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Charles Mioskowski

Publications and source records attributed to Charles Mioskowski.

62 records · Page 4Linked to original sources

Synthesis of Enzymatically Stable Analogues of GDP for Binding Studies with Transducin, the G-Protein of the Visual Photoreceptor.

The synthesis of five enzymatically stable analogues of guanosine diphosphate (GDP) has been carried out. The pyrophosphate moiety was mimicked in turn by the malonate, the acetophosphonate, the phosphonoacetate, the methylene-bis-phosphonate, and the imidodiphosphate groups. All the compounds were prepared via the synthesis of a transient fully protected nucleoside diphosphate analogue, and the final deprotection step was achieved by catalytic hydrogenolysis. The biological properties of the compounds have been evaluated toward transducin, the G-protein of the visual photoreceptor. Three guanosine imidodiphosphate derivatives bearing a linker at different positions on the sugar and on the base were then prepared and evaluated, giving some insight into the GDP binding site of transducin.

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Resin-bound 4H-1,3-oxazine-masked beta-diketones for functionalizing cleavage strategy.

Resin-bound 4H-1,3-oxazines are synthesized by the stepwise condensation of an amide resin, an aldehyde, and an alkyne. Upon DDQ activation, oxazines are converted into oxazinium salts. When treated with hydrazines, these resin-bound beta-diketone equivalents yield pyrazoles through a functionalizing release process. This multicomponent capture strategy, tedious to handle in classical synthesis in solution, is well-suited to solid-supported chemistry. It facilitates the handling of sensitive and unstable intermediates, such as N-alpha-methoxyalkylamides and 1,3-oxazinium salts.

Journal Article↗