Fluorine substituent effects for tryptophan in 13C nuclear magnetic resonance

✍ Scribed by Minsu Lee; Robert S. Phillips

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 347 KB
• Volume: 30
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260301102

✦ Synopsis

Abstract

The ^13^C and ^1^H NMR spectra of monofluorotryptophans and difluorotryptophans in methanol‐d~4~ were assigned based on 1D and 2D NMR techniques. Fluorine substituent effects on the chemical shifts (SCS~s~) of tryptophan were calculated and compared with those for indole. The fluorine SCS~s~ for the indole ring of tryptophan are 38 ∼ 39 for the α‐carbon − 11 ∼ − 15 for the β‐carbon, O ∼ 4 for the γ‐carbon and − 3 ∼ − 4 ppm for the δ‐carbon. The fluorine SCSs were also applied to 4,7‐ and 5,7‐difluorotryptophans and the effects were found to be additive.