Kadhum Abdul Amir H, Al-Amiery Ahmed A, Musa Ahmed Y, Mohamad Abu Bakar
Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia; E-Mails:
Int J Mol Sci. 2011;12(9):5747-61. doi: 10.3390/ijms12095747. Epub 2011 Sep 7.
The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2-6 are proposed on the basis of spectroscopic evidence.
研究了两种合成香豆素，即N-(4,7-二氧代-2-苯基-1,3-恶唑并[3,2-a]氮杂卓-3(2H,4H,7H)-基)-2-(2-氧代-2H-色烯-4-基氧基)乙酰胺5和N-(4-氧代-2-苯基噻唑烷-3-基)-2-(2-氧代-2H-色烯-4-基氧基)乙酰胺6的抗氧化活性，采用DPPH、过氧化氢和一氧化氮自由基方法，并与已知抗氧化剂抗坏血酸进行比较。化合物5和6由马来酸酐或巯基乙酸与化合物4，即N'-亚苄基-2-(2-氧代-2H-色烯-4-基氧基)乙酰肼加成反应高产率合成。化合物4由化合物3，即2-(2-氧代-2H-色烯-4-基氧基)乙酰肼与苯甲醛缩合而成。然而，化合物3由肼与化合物2，即2-(2-氧代-2H-色烯-4-基氧基)乙酸乙酯加成反应合成，而该化合物由溴乙酸乙酯与4-羟基香豆素1反应合成。根据光谱证据提出了合成香豆素2-6的结构。
