Lycium ruthenicum Murr is an important edible and medicinal plant widely cultivated in Northwest China. Our previous study found that its fruit possessed rich polyphenols exhibiting significant neuroprotective effects, inspiring us to investigate the active constituents of its rootstocks, which have never been reported. In this study, we rapidly identified four phenolamides (1–4) possessing monoamine oxidase B (MAO-B) inhibitory effect by using MAO-B-functionalized cellulose filter paper-based ligand fishing, and their structures were elucidated with NMR and MS. Compounds 1, 2, and 4 exhibited moderate inhibitory effect on MAO-B with IC50 values of 71.44 ± 1.81, 28.97 ± 1.20, and 25.58 ± 0.74 μM, respectively, and enzyme kinetic analysis, molecular docking, and molecular dynamics further revealed the inhibition mechanism. All four phenolamides displayed a neuroprotective effect against 1-methyl-4-phenylpyridinium -induced SH-SY5Y cells model, among which 2 and 4 significantly reduced intracellular MAO-B activity and improved the ATP content. Western blot revealed that compounds 2 and 4 alleviated the oxidative stress through up-regulation of the expression of Nrf2 and HO-1 protein, promoting mitophagy via activating the PINK1/Parkin pathway. Moreover, compounds 2 and 4 extended the lifespan, dopamine and ATP levels, locomotor behavior, and olfactory ability of the PINK1B9 flies, a drosophila model of Parkinson’s disease. Meanwhile, compounds 1–4 showed potent antioxidative activities on DPPH, ABTS+, and PTIO radical scavenging assays. These results revealed the health-promoting effects of the rootstocks in preventing and treating neurodegenerative diseases, laying the scientific foundation for the exploitation of this plant byproduct for the development of functional food formulations and pharmaceutical products.
Phenolamides (PAs) are important secondary metabolites present in plants with multiple bioactivities. This study aims to comprehensively identify and characterize PAs in tea ( Camellia sinensis ) flowers using ultra-high-performance liquid chromatography/Q-Exactive orbitrap mass spectrometry based on a lab-developed in-silico accurate-mass database. The PAs found in tea flowers were conjugates of Z/E -hydroxycinnamic acids ( p -coumaric, caffeic and ferulic acids) with polyamines (putrescine, spermidine and agmatine). The positional and Z/E isomers were distinguished through characteristic MS 2 fragmentation rules and chromatographic retention behavior summarized from some synthetic PAs. 21 types of PAs consisting of over 80 isomers were identified, and the majority of them were found in tea flowers for the first time. Among 12 tea flower varieties studied, they all possessed tris -( p -coumaroyl)-spermidine with the highest relative content, and C. sinensis 'Huangjinya' had the highest total relative contents of PAs. This study shows the richness and structural diversity of PAs in tea flowers.
Plants perceive signals associated with herbivore eggs and in response initiate ovicidal defence. However, which phytohormone pathways regulate this defence and which defensive compounds dominate it remains largely unknown. Here, we found that the hatching rate of eggs of white-backed planthopper (WBPH) Sogatella furcifera was significantly lower on a japonica rice variety P81 than an indica rice variety NB44. When infested by WBPH, P81 plants showed higher jasmonic acid (JA) and abscisic acid (ABA) responses than did NB44 plants; moreover, P81 plants produced the ovicidal compound benzyl benzoate and exhibited higher levels of some flavonoids, phenolamides, and volatiles than were found in NB44 plants. Impairing the ABA-signalling pathway, especially the JA-signalling pathway in P81 plants enhanced the survival of WBPH eggs. Decreasing levels of some flavonoids and phenolamides in P81 plants promoted WBPH egg survival. In vitro bioassays revealed that both naringenin and sakuranetin promote the ovicidal effect of benzyl benzoate on WBPH. The results demonstrate that JA- and ABA-signalling pathways jointly regulate the rice ovicidal defence against WBPH, and that benzyl benzoate, as well as some other compounds, such as naringenin and sakuranetin, contribute to the mortality of WBPH eggs.
危险品化学品经营许可证（带存储）