Synthesis and structure-activity relationship of new 1,5-dialkyl-1,5-benzodiazepines as cholecystokinin-2 receptor antagonists

This article deals with the synthesis and the activities of some 1,5-dialkyl-3-arylureido-1,5-benzodiazepin-2,4-diones which were prepared as potential CCK2 antagonists, with the intention to find a possible follow up of our lead compound GV150013, showing an improved pharmacokinetic profile. The phenyl ring at N-5 was replaced with more hydrophilic substituents, like alkyl groups bearing basic functions. In some cases, the resolution of the racemic key intermediates 3-amino-benzodiazepines was also accomplished. Among the compounds synthesized and characterised so far in this class, the 5-morpholinoethyl derivative 54, was selected as potential follow up of GV150013 and submitted for further evaluation.

Lack of stereospecificity of suid pseudorabies virus thymidine kinase

We have partially purified suid pseudorabies virus (PRV) thymidine kinase from infected thymidine kinase- mouse cells, and cytosolic swine thymidine kinase from lymphatic glands, and we have found that PRV thymidine kinase, unlike the host enzyme, shows no stereospecificity for D- and L-beta-nucleosides. In vitro, unnatural L-enantiomers, except L-deoxycytidine, function as specific inhibitors for the viral enzyme in the order: L-thymidine >> L-deoxyguanosine > L-deoxyuridine > L-deoxyadenosine. Contrary to human and swine thymidine kinases and like herpes simplex virus-1 and -2 thymidine kinases, PRV thymidine kinase phosphorylates both the natural (D-) and the unnatural (L-) thymidine enantiomers to their corresponding monophosphates with comparable efficiency. The kinetic parameters Vmax/Km for D- and L-thymidine are 3.7 and 2.3 respectively. Our results demonstrate that the lack of stereospecificity might be a common feature of the thymidine kinases that are encoded by human and animal herpes viruses. These observations could lead to the development of a novel class of antiviral drugs.