RESUMO
Rosa roxburghii Tratt pomace (RRTP) has increasingly attracted attention due to its various nutritional ingredients and health benefits. In this study, the free phenolic fraction (RRTP-FPF) and bound phenolic fraction (RRTP-BPF) were extracted from RRTP by solvent extraction method and alkaline hydrolysis method, respectively. The composition of polyphenols in RRTP-FPF and RRTP-BPF were identified by ultra-high performance liquid chromatography equipped with an electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS/MS). In vitro antioxidant assays indicated that RRTP-FPF and RRTP-BPF could scavenge radicals in a dose-dependent manner, and RRTP-BPF exhibited better scavenging activity than RRTP-FPF. In addition, RRTP-FPF and RRTP-BPF (20 â¼ 100 µg/mL) treatment for 24 h could significantly increase the survival rate and decrease reactive oxygen species (ROS) level of paraquat-exposed nematodes through improving the activities of superoxide dismutase (SOD) and catalase (CAT). These results suggest that RRTP could be as a good and cheap source of natural antioxidants.