4-Methylchromene-2,7,8-trione 1 reacts with stabilized 2a–c and non-stabilized ylides 11a–c bearing an α-methylene group to give 7,8-fused 1,3-dioxolocoumarins 4a–c and 12a–c along with betaine 6 and 7-hydroxycoumarin derivative 9. The reaction of 4,5-fused 1,3-dioxolo-o-benzoquinone 13 with the ylide 14 leads to 4-ethoxycarbonylayapin 18 and benzofuranone 19. Deethoxycarbonylation of 18
gives ayapin 20. Compounds 4b, 12a–c, 18 and 20 were tested for their ability to interact with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH), to scavenge superoxide anion radicals, to compete with DMSO for hydroxyl radicals, and to inhibit proteolysis, β-glucuronidase and soybean lipoxygenase activity in vitro. These compounds were also tested for their effect on the ferrous ion-stimulated peroxidation of linoleic acid. They showed a potent inhibitory effect (55–57%) against inflammation induced by carrageenan in the rat paw edema model. On the contrary their reducing ability was found to be low and no inhibition on soybean lipoxygenase was recorded.
4 甲基苯并二氢
吡喃-2,7,8-三酮 1 与带有 α-亚甲基的稳定化 2a-c 和非稳定化酰化物 11a-c 反应,生成 7,8 熔合
1,3-二氧戊环香豆素 4a-c 和 12a-c,以及
甜菜碱 6 和 7-羟基
香豆素衍
生物 9。4,5-融合的
1,3-二氧戊环邻苯醌 13 与
酰亚胺 14 反应生成 4-乙氧羰基矢车菊素 18 和
苯并呋喃酮 19。对 18 进行脱乙氧基羰基化反应可得到
安息香素 20。测试了化合物 4b、12a-c、18 和 20 与 1,1
-二苯基-2-苦基
肼稳定自由基 (
DPPH) 的相互作用能力、清除超
氧阴离子自由基的能力、与
二甲基亚砜竞争羟基自由基的能力,以及体外抑制蛋白质分解、β-
葡糖醛酸酶和大豆脂氧合酶活性的能力。还测试了这些化合物对亚
铁离子刺激的
亚油酸过氧化反应的影响。在大鼠爪
水肿模型中,这些化合物对角叉菜胶诱导的炎症有强效抑制作用(55-57%)。相反,它们的还原能力较低,对大豆脂氧合酶没有抑制作用。