AUTHOR=Majhi Swapna , Dhale Mohan Appasaheb , Honganoor Puttananjaiah Mohankumari 

TITLE=Inhibitory effect of Monascus purpureus pigment extracts against fungi and mechanism of action

JOURNAL=Frontiers in Sustainable Food Systems

VOLUME=Volume 7 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2023.1100961

DOI=10.3389/fsufs.2023.1100961

ISSN=2571-581X

ABSTRACT=<p>The fungus <italic>Monascus</italic> produces several secondary metabolites of different pigment hues. These pigments have shown various biological activities. In this study, <italic>Monascus purpureus</italic> pigment extracts were tested (<italic>in vitro</italic>) against <italic>Penicillium expansum</italic> MTCC 4900, <italic>Rhizopus stolinfer</italic> MTCC 10595, and <italic>Aspergillus niger</italic> MTCC 8652 for antifungal activity. The UV–visible spectrum of <italic>M. purpureus</italic> fermented rice extracts showed λmax at 395, 425, and 500 nm. This indicated the solubility of yellow, orange, and red pigments in polar-based solvent extraction. The <italic>M. purpureus</italic> pigment extracts inhibited the radial growth and conidial germination of the test fungi. The fungi treated with pigment extract stained with DiBAC (a vital stain) emitted green fluorescence under a fluorescent microscope. These results indicated that the pigment extracts have affected the membrane potential of the treated fungi. Hence, the fungicidal activity of the pigment extracts is due to the disruption of the cell membrane. The HPLC analysis of the pigment revealed the presence of two major peaks. The UV–visible spectrum corresponding to the HPLC peak at 12-min retention time revealed the presence of orange pigment rubropunctatin. Apparently the rubropunctatin present in the extracts exhibited fungicidal activity. Further studies are warranted to assess the applications of <italic>M. purpureus</italic> pigments in preventing and treating fungus-related diseases.</p>