Qiuying He, Sheng-Qiang Yang, Yik-Ling Chew, Zi-Yin Mai, Bo-Yi Fan, Jie-Lian Huang, Qianhui Chen, Li-Ping Teng, Gen-Cheng Liang
Three undescribed xanthonolignoids (1–3), together with eight known analogs (4–11), were isolated from Hypericum curvisepalum. Their structures were elucidated by mass and NMR spectroscopic analyses. In bioassays against Chromobacterium violaceum ATCC 12472, compounds 1, 4, 6, 7 and 9 exhibited potential quorum sensing (QS) inhibitory activity at 250 μM, with violacein inhibition rates of 84.92%, 74.96%, 70.47%, 71.43% and 76.87%, respectively. Furthermore, the three new compounds dose-dependently inhibited biofilm formation and significantly suppressed both swimming and swarming motility of C. violaceum ATCC 12472.