60 



D. G. Crosby a?id A. J. Vlitos 



The profile of the water fraction (Figure 2) is very simple. Based 

 on results to be described later in this paper, there is reason to believe 

 that the activity observed at Rf 0.5 to 0.6 is due to the same substance 

 responsible for that at the same place on chromatograms of the ether 

 fraction. The cause of the activity at Rf 0.3 is not yet known. No in- 

 dolic compounds could be detected on the chromatograms. 



The materials responsible for activity in these t^vo areas Avere con- 

 centrated on paper chromatograms, eluted with methanol, and re- 

 chromatographed in both water and isopropanol-ammonia-water. Rj 

 values of the active zones still corresponded to those of lAA and IAN. 

 The material having an Rf above 0.9 (called A) could be isolated on 

 Whatman No. 1 paper by ascending chromatography, and on a 

 Grycksbo filter paper column by descending chromatography. The ma- 

 terial at Rf 0.5 to 0.6 was further concentrated on Whatman No. 17 

 paper. 



o 



o 

 o 



o 

 cc 



UJ 

 CL 



o 

 cc 



CD 



240 



160 



80 



« I ■ I ■ fl M 



lAA 



IAN 



N. TABACUM 



J L 



J L 



J I I L 







0.2 



0.8 



1.0 



0.4 0.6 



Rf 

 Fig. 2. Water-soluble growth substances from N. tabacum L., 'Maryland Mammoth. 



