NMR spectra 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

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 5 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

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

The synthesis of novel zinc, cobalt, indium, and metal-free phthalocyanines carrying four 3-(4-phenyloxy)coumarins in the periphery/nonperiphery were prepared by cyclotetramerization of 3-[4-(3,4-dicyanophenyloxy)phenyl]coumarin (2)/3-[4-(2,3- dicyanophenyloxy)phenyl]coumarin (3). The novel chromogenic compounds were characterized by elemental analysis, 1 H NMR, mass spectra, F-IR, and UV-vis spectral data. The effects of the coumarin units on the zinc, indium, and metal-free phthalocyanine complexes (2a/3a, 2c/3c, 2d/3d) were also investigated.

16p langthannam 29-12-2021 14 0   Download

New azo dyes bearing 2-pyridone and benzimidazole moieties were prepared using diazotization of 4-(1Hbenzo[d]imidazol-2-yl)aniline and coupling of the obtained diazonium salt with substituted 3-cyano-2-pyridones. Obtained compounds were characterized via UV-Vis, FT-IR, and 1H and 13C NMR spectroscopy as well as by elemental analysis data. The UV-Vis spectra of the synthesized dyes were measured in thirteen solvents of different properties at room temperature. Solvatochromism and tautomerism of novel azo dyes were discussed.

12p tudichquannguyet 29-11-2021 11 0   Download

Two naphthalene pyrazole ligands were synthesized using KOH/DMSO and Cu catalyst and characterized with FT-IR, ESIMS, 1H, and 13C NMR spectroscopies. The crystal structures of 1-(2-methylnaphthalen-1-yl)-1H-pyrazole (MeNap-Pz) ligand have been determined with X-ray crystal structure analysis. Reaction of the ligands with Cu(NO3)2x3.5H2O gave two new complexes and characterized with magnetic susceptibility, molar conductance, FT-IR, LCMS-MS, ICP-OES, NMR, thermogravimetric analysis, and ESR spectra.

24p tudichquannguyet 29-11-2021 17 0   Download

One lignan (7′S,8′R,8S)-4,4′-dihydroxy-3,3′,5,5′-tetramethoxy-7′,9-epoxylignan-9′-ol-7-one (1) together with four neolignans (7α,8α)-dihydrodehydrodiconiferyl alcohol 9-O-β-D-glucopyranoside (2), (7α,8α)-dihydrodehydrodiconiferyl alcohol 9′-O-β-D-glucopyranoside (3), icariside E3 (4), and icariside E5 (5) were isolated from Pouzolzia sanguinea. Their chemical structures were elucidated by ESI-MS, NMR spectra, as well as in comparison with the data reported in literature.

7p cothumenhmong11 06-05-2021 10 2   Download

Three dihydrostilbene glycosides, 3,5-dihydroxydihydrostilbene 4′-O-β-D-glucopyranoside (1), 3,5- dimethoxydihydrostilbene 4′-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (2), 5,4′-dihydroxydihydrostilbene 3-O-β-D-glucopyranoside (3), and one lignan, nudiposide (4) were isolated from the methanol extract of leaves of Camellia sasanqua Thunb. Their chemical structures were determined by using ESI-MS and NMR spectra as well as in comparison with the reported data. Compounds 3 and 4 were reported from Camellia genus for the first time.

5p cothumenhmong11 06-05-2021 15 2   Download

Their chemical structures were determined using ESI-MS, 1D NMR, and 2D NMR spectra as well as by comparison of the spectral data with those reported in the literature. Compounds 4 and 5 were reported from Xanthium genus for the first time. To our best knowledge, all these compounds were firstly reported from X. strumarium growing in Vietnam.

6p cothumenhmong11 06-05-2021 18 2   Download

Three iridoids, asperulosidic acid (1), geniposidic acid (2), and galioside (3) and three anthraquinones, 2- hydroxymethyl-3-hydroxyanthraquinone (4), rubiadin-1-methyl ether (5), and anthragallol-2-methyl ether (6) were isolated from the methanol extract of the Morinda officinalis leaves. Their chemical structures were elucidated by ESIMS, 1D- and 2D-NMR spectra and comparison with the data reported in the literature. Galioside (3) was reported from Morinda genus for the first time.

5p nguaconbaynhay11 16-04-2021 19 1   Download

Chemical investigation of the marine sponge-derived fungal strain Aspergillus sp. IMBC-FP2.05 resulted in isolation of five compounds, including JBIR-74 (1), homogentisic acid (2), methyl (2,5-dihydroxyphenyl)acetate (3), 3- chloro-2,5-dihydroxybenzyl alcohol (4), and p-hydroxybenzaldehyde (5). Their chemical structures were identified by comprehensive analyses of the 1D and 2D NMR and mass spectra in comparison with the previously reported data. Furthermore, nitric oxide (NO) inhibitory effects of the isolated compounds in LPS-stimulated RAW264.7 cells were also reported.

5p nguaconbaynhay11 16-04-2021 9 2   Download

Simple peak-picking algorithms, such as those based on lineshape fitting, perform well when peaks are completely resolved in multidimensional NMR spectra, but often produce wrong intensities and frequencies for overlapping peak clusters.

7p vikentucky2711 26-11-2020 11 1   Download

Maesa membranacea A. DC. (Myrsinaceae) has been traditionally used for the treatment of fever and hepatitis. The phytochemical investigation of Maesa membranacea stems has led to the isolation of six compounds including kaempferol (1), (-)-epicatechin (2), betulinic acid (3), p-hydroxybenzoic acid (4), vanilic acid (5), and protocatechuic acid (6). The chemical structures of these compounds have been determined by nuclear magnetic resonance (NMR), mass spectrometry (MS) data, and by comparison with previously reported works.

4p chauchaungayxua8 02-10-2020 21 1   Download

Today, most investigations of the plant metabolome tend to be based on either nuclear magnetic resonance (NMR) spectroscopy or mass spectrometry (MS), with or without hyphenation with chromatography. Although less sensitive than MS, NMR provides a powerful complementary technique for the identification and quantification of metabolites in plant extracts.

13p trinhthamhodang1 16-11-2019 15 0   Download

Honey is a natural, sweet, and syrupy fluid which has been used in Vietnam in a variety of ways; as a food supplement, beauty product, and natural drug. However, quality control and characterization of honey are blind problems. Consumers, and even market management committees, must believe in the producer’s quality standards without using any special techniques to evaluate the botanical origins of honey in the Vietnamese market. The chemical composition and physical properties of natural honey vary per plant species of which the honey bees scrounged.

8p caygaocaolon1 13-11-2019 16 0   Download

From the leaves of Fissistigma acuminatissima growing in Vietnam, two flavonoids, catechin and isorhamnetin-3-o-rutinoside were isolated. Their structures were characterized on the basis of MS and NMR spectra data and comparison with reported data.

4p chikychiky 11-11-2018 17 1   Download

Chemical investigation of an acidic methanol extract of the whole plant of Datura metel resulted in the isolation of seven compounds, including pterodontriol B (1), disciferitriol (2), scopolamine (3), adenosine (4), thymidine (5), ilekudinoside C (6), and dioscoroside D (7). Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR and mass spectra and in comparison with reported data in the literature. Among the isolated compounds, pterodontriol B, disciferitriol, ilekudinoside C, and dioscoroside D were reported for the first time from the Datura genus.

8p giesumanh 10-11-2018 25 1   Download

From the methanol extract of Bischofia javanica Blume leaves, five compounds including 5'-β-D-glucopyranosyloxyjasmonic acid methyl ester (1), 2-(4-hydroxy-3-methoxyphenyl)ethylO-β-D-glucopyranoside (2), hexyl-O-β-D-glucopyranoside (3), friedelan-3-one (4), and gallic acid (5) were isolated. Their structures were elucidated by NMR spectra as well as in comparison with previously reported data. This is the first report on the isolation of 1, 2, and 3 from Bischofia javanica.

7p cumeo4000 01-08-2018 34 1   Download

(bq) part 2 book "a handbook of spectroscopic data chemistry" has contents: 13c nmr spectroscopy, mass spectrometry, structural data obtainable from different spectra. please refer to the content.

144p bautroibinhyen20 06-03-2017 44 4   Download