We report bending flexibility of damaged duplexes possessing an apurinic/apyrimidinic (AP) site analogue, a cyclobutane pyrimidine dimer (CPD), and a pyrimidine(6-4)pyrimidone photoproduct (6-4PP). Based on the electrochemical evaluation on electrodes, the duplex flexibilities of the lesions increased in the following order: CPD < AP < 6-4PP. We discussed the possibility that the emerging local...

An analogue of adenine, 4-aminopyrazolo(3,4d)pyrimidine (4-APP), has recently been shown to be a potential antineoplastic agent. Skipper, Robins, and Thomson (1955) demonstrated that the growth of an adenocarcinoma and two leukemias of the mouse was inhibited or retarded by the administration of 4-APP. Hsu, Robins and Cheng (1956) showed that 4-aminopyrazolo(3,4d)pyrimidine exerts differential ...

Iodocyclization of 5-amino-1-(2,4-dinitrophenyl)-1H-4-pyrazolcarboxamides with aromatic aldehydes gave a new series of pyrazolo[3,4-d]pyrimidine derivatives in a single step and their antibacterial activity comparable to Streptomycin as reference drug was evaluated.

We compared the removal of pyrimidine(6-4)pyrimidone photoproducts [(6-4) photoproducts] and cyclobutane pyrimidine dimers (CPDs) from the genome of repair-proficient Escherichia coli, using monoclonal antibodies specific for each type of lesion. We found that (6-4) photoproducts were removed at a higher rate than CPDs in the first 30 min following a moderate UV dose (40 J/m2). The difference i...

Convenient procedure for the synthesis of corresponding pyrano[2,3-d]pyrimidine derivatives were developed via one-pot three-component reaction of aryl aldehyde derivatives, malononitrile with barbituric acids in the presence of copper (II) chloride dihydrate (CuCl2.2H2O) as highly efficient Lewis acid catalyst. This protocol has advantages such as readily and inexpensive catalyst, high reactio...

Reaction of peroxides with 5-deazaflavin bound to glucose oxidase, lactate oxidase, or D-amino acid oxidase results in the formation of 5-deazaflavin 4a, 5-epoxide. The reaction of D-amino acid oxidase with m-chloroperoxybenzoate is an exception since the reagent reacts rapidly with the protein moiety to form m-chlorobenzoate which then binds noncovalently near the unmodified coenzyme. Epoxide ...

A new reaction of 4-arylidene-3-methylisoxazol-5(4H)-one or 4-arylidene-2-phenyloxazol-5(4H)-one with 2,6-diaminopyrimidin-4(3H)-one is described and a number of new pyrido[2,3-d]pyrimidine-4,7-dione derivatives are synthesized. This protocol has the advantages of good yields, broad substrate scope and simple work-up.