Two more unexpected compounds have been detected from Kobayashi Pharmaceutical's supplements containing beni kо̄ji (red fermented rice), health ministry officials said Tuesday.

The two compounds are believed to have been created by contamination of blue mold in the process of producing the active ingredient, called monacolin K, by red yeast fungi.

Meanwhile, tests on rats have showed that puberulic acid, a natural compound derived from blue mold, which had been detected from the supplements, has an adverse effect on renal function, according to the officials.

The National Institute of Health Sciences received beni kо̄ji ingredient samples for the past three years from Kobayashi Pharmaceutical and analyzed samples produced between June and August last year, which were used by many people who reported health damage.

Since April, the company has collected substances from the incubation room at its plant in the city of Osaka, which closed in December last year, and the inner surface of the culture tank lid at a subsidiary plant in the western prefecture of Wakayama, providing them to the institute.

When the rats were fed the supplements that had caused the health problems and the puberulic acid alone, degeneration and necrosis were observed in some of their kidneys.

The ministry believes that the contamination of blue mold occurred during the cultivation of red rice malt.

It also plans to continue to study the impact of the other two compounds on kidney health.