Flavonoit glycosit từ cây cách thư Poilanei Fissistigma poilanei (Ast) Tsiang & P. T. Li], họ na (Annonaceae)
Vietnam Journal of Chemistry - Tập 47 Số 4 - 2012
Three flavonoid glycosides: (2R,3R)-3’,4’,5,7-tetrahydroxydihydroflavonol-3-O-a-L rhamnopyranoside (1), (+)-catechin 3-O-a-L-rhamnopyranoside (2) and quercetine 3,7 dimethoxy-3’-O-a-L-rhamnopyranosyl-(1®2)-b-D-glucopyranoside (3) were isolated from the ethyl acetate extract of Fissistigma poilanei. Their structures were elucidated by analysis of MS and NMR spectra and comparison with the publishe...... hiện toàn bộ
Nghiên cứu chế tạo, khảo sát cấu trúc và tính chất vật liệu compozit etylen vinyl axetat copolyme/nanoclay hữu cơ
Vietnam Journal of Chemistry - Tập 47 Số 3 - 2012
Ethylene-vinyl acetate copolymer (EVA)/organic montmorillonite (O-MMT) composites were prepared via direct melt mixing EVA containing vinyl acetate (VA) of 9% with O-MMT in an intermixed Haake at 160oC. The relative melt viscosity of EVA and EVA/O-MMT composites were evaluated according to changing of torque of the materials during melt mixing process. Their structures were investigated with X-ray...... hiện toàn bộ
Synthesis and antibacterial activities of some novel hybrid compounds based on 2‐mercapto‐3‐arylquinazolin‐4(3H)‐one scaffold bearing specific coumarin
Vietnam Journal of Chemistry - Tập 61 Số S2 - Trang 131-136 - 2023
Linh Bui Thi Thuy, Phuoc Le Thien, Chi–Hien Dang, Hai Ha Pham Thi, Cong Tien Nguyen
AbstractTwo series of novel hybrid compounds, in which a variety of 2‐mercapto‐3‐arylquinazolin‐4(3H)‐ones (3a‐d)/6‐bromo‐2‐mercapto‐3‐phenylquinazolin‐4(3H)‐one (9) act as fundamental moieties are incorporated in particular 3‐(2‐bromoacetyl)‐2H... hiện toàn bộ
Khả năng bảo vệ xúc tác cracking trước sự tác động của kim loại nặng trong nguyên liệu khi sử dụng pha nền hoạt động là kaolin Việt Nam biến tính
Vietnam Journal of Chemistry - Tập 46 Số 1 - 2012
Modern fluid catalytic cracking (FCC) catalysts are composed of crystalline zeolite Y which is surrounded and held together by an amorphous silica/alumina matrix. Matrix contributes significantly to the overall performance of FCC catalysts. Catalyst matrix has many of the functions such as upgrading bottoms, reducing SOx emissions, and passivating catalyst poisons. The catalyst matrix plays an imp...... hiện toàn bộ
Chemical constituents of the leaves of Alnus nepalensis D. Don. (Betulaceae)
Vietnam Journal of Chemistry - Tập 46 Số 4 - 2012
Taraxeryl acetate (1), physcion (2), 1-nonacosanol (3), b-sitosterol (4), quercetin (5), b-sitosterol 3-O-b-D-glucopyranoside (6), and quercitrin (7) were isolated from the leaves of Alnus nepalensis D. Don. (Betulaceae). Their structures were determined by spectroscopic methods.
Diterpenoid mới được phân lập từ cây thuốc giấu Euphorbia tithymaloides (P.).
Vietnam Journal of Chemistry - Tập 54 Số 3 - Trang 274 - 2016
Cầm Thị Ính, Nguyễn Thị Hồng Vân, Phạm Minh Quân, Trần Thị Quỳnh Trang, Trịnh Anh Viên, Nguyễn Thị Thuỷ, Đỗ Thị Thảo
A new compound 1α,13β,14α-trihydroxy-3β-benzoyloxy-7β-methoxy-9β,15β-diacetoxyjatrophan-5,11E-dien (1), and two known compounds poly-O-acylated jatrophan diterpenoids (2, 3) were isolated and identified from Euphorbia tithymaloides (P.). Their structures were elucidated by spectroscopic methods and comparison with the reported data. Compound 1 showed good cytotoxicity against four cancer lines. Ke...... hiện toàn bộ
Nghiên cứu chế tạo vật liệu nanocompozit trên cơ sở nhựa epoxy DER 331 và nanoclay. Phần 1. Nghiên cứu chế độ phân tán nanoclay vào nhựa epoxy, ảnh hưởng của hàm lượng nanoclay đến tính chất cơ học của vật liệu.
Vietnam Journal of Chemistry - Tập 52 Số 1 - 2014
In this paper, the influence of dispersion methods on dispersion degree of nanoclay in epoxy matrix was studied. The dispersion degree of nanoclay was evaluated by various, method, namely XRD, viscosity measurement and TEM techniques. The results showed that high speed stirring (2000 rpm) may create the interchalated structure of nanoclay in matrix: the d-spacing of I28E increased from 23.33 Å to ...... hiện toàn bộ
Deprotonation of safrole in the coordination entity of platinum (II).
Vietnam Journal of Chemistry - Tập 48 Số 2 - 2012
The interaction of K[Pt(Saf)Cl3] (Saf: safrole) with AgNO3, SnCl2, KOH and ethanol-water solutions was investigated. For the first time, a dinuclear chelate ring complex [Pt2Cl2(Saf-1H)2], in which deprotonated safrole is bound up with platinum(II) both at benzene carbon and at ethylenic double bond of the side chain was isolated and characterized by elemental, thermal analysis, ESI MS, IR- and ...... hiện toàn bộ
CYANIDE DETECTION ABILITY OF THE PbO2 ELECTRODE SYNTHESIZED BY PULSED CURRENT METHOD
Vietnam Journal of Chemistry - Tập 49 Số 2 - 2012
Duong Thi Doan, Phan Thi Binh, Mai Thi Thanh Thuy, Nguyen Van Toan
Lead dioxide electrode was prepared by pulsed current method on stainless steel (pulse height: 30 mA/cm2, pulse width: 1 s, Q = 5100 mAs) from solution of 0.5 M HNO3 + 0.5 M Pb(NO3)2 + 0.05 M Cu(NO3)2 at room temperature. The electro-catalytic oxidation of cyanide on PbO2 was investigated by potentiodynamic method at different scan rates in medium of 0.1 M NaOH. The result showed that PbO2 can el...... hiện toàn bộ
Ảnh hưởng của cấu trúc chất mang tới khả năng làm việc của xúc tác CO/SiO2 trong quá trình tổng hợp Fischer-Tropsch
Vietnam Journal of Chemistry - Tập 52 Số 3 - 2014
The influence of the support texture (Silicagel, Silicalit and MCM-41) on working performance of Co/SiO2 for the Fischer-Tropsch synthesis has been studied. The differences in textures of three SiO2 types were characterized by BET, SEM and FE-SEM-EDX techniques. The results showed that different textures of the three SiO2 materials strongly affected not only on distribution of catalytic sites (cob...... hiện toàn bộ