Publisher Summary The beginning of pyrimidine chemistry may be traced back to the isolation of alloxan, a pyrimidine derivative. The synthesis of barbituric acid from urea and malonic acid perhaps marked the next major event in the development. Since then pyrimidines have occupied a unique and important place in the fields of biological and medicinal chemistry. It is well known that uracil, thymine, and cytosine are essential constituents in nucleic acids; thiamine that possesses antiberiberi activity was the first vitamin discovered in the B series; barbiturates are widely used as sedatives; pyrimethamine is highly potent against erythrocytic parasites in antimalarial study; aminometradine (Mictine) is an orally effective diuretic; and the 5-halogen-substituted uracils and derivatives have recently been reported as antitumour or antiviral agents, or both. Other pyrimidine derivatives have been found to possess fungicidal, antibacterial, antimitotic, antithyroid and surface-anaesthesia activities. With the exception of pyrimidine antibiotics, in this chapter, pyrimidines are classified based on special structural features and functional groups. The chapter discusses the following areas: 2,4- diaminopyrimidines, halogenated pyrimidines, sulphur-substituted pyrimidines, 2-substituted 4-amino-5-hydroxymethylpyrimidines, pyrimidine sulphonamides and pyrimidine antibiotics.

Some pyrimidines of biological and medicinal interest. 3.

Inhibition of the Synthesis of Deoxyribonucleic Acid in Bacteria by 6-(p-Hydroxyphenylazo)-2,4-dihydroxypyrimidine: I. METABOLIC STUDIES IN STREPTOCOCCUS FECALIS

The expression of transmembrane transporter multidrug resistance-associated protein 1 (MRP1) confers the multidrug-resistant phenotype (MDR) on cancer cells. Since the activity of the other MDR transporter, P-glycoprotein, is sensitive to membrane perturbation, we aimed to check whether the changes in lipid bilayer properties induced by flavones (apigenin, acacetin) and flavonols (morin, myricetin) were related to their MRP1 inhibitory activity. All the flavonoids inhibited the efflux of MRP1 fluorescent substrate from human erythrocytes and breast cancer cells. Morin was also found to stimulate the ATPase activity of erythrocyte ghosts. All flavonoids intercalated into phosphatidylcholine bilayers as judged by differential scanning calorimetry and fluorescence spectroscopy with the use of two carbocyanine dyes. The model of an intramembrane localization for flavones and flavonols was proposed. No clear relationship was found between the membrane-perturbing activity of flavonoids and their potency to inhibit MRP1. We concluded that mechanisms other than perturbation of the lipid phase of membranes were responsible for inhibition of MRP1 by the flavonoids.

https://link.springer.com/content/pdf/10.2478%2Fs11658-008-0044-3.pdf

D. Sen

Papers

Effect of a number of n-pyrimidyl amino acids and of some of their 5-arylazo derivatives on the growth of certain microorganisms.