Stimulation of chalcone synthase activity by yeast extract in cultured Glycyrrhiza echinata cells and 5-deoxyflavanone formation by isolated protoplasts.
Chalcone synthase activity catalyzing the formation of naringenin (5-hydroxyflavanone) was detected in cell suspension cultures of Glycyrrhiza echinata. This activity rapidly increased by treatment of the cells with yeast extract, while non-treated cells showed a constant low activity. Isolated G. echinata protoplasts accumulated retrochalcone (echinatin) and its biosynthetic intermediate (licodione) during 24 h of culture. When the protoplasts were incubated with [(14)C(U)]phenylalanine, liquiritigenin (5-deoxyflavanone) was transiently labeled, indicating the induction of 6'-deoxychalcone synthase. The formation of liquiritigenin, in addition to naringenin, was observed when the crude extracts from the protoplasts were assaved for CHS activity.
School of Pharmaceutical Sciences, Kitasato University, Minato-ku, 108, Tokyo, Japan.
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Ayabe
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Udagawa
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Furuya