Serum vasoconstrictor (serotonin) the presence of creatinine in the complex; a proposed structure of the vasoconstrictor principle.

摘要: In the fourth paper in this series (1) isolation of substance believed to be responsible for marked vasoconstrictor activity serum was reported. This characterized as an indole derivative from its ultraviolet absorption spectrum and behavior various color other chemical reactions. The analytical data agreed well with empirical formula C14Hz103Nb.H2S04. titration curve aqueous solution revealed two titratable groups PK’~ 4.9 pK’2 9.8. Both these were basic nature, pK’ value weaker suggested acylated guanidine structure. Indeed, very close that reported literature creatinine, while formation ammonia on treatment alkali presence one N-methyl grouping a creatinine residue might present molecule. fact only exceedingly small quantities pure available led investigation possibility by calorimetric means, it quickly determined serotonin sulfate responded positively both Jaffe alkaline picrate reagent Benedict 3,5dinitrobenzoic acid reagent, intensity equal (within experimental error about 10 per cent) molar basis. Benedict’s study (2) specificity 3,5-dinitrobenzoic respect showed derivatives closely related compounds such glycocyamidine could readily distinguished measuring rate development. Comparison fashion again almost identical behavior. It then became necessary investigate question whether creatinine-like actually part molecular structure serotonin, or whether, now seemed more likely, entity isolated designated not reality complex containing base, sulfuric acid. chromatogram developed butanol latter indeed case, chromogen completely separable chromogen.