Liu Yao, Wen Fang, Yang Hehe, Bao Liangliang, Zhao Zhihong, Zhong Zhimei
College of Sciences, Inner Mongolia Agricultural University, Hohhot, 010018, China.
Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resource, Hohhot, 010018, China.
Heliyon. 2022 Sep 15;8(9):e10624. doi: 10.1016/j.heliyon.2022.e10624. eCollection 2022 Sep.
Chitooligosaccharides with two different molecular weights are acylated with three containing benzene carboxylic acids: salicylic acid (BHA), α-naphthylacetic acid (NAA) and indole-3-butyric acid (IBA) to obtain o-hydroxybenzoyl-chitooligosaccharide, α-naphthylacetyl-chitooligosaccharide, and 3-Indolebutyryl-chitooligosaccharide. The structure of the derivatives was characterized by FT-IR spectroscopy, C NMR spectroscopy and elemental analysis. According to several amide characteristic absorption peaks between 1750 cm-1500 cm in the FT-IR spectrum, it can be determined that the target group has been successfully grafted. And there are obvious characteristic absorption peaks of aromatic ring at 900-650 cm. The six chemical shifts of 98.02, 76.42, 74.83, 72.00, 60.39, 55.37 ppm in C NMR proved that the chitooligosaccharide did not destroy its own sugar ring structure during the reaction. The antioxidant activities of the derivatives, such as hydroxyl radical (·OH) scavenging ability, superoxide anion (O·) scavenging ability, reducing ability, and DPPH radical scavenging ability were investigated using various established systems. Comparing with chitooligosaccharide and containing benzene carboxylic acids, most derivatives have strong scavenging ability toward superoxide anions and DPPH radicals, and the clearance rate up to 47.44% and 80.27% separately. The reducing ability and hydroxyl free radical scavenging ability of the derivatives are only 0.032 Abs and 11.43%. The above results showed that the antioxidant activity of some derivatives was higher than that of chitooligosaccharide. The water solubility of the new derivatives was also greatly improved than that of containing benzene carboxylic acids. Therefore, the application of phenyl-acyl-chitooligosaccharide in antioxidants has laid a foundation, and has certain potential application value in the fields of medicine and agriculture and animal husbandry.
水杨酸（BHA）、α-萘乙酸（NAA）和吲哚-3-丁酸（IBA）进行酰化反应，得到邻羟基苯甲酰基壳寡糖、α-萘乙酰基壳寡糖和3-吲哚丁酰基壳寡糖。通过傅里叶变换红外光谱（FT-IR）、碳核磁共振光谱（C NMR）和元素分析对衍生物的结构进行了表征。根据FT-IR光谱中1750 cm-1500 cm之间的几个酰胺特征吸收峰，可以确定目标基团已成功接枝。并且在900-650 cm处有明显的芳香环特征吸收峰。C NMR中98.02、76.42、74.83、72.00、60.39、55.37 ppm的六个化学位移证明壳寡糖在反应过程中没有破坏其自身的糖环结构。使用各种既定体系研究了衍生物的抗氧化活性，如羟基自由基（·OH）清除能力、超氧阴离子（O·）清除能力、还原能力和DPPH自由基清除能力。与壳寡糖和含苯羧酸相比，大多数衍生物对超氧阴离子和DPPH自由基具有较强的清除能力，清除率分别高达47.44%和80.27%。衍生物的还原能力和羟基自由基清除能力分别仅为0.032 Abs和11.43%。上述结果表明，一些衍生物的抗氧化活性高于壳寡糖。新衍生物的水溶性也比含苯羧酸有了很大提高。因此，苯基酰基壳寡糖在抗氧化剂中的应用奠定了基础，在医药、农牧业领域具有一定的潜在应用价值。
