Science and Technology Development Journal 2020-01-17T13:11:32+00:00 Phuc Van Pham Open Journal Systems Chemical constituents of the ethyl acetate extract from the leaf of mugwort (Artemisia vulgaris L.) 2020-01-17T13:11:30+00:00 Truong Van Nguyen Thien Thien Tai Phan Tung Thanh Phan Lien Kim Thi Tran Nhu Tiet Thi Tran Phu Hoang Dang Linh Phi Nguyen Quang That Ton <p><strong>Introduction</strong>: Mugwort (<em>Artemisia vulgaris</em> L.) is a familiar herbal medicine and also a daily vegetable. It is one of the ingredients in the famous remedy "Cao ích mẫu" specializing in menstrual disorders or the omelet with mugwort that helps save blood flow to the brain to treat headaches. In both traditional medicine and the new drugs, diseases are usually treated by mugwort as diabetes, epilepsy combination for psychoneurosis, depression, irritability, insomnia, anxiety, and stress. To demonstrate the medicinal uses, the chemical constituents of this herbal were continually studied.</p> <p><strong>Methods</strong>: The leaves of mugwort were collected in Ba Ria - Vung Tau province, Vietnam. The plant was identified by the late pharmacist and botanist Binh Duc Phan. A voucher specimen (AV001) was deposited in the herbarium of the Department of Organic Chemistry, VNUHCM–University of Science. Dried leaf powder of <em>A. vulgaris</em> (11 kg) was extracted with methanol and evaporated under reduced pressure to give a methanol extract (910 g), which was dissolved in methanol-water (1:9) and then successively partitioned with petroleum ether, chloroform, and ethyl acetate. From the previously researched ethyl acetate fraction, nine compounds were isolated: six known phenolic compounds (luteolin, 6-methoxyluteolin, eupatilin, o-coumaric acid, vanillic acid, and protocatechuic acid), sinapyl alcohol diisovalerate, vulgarin, and one new compound (artanoic acid).</p> <p><strong> Results</strong>: In this research, ethyl acetate fraction was also studied. From subfraction EA4, six compounds were isolated by three skeletons: phenolic compounds (5,4′ -dihydroxyflavone and 4-hydroxyphenyl acetate), phenyl propanoid (methyl 2-O-b -D-glucopyranosylcoumarate and 2-O-b -D-glucopyranosylcoumaric acid) and uracil (5-methyluracil and uridine). The structure of the isolated compounds was determined to base on 1D, 2D NMR spectra, HR-ESI-MS, and comparison with published data.</p> <p><strong>Conclusion</strong>: Particularly, four compounds (methyl 2-O-b -D-glucopyranosylcoumarate, 2-O-b -D-glucopyranosylcoumaric acid, 5-methyluracil, and uridine) were known for the first time from this species.</p> <p>&nbsp;</p> 2019-12-31T00:00:00+00:00 ##submission.copyrightStatement## Characterization of the silver thin films produced at different substrate temperatures 2020-01-17T13:11:28+00:00 Ton Nu Quynh Trang Le Thi Ngoc Tu Tran Van Man Vu Thi Hanh Thu <p><strong>Introduction</strong>: In recent decades, the antimicrobial surfaces/coating properties towards a longlasting microbicidal effect have drawn enormous attention by researchers, they have been developed and used in a wide variety of high-touch hospital devices as a potential approach.</p> <p><strong>Methods</strong>: In this work, Ag NPs was synthesized by sputtering method at the different annealing temperatures of 100◦C, 200◦C, 300◦C, and 400◦C.</p> <p><strong>Results</strong>: As a result, the as-synthesized Ag-300 exhibits the highest E. coli antibacterial performance compared with others. This can be attributed to the change of the Ag NPs toxicity based on the growth of nanoparticles during the deposition process related to the Ostwald ripening process, thermal activation and coalescence particles.</p> <p><strong>Conclusion</strong>: This work provides an essential insight into the antimicrobial activity of Ag NPs-based films synthesized through the vacuum deposition technique, resulting in opening a new approach for enhancing the antimicrobial efficacy and prospects.</p> <p>&nbsp;</p> <p>&nbsp;</p> 2020-01-01T14:44:47+00:00 ##submission.copyrightStatement## Four flavonols from the seed of Hibiscus sabdariffa. Linn. growing in Binh Thuan Province 2020-01-17T13:11:32+00:00 Pham Nguyen Kim Tuyen Truong Van Tien Tran The Anh Huy Nguyen Thi Hoa Huynh Bui Linh Chi Nguyen Thi Hoai Thu Huy Thuc Duong Nguyen Kim Phi Phung <p><strong>Introduction: </strong><em>Hibiscus sabdariffa</em> Linn. (Malvaceae) is a medicinal plant popularly distributed in Asian countries. As of 2019, no chemical investigations from the Vietnamese plant were found. This paper reported the isolation and elucidation of compounds isolated from the seeds of <em>Hibiscus sabdariffa</em> Linn. (Malvaceae) growing in Binh Thuan province.</p> <p><strong>Method: </strong>The maceration was applied to the seeds of the plant to afford the crude extract which was then fractionated by liquid-liquid extraction to obtain the ethyl acetate extract. The extract was carried out by using normal phase silica gel column chromatography and thin-layer chromatography. Analysis of spectroscopic data including HR-ESI-MS, 1D and 2D-NMR and a comparison of the NMR data with that in the literature led to the structural elucidation of isolated compounds.</p> <p><strong>Results: </strong>Four flavonols comprising quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (<strong>1</strong>), quercetin 3-O-β-D-glucopyranoside (<strong>2</strong>), quercetin (<strong>3</strong>) and kaempferol (<strong>4</strong>) were isolated from the ethyl acetate extract.</p> <p><strong>Conclusions:</strong> This is the first time the isolated compounds were found from the seeds of this plant.</p> 2019-11-30T00:00:00+00:00 ##submission.copyrightStatement##