Synthesis and Structures of Diindeno-Fused 1,12-Diphenylbenzo[c]phenanthrene and 1,14-Diphenyl[5]helicene Bearing Severe Helical Twists
摘要:
Diindeno-fused 1,12-diphenylbenzo[c] phenanthrene 15 and 1,14-diphenyl[5] helicene 20 were prepared in a four-step synthetic sequence from 2,7-naphthalenedicarboxylic acid and 3,6-phenanthrenedicarboxylic acid, respectively. The X-ray structures of 15 and 20 show that the fused ring systems possess severe helical twists. The rotational barriers of the phenyl substituents were determined by the analysis of temperature-dependent H-1 NMR spectra.
Self-complementary oligodeoxynucleotides containing 3,6-disubstituted phenanthrenes adopt highly stable, hairpin-like structures. The thermodynamic stability of the hairpin mimics depends on the overall length of the phenanthrene building block. Hairpin loops composed of a phenanthrene-3,6-dicarboxamide and ethylene linkers were found to be optimal. The hairpin mimics are more stable than the analogous
A series of cross-linkingagents of varying rigidity and length were designed to stabilize helical structures in shortpeptides and were then synthesized. The sequences of the shortpeptides employed in this study each include two X residues (X=Dap, Dab, Orn, and Lys) at the i/i+4, i/i+7, or i/i+11 positions to provide the sites for cross-linking. These peptides were subjected to reaction with the
设计了一系列具有不同刚度和长度的交联剂,以稳定短肽中的螺旋结构,然后进行合成。本研究中使用的短肽序列各在i / i + 4,i / i + 7或i / i + 11位置包含两个X残基(X = Dap,Dab,Orn和Lys),以提供用于交叉链接的网站。使这些肽与合成的交联剂反应,并通过圆二色性详细分析所得的交联肽的螺旋含量。对于每种肽类,我们发现与交联剂的组合适用于在5摄氏度下构建高达95%的螺旋度的稳定螺旋结构。我们的方法还可以应用于天然蛋白质(例如,修订版
DNA Containing Non-Nucleosidic Phenanthrene Building Blocks with Asymmetrical Linkers
作者:Simon M. Langenegger、Vladimir L. Malinovskii、Daniel Wenger、Sarah Werder、Robert Häner
DOI:10.1080/15257770701506319
日期:2007.11.26
The synthesis and hybridization properties of oligonucleotides containing phenanthrene building blocks with non-nucleosidic linkers of different length are described. It was found that the length of the linkers, as well as the combination of unequal linkers can have a substantial influence on the thermal stability of the modified DNA.