posted on 2021-05-24, 15:42authored byPei-Feng Zhu, Gui-Guang Cheng, Lan-Qin Zhao, Afsar Khan, Xing-Wei Yang, Bu-Yun Zhang, Meng-Cheng Li, Ya-Ping Liu, Xiao-Dong Luo
Rhynchanthus beesianus (Zingiberaceae)
has been an important food spice and vegetable in southern China.
Fifteen phenolic compounds (1–15)
including three new diarylheptanoids, rhynchanines A–C (1–3) and one new phenylpropanoid, 4-O-methylstroside B (9), were isolated from R. beesianus rhizomes. The structures of new compounds
were elucidated by comprehensive analyses through NMR, HRMS technique,
acid hydrolysis, and Mosher’s reaction. Among them, compound 5 is the first isolated natural product and its NMR data are
reported. Most of the isolated compounds, especially 3–6 and 8, showed significant antioxidant
activities on DPPH, ABTS+ radical scavenging, and FRAP
assays. Furthermore, the antioxidant phenolic compounds were evaluated
for their cytoprotective capacity against H2O2-induced oxidative stress in HepG-2 cells. Compounds 3 and 5 could significantly inhibit reactive oxygen species
production, and compounds 3, 5, and 6 could remarkably prevent the cell apoptosis. Then, the R. beesianus rhizome, which contained phenolic compounds,
might serve as a functional food for potential application on preventing
oxidative stress-connected diseases.