~1H and ~(13)C NMR assignments for the cyanine dyes SYBR safe and thiazole orange

摘要

Analysis of ~1H and ~(13)C NMR and mass spectral data for the fluorescent nucleic acid stain SYBR Safe indicates that it contains a cyanine-based cationic core structure identical to thiazole orange. The difference between these two compounds is the type of N-substitution on the quinolinium ring system (SYBR Safe, n-Pr; thiazole orange, Me). The ~1H and ~(13)C NMR resonances for both compounds were assigned on the basis of one-and two-dimensional (COSY, ROESY, HSQC, and HMBC) experiments. The preferred conformation of these compounds was computed by ab initio methods and found to be consistent with the NMR data.