Exogenous l-tyrosine metabolism and dhurrin turnover in sorghum seedlings

Citations of this article
Mendeley users who have this article in their library.
Get full text


It was shown that dhurrin (p-hydroxymandelonitrile-β-glucopyranoside) was actively metabolized by etiolated Sorghum vulgare seedlings. A turnover rate of about 0·05 μmole/hr was found in seedlings containing 1·0 μmole dhurrin/shoot. These studies showed a logarithmic decrease in the specific activity of14C labelled dhurrin when unlabelled l-tyrosine was administered to the seedlings. The increase in specific activity of dhurrin was shown to be a logarithmic function of time when seedlings were administered [2-14C]-l-tyrosine. In addition, it was concluded that a major fraction of the dhurrin in the seedlings was derived from endogenous sources rather than from exogenously supplied l-tyrosine. Sorghum seedlings were shown to metabolize [1-14C]-, [2-14C]-, [3-14C]-, and [U-14C]-l-tyrosine to14CO2. Based on the time course of14CO2released from l-tyrosine labelled in carbon atom 1, 2 or 3 as compared to uniformly labelled l-tyrosine, the data suggest that sorghum seedlings catabolized a portion of the aromatic ring carbon atoms to14CO2. The dhurrin present 50 hr after administering [2-14C]-l-tyrosine represented only 3% of the14C found in the various extracts, residues and CO2. A procedure for isolating dhurrin from perchloric acid extracts is described. © 1972.




Bough, W. A., & Gander, J. E. (1971). Exogenous l-tyrosine metabolism and dhurrin turnover in sorghum seedlings. Phytochemistry, 10(1), 67–77. https://doi.org/10.1016/S0031-9422(00)90252-8

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free