A one-flask synthesis of α,α-bisphosphonates via enolate chemistry

Chemical approaches to inhibitors of isoprenoid biosynthesis: targeting farnesyl and geranylgeranyl pyrophosphate synthases

The chemical synthesis of farnesyl and geranylgeranyl pyrophosphate synthase inhibitors are surveyed.

Synthetic Procedures Leading towards Aminobisphosphonates

Growing interest in the biological activity of aminobisphosphonates has stimulated the development of methods for their synthesis. Although several general procedures were previously elaborated to reach this goal, aminobisphosphonate chemistry is still developing quite substantially. Thus, innovative modifications of the existing commonly used reactions, as well as development of new procedures, are presented in this review, concentrating on recent achievements. Additionally, selected examples of aminobisphosphonate derivatization illustrate their usefulness for obtaining new diagnostic and therapeutic agents.

Synthesis of 5- and 6-N-heterocyclic methylenebisphosphonate derivatives and evaluation of their cytogenetic activity in normal human lymphocyte cultures

Methods for the preparation of various aminomethylene bisphosphonates were developed. The required bisphosphonates were obtained by applying tetraethyl methylenebisphosphonate reagent to different types of oxazinones and the relevant Schiff base derivatives. Based on the prediction results (Pass program), we further estimated the sister chromatid exchange frequency and proliferation rate index values of human lymphocyte cultures after the administration of four newly synthesized bisphosphonates in order to evaluate their cytotoxic/cytostatic and possible antineoplastic potency. The results showed that all four bisphosphonates cause a dose-dependent increase in sister chromatid exchange frequency, followed by a decrease in proliferation rate index in both experiments compared to the control.

Synthesis and reactivity of alkyl-1,1,1-trisphosphonate esters

The α-trisphosphonic acid esters provide a unique spatial arrangement of three phosphonate groups and may represent an attractive motif for inhibitors of enzymes that utilize di- or triphosphate substrates. To advance studies of this unique functionality, a general route to alkyl derivatives of the parent system (R = H) has been developed. A set of new α-alkyl-1,1,1-trisphosphonate esters has been prepared through phosphinylation and subsequent oxidation of tetraethyl alkylbisphosphonates, and the reactivity of these new compounds has been studied in representative reactions that afford additional examples of this functionality.

Synthesis of fluorescently tagged isoprenoid bisphosphonates that inhibit protein geranylgeranylation

Geminal bisphosphonates can be used for a variety of purposes in human disease including reduction of bone resorption in osteoporosis, treatment of fractures associated with malignancies of the prostate, breast, and lung, and direct anticancer activity against bone marrow derived malignancies. Previous research led to identification of some novel isoprenoid bisphosphonates that inhibit geranylgeranyl pyrophosphate (GGPP) synthesis and diminish protein geranylgeranylation. Described here is the synthesis of fluorescent anthranilate analogues of the most active isoprenoid bisphosphonates and examine their ability to impact post-translational processing of the small GTPases Ras, Rap1a, and Rab6. Similar to their non-fluorescent counterparts, some of these fluorescent isoprenoid bisphosphonates diminish protein geranylgeranylation. Their biological activity and fluorescent character suggest that they may be useful in studies of bisphosphonate localization both in cultured cells and in whole organisms.

Synthesis and biological activity of isoprenoid bisphosphonates

Bisphosphonates have been used in the clinic to treat osteoporosis and to reduce bone resorption and the accompanying pathological bone fractures that attend a number of malignancies including multiple myeloma and cancers of the prostate, breast, and lung. There is also evidence that some bisphosphonates have direct anticancer activity. Expansion of the current class of bisphosphonates may lead to compounds that more selectively and potently target these cancers through inhibition of the mevalonate pathway. To this end, a set of dialkyl bisphosphonates bearing isoprenoid chains of varying lengths has been synthesized. Some of these compounds were found to have biological activity on post-translational processing of the oncogenic small GTPases, Ras and Rap1a, in human-derived K562 leukemia cells. Most importantly, these compounds impair protein geranylgeranylation and not protein farnesylation.