Kinin activity of extracts of pumpkin seeds

Abstract

Pumpkin seed extract contains substances which are highly active in promoting growth of tobacco pith tissue. The active substances are adsorbed on Dowex-50W ion-exchange resin and can be eluted by ammonia. Paper chromatography has revealed the presence of at least two active substances in the eluate. The fast moving compound may be similar to zeatin, triacanthine or 6-(γ,γ-dimethylallylamino)-purine. However, the exact identity is yet to be determined. The Rf of the slow moving compound does not tally with any of the known kinins. The active factors of pumpkin show a close resemblance with factors II and III of watermelon seeds.