Trapa quadrispinosa, a water caltrop cultivar, has long been consumed as a food in Asian countries and its pericarp is discarded as waste after the fruit is harvested. In this study, a reliable method was established using UPLC-QTOF-MS/MS to identify the main compounds in Trapa quadrispinosa pericarps (TQP). The UPLC parameters including column, mobile phase, and temperature were optimized. The extraction parameters including solvents, temperatures and solid-to-liquid ratios were also optimized. A total of 35 compounds were tentatively assigned. The QTOF-MS/MS fragmentation pathways of these compounds were proposed. The most abundant compound (1,2,3,6-tetra-O-galloyl-β-d-glucose) was further purified by a semi-preparative HPLC and confirmed by ¹H- and ¹³C-NMR. Hydrolyzable tannins (gallotannins and ellagitannins) consisting of almost 90% polyphenols were obtained from the TQP extracts. Three of the main hydrolyzable tannins were 1,2,3,6-tetra-O-galloyl-β-d-glucose, tri-O-galloyl-hexahydroxydiphenoyl-d-glucose, and tri-O-galloyl-d-glucose. The TQP extracts exhibited better antioxidant activity in the DPPH assay than that of the ascorbic acid standard. This study provides valuable information for the utilization of TQP as an alternative source of plant-derived antioxidants.

Trapa quadrispinosa是一种菱角栽培品种，长期以来在亚洲国家被当作食品食用，其果皮在收获果实后作为废物丢弃。在这项研究中，使用UPLC-QTOF-MS / MS来识别主要化合物成立的可靠方法菱quadrispinosa果壳（TQP）。优化了UPLC参数，包括色谱柱，流动相和温度。还优化了萃取参数，包括溶剂，温度和固液比。暂定分配了35种化合物。提出了这些化合物的QTOF-MS / MS裂解途径。最丰富的化合物（1,2,3,6-四-O-galloyl- β - d-葡萄糖）通过半制备型HPLC进一步纯化，并通过¹ H-和¹³ C-NMR。从TQP提取物中获得了由几乎90％的多酚组成的可水解单宁（半乳鞣质和鞣花单宁）。主可水解的单宁的三个是1,2,3,6-四-O- galloyl- β - d -葡萄糖，三-O-没食子酰基hexahydroxydiphenoyl- ð葡萄糖，和三-O- galloyl- d葡萄糖。TQP提取物在DPPH分析中显示出比抗坏血酸标准品更好的抗氧化活性。这项研究为利用TQP作为植物抗氧化剂的替代来源提供了有价值的信息。