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。
An unexpected cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates to construct 2,3-dihydrobenzofuran spirooxindoles
作者:Kuan Zhang、Huabin Han、Lele Wang、Ziying Zhang、Qilin Wang、Wenjing Zhang、Zhanwei Bu
DOI:10.1039/c9cc07114h
日期:——
An unexpected Michael addition-inspired ring-opening/closure cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates was developed to access new dihydrobenzofuran or dihydrobenzothiophene spirooxindoles in 68–98% yields. This reaction not only provides an expedient and convenient method to assemble dihydrobenzofuran spirooxindoles, but also establishes a new reaction mode of coumarin-3-carboxylates
dihydrobenzofuran-fused pyridones in moderate to good yields with good functional group compatibility. The reaction likely involves a radical relay annulation, leading to the ring opening of the lactone moiety of the coumarins, and simultaneous formation of three new bonds. The investigation of photoluminescent properties reveals that several obtained compounds may have potential as fluorescent materials.
Study insights into the different cyclization mechanisms of ethyl cyanoacetate with salicylaldehyde and efficient synthesis of coumarin-3-carboxylate ester
cyclization of the phenolic hydroxyl group to the cyano or ester carbonyl group within the intermediate. Product distribution correlates well with the acid–base properties of the catalyst and the ability of the catalyst for forming complex by hydrogen bonds. Also, an efficient and facile approach was developed for the preparation of coumarin-3-carboxylate ester as a major product from the reaction of ethyl cyanoacetate
Pd(II)‐Catalyzed Benzimidazole‐Assisted Annulation of 3‐(1H‐Benzo[d]imidazol‐2‐yl)‐2H‐chromen‐2‐one: Access to Imidazo[1,2‐a]chromeno[3,4‐c]pyridine
作者:Dinesh Singla、Vijay Luxami、Kamaldeep Paul
DOI:10.1002/ejoc.202300531
日期:2023.9.6
Here reports an synthetic method to access polycyclic aromatic hydrocarbons of imidazo[1,2-a]chromeno[3,4-c]pyridine, by palladium-catalyzedoxidative annulation of 3-(1H-benzo[d]imidazol-2-yl)-2H-chromen-2-one with alkenes using benzimidazole as directing group. In addition, their photophysical properties have been well elucidated with improved quantum yields.
这里报道了一种通过钯催化的3-(1 H-苯并[ d ]咪唑-2-)氧化成环反应获得咪唑并[1,2- a ]色并[3,4- c ]吡啶多环芳烃的合成方法yl)-2 H -chromen-2-one 与烯烃,使用苯并咪唑作为导向基团。此外,随着量子产率的提高,它们的光物理性质也得到了很好的阐明。