Inhibitory effect of flavonoids on DNA-dependent DNA and RNA polymerases

Flavonoids, (-)-epigallocatechin (1), myricetin (2) and quercetin (3), were investigated for inhibitory effects on E. coli DNA polymerase I and T7 bacteriophage RNA polymerase. In both DNA and RNA synthesis, 1 and 3 inhibited enzyme reactions by non-competitive and mixed type inhibition respectively, with regard to template DNAs. Myricetin (2) inhibited DNA and RNA polymerase reactions by mixed type and competitive type inhibition, respectively, with template DNAs. It was suggested that 2 interacts with covalently closed circular DNA.     

Temperature dependence of the deformability of Carp (Cyprinus carpio) red blood cells

Summary Measurements were made of the deformability of the red cells of carp at different temperatures and compared with previous results obtained with another teleost fish (yellowtail) and human red cells. Changes with temperature are similar to those obtained with yellowtail, but interpretation of differences in terms of mean corpuscular volume alone are insufficient to account for the variations, which seem to be mainly due to differences in cellular deformability of the cells themselves.Acknowledgment. We wish to thank Karlheinz Götz for his excellent technical assistance. Reprint requests should be addressed to G.M.H.