4-甲基-7-羟基香豆素抗氧化性能研究

Study on the antioxidant properties of 4-methyl-7-hydroxycoumarin

摘要:

以间苯二酚为原料，在酸催化下与乙酰乙酸乙酯发生取代、环化脱水反应，得到4-甲基-7-羟基香豆素(1)，化合物1再经酯化获得4-甲基-7-乙酰氧基香豆素(2)，通过核磁共振氢谱（nuclear magnetic resonance hydrogen spectroscopy，1HNMR）、核磁共振碳谱（nuclear magnetic resonance carbon spectroscopy，13CNMR）和超高效液相色谱-电喷雾离子源质谱联用仪（ultra high performance liquid chromatograph electrospray ion source mass spectrometer，UHPLC-ESI-MS）对合成产物结构进行了表征。采用多种自由基氧化DNA的反应体系来检测化合物的抗氧化活性，其中包括抑制2,2’-偶氮二异丁基脒二盐酸盐(2,2’-azobis(2-amidinopropanehydrochloride)，AAPH)、HO?、Cu2 /还原型谷胱甘肽(glutathione，GSH)引发的DNA氧化反应。此外，还通过淬灭自由基体系，探索了化合物还原自由基的能力，其中自由基包括2,2′-偶氮-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐自由基(2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical，ABTS ?)、二苯苦味酰肼自由基(2,2’-diphenyl-1-picrylhydrazyl，DPPH)、2,6-二叔丁基-(3,5-二叔丁基-4-氧代-2,5-环己二烯)-对-甲苯氧(galvinoxyl)自由基，进而探究羟基对香豆素抗氧化性能的影响。结果表明：1）化合物1不仅能够很好地抑制AAPH、HO?、Cu2 /GSH自由基引发的DNA氧化反应，也能够捕获ABTS ?、DPPH、galvinoxyl自由基；2）化合物2仅能够抑制HO?和Cu2 /GSH自由基引发的DNA氧化反应，捕获ABTS ?和DPPH两种自由基。3）化合物1抑制自由基引发的DNA氧化反应活性和捕获自由基能力均优于化合物2，说明化合物1具有较强自由基的清除能力和还原能力，是一种潜在的抗氧化剂。

Abstract:

4-methyl-7-hydroxycoumarin was prepared by the acid-catalytic reaction of the resorcinol with ethyl acetoacetate and then 4-methyl-7-acetoxylcoumarin was obtained by the esterification of 4-methyl-7-hydroxycoumarin. The structure of the compound was confirmed by melting point, nuclear magnetic resonance hydrogen spectroscopy (1H NMR), nuclear magnetic resonance carbon spectroscopy(13C NMR) spectrum, and ultra high performance liquid chromatograph electrospray ion source mass spectrometer(UHPLC-ESI-MS). Antioxidant abilities of the obtained compounds were evaluated by inhibiting 2,2’-azobis(2-amidinopropanehydrochloride) (AAPH)-, Cu2 /glutathione (GSH)-, and ?OH- induced oxidation of DNA. The radical-scavenging properties of the obtained compounds were estimated by quenching 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS ?), 2,2’-diphenyl-1-picrylhydrazyl (DPPH), and galvinoxyl radicals, and then the structure-activity relationship of these compounds could be explored. The results showed: (1) 4-methyl-7-hydroxylcoumarin not only exhibited the ability to protect DNA against AAPH, Cu2 /GSH and ?OH-induced oxidation, but also scavenged ABTS ?, DPPH, and galvinoxyl radical, respectively; (2) 4-methyl-7-acetoxylcoumarin can only inhibit the DNA oxidation reaction by ?OH and Cu2 /GSH, and scavenge ABTS ? and DPPH radicals; (3) 4-methyl-7-acetoxylcoumarin had antioxidant property, while antioxidant property was reduced when hydroxyl was protected, revealing that 4-methyl-7-hydroxylcoumarin has strong radical-scavenging properties and reduction ability , can be a potential antioxidant.