Publications by authors named "Le Dang Quang"

This study presents the process of extracting lignin from sugarcane bagasse collected in the Mekong Delta, Vietnam by the alkali method. NaOH has been used as an effective, environmentally friendly chemical to enhance the extraction process. The obtained lignin was applied for methylene blue (MB) and hexavalent chromium (Cr(vi)) removal.

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Due to the large size and high flexibility of the catalytic active site of BACE1 enzyme, the development of nonpeptide inhibitors with optimal pharmacological properties is still highly demanding. In this work, we have discovered 2-aminobenzimidazole-containg ether scaffolds having potent and selective inhibitory potentials against BACE1 enzyme. We have synthesized novel 29 compounds and optimization of aryl linker region resulted in highly potent BACE1 inhibitory activities with EC values of 0.

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Two new rearranged 2,3--tirucallane triterpenoids, meliadubins A () and B (), along with four known compounds, -, were isolated from the barks of Cav. Compound exhibited a significant inflammatory inhibition effect toward superoxide anion generation in human neutrophils (EC at 5.54 ± 0.

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Five new flavonoid C-glycosides named desmodinosides A-E (1-5) and one known compound, apigenin 6-C-β-d-xylopyranosyl-2''-O-β-D-glucopyranoside (6) have been isolated from the methanol extract of the aerial parts of Desmodium heterocarpon var. stigosum. These compounds were determined by 1D and 2D-NMR and HR-MS spectroscopies.

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In the present study, the biosynthesis of stable silver nanoparticles (BioAgNPs) was accomplished successfully for the first time by using an aqueous extract derived from the buds of (SN) as both a reducing and a stabilizing agent. Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM) investigations revealed that the biosynthesized BioAgNPs were predominantly spherical with an average size of 10-30 nm. It was found that the outstanding stability of the BioAgNPs colloidal solution was assigned to the additive effect of the surrounding protective organic layer and the highly negatively charged surface of the nanoparticles.

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From the aerial parts of , four thymol derivatives (-) were isolated and structurally elucidated by NMR and mass spectroscopic methods. Of which, a new dimeric thymol derivative () was characterized and its absolute configuration was established by electronic circular dichroism quantum method. In addition, the 1D and 2D NMR as well as HR-ESI mass spectral data of were provided for the first time.

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Multiple myeloma is a deadly cancer that is a complex and multifactorial disease. In the present study, 12 belinostat derivatives (four resynthesized and eight new), HDAC inhibitors, were resynthesized either Knoevenagel condensation, or Wittig reaction, or Heck reaction. Then an evaluation of the antiproliferative activities against myeloma cells MOPC-315 was carried out.

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Article Synopsis
  • Researchers investigated methanol extracts for new antifungal compounds targeting plant pathogens, isolating seven compounds from the butanol-soluble fraction.
  • Among these, six were identified as flavone 6- or 8-glycosides, with three showing moderate antifungal activity, particularly one compound that was most effective against a specific pathogen.
  • The study also highlighted that a nanoemulsion of the methanol extract improved antifungal effectiveness, suggesting potential for developing new fungicides based on these findings.
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Phytochemical study on the methanolic extract of the leaves of Vietnamese plant Pierre ex Pit. has led to the isolation of a new cycloartane coronalyl acetate () together with six known ones, coronlolide methyl ester (), sootepin D (), coronalolide (), coronalolic acid (), sootepin G () and 23-deoxojessic acid (). Their structures were elucidated by a combination of 2 D NMR and HR-ESI-MS spectroscopies.

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A new sesquiterpene glucoside (), two new norsesquiterpenes (, ), and a new homomonoterpene (), named myobontioids A-D respectively, along with twelve known flavonoids and lignans () were isolated from A. Gray. Flavanones - specifically inhibited and at the concentrations of 125, 250 and 500 µg.

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In the search for new natural resources showing plant disease control effects, we found that the methanol extract of suppressed fungal disease development in plants. To identify the bioactive substances, the methanol extract of was extracted by organic solvents, and consequently, four new 2-oxo-clerodane diterpenes (), a new 4(3 → 2)--clerodane diterpene (), together with ten known compounds () were isolated and identified from the extracts. Of the new compounds, compound showed a broad spectrum of antifungal activity with moderated minimum inhibitory concentration (MIC) values in a range of 50-100 μg/mL against tested fungal pathogens.

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Background: Waltheria indica exhibited strong nematocidal activity against Meloidogyne incognita, a causal agent of root-knot nematode disease. This study aimed to characterize the nematocidal metabolites and to evaluate the efficacy of the formulated extract of W. indica in the biological control of M.

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Plants contain a number of bioactive compounds that exhibit antimicrobial activity, which can be recognized as an important source of agrochemicals for plant disease control. As part of our search for new antimicrobial agents from natural sources, we found that a crude methanol extract of Trevesia palmata exhibited a promising antifungal activity against phytopathogenic fungi, such as Magnaporthe oryzae and Botrytis cinerea. Furthermore, based on activity-guided fractionation, we isolated five antifungal compounds from the methanol extract of T.

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The in vivo antifungal activity of crude extracts of Dipsacus asper roots was evaluated against the phytopathogenic fungi Botrytis cinerea, Colletotrichum coccodes, Blumeria graminis f. sp. hordei, Magnaporthe grisea, Phytophthora infestans, Puccinia recondita and Rhizoctonia solani using a whole-plant assay method.

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Background: Polygonum chinense Linn. is a common medicinal plant in Southeast Asia and has been used in traditional medicine in Vietnam. The plant contains phytochemicals with various biological properties; however, its antiviral effect has not yet been demonstrated.

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Background: Medicinal plants are widely used for the treatment of different infectious diseases. Infectious diseases caused by bacteria have a large impact on public health. This study aimed to determine the in vitro antibacterial activity of the medicinal plants traditionally used in Vietnam against the bacterial strains associated with infectious diseases.

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The antagonistic fungus Simplicillium lamellicola BCP has been developed as a microbial biopesticide that effectively controls the development of various plant diseases caused by both pathogenic bacteria and pathogenic fungi. Antibacterial bioassay-directed fractionation was used to isolate mannosyl lipids from S. lamellicola BCP, and the structures of these compounds were elucidated using spectral analysis and chemical degradation.

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