Biotransformation of potato stress metabolites rishitin, lubimin, and 15-dihydro lubimin by potato and soybean cell cultures.

Potato callus and cell suspensions of potato and soybean were exogenously supplied with potato phytoalexin rishitin, much of which was converted by both species to an unknown tenatively identified as glutinosone. Exogenous lubimin was unaffected by the potato cell culture, but was transformed to 15-dihydro lubimin by the soybean cell suspensions. The stability of the exogenous lubimin may be ascribed to a second block in the rishitin pathway of the potato cell culture.

Biotransformation of the potato stress metabolite, solavetivone, by cell suspension cultures of two solanaceous and three non-solanaceous species.

Cell suspension cultures of several plant species which were exogenously supplied solavetivone accumulated four hydroxylated derivatives. Only solanaceous cell cultures converted exogenously supplied solavetivone to sesquiterpenoid compounds identified with the plant response to biotic stress. Failure of potato cell cultures to make these compounds under biotic stress may be linked to their inability to produce adequate levels of solavetivone.

Stress Metabolites of the Potato and Other Solanaceous Plants.

The effect of stress on the chemical composition of the Solanaceae , primarily Solanum tuberosum (potato), may be profound and have significant health implications. Changes in glycoalkaloids, steroids, sesquiterpenes and other lipids that result from specific and non-specific stress are discussed. The biochemistry and toxicology of these compounds are reviewed.

Quantitative determination of hexosamines in glycoprotein by ion-exchange chromatography.

An ion-exchange chromatographic method for the quantitative determination of glucosamine and galactosamine in glycoproteins is described. The hexosamines are completely separated from interfering peptides of the acid hydrolysate using a small column of cation exchanger in a manner described earlier by Boas. Chromatographic separation of the hexosamine fraction and the determination of glucosamine and galactosamine are accomplished on an amino acid analyzer with ninhydrin.