Syntheses, Constitutions and Properties of Stentorin and Isostentorin

Article abstract of DOI:10.1007/BF00807060

Stentorin and Isostentorin were synthesized from 2-isopropyl-1,3,6,8-tetrahydroxyanthrone by dimerization and chromatographic separation of the resulting regioisomers.The anthrone was prepared in four steps starting from easily available properly substituted benzene derivatives; the overall yield of the stentorins was 11percent.The constitutions of stentorin and isostentorin could be unequivocally assigned from the 1H NMR spectra of their potassium salts and were found to be in agreement with those derived recently by means of a rational synthesis.The spectroscopic, dissociation, and acid-base properties in ground and excited states as well as the chiroptical properties of the human serum albumin complexes were investigated and discussed comparing them with respective data of hypericin, fringelite D, and the natural Stentor pigment. - Keywords: Stentorin; Isostentorin; Synthesis; Dissociation; Protonation; Deprotonation; Spectroscopic properties; Association