Stable analogues of geranylgeranyl diphosphate possessing improved geranylgeranyl versus farnesyl protein transferase inhibitory selectivity

Screening for Small Molecule Modulators of Trypanosoma brucei Hsp70 Chaperone Activity Based upon Alcyonarian Coral-Derived Natural Products

The Trypanosoma brucei Hsp70/J-protein machinery plays an essential role in survival, differentiation, and pathogenesis of the protozoan parasite, and is an emerging target against African Trypanosomiasis. This study evaluated a set of small molecules, inspired by the malonganenones and nuttingins, as modulators of the chaperone activity of the cytosolic heat inducible T. brucei Hsp70 and constitutive TbHsp70.4 proteins. The compounds were assessed for cytotoxicity on both the bloodstream form of T. b. brucei parasites and a mammalian cell line. The compounds were then investigated for their modulatory effect on the aggregation suppression and ATPase activities of the TbHsp70 proteins. A structure-activity relationship for the malonganenone-class of alkaloids is proposed based upon these results.

Synthesis of stable analogues of geranylgeranyl diphosphate possessing a (Z,E,E)-geranylgeranyl side chain, docking analysis, and biological assays for prenyl protein transferase inhibition

Herein, we report the synthesis of novel stable analogues of geranylgeranyl diphosphate (GGPP), in which the "natural" all-trans geranylgeranyl portion has been replaced by a (Z,E,E)-geranylgeranyl chain. The change in configuration and consequent change in the relative position of the polar portion with the lipophilic side chain did not improve the properties of the E,E,E analogues in their inhibition of geranylgeranyl protein transferase I (GGTase I). However, a significant level of GGTase I inhibition and selectivity for GGTase I over farnesyl transferase (FTase) was maintained the unsubstituted phosphonoacetamidoxy derivative 4 a. This has shed light on the relative importance of the configuration at the C2=C3 double bond among GGPP derivatives. Moreover, the biological activities of all the compounds reported herein, in particular the preferential FTase inhibitory activity shown by compound 6, were in good agreement with the results of docking analysis.

Phosphonomethylphosphorylmethyl(oxy)-analogues of geranylgeranyl diphosphate as stable and selective geranylgeranyl protein transferase inhibitors

The diphosphate moiety of geranylgeranyldiphosphate (GGdP) was replaced with metabolically and hydrolytically stable analogous polar portions, in an attempt to obtain new geranylgeranyltransferase (GGTase) inhibitors, which could also be selective over congener enzyme farnesyltransferase (FTase). In particular, the phosphonomethylphosphorylmethoxy derivative showed the highest inhibition potency, accompanied by a satisfactory GGTase/FTase selectivity.

Stable propylphosphonic acid analogues of geranylgeranyl diphosphate possessing inhibitory activity on geranylgeranyl protein transferase

Stable analogues of geranylgeranyl diphosphate, possessing 3-(phosphono)propionamido moieties in the place of the metabolically unstable diphosphate portion, were prepared and submitted to prenyltransferase (GGTase and FTase) inhibition assays. In one case, an excellent GGTase inhibitory activity was obtained (IC(50) = 39 nM), accompanied by a certain degree of GGTase vs. FTase selectivity.