AbstractTwelve N2′‐branched acyclic nucleoside phosphonates and bisphosphonates were synthesized as potential inhibitors of Plasmodium falciparum hypoxanthine‐guanine‐xanthine phosphoribosyltransferase (PfHGXPRT), the key enzyme in the purine salvage pathway for production of purine nucleotides. The chemical structures were designed with the aim to study selectivity of the inhibitors for PfHGXPRT over human HGPRT. The newly prepared compounds contain 9‐deazahypoxanthine connected to a phosphonate group via a five‐atom‐linker bearing a nitrogen atom (N2′) as a branching point. All compounds, with the additional phosphonate group(s) in the second aliphatic linker attached to N2′ atom, were low micromolar inhibitors of PfHGXPRT with low to modest selectivity for the parasite enzyme over human HGPRT. The effect of the addition of different chemical groups/linkers to N2′ atom on the inhibition constants and selectivity is discussed.
摘要 合成了 12 种 N2′-支链无环核苷膦酸盐和双膦酸盐,作为恶性疟原虫次黄嘌呤-鸟嘌呤-黄嘌呤磷酸核糖转移酶(PfHGXPRT)的潜在抑制剂,PfHGXPRT 是生产嘌呤核苷酸的嘌呤挽救途径中的关键酶。设计这些化学结构的目的是研究这些抑制剂对 PfHGXPRT 和人类 HGPRT 的选择性。新制备的化合物含有 9-脱氮次黄嘌呤,通过含氮原子(N2′)的五原子连接体作为分支点与膦酸基相连。所有化合物的第二个脂肪族连接体中的附加膦酸基都与 N2′原子相连,它们都是 PfHGXPRT 的低微摩尔抑制剂,对寄生虫酶的选择性较低,甚至略高于人类 HGPRT。本文讨论了在 N2′原子上添加不同化学基团/连接体对抑制常数和选择性的影响。