磷脂脂质体对三种天然黄酮化合物稳定作用  

The Stability Effect for Three Natural Flavonoids by Lecithin Liposomes

作　　者：龚双梅[1] 赵良容[1] 张荣荣[1] 李晓波[1] 杨昌英[1] 

机构地区：[1]天然产物研究与利用湖北省重点实验室三峡大学,宜昌443002

出　　处：《天然产物研究与开发》2012年第12期1791-1796,共6页Natural Product Research and Development

基　　金：湖北省自然科学基金项目(2010CDB10704)

摘　　要：黄酮化合物由于自身的稳定性问题使临床使用受限,脂质体包埋是一种重要的解决方式。本文研究三种天然黄酮槲皮素,山奈酚及木犀草素与卵磷脂脂质体的结合性质,脂质环境对化合物酚羟基的去质子化能力及捕获Al3+能力的影响,探讨脂质体稳定黄酮的机制。结果表明,三种黄酮化合物能与脂质体不同程度的结合,木犀草素能进入脂质双层内部,而槲皮素和山奈酚主要结合于脂双层外部的极性头部,因此木犀草素酚羟基去质子化能力显著降低,pKa明显增大,而后两者pKa受脂质体影响较小。在脂质环境中,三种化合物与Al3+的螯合能力显著下降,但差异并不明显,虽然木犀草素能进入脂质双层,但膜流动性的增加会导致Al3+进入脂质环境变得困难,因此螯合能力也明显下降。可见卵磷脂脂质体能对木犀草素起到明显的稳定和保护作用,但对槲皮素和山奈酚作用较弱。The clinical usage of flavonoids is limited due to its own stability problems, and the embedding in liposomes is an important solution. In this paper, the binding properties of three natural flavonoids, quercetin, kaempferot and luteolin, with lecithin liposomes were studied ,the deprotonation of phenolic hydroxyl and the capture capacity of the Al^3＋ of com- pounds in lipid environment were evaluated for the investigation of the stable mechanism of liposomes for flavonoids. The resuhs showed that luteolin could be embedded into the lipid bilayer interior, which significantly lowered its pKa. Other- wise, quercetin and kaempferol bound only in the polar head of the lipid bilayer external, their pKa were less influenced by the liposomes. In lipid environment, the Al^3＋ chelation of three compounds were all significantly decreased. The rea- son of the chelation decrease for luteolin was deduced as that theAl^3＋. moved into the lipid bilayer more difficultly for the increase of membrane fluidity caused by the binding of luteolin. Therefore, liposomes could play an obvious role in the stability of luteolin, but the protection of liposomes for quercetin and kaempferol were rather weak.

关 键 词：脂质体 黄酮化合物 结合 PKA Al3+ 

分 类 号：O621.2[理学—有机化学]