Abstract

Agaricus bisporus is one of the most widely cultivated edible mushrooms in the world. The chemical components of A. bisporus have a wide range of biological activities. In order to deeply understand the antioxidant properties of A. bisporus, this study conducted an investigation on the components of A. bisporus fermentation. Through the single factor experiment and response surface optimization, it was found that when the C/N ratio was 45:1, the inoculum concentration was 10%, and the fermentation time was 7 d, the n-butanol extract of the fermentation product had the strongest scavenging capacity for free radical generated through 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS·⁺). The concentration for 50% of the maximal effect (EC₅₀) was 0.33 ± 0.01 mg/mL. Moreover, in order to identify the two main components, the elution–extrusion counter-current chromatography (EECCC) was employed for separation, where 5,5'-oxy-dimethyl-bis(2-furfuraldehyde) and 5-(butoxymethyl) furfural were obtained. The antioxidant activity of 5,5'-oxy-dimethyl-bis(2-furfuraldehyde) (EC₅₀ = 0.26 ± 0.01 mg/mL) was superior to that of 5-butylmethyl furfural (EC₅₀ = 1.52 ± 0.02 mg/mL), indicating that 5,5'-oxy-dimethyl-bis(2-furfuraldehyde) was the main antioxidant in the fermentation products. The thermodynamic parameters and frontier molecular orbitals of 5,5'-oxy-dimethyl-bis (2-furanaldehyde) was evaluated by density functional theory (DFT). The result indicated 5,5'-oxy-dimethyl-bis(2-furanaldehyde) scavenged free radicals in polar media through single electron transfer followed by proton transfer (SET-PT).

摘要

双孢蘑菇是世界上栽培最广泛的食用菌之一。双孢蘑菇的化学成分具有广泛的生物活性。为了深入了解双孢蘑菇的抗氧化特性，本研究对双孢蘑菇发酵成分进行了研究。通过单因素实验和响应面优化发现,当C/N比为45:1、接种浓度为10%、发酵时间为7 d时,发酵产物正丁醇提取物对2,2'-连氮基双(3-乙基苯并噻唑啉)-6-磺酸(ABTS· ⁺ )产生的自由基的清除能力最强。50% 最大效应 (EC ₅₀ ) 的浓度为 0.33 ± 0.01 mg/mL。此外，为了鉴定两种主要成分，采用洗脱-挤出逆流色谱（EECCC）进行分离，其中5,5'-氧基-二甲基-双(2-糠醛)和5-(丁氧基甲基)糠醛获得。5,5'-氧基-二甲基-双(2-糠醛) (EC ₅₀ = 0.26 ± 0.01 mg/mL) 的抗氧化活性优于 5-丁基甲基糠醛 (EC ₅₀ = 1.52 ± 0.02 mg/mL) ，表明5,5'-氧基-二甲基-双(2-糠醛)是发酵产物中的主要抗氧化剂。采用密度泛函理论（DFT）评估了5,5'-氧-二甲基-双（2-呋喃醛）的热力学参数和前沿分子轨道。结果表明，5,5'-氧基-二甲基-双(2-呋喃醛)通过单电子转移和质子转移(SET-PT)清除极性介质中的自由基。