Probing the ATP Ribose-Binding Domain of Cyclin-Dependent Kinases 1 and 2 with O6-Substituted Guanine Derivatives
摘要:
O-6-Substituted guanines are adenosine 5'-triphosphate (ATP) competitive inhibitors of CDK1/cyclin B I and CDK2/cyclin A, the O-6 substituent occupying the kinase ribose binding site. Fifty-eight O-6-substituted guanines were prepared to probe the ribose pocket, and the structures of four representative compounds bound to monomeric CDK2 were determined by X-ray crystallography. Optimum binding occurs with a moderately sized aliphatic 06 substituent that packs tightly against the hydrophobic patch presented by the glycine loop, centered on Val18, an interaction promoted by the conformational restraints imposed in a cyclohexylmethyl or cyclohexenylmethyl ring. Structure-based design generated (R)-(2-amino-9H-purin-6-yloxymethyl)pyrrolidin-2-one (56), which reproduces the reported hydrogen bonds formed between ATP and Asp86 and Gln131 but failed to improve inhibitory potency. Thus, the parent compound O-6-cyclohexylmethylguanine (NU2058, 25) is the preferred starting point for exploring other areas of the kinase active site.
Iron-Assisted Nucleophilic Aromatic Substitution on Solid Phase
作者:Thomas Ruhland、Kia S. Bang、Kim Andersen
DOI:10.1021/jo025721q
日期:2002.7.1
Iron-assisted S(N)Ar reactions were performed for the first time on solid phase, and a library of 36 unsymmetrically substituted phenylpiperazines and phenyl-1,4-diazepanes was synthesized with this novel strategy. The scope of iron-assisted S(N)Ar reactions on solid phase was investigated, and reactions of representative nucleophiles from groups VI (O, S, and Se) and V (N and P) of the periodic table