Two new chromones from <i>Portulaca oleracea</i> L. and their bioactivities

Two new chromones, oleracone H (<b>1</b>) and oleracone I (<b>2</b>), were isolated from <i>Portulaca oleracea</i> L. and identified by UV, IR, UHPLC-ESI-QTOF/MS, 1D NMR, 2D NMR, and CD spectra. In 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical quenching assay, oleracone H (<b>1</b>) and oleracone I (<b>2</b>) presented scavenging activities with IC₅₀ values (half maximal inhibitory concentration) of 16.33 ± 0.20 μM and 22.36 ± 0.41 μM and the abilities of inhibiting the inflammatory factors IL-1<i>β</i> and TNF-<i>α</i> of the two compounds were superior to that of the positive control at 10 μM.本研究从马齿苋（Portulaca oleracea L.）中分离得到两个新型色酮类化合物——oleracone H（1）与oleracone I（2），并经紫外光谱（UV）、红外光谱（IR）、超高效液相色谱-电喷雾电离四极杆-飞行时间质谱（UHPLC-ESI-QTOF/MS）、一维核磁共振谱（1D NMR）、二维核磁共振谱（2D NMR）及圆二色谱（CD）完成结构鉴定。在1,1-二苯基-2-苦基肼（1,1-diphenyl-2-picryl-hydrazyl, DPPH）自由基淬灭实验中，oleracone H（1）与oleracone I（2）展现出自由基清除活性，其半数抑制浓度（half maximal inhibitory concentration, IC₅₀）分别为16.33 ± 0.20 μM与22.36 ± 0.41 μM；且在10 μM浓度下，两种化合物对炎症因子白细胞介素-1β（IL-1β）与肿瘤坏死因子-α（TNF-α）的抑制活性均优于阳性对照。