3-alkyl- and 3-aryl-(7-oxo-7H-furo[3, 2-g]chromen-5-yl)alkanoic acids as inhibitors of leukotriene B4 biosynthesis.

The synthesis and biological properties of 3-alkyl-and 3-aryl-(7-oxo-7H-furo [3, 2-g]chromen-5-yl)alkanoic acids are described. The compounds were evaluated for their ability to inhibit soybean 15-lipoxygenase (15-LO) and the production of leukotriene B(4) (LTB(4)) in bovine polymorphonuclear leukocytes. The furocoumarins were further investigated for their lipophilicity and their capacity to photobleach N, N-dimethyl-p-nitrosoaniline (RNO) after irradiation with UVA light. The synthesised furocoumarins showed only a moderate ability to inhibit the 15-LO and the production of LT B(4). The 3-alkyl substituted furocoumarins had a higher capacity to photobleach RNO than then the 3-aryl substituted furocoumarinso. The inhibitory activity of the newcompounds was quite modest in comparison to other known inhibitors of 15-LO and LTB(4) production. Nevertheless, they may provide the basis for the development of more potent antiinflammatory potential photoreactive furocoumarins.