Publications by authors named "Robert H Lemus"

4-(Phenylamino)-5-phenyl-7-(5-deoxy-beta-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine 1 and related compounds known as "diaryltubercidin" analogues are potent inhibitors of adenosine kinase (AK) and are orally active in animal models of pain such as the rat formalin paw model (GP3269 ED50= 6.4 mg/kg). However, the utility of this compound class is limited by poor water solubility that can be attributed to the high energy of crystallization caused by stacking of the parallel C4 and C5 aryl rings in the solid state (compound 1 and GP3269 each with pH 7.

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A new class of phosphate and phosphonate prodrugs, called HepDirect prodrugs, is described that combines properties of rapid liver cleavage with high plasma and tissue stability to achieve increased drug levels in the liver. The prodrugs are substituted cyclic 1,3-propanyl esters designed to undergo an oxidative cleavage reaction catalyzed by a cytochrome P(450) (CYP) expressed predominantly in the liver. Reported herein is the discovery of a prodrug series containing an aryl substituent at C4 and its use for the delivery of nucleoside-based drugs to the liver.

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A series of pyrimidoquinazoline analogues, possessing either 4,5-g or 5,4-g fusion, were studied with respect to cytotoxicity, topoisomerase II inhibitory activity, in vivo activity, and DNA cleavage and DNA-protein cross-linking properties. These analogues were designed as electron-deficient anthraquinones with dual alkylating centers to cross-link DNA with topoisomerase II. Our studies verified the presence of DNA-protein cross-linking in vitro as well as topoisomerase II poisoning by pyrimidoquinazoline analogues.

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