Shuang-Shuang Mao, Cui-Ting Luo, Huan-huan Zheng, Jie Liu and Heru Chen
18 xanthones (1-18) were isolated from the ethanol aqueous extract of Swertia mussotii. Their structures were elucidated via spectroscopic analyses including IR, UV, NMR, and MS. The nitrite scavenging activities of all the xanthones were evaluated. The results disclose that all the tested xanthones display moderate to good nitrite scavenging activity in both conditions including mimetic gastric and intestinal environment, where 18 is the most active compound with the clearance rates (%) of 26.0 ± 0.5 and 24.6 ± 0.8, respectively. The nitrite-scavenging mechanism was put forward and confirmed. A preliminary structure-activity relationship is also included here.