Chemical Resources Laboratory, Tokyo Institute of Technology, 4259, Yokahama 226-8503, Japan.
Phys Chem Chem Phys. 2011 May 7;13(17):7812-20. doi: 10.1039/c0cp02695f. Epub 2011 Mar 29.
The conformational reduction in catecholamine neurotransmitters was studied by resonance enhanced multi photon ionization (REMPI), ultraviolet-ultraviolet (UV-UV) hole burning and infrared (IR) dip spectroscopy with applying a laser desorption supersonic jet technique to DOPA, which is one of the catecholamine neurotransmitters and has one more phenolic OH group than tyrosine. It is concluded that DOPA has a single observable conformer in the gas phase at low temperature. Quantum chemical calculations at several levels with or without the dispersion correction were also carried out to study stable conformations. From the comparison between the computational IR spectra and the experimental ones, the most stable structure was determined. It is strongly suggested that the conformational reduction is caused by electrostatic interactions, such as a dipole-dipole interaction, between the chain and OH groups.
用激光解吸超音速喷射技术研究了儿茶酚胺神经递质的构象还原，方法是共振增强多光子电离（REMPI）、紫外-紫外（UV-UV）孔烧蚀和红外（IR）光谱。所研究的物质是儿茶酚胺神经递质之一的多巴，它比酪氨酸多一个酚羟基。研究结果表明，多巴在低温下的气相中只有一种可观测的构象。还进行了几个层次的量子化学计算，包括有无色散校正，以研究稳定构象。通过比较计算红外光谱和实验光谱，确定了最稳定的结构。强烈建议构象还原是由链和 OH 基团之间的静电相互作用，如偶极-偶极相互作用引起的。
