Über ein Phytohormon der Zellstreckung. Zur Chemie des krystallisierten Auxins. 5. Mitteilung über pflanzliche Wachstumsstoffe.

Abstract

Auxin, the growth substance which promotes growth by increase in cell size, and which has been obtained in crystalline form from human urine, has the formula C18H32O5, and is a monobasic acid. The following derivatives were prepared: methyl and p-phenylphenacyl esters, tri (m-dinitrobenzoyl) auxin, dihydroauxin, and dihydro-auxinlactone. Auxin becomes inactive as a growth promoter after several months even if kept under vacuum in the dark. Preliminary studies indicate that inactiva-tion results from molecular rearrangement.