A Stereoselective Palladium/Copper-Catalyzed Route to Isoprenoids: Synthesis and Biological Evaluation of 13-Methylidenefarnesyl Diphosphate
摘要:
The novel farnesyl diphosphate (FPP) analog 13-methylidenefarnesyl diphosphate (3-VFPP, 4) was designed as a potential mechanism-based inhibitor of the FPP-utilizing enzyme protein-farnesyl transferase (PFTase). A six-step stereoselective route to 3-VFPP is described. The key step in the synthetic sequence involved the stereoselective coupling of vinyl triflate 16 with vinyltributyltin using Pd(AsPh(3))(2) and CuI as catalysts to afford primarily the desired (Z)-divinyl ester 15. It was also demonstrated that other 3-substituted farnesyl analogs can be prepared in a highly stereoselective manner by this Pd(0)/CuI-catalyzed route. The presence of CuI significantly increases the stereoselectivity of the coupling reaction, and a possible mechanistic rationale for this observation is presented. Biological evaluation of 3-VFPP demonstrates that it is not a time-dependent inhibitor of recombinant yeast PFTase. Instead, 3-VFPP is an alternative substrate for this. enzyme that exhibits a K-m comparable to FPP but a k(cat) significantly lower than the natural substrate.
Stereospecific Synthesis and Biological Evaluation of Farnesyl Diphosphate Isomers
作者:Ying Shao、Jeffrey T. Eummer、Richard A. Gibbs
DOI:10.1021/ol990714i
日期:1999.8.1
unified, stereospecific synthetic route to the three geometric isomers of (E,E)-farnesyl diphosphate (E,E-FPP) (1, 2, and 3) has been developed. The key feature of this synthesis is the ability to control the stereochemistry of triflation of the beta-ketoester 10 to give either 11 or 14. Preliminary evaluation of these compounds with protein-farnesyl transferase indicates that 1 and 2 are surprisingly
Competitive inhibition of aristolochene synthase by phenyl-substituted farnesyl diphosphates: evidence of active site plasticity
作者:David J. Miller、Fanglei Yu、Neil J. Young、Rudolf K. Allemann
DOI:10.1039/b713301b
日期:——
largest part to the binding of the substrate to AS and that the active sites of terpene synthases are sufficiently flexible to accommodate even substrate analogues with large substituents suggesting a potential way for the generation of non-natural terpenoids. Molecular mechanics simulations of the enzyme bound inhibitors suggested that small changes in orientations of active site residues and subtle