Potential inhibitors of nucleotide biosynthesis. 1. Nitrosoureidonucleosides. 2
摘要:
Several nitrosoureidonucleosides (9a, 9b, 11a, 11b, 18 and 20) designed as inhibitors of enzymes that metabolize purine and pyrimidine nucleotides have been prepared and their chemical and biological properties studied. The low level of biological activity observed may be due to the unexpected stability of these nitrosoureas compared to biologically active compounds such as N-methyl-N-nitrosourea (MNU), N,N'-bis(2-chloroethyl)-N'-nitrosourea (BCNU), and N,N'-dicyclohexyl-N-nitrosourea (DCyNU).
Is There Stereoelectronic Control in Hydrolysis of Cyclic Guanidinium Ions?
作者:Charles L. Perrin、David B. Young
DOI:10.1021/ja003672y
日期:2001.5.1
To assess stereoelectronic effects in the cleavage of tetrahedral intermediates, a series of five-, six-, and seven-membered cyclic guanidinium salts was synthesized. If stereoelectroniccontrol by antiperiplanar lone pairs is operative, these are expected to hydrolyze with endocyclic C-N cleavage to acyclic ureas. However, hydrolysis in basic media produces mixtures of cyclic and acyclic products