Chemical structures

This work aims to investigate the mechanism of Pd nucleation and growth onto glassy carbon electrode from ChCl/urea/palladium mixture at room temperature using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. Furthermore, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy were used to examine the crystalline structure, morphology and compositions of deposited Pd samples.

14p viambani 18-06-2024 2 1   Download

Sarcosperma, which belongs to the Sapotaceae family, is composed of 11 species distributed in Asia, five of which are found in Viet Nam. As a result, in a recent paper, we reported on the isolation of two new compounds, sarcokontums A and B, from the stems and leaves of this plant.

10p viamancio 04-06-2024 1 0   Download

Bisulfate intercalated graphites with different particle sizes were prepared by a chemically oxidative method using natural flaky graphites as raw materials. The morphology and structure of the expandable graphites were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction patterns, and scanning electron microscope.

14p viamancio 04-06-2024 1 0   Download

Achyranthes aspera L., belongs to the genus Achyranthes (Amaranthaceae). It is a well-known medicine in traditional remedies in Viet Nam, China and India. A. aspera leaves has a bitter, sour taste, clearing heat, decongesting, low leprosy, strong blood circulation. This paper reported the isolation of five ecdysterols and a saponin from Achyranthes aspera.

9p viamancio 04-06-2024 2 0   Download

The preparation of this second edition is motivated by the effectiveness of the first edition in classroom instruction, so the original structure and content have been retained. Our changes have been directed to the needs of students and other readers.

380p vimeyers 29-05-2024 4 2   Download

Ebook "Advances in geophysic - Volume 35: Seismological structure of slabs" provides an overview of the progress made in illuminating the properties of deep slabs and the surrounding mantle, since the introduction of the plate tectonics model to the earth sciences 25 years ago. The thermal and chemical characteristics of the subducted lithosphere are determined through thermal and petrological modelling, with seismological observations providing critical constraints on model parameters.

193p giangdongdinh 28-05-2024 3 2   Download

Among all types of DNA damage, DNA double-strand breaks (DSBs) are considered the most deleterious form induced by either endogenous factors (oxi-dative damages, mismatches, altered chromatin structures, and missing, or modified nucleotides) or exogenous factors, i.e., ultraviolet (UV) radiation, ionizing radiation (IR), and chemicals or drugs. This study aimed: To evaluate the effect of DNAPKi NU7441 on the HCT116 cell line.

11p vijaychest 16-05-2024 2 1   Download

Part 1 book "Advanced organic chemistry" includes contents: Chemical bonding and molecular structure; stereochemistry, conformation, and stereoselectivity; structural effects on stability and reactivity; nucleophilic substitution; polar addition and elimination reactions.

596p dianmotminh01 14-05-2024 2 0   Download

A magnetic molecularly imprinted electrochemical sensor was developed for selective determination of sufentanil (SUF) based on carbon paste electrode (CPE) modified with methacrylic acid-ethylene glycol dimethacrylate-coated Fe3O4 nanoparticles (Fe3O4@MAA-EGDMA NPs). The structural properties, chemical structure, and electrochemical behaviors of the imprinted sensor were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), and square wave voltammetry (SWV), respectively.

14p dianmotminh02 03-05-2024 4 1   Download

A new megastigmane glycoside, (3S,5R,6R,9S)-6,9-epoxiionane-3,5-diol 3-O-βprimeveroside together with 7 compounds were isolated from Achyranthes aspera L. The chemical structures were elucidated through 1D-, 2DNMR, and HR-ESI-MS experiment. The absolute configuration of 1 was determined using combination of the experimental and theoretical calculation of CD spectra. Compounds 2 and 7 were reported for the first time from the genus Achyranthes.

5p dianmotminh02 03-05-2024 2 1   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

In this research, in an attempt to make use of the kaolin resources in Vietnam, we present a synthetic process of zeolite A via hydrothermal from kaolinite, together with the modification process of zeolite A using different metallic cations. The characteristics of the prepared zeolite LTAs such as chemical composition and crystalline structure, as well as their catalytic activity in the methanation reaction of carbon dioxide (CO2) to methane (CH4) were extensively investigated.

8p dianmotminh02 03-05-2024 3 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

CuO nanoparticles were synthesized by alcohol-assisted hydrothermal method at various pH values, using sodium hydroxide as a precursor for pH control. The chemical composition, morphological and structural properties of the obtained CuO nanoparticles were investigated by the Raman and energy-dispersive X-ray spectroscopies, the field-emission scanning electron microscopy, and the X-ray diffraction.

12p dianmotminh02 03-05-2024 2 1   Download

This global minimum structure has the shape of a tetragonal bipyramid having two Sc atoms at two tops of pyramids binding with one edge of Ge-Ge. The ground electronic state of the global minimum isomer is the 2B2 state in the C2v symmetry. The most stable isomer of Sc2Ge6 − has been used to study the CO adsorption. The calculated results indicate that the Sc2Ge6 − cluster has a good interaction with the CO molecule. The adsorption positions are around the Sc atom with two stable models include adsorbing the C atom and adsorbing both the C and O atoms of the CO molecule.

7p dianmotminh02 03-05-2024 2 1   Download

The influence of the black seed oil modified epoxy resin (EBSO)/monomer 3,4-epoxycyclohexylmethyl 3,4- epoxycyclohexane carboxylate (BCDE) weight ratio in the coatings based on the compounds and photoinitiator triarylsulfonium hexafluoroantimonate (TAS) on thermal properties of photocrosslinked coatings have been studied. The chemical structure of investigated UV-cured coatings was characterized by IR spectrometric analysis. Their thermogravimetric (TG) and differential scanning calorimetry (DSC) behavior were determined by TG and DSC analysis, respectively.

9p dianmotminh02 03-05-2024 3 1   Download

The methanol extracts as well as some compounds from this plant exhibited anti-inflammatory, antimicrobial activity, antioxidant, hepatoprotective and anti-cancer effect, and antiosteoporotic. On going to search for bioactive components from the Vietnamese plant, this paper reported the isolation of seven phenolic compounds including one new from the aerial parts of A. ilicifolius. The cytotoxic activity of the isolates against two cancer cell lines (HepG2 and SK-LU1) were also screened and reported herein.

5p dianmotminh02 03-05-2024 5 1   Download

The highest luminescence product consists of spheroidal and relatively uniform particles with sizes around 0.6-1.0 µm. The variation of the precipitated precursor with temperature, the influence of sintering temperature on structure and luminescence, the mineralization role of boric acid and the chemical reactions that occur with generation of precipitated precursors and upon heating to give luminescent solid solution products are mentioned.

10p dianmotminh02 03-05-2024 2 1   Download

The first chemical investigation on Cardiospermum halicacabum L. growing in Vietnam led to the isolation and structural determination of nine flavonoid compounds, including quercetin 3-O-β-D-glucoside, quercetin 3-O-α-Lrhamnoside, quercetin, kaempferol 3-O-α-L-rhamnoside, kaempferol, apigenin 7-O-β-D-glucuronide butyl ester, apigenin 7-O-β-D-glucuronide methyl ester, apigenin, and luteolin.

4p dianmotminh02 03-05-2024 5 1   Download

Phytochemical study on the leaves of Fissistigma balansae led to the isolation of one new sesquiterpene glycoside, (3S,6E)-3-O-β-D-glucopyranosyl-8-hydroxy-3,7,11-trimethyldodeca-1,6,10-triene, and six known compounds, aromandendrane-4β,10α-diol, phloridzosid, astragalin, isoquercitrin, and rutin, acanthoside B. Their chemical structures were identified by HR-ESI-MS and NMR (1D and 2D) spectra. This is the first report of these compounds from F. balansae.

5p dianmotminh02 03-05-2024 5 1   Download