Novel approaches towards the synthesis of protein tyrosine phosphatase inhibitors and alternative strategies in the design of transition state analogues for phosphatase abzymes

The work reported herein spans two different projects. In the first section, SPSOS chemistry is used to prepare two series of compounds bearing the difluoromethylene phosphonic (DFMP) acid moiety that are screened against PTP1B. Non crosslinked polystyrene (NCPS) is employed as a support for the synthesis of both series of inhibitors allowing for homogeneous reaction conditions and non-destructive monitoring of the reaction progress by 19F NMR. In the first series, a Suzuki reaction is used to prepare a series of biaryl phosphonic acids while a Wittig reaction is used to synthesize the second styrl-like series of compounds. Compounds from both libraries ranged in purity from 43 to 99% and were suitable for assaying without the need for further purification. The best inhibitors from the Suzuki and Wittig libraries had Ki's of 1.7 and 5 μM respectively.; In the second section of the thesis, isomeric 2,5-di-p-nitrophenyl phospholanate esters were synthesized and employed as transition state analogues for the purpose of obtaining catalytic antibodies capable of hydrolyzing model phosphotriester and phosphono diester substrates. Crucial to the hapten design was the C-P-C bond angle of the cyclic TSA's. The value of this angle was determined by X-ray crystallography of one of the final TSA products as well as various synthetic intermediates. The TSA's were conjugated to carrier proteins and immunized into mice for the purposes of isolating antibodies. One antibody, Jel 541, was found to be able to differentiate between the TSA's and exhibit catalytic activity in hydrolyzing the substrates significantly above background rates.