National Engineering Laboratory of Intelligent Food Technology and Equipment, Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Key Laboratory for Agro-Products Nutritional Evaluation of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, Fuli Institute of Food Science, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China.
Analysis Center of Agrobiology and Environmental Sciences, Zhejiang University, Hangzhou, 310058, China.
Sci Rep. 2017 Aug 30;7(1):10068. doi: 10.1038/s41598-017-10411-0.
This study was aimed at investigating the chemical stability (the thermal, light and pH stability) of phenylethanoid glycosides (PhGs) in Osmanthus fragrans Lour. flowers, identifying the degradation products of acteoside and salidroside (major PhGs in O. fragrans flowers) by UPLC-QTOF-MS and studying the anti-hypoxia activity of PhGs after degradation. The degradation of PhGs followed first-order reaction kinetics, and the rate constant of acteoside (4.3 to 203.4 × 10 day) was higher than that of salidroside (3.9 to 33.3 × 10 day) in O. fragrans flowers. Salidroside was mainly hydrolyzed to tyrosol during storage, and the degradation products of acteoside were verbasoside, caffeic acid, isoacteoside, etc. In a model of cobalt chloride (CoCl)-induced hypoxia in PC12 cells, the anti-hypoxia ability of PhGs decreased after degradation, which resulted from the reduction of PhGs contents. Particularly, caffeic acid exhibited stronger anti-hypoxia ability than acteoside and could slightly increase the anti-hypoxia ability of degraded acteoside. The results revealed that high temperature, high pH and light exposure caused PhGs degradation, and thus the anti-hypoxia ability of PhGs reduced.
本研究旨在研究桂花中苯乙醇苷类化合物（PhGs）的化学稳定性（热稳定性、光稳定性和 pH 稳定性），通过 UPLC-QTOF-MS 鉴定紫丁香苷和红景天苷（桂花中主要的 PhGs）的降解产物，并研究 PhGs 降解后的抗缺氧活性。PhGs 的降解遵循一级反应动力学，紫丁香苷（4.3 到 203.4×10-2 day-1）的速率常数高于红景天苷（3.9 到 33.3×10-2 day-1）在桂花中。红景天苷在贮藏过程中主要水解生成酪醇，紫丁香苷的降解产物有獐牙菜苷、咖啡酸、异紫丁香苷等。在氯化钴（CoCl）诱导的 PC12 细胞缺氧模型中，PhGs 降解后抗缺氧能力降低，这是由于 PhGs 含量减少所致。特别是咖啡酸的抗缺氧能力强于紫丁香苷，可略微增加降解紫丁香苷的抗缺氧能力。结果表明，高温、高 pH 值和光照会导致 PhGs 降解，从而降低 PhGs 的抗缺氧能力。
