A facile macroporous resin-based method for separation of yellow and orange Monascus pigments

The yellow Monascus pigments (YMPs) named monascin and ankaflavin and the orange Monascus pigments (OMPs) named rubropunctatin and monascorubrin are two groups of bioactive components in a mixture state in the Monascus fermented products. In order to separate these two groups of bioactive pigments, a facile macroporous resin-based method was developed. The weak-polar resin CAD-40 was selected from the seven tested macroporous resins as it revealed better properties for the adsorption and desorption of the YMPs and OMPs. Then, CAD-40 resin was used for column-chromatographic separation. After eluted by 4 bed volumes of ethanol, the yellow group (monascin and ankaflavin) and the orange group (rubropunctatin and monascorubrin) were successfully separated and purified, with an increased content from 49.3% and 44.2% in the crude pigment extract to 85.2% and 83.0% in the final products, respectively. This method would be helpful for the large-scale separation and purification of Monascus pigment products with specific bioactivity.