Lyciyunin, a new dimer of feruloyltyramine and five bioactive tyramines from the root of Lycium yunnanense Kuang

Abstract

Lyciyunin, a new dimer of feruloyltyramine (1), together with five known tyramines (2–6), was isolated from the water-soluble fraction of an EtOH extract of the root of L. yunnanense. Based on HR-TOF-MS, NMR spectral data and quantum chemistry ECD calculations, the structure of this new compound was determined, including its absolute configuration. Compounds (1–6) were tested for their antioxidant activity using in vitro DPPH radical scavenging assay, and 1–6 showed the moderate antioxidant activities with IC₅₀ values of 12.44 ± 0.39, 21.29 ± 0.75, 24.44 ± 1.63, 21.15 ± 0.66, 21.15 ± 0.66 and 45.15 ± 0.56 μM, respectively. Compounds (5–6) showed anti-inflammatory activity in LPS-induced RAW 264.7 macrophages with the IC₅₀ values of 43.95 ± 6.11 and 33.50 ± 2.04 μM, respectively.

Graphical abstract

Keywords:

• Lycium yunnanense Kuang
• Lyciyunin
• feruloyltyramine
• ECD calculations
• antioxidant activity
• anti-inflammatory activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 81573578] and a grant (2017-110108-83-03-001423) from State Bureau of Chinese Medicine.