Eiji Mizuta

Solution conformation of endothelin determined by nuclear magnetic resonance and distance geometry

Endothelin; Vasoconstrictor peptide; Three‐dimensional structure; NMR, 1H; Distance geometry

A novel photo-induced methylation of pyrimidines and condensed pyrimidines☆

Abstract A new photo-induced methylation of pyrimidines and condensed pyrimidines by irradiating an acidic solution of the bases in methanol is described. The scope and limitation, effects of acids, the calculation of the reactivity indices by the MO method, effect of bases on ·CH2OH radical formation, and the reaction mechanism are discussed.

Conformational Analysis of 1,1a, 6,10b-Tetrahydrodibenzo [b, f]-cycloprop [d] azepine Derivatives

Detailed inspection of the nuclear magnetic resonance spectra of 1, 1a, 6, 10b-tetrahydrodibenzo [b, f] cycloprop [d] azepines (1) in CDCl3 solutions has revealed that the state of conformational equilibrium falls into the following five categories according to the nitrogen substituent Z : 1) There exists a slow equilibrium between conformers I and IV, conformers II and III being either involved in a fast process or not involved at all. 2) Thre eexists a slow (much slower than category 1) equilibrium between conformers I and IV, conformers II and III being either involved in a fast process or not involved at all. 3) Conformer I is the sole one that is present, conformer III being either involved in a fast process or not involved at all. 4) Conformer IV (≡II) is the sole one that is present. 5) There exists a fast equilibrium between conformers I and IV, conformers II and III being either involved in a fast process or not involved at all.