Binh province, Vietnam. Their structures were identified as hispidulin (1), nepetin (2) and luteotin (3) by analysis of these spectroscopic MS, NMR data and comparison with reported data.

4p viericschmid 12-01-2022 16 0   Download

The compounds were identified by the use of 1D- and 2D-NMR and UV spectroscopic techniques and by comparisons with the reported data. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of the acetone, methanol, and water extracts of the plant and of the flavones penduletin and apigenin were evaluated at 200 µg/mL. The water extract exhibited better activity against the enzyme AChE as compared to both the acetone and the methanol extracts. Penduletin (1) showed significant activity against BChE (66.

9p langthannam 29-12-2021 10 0   Download

A series of binucleating Cu(II), Ni(II), and Zn(II) complexes of bicompartmental ligands with ONO donors were prepared. The ligands were synthesized by the condensation of 5-substituted-3-phenyl-1H -indole-2-carboxyhydrazides and 4,6-diacetylresorcinol. The newly synthesized ligands and their complexes were characterized by elemental analysis and various spectral studies like IR, 1H NMR, ESI-mass, UV-Vis, ESR, thermal studies, magnetic susceptibility, molar conductance, and powder-XRD data.

21p langthannam 29-12-2021 8 0   Download

The new heterobimetallic [Mg(II)-Ti(IV)]-µ-oxoisopropoxide was synthesized on treatment of magnesium acetate with titanium(IV) isopropoxide in refluxing decalin in 1:2 molar ratio and characterized by liberated isopropanol, elemental, spectral (IR, 1H and 13C NMR, and mass), thermal analysis, and molecular weight data.

9p langthannam 29-12-2021 7 0   Download