Phenolic compounds from cultivated <i>Glycyrrhiza uralensis</i> and their PD-1/PD-L1 inhibitory activities

Abstract

One new compound (<b>1</b>) and fifteen known phenolic compounds (<b>2-16</b>) were isolated and identified from the roots and rhizomes of <i>Glycyrrhiza uralensis</i>, including ten flavonoids, four coumarins, and two benzofurans compounds. Their structures were identified by NMR and MS analysis. Most of these compounds showed weak PD-1/PD-L1 inhibitory activities with the inhibition ratios from 30 to 65% at 100 uM. To our knowledge, it is the first time that their PD-1/PD-L1 inhibition activities were reported.