ORIGIN OF CARBONS OF DIHYDROFURAN RING AND C-6 IN BIOSYNTHESIS OF ROTENONE

For the investigation of rotenone biosynthesis, acetate-2-14C, mevalonic acid-2-14C lactone and methionine-methyl-14C were administered to Derris elliptica plants, respectively, and the distribution of carbon-14 in the labeled rotenone was determined by degradation. When mevalonic acid-2-14C lactone was incorporated into rotenone, the radioactivity was found equally in the carbons at both C-7′ and C-8′, indicating that these carbons are derived from the carbon-2 of mevalonic lactone. In the case of methionine-methyl-14C about 80% of the total radioactivity was found to enter two methoxyl groups. This result demonstrates that methionine is an efficient precursor of the methoxyl group. Furthermore, it is also suggested that methionine may be a precursor of the carbon at C-6. © 1969 Taylor and Francis Group LLC.