薬品のポーラログラフ的研究 (第22報)

Abstract

Normal- (I) and iso-dihydrothiamine (II) indicate cathodic wave (E1/2 -1.27 to -1.55V, kD 13.6 μA⋅mM-1⋅mg.-2/3⋅sec. 1/2), considered to be due to reduction of the pyrimidine portion in acid reaction but pseudo-dihydrothiamine (III) does not indicate such a wave. (I), (II), and (III) indicate anodic wave (E -0.3V, kD -1.4) with dropping mercury electrode, probably by the formation of a mercury complex. With the rotating platinum electrode, (I) indicates an anodic wave (E1/2 +0.6V), assumed as due to its oxidation to thiamine. (I) and (II) change in aqueous solution, irrespective of the presence or absence of oxygen, into 3-acetyl-3-mercapto-1-propanol, tris (2-methyl-4-amino-5-pyrimidylmethyl) hexahydro-s-triazine (VII), and (III). (I), (II), and (III) all react with equivalent amount of p-chloromercuribenzoate to forms a reaction product of 3-mercapto-1-propanol and p-chloromercuribenzoate. (VII) indicates a reduction wave of the pyrimidine ring.