Investigation of acetylcholine under the influence of different electrostatic fields by FT-IR difference spectroscopy

In this study we analyse structural changes of the neurotransmitter acetylcholine (ACh) under the influence of phenol and the electrolytes Li+, Na+, K+, Cl-, Br- and I-. By FT-IR difference spectroscopy, spectral changes, especially in the region of the around 1250-1240 cm(-1) are investigated. Our data show a shift of the band envelope in this region to lower wavenumber in the presence of phenol and I- and to higher wavenumber in the presence of the cations. From studies with ethyl acetate we find shifts of the nu(c-o-c) to lower wavenumber under the influence of Li+ ions. We also find major changes of the band envelope in the presence of phenol. No such changes are found if AChCl is compared to AChI.