Antioxidants have been the subject of intense research interest due to their numerous health benefits. In this work, a series of new conjugates of hydroxytyrosol and coumarin were synthesized and evaluated for their free radical scavenging, toxicity and antioxidant mechanism in vitro. The all target compounds 14a–t exhibited better radical scavenging activity than BHT, hydroxytyrosol, and coumarin
抗氧化剂由于其许多健康益处而已成为人们广泛研究的主题。在这项工作中,合成了一系列新型的羟基酪醇和香豆素共轭物,并对其体外自由基清除,毒性和抗氧化机理进行了评估。在DPPH自由基和ABTS +自由基阳离子清除试验中,所有目标化合物14a–t均表现出比BHT,羟基酪醇和香豆素更好的自由基清除活性。结构-活性关系研究表明,香豆素环上羟基的数量和位置对于良好的抗氧化能力至关重要。此外,最有前途的化合物14q在正常的WI-38和GES细胞中,溶血试验显示的毒性比BHT弱,抗增殖作用较弱,并且H 2 O 2诱导的HepG2细胞活力增强。另外,14q降低了HepG2细胞的凋亡百分比,减少了ROS的产生和LDH的释放,并改善了H 2 O 2处理的HepG2细胞中的GSH和SOD水平。最后,在甲醇溶液中,14q比羟基酪醇具有更高的稳定性。这些结果表明,羟基酪醇和香豆素的结合物显示出更好的抗氧化能力,并且是发现新型潜在抗氧化剂的有效方法。
ZnO/MgO containing ZnO nanoparticles as a highly effective heterogeneous base catalyst for the synthesis of 4H-pyrans and coumarins in [bmim]BF4
作者:H. Valizadeh、A. A. Azimi
DOI:10.1007/bf03246209
日期:2011.3
4H-Pyrans and coumarins were synthesized through one-pot reactions using ZnO/MgO solid sample containing ZnO nanoparticles as an efficient reusable catalyst in ionicliquid, [bmim]BF4. The catalyst is inexpensive and readily available, stable and storable, easily recycled and reused for several cycles with consistent activity. The procedure offers advantages in terms of high yields, short reaction
Imidazolium-Based Phosphinite Ionic Liquid (IL-OPPh<sub>2</sub>) as Reusable Catalyst and Solvent for the Knoevenagel Condensation Reaction
作者:Hassan Valizadeh、Hamid Gholipour
DOI:10.1080/00397910903097310
日期:2010.4.26
task-specific ionic liquid (IL, OPPh2) that bears a phosphinite weak Lewis base group in an imidazolium cation was found to efficiently catalyze the Knoevenagel condensation of arylaldehydes with malononitrile, dimethyl(diethyl)malonate, and ethylcyanoacetate. This IL plays a dual role as both the reaction media and also catalyst, and it can be easily recovered and reused in several runs. Satisfactory results
One-Pot Wittig and Knoevenagel Reactions in Ionic Liquid as Convenient Methods for the Synthesis of Coumarin Derivatives
作者:Hassan Valizadeh、Sevil Vaghefi
DOI:10.1080/00397910802573163
日期:2009.4.7
condensation, higher conversions were observed via Wittigreaction of these compounds with 2-hydroxybenzaldehyde derivatives and triphenylphosphine. Other 2-hydroxybenzaldehyde derivatives, methyl- and ethylchloroacetates, were reacted in ionic liquids to afford simple coumarins in good yields. These reactions widen the applicability of ionic liquid in organic synthesis.
ZnO nanoparticle as catalyst for efficient green one-pot synthesis of coumarins through Knoevenagel condensation
作者:B VINAY KUMAR、HALEHATTY S BHOJYA NAIK、D GIRIJA、B VIJAYA KUMAR
DOI:10.1007/s12039-011-0133-0
日期:2011.9
Green chemistry protocols with the reusability of the nano particle as catalyst in the synthesis of coumarins is described. The zinc oxide (ZnO) nanoparticles functions as highly effective catalyst for the reactions of various o-hydroxy benzaldehydes with 1,3-dicarbonyl compounds under microwave and thermal conditions to afford the corresponding coumarins in moderate to good yields. The catalyst is