Antioxidants and alpha-glucosidase inhibitors from Ipomoea batatas leaves identified by bioassay-guided approach and structure-activity relationships

作者：Zhang, Lu; Tu, Zong-cai^*; Yuan, Tao; Wang, Hui; Xie, Xing; Fu, Zhi-feng

来源：Food Chemistry, 2016, 208: 61-67.

DOI：10.1016/j.foodchem.2016.03.079

• Ipomoea batatas leaves
• alpha-Glucosidase
• Antioxidant activity
• Identification

Sweet potato (Ipomoea batatas) leaf (SPL) is an underused commercial vegetable with considerable bio-activities. By means of DPPH center dot scavenging ability and alpha-glucosidase inhibitory oriented isolation, 9 and 7 compounds were isolated and identified, respectively. Among them, trans-N-(p-coumaroyl)tyramine (1), trans-N-feruloyltyramine (2), cis-N-feruloyltyramine (3), 4,5-feruloylcourmaoylquinic acid (8), caffeic acid ethyl ester (10), 7-hydroxy-5-methoxycoumarin (11), 7,3'-dimethylquercetin (13) and indole-3-carboxaldehyde (15), were firstly identified from SPL, and four of them (1, 2, 3 and 10) were firstly identified from genus Ipomoea. Phenethyl cinnamides and 3,4,5-triCQA exhibited the strongest alpha-glucosidase inhibition, while 3,4,5-triCQA and diCQAs were the dominant antioxidants. Structure-activity relationship revealed that higher caffeoylation of quinic acid and lower methoxylation of flavonols resulted in stronger antioxidant activity, and methylation and cis-configuration structure of phenethyl cinnamides weaken the alpha-glucosidase inhibition. Aforementioned results could help to explain the antioxidant activity and anti-diabetic activity of SPL, and provide theoretical basis for its further application.

• 出版日期2016-10-1
• 单位江西师范大学; 中国科学院; 南昌大学; 食品科学与技术国家重点实验室; 中国科学院新疆理化技术研究所