Title
New phenylpropanoid-substituted flavan-3-ols and flavonols from the leaves of Uncaria rhynchophylla
Author
Ruxin Li, Jintang Cheng, Mengjiao Jiao, Li Li, Cong Guo, Sha Chen, An Liu
Year
2017
Journal
Fitoterapia
Abstract
Uncariols A (1) and B (2), two new phenylpropanoid-substituted flavan-3-ols, and (±)-uncariols C (3a/3b) and D (4a/4b), two pairs of new phenylpropanoid-substituted flavonol enantiomers, together with nine known compounds (5–13), were isolated from the leaves of Uncaria rhynchophylla. The structures of 1–4 were established primarily by NMR and HRESIMS experiments. The absolute configurations of the new ones were deduced via the circular dichroism (CD) and quantum chemical calculations of the electronic circular dichroic (ECD) spectra. In addition, all of the isolated compounds showed potent antioxidant activity in the DPPH radical scavenging test.
Instrument
J-815
Keywords
Circular dichroism, Absolute configuration, Natural products, Medicinal