It has previously been shown that formaldehyde causes the formation of hydroxymethylated derivatives with nucleobases, but these were identified after separation of the reaction products; such handling might destroy labile derivatives or remove products present in small proportions. This work is bas
1H- and 13C-nmr studies on caffeine and its interaction with nucleic acids
✍ Scribed by Lou-sing Kan; Philip N. Borer; Doris M. Cheng; Paul O. P. Ts'o
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1980
- Tongue
- English
- Weight
- 648 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The relative orientation of caffeine in stacks formed by self‐association in aqueous solution has been evaluated by both ^1^H‐ and ^13^C‐nmr spectroscopy. The data, which were interpreted through the calculation of ring‐current and atomic diamagnetic anisotropic effects of the caffeine molecule, suggest two caffeine bases may stack in a nearly orthogonal manner. The interactions between caffeine and adenylyl‐3′,5′‐adenosine, polyadenylic acid, and ribo‐(A‐A‐G‐C‐U‐U)~2~ helix were also studied by nmr at different caffeine/base ratios and at varying temperatures. The results show that caffeine tends to stack on the top of the terminal purine bases or to insert (the single‐stranded) or to intercalate (the double‐stranded) between purine bases.
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