Relative reactivities of histamine and indoleamines with acetaldehyde.
Relative reactivities of histamine and indoleamines such as tryptamine, 5-hydroxytryptamine and 5-methoxytryptamine with acetaldehyde (AA) under physiological conditions were investigated. AA was found to have much higher reactivity towards histamine than towards indoleamines. For example, when a reaction mixture of AA (1 mM) and histamine or tryptamine (5 mM) in 0.1 M phosphate buffer (pH 7.4) was incubated at 37 degrees C for 24 h, AA decreased by 11% in the case of tryptamine, while in the case of histamine, it decreased 88%. In addition, the reaction product of AA with histamine was investigated. Mixtures of a fixed amount of histamine (5 mM) and various amounts of AA (1-20 mM) in phosphate buffer (pH 7.4) were incubated for 5 h at 37 degrees C. In all cases, only one product, 4-methylspinaceamine (4-MSPA), was observed. The yield of 4-MSPA was in approximate agreement with the losses of histamine and AA, indicating that the loss of histamine caused by the reaction of AA was quantatively converted to 4-MSPA. These results show that the reaction of AA with histamine easily takes place to produce 4-MSPA in an aqueous medium close to physiological conditions.
Ohya
Takeshi
T
Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan. tohya@josai.ac.jp
Niitsu
Masaru
M
D000079:Acetaldehyde / Q000032:analysis / Q000378:metabolism*; D001679:Biogenic Amines / Q000032:analysis / Q000378:metabolism*; D006632:Histamine / Q000032:analysis / Q000378:metabolism*; D007211:Indoles / Q000032:analysis / Q000378:metabolism*
D001679:Biogenic Amines; D007211:Indoles; D006632:Histamine; D000079:Acetaldehyde