Revised identification of the chromophore of a cell division factor from crown gall tumor cells of Vinca rosea L.

Low-resolution mass spectrometry, UV spectra in acid, neutral, and alkaline solution, and nuclear magnetic resonance indicated that the chromophore of one member of a new class of cell division-promoting factors isolated from crown gall tumor tissues consisted of a 3,7-alkyl-2-alkylthio-6-purinone with one free proton in the ring. Glucose constitutes the sugar moiety.