Fungal Metabolism of the Prenylated Isoflavone 2,3-Dehydrokievitone

T he p reny la ted isoflavone, 2 ,3-dehydrokievitone [5 ,7 ,2 ',4 '-tetrahydroxy-8-(3 ,3-dim ethylally l)isoflavone, 1], was m etabolized by both Aspergillus flavus and Botrytis cinerea to yield the sam e th ree com pounds, a dihydrofurano-isoflavone (D K -M 1, 2), a d ihydropyrano-isoflavone (D K M 2, 3), and a glycol (D K -M 3, 4). A lthough structure 3 has previously been assigned to lunatone , an isoflavone from CuCU-stressed lima bean (Phaseolus lunatus) seedlings, a com parison of spectroscopic (M S, 'H N M R ) data indicated that the Phaseolus com pound was not identical with m etabolite D K -M 2 found in Aspergillus and Botrytis cultures. Evidence is p resen ted to suggest th at lunatone is probably identical with the furano-substitu ted m etabolite D K -M 1 (2).