Synthesis and antioxidant activity of new tetraarylpyrroles.

The synthesis and in vitro antioxidant activity of 17 new tetraarylpyrroles are investigated by 2 tests highly documented in the literature: capability to prevent Fe(2+)-induced lipid peroxidation on microsomes, which is a membrane preparation rich in polyunsaturated fatty acids, and direct scavenging effect on a stable free radical, 1,l-diphenyl-2-picryl-hydrazyl (DPPH). For the Fe(2+)-induced microsomal lipid peroxidation system, the results show that molecules which possess 2-pyrazinyl or 2-pyridyl in the 3- and 4-positions on the pyrrole ring are the most efficient. Introduction of methoxy groups on the phenyl ring in the 2- and 5-positions increases the effects but the higher activity is obtained with 2-furyl or 2-thienyl.

Comparative inhibition of human alkaline phosphatase and diamine oxidase by bromo-levamisole, cimetidine and various derivatives.

Analogues of bromo-levamisole and guanidine derivatives including cimetidine are examined in vitro in order to investigate their comparative inhibition, towards alkaline phosphatase (ALP) from human liver and diamine-oxidase (DAO) from human placenta. Bromo-levamisole, considered as a potent selective uncompetitive inhibitor of ALP (Ki, 2.8.