Synthesized tyrosyl hydroxyphenylacetate, a novel antioxidant, anti-stress and antibacterial compound

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• 作者：Imen Aissa^a ; Mohamed Bouaziz^b ; Fakher Frikha^a ; Riadh Ben Mansour^c ; Youssef Gargouri^a ; ^{ytgargouri@yahoo.fr}
• 关键词：Ty ; tyrosol ; p-HPA ; p-hydroxyphenylacetic acid ; Ty-HPA ; tyrosyl hydroxyphenylacetate ; RSM ; response surface methodology ; LC/MS ; liquid chromatography coupled to mass spectrometry ; FT-IR ; Fourier transformed infrared spectroscopy ; NMR ; nuclear magnetic res
• 刊名：Process Biochemistry
• 出版年：2012
• 出版时间：December, 2012
• 年：2012
• 卷：47
• 期：12
• 页码：2356-2364
• 全文大小：1043 K

文摘

New tyrosyl ester derivative, a naturally occurring phenol with interesting biological properties, has been synthesized in good yield by a direct esterification of tyrosol (Ty) with p-hydroxyphenylacetic acid (p-HPA) using Candida antarctica lipase as a catalyst. The response surface methodology was used to modulate the effects of the enzyme amount (10-50 mg), the tert-butanol/hexane (v/v) ratio (0.16-0.84), the temperature (35-55 ¡ãC) and the reaction time (15-45 h) on the tyrosyl hydroxyphenylacetate (Ty-HPA) conversion yield. Under the optimal predicted conditions (enzyme amount: 10 mg, solvents volume ratio 0.16, reaction temperature; 45 ¡ãC and 34 h of incubation), a high conversion yield of 79.33 ¡À 4 % was reached. The obtained ester was purified and characterized by NMR, LC/MS and FT-IR methods. ABTS free radical quenching potency demonstrated that the esterified tyrosol (Ty-HPA) was more effective than the natural separated antioxidants: Ty and p-HPA. Furthermore, when used at a non-cytotoxic concentration (100 ¦ÌM), tyrosyl ester showed significant effectiveness in preventing iron-induced oxidative stress in blood cells compared to the two separated compounds. The antibacterial activity of Ty, p-HPA, mixed solution of Ty + p-HPA and Ty-HPA was performed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using a micro-well dilution method. Compared to the separated substrates, synthesized ester exhibits the most antibacterial effect mainly against Gram+ bacteria.