Diadenosine Boranotetraphosph(on)ates as Antithrombotic Drugs

描述（由申请人提供）：有很大兴趣开发新的抗血小板药物，这些药物将直接和可逆地起作用，避免当前选择的药物氯吡格雷的明显问题。二腺苷P1， p4 -四磷酸（Ap4A）及其膦酸盐和硫膦酸盐类似物如Ap(S)pCHClpp(S)A在体外抑制血小板聚集，并在体内显示抗血栓活性，具有低急性和慢性毒性。该类已被证明可可逆地抑制血小板ADP受体，但确切的受体靶点尚不清楚。现有数据表明P2Y1靶向，但也不排除P2Y12抑制。双核苷多磷酸盐在血液中迅速降解，但更稳定的磷酸盐的发展受到不适合大规模制备的低效合成方法的限制。我们发现了一种新的、高收率的合成四磷酸二核苷和四磷酸盐的新方法，该方法基于一种新的试剂类：稳定但反应性强的焦磷酸盐和亚二膦酸双咪唑烷。此外，核苷磷酸的新型硼酰衍生物已被描述为具有显着的特性组合，例如化学和酶稳定性以及低毒性，使其成为有用的生物试剂和治疗药物。然而，没有描述过四磷酸二核苷或四磷酸盐的硼酰衍生物。为了研究其抗血小板活性，并确定其对P2Y1、P2Y12和P2X1受体的拮抗剂/激动剂性质，我们拟利用新的合成方法制备boranyl-Ap4A类似物和作为对照的硫代膦酸盐Ap(S)pCHClpp(S)A。我们还将测量新的borano-Ap4A类似物在大鼠、狗和人血浆中的稳定性。我们的近期目标是验证和进一步发展我们合成双核苷多磷酸的新突破性方法，确定Ap4A类似物是否靶向P2Y1，甚至更好地靶向P2Y1和P2Y12血小板受体，并证明新型硼酰双核苷酸类似物的治疗潜力和血浆稳定性。我们的长期目标是发现治疗动脉血栓形成的新化合物和新方法，特别是针对血小板P2Y1或P2Y1和P2Y12受体的快速可逆抗血小板药物，以补充现有的主要针对血小板P2Y12受体的抗血小板药物。该项目将产生一种有效的抗血栓药物，用于治疗动脉血栓形成。候选药物将直接和可逆地抑制参与血小板聚集的一种或两种受体，并且不具有氯吡格雷等现有药物作用缓慢和可变的缺点。该新药将补充正在开发的治疗动脉血栓形成的相关药物。

DESCRIPTION (provided by applicant): There is significant interest in development of new antiplatelet drugs that will act directly and reversibly, avoiding clear problems with the current drug of choice, clopidogrel. Diadenosine P1,P4-tetraphosphate (Ap4A) and its phosphonate and thiophosphonate analogs such as Ap(S)pCHClpp(S)A inhibit platelet aggregation in vitro, and show antithrombotic activity in vivo, with low acute and chronic toxicity. The class has been shown to reversibly inhibit platelet ADP receptors, but the exact receptor target is not known. Existing data suggest P2Y1 targeting, but does not rule out P2Y12 inhibition as well. Bis-nucleoside polyphosphates are rapidly degraded in blood, but development of the more stable phosphonates is limited by inefficient synthesis methods that are unsuitable for large scale preparation. We have discovered a new, high yield method for synthesis of dinucleoside tetraphosphates and tetraphosphonates based on a new reagent class: stable but reactive bis-imidazolides of pyrophosphate and methylenebisphosphonates. In addition, novel boranyl derivatives of nucleoside phosphates have been described with a remarkable combination of properties, such as chemical and enzymatic stability and low toxicity, that make them useful as biological reagents and therapeutics. No boranyl derivatives of dinucleoside tetraphosphates or tetraphosphonates, however, have been described. We propose to exploit the new synthetic method to prepare selected boranyl-Ap4A analogs and, as control, the thiophosphonate Ap(S)pCHClpp(S)A, in order to study their antiplatelet activity, and to determine their antagonist/agonist properties toward P2Y1, P2Y12, and P2X1 receptors. We will also measure the stability of the new borano-Ap4A analogs in rat, dog, and human plasma. Our immediate goals are to validate and further develop our new breakthrough method for synthesis of bis-nucleoside polyphosphates, to determine if the class of Ap4A analogs targets P2Y1, or even better, both P2Y1 and P2Y12 platelet receptors, and to demonstrate the therapeutic potential and plasma stability of novel boranyl bis-nucleotide analogs. Our long range goals are to discover novel compounds and methods for treatment of arterial thrombosis, and more particularly, a fast and reversibly acting antiplatelet agent targeting platelet P2Y1, or better, both P2Y1 and P2Y12 receptors, to complement existing antiplatelet therapeutics which mainly target the platelet P2Y12 receptor. Public Health Relevance Statement This project will result in an effective antithrombotic drug that will be used to treat arterial thrombosis. The candidate drug will directly and reversibly inhibit one or both of the receptors involved in platelet aggregation, and will not have the drawbacks of slow and variable action of current drugs such as clopidogrel. The new drug will complement related drugs under development for arterial thrombosis.