Phenolic compounds from cultivated and their PD-1/PD-L1 inhibitory activities.

One new compound () and fifteen known phenolic compounds () were isolated and identified from the roots and rhizomes of , 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.