The importance of functional groups in nucleoside antibiotic mureidomycin A (MRD A) for biological activity has been examined by derivatisation of samples of the natural product, and by synthesis of uridine-containing analogues. N-Succinyl and di- and tri-acetyl derivatives MRD A have been prepared, and were found to have reduced activity as inhibitors of E. coli translocase I. The enamide alkene of MRD A was found to be extremely resistant towards hydrogenation by a variety of reagents. Several 5â²-functionalised uridine derivatives were synthesised from N
3-p-methoxybenzyl-2â²,3â²-isopropylideneuridine. A series of 5â²-aminoacyl derivatives were prepared, and the 3-aminopropionyl (IC50 260 µM) and 7-aminoheptanoyl (IC50 1.5 mM) derivatives were found to act as reversible inhibitors. An analogue mimicking the carboxy terminus of MRD A was synthesised, and also acted as an inhibitor of translocase I (IC50 1.9 mM). A phosphonate analogue designed as a possible suicide inhibitor showed modest inhibition (IC50 3.7 mM), which was shown to be irreversible.
功能团在核苷类抗生素mureidomycin A (MRD A)
生物活性中的重要性,通过对
天然产物样品的衍生化和合成含
尿苷类似物进行了研究。已制备N-琥珀酰和二、三乙酰衍
生物MRD A,发现它们作为大肠杆菌转位酶I
抑制剂的活性降低。MRD A的烯酰胺烯对多种试剂的氢化表现出极强的抗性。从N-3-对
甲氧基苯甲基-2′,3′-异
丙烯基
尿苷合成了几种5′-功能化的
尿苷衍
生物。制备了一系列5′-
氨酰衍
生物,其中3-
氨基丙酰基(IC50 260 μM)和
7-氨基庚酸(IC50 1.5 mM)衍
生物被发现作为可逆
抑制剂。一种模仿MRD A羧基末端的类似物被合成,并且也作为转位酶I的
抑制剂(IC50 1.9 mM)。一种设计为可能自杀
抑制剂的
磷onate类似物显示出适度抑制(IC50 3.7 mM),且被证明是不可逆的。