Birnbaum K B
National Research Council of Canada, Ottawa, Canada.
Acta Biochim Pol. 1996;43(1):65-76.
The crystal structure of the acyclonucleoside, 9-[4-hydroxy-2-(hydroxymethyl)-butyl]guanine (2HM-HBG), has been compared with related acyclonucleosides, and that of the acyclonucleotide, 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine-3',5'-cyclic phosphate (DHPG-cMP), also with its parent second messenger cGMP and cyclic monophosphate nucleotides. There is considerable conformational flexibility in the acyclic chain of these compounds with several conformations coexisting in the solid state. This flexibility together with the narrow range of the glycosidic torsion angles (from 69 degrees to 94 degrees, with an average of 83(3) degrees for 11 molecules when the aglycon is guanine, and from 92 degrees to 108 degrees with an average of 103(3) degrees for 4 molecules when the aglycon is adenine) may be essential for the antiviral activity of these compounds and their ability to act as substrates. The mechanism of antiviral activity of, 9-[(1,3-dihydroxy-2-propoxy)methyl] guanine-3',5'-cyclic phosphate is different from that of the acyclonucleosides, and is discussed in the light of it being a close structural analogue to the second messenger cGMP.
已将无环核苷9-[4-羟基-2-(羟甲基)丁基]鸟嘌呤（2HM-HBG）的晶体结构与相关无环核苷的晶体结构进行了比较，并且将无环核苷酸9-[(1,3-二羟基-2-丙氧基)甲基]鸟嘌呤-3',5'-环磷酸酯（DHPG-cMP）的晶体结构与其母体第二信使环鸟苷酸（cGMP）及环一磷酸核苷酸进行了比较。这些化合物的无环链具有相当大的构象灵活性，在固态中有几种构象共存。这种灵活性以及糖苷扭转角的狭窄范围（当苷元为鸟嘌呤时，11个分子的扭转角范围为69度至94度，平均为83(3)度；当苷元为腺嘌呤时，4个分子的扭转角范围为92度至108度，平均为103(3)度）可能对这些化合物的抗病毒活性及其作为底物的能力至关重要。9-[(1,3-二羟基-2-丙氧基)甲基]鸟嘌呤-3',5'-环磷酸酯的抗病毒活性机制与无环核苷不同，鉴于其是第二信使cGMP的紧密结构类似物，对此进行了讨论。
