Hexone Bases

HEXONE BASES, a name proposed by Kossel to designate a group of three amino acids containing 6 carbon atoms and 2 or more amine or imine nitrogen atoms in the molecule, and possessing alkaline properties by virtue of this. These amino acids are: Lysine, alpha, epsilon-diaminocaproic acid: NH₂ . CH₂ . (CH₂)₃ . CH(NH₂) . COOH; Histidine, beta-imidazolyl-alpha-aminopropionic acid: CH = N \ / CH - NH \/ C . CH₂ . CH(NH₂) . COOH;

CH = C . CH₂ . CH(NH₂) . COOH; Arginine, delta-guanido-alpha-aminovalerianic acid:

NH : C(NH₂) . NH . CH₂ . (CH₂)₂ . CH(NH₂) . COOH. All three amino acids occur in the animal organism and in plants (especially in germinating seeds) in a free state and participate in the building of proteins. Hexone bases are readily soluble in water, have a strongly alkaline reaction, and, unlike monoamino acids, are precipitated by phosphotungstic acid even from dilute solutions. Proteins containing many hexone bases in their molecule have an alkaline character (globin, histon). Under the influence of microorganisms, hexone bases lose CO₂ and are converted: lysine into cadaverine NH₂.(CH₂)₅.NH₂, histidine into beta-imidazolyl-ethylamine CH = N \ / CH - NH \/ C . CH₂ . CH₂ . NH₂, arginine into putrescine NH₂.(CH₂)₄.NH₂ (see Ptomaines). Upon the action of the enzyme arginase, arginine is decomposed with the formation of urea and ornithine NH₂.CH₂.(CH₂)₂.CH(NH₂).COOH.

Upon the action of the enzyme arginase, arginine is decomposed with the formation of urea and ornithine NH₂.(CH₂)₃.CH(NH₂).COOH.