Li Zhong Yan, Yuan Lin, Zhang Min, Zhong Yun Qiang, Yuan Xian You
Key Laboratory of Comprehensive Utilization of Advantage Plants Resources in Hunan South, Hunan University of Science and Engineering, Yongzhou, Hunan 425199, China.
J Nanosci Nanotechnol. 2018 Feb 1;18(2):1215-1219. doi: 10.1166/jnn.2018.14109.
The title compound 5,6-O-(4-chlorophenyl)-L-ascorbic acid (C13H11ClO6) was synthesized using nanosolid superacid SO2-4/SnO2 as a catalyst and its structure was characterized by IR, 1H NMR and single-crystal X-ray diffraction. 1H NMR data indicated the product is a mixture of two diastereomer compounds (a(7S) and b(7R)). And the crystal of one diastereomer compound a(7S) belongs to orthorhombic system, space group P212121 with a = 6.501(4), b = 7.803(5), c = 25.013(15) Å, V 1268.7(13) Å3, Z = 4, Dc 1.564g/cm3, μ(Mo-Kα) = 0.325 mm-1, F(000) = 616, R = 0.0255 and wR(I > 2σ (I)) = 0.0624. X-ray crystal structure data display that the hydrogen bonding interactions observed link the molecules to form a three-dimensional system. In addition, 5,6-O-(4-chlorophenyl)-L-ascorbic acid (CPAA) exhibited strong free-radical scavenging activities in vitro against 2,2-diphenyl-1-picrylhydrazyl and superoxide anion. Therefore, CPAA should be investigated further as a worthy antioxidant.
以纳米固体超强酸SO2-4/SnO2为催化剂合成了标题化合物5,6-O-(4-氯苯基)-L-抗坏血酸（C13H11ClO6），并通过红外光谱、1H核磁共振和单晶X射线衍射对其结构进行了表征。1H核磁共振数据表明该产物是两种非对映异构体化合物（a(7S)和b(7R)）的混合物。其中一种非对映异构体化合物a(7S)的晶体属于正交晶系，空间群为P212121，a = 6.501(4)，b = 7.803(5)，c = 25.013(15) Å，V 1268.7(13) Å3，Z = 4，Dc 1.564g/cm3，μ(Mo-Kα) = 0.325 mm-1，F(000) = 616，R = 0.0255，wR(I > 2σ (I)) = 0.0624。X射线晶体结构数据显示，观察到的氢键相互作用将分子连接形成一个三维体系。此外，5,6-O-(4-氯苯基)-L-抗坏血酸（CPAA）在体外对2,2-二苯基-1-苦基肼基和超氧阴离子表现出较强的自由基清除活性。因此，CPAA作为一种有价值的抗氧化剂值得进一步研究。
