Unintended metabolites in Monascus pilosus (beni-koji) cultures resulting from Penicillium adametzioides contamination.

The health hazards, including kidney damage, were reported following the ingestion of a health food product, so-called "foods with functional claims (FFC)'', containing beni-koji (red yeast rice), a product of Monascus pilosus very recently in Japan. Puberulic acid (PA) was detected as an unexpected compound in FFC products, and further investigation was required to identify additional unintended compounds and determine the route of PA contamination. To date, we have reported the possibility contamination of FFC products by Penicillium adametzioides in a manufacturing facility, and the presence of two novel unintended compounds, designated as compounds 1 and 2. However, the mechanism underlying the formation of compounds 1 and 2 in FFC products remains unclear. To investigate this mechanism, culture extracts of M. pilosus, P. adametzioides, and their co-cultures were analyzed. Two unintended metabolites were detected in the co-culture samples of M. pilosus and P. adametzioides.