Study of reason of "the older, the better" of Pericarpium Citri Reticulatae(PCR) which contributed increase of flavonoids

Abstract

This study is to explore the reason of "the older, the better" of PCR and itsincrease of flavonoids. We identified the fun- gus isolated from the PCR using microscopic and molecular identification. HPLC method was used to determine the content of 4 fla- vonoids and to clarifythe regularity of them; UV spectrophotometry method was used to determine the total content of flavonoids; reverse thinking was applied to screen the fungus that have close relation to the change of flavonoids. Finally, we have isolated and identified 25 fungusfrom the PCR, which belong to 2 genus and 4 species, including pencillium commune, P. minioluteeum, P. citrinum, Aspergillus flavus and A. niger. The content of flavonoids was increased in the mildew PCR due to A. niger and other fungus. Therefore, "the ol- der, the better" of PCR had its scientific reason that the increase of flavonoids had a close relation of the metabolic activity of A. niger and other fungus.