Harmine

Harmine is a fluorescent beta-carboline alkaloid. It is a useful fluorescent pH indicator which shows a color change from pH 7.2 (blue fluorescence) to pH 8.9 (yellow fluorescence). It is used with the radioisotope carbon-11 in positron emission tomography neuroimaging to examine its binding to MAO-A. It has several targets and biological activities. It is a potent ATP-competitive and selective inhibitor of DYRK1A, DYRK2 and DYRK3, a competitive and reversible monoamine oxidase inhibitor (MAOI) that reversibly inhibits MAO-A (monoamine oxidase A) but has no effect on MAO-B and a acetylcholinesterase inhibitor (AChEI). It has shown antiviral, antimalarial, anticancer, antidiabetic and osteoclastogenesis activities.