Über den Einbau von 5.7.4′-Trihydroxyflavanon-[2.6.8.10-14C4] in Cyanidin und die Isoflavone Biochanin-A und Formononetin

Abstract

Phloroglucinol- [2.4.6-14C3] was synthesized from ethyl malonate- [2-14C] and condensed with p-carbethoxycoumaryl chloride; the resulting product was saponified to form 5.7.4'-trihydroxyflavanone- [6.8.10-14C3] (II). The latter compound was mixed with 5.7.4′-trihydroxyflavanone-[2-14C] to yield the desired 5.7.4'-trihydroxyflavanone-[2.6.8.10-14C4] (III). Administration of a sample of III in which the activity ratio ring A/C-2 was 1: 2.04 to red cabbage seedlings led to a cyanidin with an activity ratio ring A/C-2 of 1: 2, as was shown by degradation of the cyanidin to phloroglucinol and protocatechuic acid. This result proves that III is incorporated intact into cyanidin. After administration of III to chana germ (Cicer arietinum) Biochanin A (5.7-dihydroxy-4′-methoxyisoflavone) with an activity ratio of 1:2.24 was obtained. In contrast, there was only a small amount of incorporation of III into formononetin (7-hydroxy-4'-methoxyisoflavone), and the activity ratio fell to 1 : 7. These results prove the intact and specific incorporation of III into Biochanin A. When II is fed to Cicer arietinum about 3% of the total activity is found in the respiratory carbon dioxide after 48 hours. From this observation it can be concluded that the plant is able to degrade ring A of II.