Studies on quinic acid biosynthesis in Quercus pedunculata Ehrh. seedlings

The time course of ¹⁴C incorporation into shikimic (SA) andquinic acids (QA) was examined in Quercus pedunculata seedlingsof different age fed with ¹⁴C glucose-6-phosphate (G6P) or ¹⁴Cdehydroquinic acid (DHQ). QA was actively synthesized from G6Pand exhibited the highest radioactivity among the organic acids.In contrast, DHQ, a good precursor of shikimate, was poor forquinate synthesis. In both cases, QA and SA presented parallelchanges in specific radioactivities with time. The experimental results suggest that in oak leaves QA is formedby a route that is independent of the shikimate pathway andthat this compound undergoes an important turnover. Moreover,depending on the physiological state of the plants, there aredifferences in the relative biosynthetic rates of the two acids. (Received April 23, 1980; )