Characterization of novel 10-substituted 1,8-dihydroxy-9(10H)-anthracenone derivatives by mass spectrometry.

Anthralin and its derivatives containing a variety of simple or functionalized aliphatic and aromatic substituents are of special interest in research on psoriasis. In this connection, 10-arylthio-1,8-dihydroxy-9(10H)-anthracenones were synthesized and examined by means of mass spectrometry. In general, the molecules in question fragmented upon electron impact into ions at m/z 225 (C-S bond cleavage and charge retention at the anthralin component) and into ions of unknown structure at m/z 226, requiring H-migration from the S-bound substituent R into the anthralin moiety. Since mass spectrometry methods furnished us elegant, matchless means of tracing the amounts of material in the analysis, especially in the case of physiologically active compounds, we decided to use mass spectrometry procedures for unequivocal identification and purity determination of 10-arylthio-anthralins.