Abstract:
The effect of varying concentrations of dimethyl sulfoxide (DMSO) on component fractions of the brownish-black pigment, aspergilline, of Aspergillus carbonarius was investigated. The fungus was grown in the presence of varying concentrations of the pigment, inhibitor DMSO. Pigment components were separated by column chromatography. Spectrophotometric analysis established the presence of three component fractions within the pigment. An elution profile revealed that the fractions consisted of a large first peak with increasingly smaller second and third peaks. DMSO inhibited production of all fractions of the pigment. Over 30 per cent of the original first fraction was retained while only 5 per cent or less of fraction two and fraction three were retained. The role of these components of aspergilline is not known. It may be that the second and third fractions are precursors to the pigment in the larger first peak. An investigation was also conducted to establish a procedure which would allow separation of the components of aspergilline utilizing the simpler method of zone electrophoresis. A variety of procedures were tried in which support type, buffer pH and pigment pH were varied. Separation was poor and not satisfactory for analysis.
