Chemical structures

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.

7p viyoko 01-10-2024 1 1   Download

The volatile organic compounds (VOCs) sensing layers were studied using ZnO nanomaterials with different morphologies including hierarchical nanostructure (ZnO-H), nanorods (ZnO-NRs), commercial nanoparticles (ZnOCNPs) and wet chemical synthesized nanoparticles (ZnO-HNPs). ZnO hierarchical structure was fabricated by an electrospinning technique followed by hydrothermal process.

6p vikwong 29-09-2024 2 1   Download

Alginate-stabilized Cu2O@Cu nanoparticles were fabricated by chemical reduction method using nature polymer alginate as a stabilizing agent. Transmission electron microscopy (TEM), X-ray powder diffraction (XRD), infrared (FT-IR) spectrum, and UV-Vis analysis were used to investigate the morphology, size, structure, and stability of the nanoparticles synthesized.

6p vikwong 29-09-2024 5 1   Download

Zeolite seed-based mesoporous aluminosilicate material MSU-S is normally synthesized from pure chemicals. In the study, MSU-S material was synthesized using natural resources such as rice husk, and kaolin in Vietnam. Here, a systematic investigation is conducted to find the relationship between the synthesis conditions (aging time, hydrothermal time, hydrothermal temperature, pH environment) and the formation of mesoporous structure, as well as the material properties.

6p vikwong 29-09-2024 6 1   Download

This study aims to investigate the effectiveness of the green microwave technique in producing 1T/2H-MoS2 nanomaterials using polyol solvents. The paper presents a thorough analysis of the structural and property characteristics of the synthesized materials and elucidates the underlying chemical mechanism that governs the formation of hybrid-phase nanostructures. Additionally, the role of polyol solvents in the practical synthesis of nano MoS2 under microwave heating is evaluated and explained.

15p xuanphongdacy06 18-09-2024 1 1   Download

In this study, Zinc oxide (ZnO) nanoparticles with a size of about 50 - 70 nm were green-synthesized using tea leaves and ZnO/Polypyrrole (ZnO/Ppy) nanocomposites were obtained by ultrasonic-assisted chemical polymerization method using pyrrole monomer and the nanoparticles. The characterization of the materials is conducted using several analytical techniques, including Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) and Ultraviolet visible spectrum (UV-Vis).

11p xuanphongdacy06 18-09-2024 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 4 2   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 8 2   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 4 2   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 3 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 6 2   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 8 2   Download

This article, we present a thorough and straightforward hydrothermal method towards the production of reduced graphene oxide templated MIL-53(Fe) hybrids RGO@MIL-53(Fe). The structural characteristics of created hybrids were identified by using BET, FESEM, powder X-ray diffraction, and FTIR techniques. Methylene blue (MB) dye (a model water pollutant) was used to evaluate H2O2-assisted photo-catalytic efficiency of RGO@MIL-53(Fe).

9p dianmotminh02 03-05-2024 4 2   Download

This study revealed that the major contributing descriptors of 2D QSAR studies are DeltaEpsilonB and DeltaPsiA and 3D QSAR model proves the steric as well as electrostatic effects determine the binding affinity for the drug development. The results of the current computational studies are useful for further designing novel chemical entities of anti-microbial agent.

19p dianmotminh02 03-05-2024 8 3   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 10 4   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 9 3   Download

This article presents computational insights into the geometric and electronic structures of NbSi4 −/0 clusters using density functional theory and the CASSCF/CASPT2 method. The anionic and neutral ground states are identified as the 1A′ and 2A′ states, respectively, within a trigonal bipyramidal isomer where the Nb atom occupies the equatorial position. The adiabatic detachment energy for the transition from the anionic ground state 1A′ to the neutral ground state 2A′ is estimated to be 2.30 eV.

8p dianmotminh02 03-05-2024 5 2   Download

Master's thesis of Science "Investigation into the modulation of circadian clock proteins by dietary compounds and small molecules" is structured as follows: Chapter 1 Introduction; Chapter 2 Identification of novel bioactive compounds from Olea europaea by evaluation of chemical compounds in the OliveNetTM library: in silico bioactivity and molecular modelling, and in vitro validation of hERG activity; Chapter 3 Modulation of circadian core clock proteins by dietary compounds; Chapter 4 Molecular mechanisms of action of selected olive phenolics against epigenetic modifiers and the structur...

235p runthenight04 02-02-2023 5 3   Download

The study "Studies on film forming corrosion inhibitors on aluminium alloy, AA2024-T3" presents key aspects of the film forming behaviour of the selected inhibitors and the test methods used to evaluate the inhibitor induced films in a chloride solution. This study also aims to provide significant insights to the film tenacity, the influence of the molecular structure as well as the film stability in the absence of inhibitors to provide a deeper understanding of the film forming and film breakdown mechanisms.

154p runthenight04 02-02-2023 11 2   Download

Regenerating jute into high-tech nanofibres is an alternative way to use jute fibres. However, dissolving jute has always been a challenge. The complex hierarchal structure of lignin is the main obstacle for hydrolysis of lignocellulosic fibres in obtaining value-added products. This work aims to develop regenerated jute nanofibres through electrospinning. A literature review was conducted to investigate on the methods of regenerating jute for value added products.

122p runordie3 06-07-2022 13 3   Download