Quinic acid esters from Erycibe obtusifolia with antioxidant and tyrosinase inhibitory activities

Abstract

A new quinic acid derivative, 3-O-syringoylquinic acid methyl ester (1), along with eight known quinic acid derivatives (2-9), three coumarins (10-12), one phenylpropanoid (13), three feruloyltyramine derivatives (14-16), one lignan (17) and two isoflavones (18-19) were isolated from an ethyl acetate-soluble fraction of the roots and stems of Erycibe obtusifolia. The structure was elucidated on the basis of spectroscopic methods such as 1D and 2D-NMR, including HR-ESI-MS spectrometry. All of these compounds were investigated for their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and inhibitory effects on mushroom tyrosinase. Compounds 2–9, quinic acid derivatives with caffeoyl moiety, showed significant DPPH radical scavenging activity. Moreover, compounds 2 and 5–10 showed weak mushroom tyrosinase inhibitory effects.

Graphical Abstract

Keywords:

• Erycibe obtusifolia
• convolvulaceae
• 1,1-diphenyl-2-picrylhydrazyl (DPPH)
• tyrosinase
• quinic acid derivatives

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Medical Research Center Program (MRC, 2017R1A5A2015541) through the National Research Foundation of Korea.