Thymidine phosphorylase (TP) is an angiogenic enzyme. It plays an important role in angiogenesis, tumour growth, invasion and metastasis. In current research work, we study the effect of structural modification of dihydropyrimidine-2-ones (DHPM-2-ones) on TP inhibition. A series of eighteen new derivatives of 3,4-dihydropyrimidone-2-one were designed and synthesized through the structural modification at C-6 position. All these new derivatives were then assessed for in-vitro inhibition of thymidine phosphorylase (TP) from E. coli. Oxadiazole derivatives 4a-e exhibited excellent TP-inhibition at low micromolar concentration levels better than standard drug 7-deazaxanthine (7-DX). Among all these compounds, 4b was found to be the most potent with IC₅₀ = 1.09 ± 0.004 μM. Anti-angiogenesis potential of representative compounds were also studied in a chorioallantoic membrane (CAM) assay. Here again, compound 4b was found to be the potent anti-angiogenesis compound in a CAM assay. Docking studies were also performed with Molecular Operating Environment (MOE) to further analyse the mode of inhibition of these compounds. Binding mode analysis of the most active inhibitors showed that these are well accommodated into the binding site of enzyme though stable hydrogen bonding and hydrophobic interactions.

胸苷磷酸化酶（TP）是一种血管生成酶。它在血管生成，肿瘤生长，侵袭和转移中起重要作用。在当前的研究工作中，我们研究了二氢嘧啶-2-酮（DHPM-2-ones）的结构修饰对TP抑制的影响。通过在C-6位的结构修饰，设计并合成了一系列十八个3,4-二氢嘧啶-2-酮新衍生物。然后评估所有这些新的衍生物对大肠杆菌中胸苷磷酸化酶（TP）的体外抑制。恶二唑衍生物4a-e在低微摩尔浓度下表现出优异的TP抑制作用，优于标准药物7-地塞黄嘌呤（7-DX）。在所有这些化合物中，4b被发现是最有效的，IC ₅₀  = 1.09±0.004μM。还通过绒毛膜尿囊膜（CAM）测定法研究了代表性化合物的抗血管生成潜力。同样，在CAM测定中，发现化合物4b是有效的抗血管生成化合物。还使用分子操作环境（MOE）进行了对接研究，以进一步分析这些化合物的抑制方式。对最具活性的抑制剂的结合模式分析表明，尽管它们具有稳定的氢键结合和疏水相互作用，但它们能很好地容纳在酶的结合位点中。