Thiết lập chất chuẩn và định lượng huperzin a trong một số loài họ thạch tùng ở Việt Nam - Nguyen Ngoc ChuongThiết lập chất chuẩn huperzin A từ nguồn chất tinh khiết phân lập được từ cây Râu rồng có độ tinh khiết cao 99,13 % và được thẩm định theo các tiêu chuẩn đầy đủ của một chất chuẩn gốc đáng tin cậy trong kiểm nghiệm dược liệu. Quy trình phân tích huperzin A trong dược liệu bằng HPLC được xây dựng và thẩm định. Các quy trình định tính và định lượn...
8 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 689 | Lượt tải: 0
Isolation and structure elucidation of three flavonoids from the seed of ziziphus mauritiana lamThree flavonoids, spinosin (1), 6’’’- feruloyl spinosin (2) and 6’’’-sinapoyl spinosin (3) were isolated from EtOH extract of seed of Ziziphus mauritiana. Their structures were elucidated by the analysis of their spectroscopic data (ESI-MS,1H-NMR,13C-NMR, DEPT, HSQC and HMBC) and compared with literatures. The 1H and 13C NMR spectra of 1, 2 and ...
8 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 486 | Lượt tải: 0
Initial research on chemical constituents of curcuma singularis rhizomes - Nguyen Manh CuongCompound 3 was isolated as colourless crystals. The 1H-NMR of 3 showed the presence of a sesquiterpene of carotane skeleton, including, one methyl group at δH 1,15 (s, 7-CH3), and two methyl protons of isopropyl group at [δH 0.94 (d, J = 7.0 Hz, H-13), δH 1.02 (d, J = 6.5 Hz, H- 12)], three methylene protons at [δH 1.68 (m, Ha-8), δH 1.71 (m, Ha...
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Preparation of polymer composites based on unsaturated polyester reinforced by natural fiber and cellulose microfiber from lung waste in Nghe AnThe results of tensile, flexural and impact tests showed that the MFC content of 0.3 % was the optimal content for preparation of polymer composite and it would be used to investigate fatigue property. The presence of MFC strongly improved the fatigue property of material. At 0.3 % MFC, sample D1 was destroyed after 23826 cycles compared to 1016...
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Structural characteristics and anticoagulant activity of sulfate polysaccharide from the brown alga sargassum aliqFour fractions of sulfate polysaccharide extracted from the brown alga Sargassum aliqualium (Fucales, sargassaceae) were fractionated by using anion – exchange chromatography. Their structural characteristics were determined by desulfation, methylation and NMR spectroscopic methods. The results showed that four sulfate polysaccharides have bran...
6 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 495 | Lượt tải: 0
In vitro antioxidant and antibacterial activities of fractionated extracts and isolation of bioactive components from breynia vitis-Idaea (burm. f.) c. e. c. fischer leaves - Nguyen Thi Lan HuongBreynia vitis-idaea was used for curing body aches and skin diseases. Ethanol and ethyl acetate extract of the leaves of this plant recorded inhibitory activity against E. faecalis, which causes stomachache, S. aureus and MRSA, which cause skin infections, with MIC under 3 mg/ml. With regard to E. coli, Sal. typhi and P. aeruginosa, all of the e...
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Antioxidant and antibacterial activities of extracts from seeds of musa balbisiana - Bui Tan NghiaAntibacterial activity of all extracts of seeded banana was evaluated against two Gram positive bacteria Enterococcus faecalis and Staphylococcus aureus by disc diffusion method. They are common cause of human infections. Moreover, Enterococcus faecalisis resistant to many commonlyusedantimicrobial agents,so a new antibacterial product is n...
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Study on some factors of magnetic fluid chitosancoated fe3o4 nanoparticles fabrication via hydrothermal methodTo visualize the effect of the independent variables on the dependent variable, surface response and contour plots of the quadric polynomial model were generated by varying two of the independent variables within the experimental range while holding the other constant at the centre point using the Design-Expert software (Figure 2). These respons...
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Chemical constituents from the mycelium of isaria japonica yasuda - Nguyen Ngoc TuanIn the present study, we have succeeded in cultivating I. japnonica in a liquid medium and studying chemical composition of the mycelium of I. japnonica Yasuda in Pumat, Nghean province resulted in the identification of eight compounds, including two steroids (ergosterol, ergosterol peroxide), one flavonoid (tricine), one phenolic (2-hydroxy-3-p...
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Computational study of molecular structures and antioxidant mechanism of ovothiols - Le Tien DungIn this work, the antioxidant activity of OSHA , OSHB and OSHC has been computationally. Several thermo-parameters including BDE, IE, PDE and quantum chemical indexes η, ω and µ were calculated using DFT/6-311++G(2df,2p) basis sets show that the antioxidant capacities of OSHA and OSHC are bettter than that of OSHB. In terms of theoretical reacti...
6 trang | Chia sẻ: honghp95 | Ngày: 02/12/2020 | Lượt xem: 545 | Lượt tải: 0
