Metabolism and mode of action 



that a small amount of lAA was also evident in the extract of the AIN 

 solution. With the extracts of all four compounds, peaks of activity occurred 

 in the areas corresponding to the positions of unchanged acid, amide, 

 nitrile, and ester. In the case of lAAm and I AMe, there is clear evidence of a 

 second peak of activity between /?y 0-1 -0-3 which strongly indicates the 

 formation of lAA from these compounds. The results of the pea curvature 

 test {Figure 8) support this conclusion for they confirm the presence of 

 activity in the lAA region on chromatograms developed from pea-treated 

 lAA, lAAm, and lAMe. Activity is also found in this test in the areas 

 corresponding to unchanged lAAm and lAMe. 



Rf value 

 0-0-1 0-1-0-Z 0-2-0-3 0-3-0-H O-f-0-5 0-5-0-6 0-6-0-7 0-7-0-8 0-8-0-9 0-9-1-0 



Wafer 



lAA 



lAAm 



IAN 



lAMe 



Solutions treated wlfti tomato tissue 

 Figure 11. Bio-assay of chromatogram of extracts from tomato-treated solutions using the pea curvature 



test. 



Solutions treated with tomato, celery, and maize tissues 



The effects of tomato tissue treatment were essentially similar to those 

 produced by pea tissue as is shown by the colour chromatograms {Figure 9) , 

 the histogram of the wheat cylinder test results {Figure 12), and the results of 

 the pea test {Figure 11). Treatment with celery tissue, however, while 

 producing some breakdown of IAN leading to the production of a trace of 

 ICA but no lAA, also failed to produce enough lAA from lAAm to enable 

 its detection on the colour chromatogram {Figure 10). The production of a 

 little lAA from the amide is, however, suggested by the corresponding results 

 in the wheat cylinder test {Figure 13), though the results in the pea test 

 {Figure 15) show no trace of the acid. The methyl ester, on the other hand, 

 was again readily converted to lAA. 



The histograms of both tomato and celery treated IAN show less activity 

 between /?/ 0-8-0-9 than between 0-7-0-8 or 0-9-1 -0. In these instances the 

 elongation of the wheat segments used to determine the biological activity 



242 



