排序方式: 共有77条查询结果,搜索用时 15 毫秒
21.
John A. Donnelly Clement L. Higginbotham 《Monatshefte für Chemie / Chemical Monthly》1991,122(1-2):83-87
Summary The title chalcone derivatives react with aqueous sodium hydroxide of various concentrations to form aurones as the major product, together with small amounts of flavones. However, the introduction of 4-nitro or 4-chloro substituents resulted in the formation of flavones as the major product.
O-Heterocyclen mittels Cyclisierung von an der Seitenkette brommethoxylierten 2-Acetoxychalconen
Zusammenfassung Die im Titel genannten Chalconderivate reagieren mit Natronlauge in verschiedenen Konzentrationen, wobei Aurone zusammen mit geringen Mengen an Flavonen entstehen. Die Einführung von 4-Nitro- oder 4-Chlor-Substituenten führte jedoch zur bevorzugten Bildung von Flavonen.相似文献
22.
ZHU Jin-tao~ 《高等学校化学研究》2001,17(3):259-263
Chrysin(1) and tectochrysin(2) were respectively synthesized in four steps from 1,3,5-tribromobenzene in an overall yield of 46.8% and that of 37.0% with the key step being the Bu_4NBr catalyzed hydrolysis of 1-phenyl-3-(2′,4′,6′-trimethoxyphenyl)-1, 3-propanedione (11) under different conditions. 相似文献
23.
《Arabian Journal of Chemistry》2019,12(7):1260-1267
Phytochemical investigation of the antidiabetic chloroform fraction of the ethanolic extract obtained from the aerial parts of Callistemon lanceolatus DC led to the isolation of three new phytoconstituents, one flavone, 8-(1″-hydroxyisopranyl)-5,6-dihydroxy-7,4′-dimethoxy flavone (1) and two phenolic esters, 2,3,4-trihydroxyphenethyl tetracontanoate (2) and 2,3,4-trihydroxyphenethyl tetracontanoate-4-β-xylopyranoside (3). The isolated compound 1 exhibited significant in vivo blood glucose lowering effect comparable to the standard drugs Pioglitazone and Rosiglitazone in streptozotocin induced diabetic rats without causing any toxic effect on the pancreas and liver. Compound 1 showed a glide score of −7.89 against PPAR-γ target in molecular docking studies which is significantly higher than the glide score of reference molecule Rosiglitazone (glide score of −5.77). Compound 1 also exhibited moderate in vitro PPAR-γ transactivation activity of 48.52% in comparison with standard drugs rosiglitazone and pioglitazone, which showed a transactivation activity of 80.47% and 65.27%, respectively. 相似文献
24.
HPLC法测定柴胡地上部分的黄酮苷元 总被引:1,自引:0,他引:1
运用HPLC法测定青海不同产地4种柴胡地上部分的黄酮, 为柴胡药材的综合有效利用提供依据. 采用C18色谱柱以V(甲醇):V(0.1% H3PO4)=1:1为流动相, 流速1 mL/min, 检测波长360 nm. 青海产柴胡地上部分均含丰富的黄酮, 其中以秦岭柴胡黄酮质量分数最高, 槲皮素质量分数达到2.27%, 总黄酮质量分数大于6.50%. 本方法简便, 对黄酮的定量准确, 改变以往柴胡只使用地下部分而弃去地上部分的局面, 提高柴胡药材的有效利用率. 相似文献
25.
Sayed Alam 《Journal of Chemical Sciences》2004,116(6):325-331
Some derivatives of 2-phenyl-chromen-4-one (flavone ring) have been synthesized and tested for antibacterial and antifungal
activities along with their chalcone precursors against four human pathogenic bacteria and five plant mould fungi. The structures
of the synthesized compounds were elucidated by UV, IR and1H NMR spectroscopic techniques, and elemental analysis. The antibacterial and antifungal screens of the synthesized compounds
were performed in vitro by the filter paper disc diffusion method and the poisoned food technique. 相似文献
26.
27.
石香薷中两个新黄酮甙的研究 总被引:4,自引:0,他引:4
石香薷中两个新黄酮甙的研究郑尚珍,孙丽萍,沈序维王毅(西北师范大学化学系,兰州,730070)(中国科学院兰州化学物理研究所)关键词石香薷,唇形科,黄酮甙唇形科植物石香薷(MOslachinensisMaxim)作为中药,用来治疗暑湿感冒、头痛、腹痛... 相似文献
28.
From the ethanol extract of the seeds ofOroxylum indicum a new flavone glucuronide named oroxindin has been isolated. Based on chemical as well as UV, IR, PMR and mass spectral data
oroxindin has been constituted as 5-hydroxy-8-methoxy-7-0-β-D-glucopyranuronosyl flavone (wogonin-7-0-β-D-glucuronide). 相似文献
29.
In this paper, the application of polyethylene glycol (PEG) aqueous solution as a green solvent in microwave-assisted extraction (MAE) was firstly developed for the extraction of flavone and coumarin compounds from medicinal plants. The PEG solutions were optimized by a mono-factor test, and the other conditions of MAE including the size of sample, liquid/solid ratio, extraction temperature and extraction time were optimized by means of an orthogonal design L(9) (3(4)). Subsequently, PEG-MAE, organic solvent-MAE, and conventional heating reflux extraction (HRE) were evaluated with nevadensin extraction from Lysionotus pauciflorus, aesculin and aesculetin extraction from Cortex fraxini. Furthermore, the mechanism of PEG-MAE was investigated, including microwave-absorptive property and viscosity of PEG solutions, the kinetic mechanism of PEG-MAE and different microstructures of those samples before and after extraction. Under optimized conditions, the extraction yields of nevadensin from L. pauciflorus, aesculin and aesculetin from C. fraxini were 98.7%, 97.7% and 95.9% in a one-step extraction, respectively. The recoveries of nevadensin, aesculin and aesculetin were in the range of 92.0-103% with relative standard derivation lower than 3.6% by the proposed procedure. Compared with organic solvent-MAE and conventional extraction procedures, the proposed methods were effective and alternative for the extraction of flavone and coumarin compounds from medicinal plants. On the basis of the results, PEG solution as a green solvent in the MAE of active compounds from medicinal plants showed a great promising prospect. 相似文献
30.