52 P. Larsen and T. Aasheim 



SUMMARY 



Preparations of synthetic indole-3-acetaldehyde (lAAld) and in- 

 dole-3-acetonitriIe (IAN) were chromatographed (descending) on 

 Whatman No. 1 filter paper in water-saturated n-hexane. Chromato- 

 grams were developed by spraying with dimethylaminocinnamalde- 

 hyde (DMCA) . The colors obtained with this reagent are clear blue 

 for lAAld and purple for IAN. Rf values, determined after Bi/o hrs. at 

 20° C, were 0.055 for lAAld and 0.10 for IAN. Good separation was 

 obtained by running the chromatograms for 18 hrs., letting the front 

 run off the paper. 



Ether extracts of etiolated epicotyls of pea (Pisum) and of the 

 etiolated, inner leaves of a head of cabbage (Brassica) were chroma- 

 tographed under the same conditions as the synthetic compounds. 

 Pisum yielded a clear blue spot at the same location as synthetic 

 lAAld, but no spot at the IAN locus. Brassica yielded a purple spot 

 at the same location as IAN, but no spot at the lAAld locus. \Vith 

 Brassica, however, colored spots were also observed at Rf 0.135 (pur- 

 ple) and Rf 0.4 (reddish purple) . 



The auxin activity (Avena coleoptile curvature test) of synthetic 

 lAAld and of the material from the zone containing the lAAld locus 

 in Pisum could be increased several-fold by treatment with soil, 

 whereas the activity of IAN almost disappears by the same treatment. 

 \Vith Brassica, auxin activity was found both in the IAN zone and in 

 the zone corresponding to the locus of lAAld. No colored spot, hoAV- 

 ever, was developed in the latter, and the auxin activity in this zone 

 was reduced very considerably by treatment with soil. 



It is concluded that the Pisum extracts contain lAAld, but very 

 little, if any, IAN, and that the Brassica extracts contain large amounts 

 of IAN, but considerably less lAAld, if any. 



LITERATURE CITED 



1. Bentley, Joyce A. The naturally-occurring auxins and inhibitors. Ann. Rev. 

 Plant Physiol. 9: 17-80. 1958. 



2. .Chemistry of the native auxins. //;.■ H. Burstrom (ed.), Encyclopedia of 



Plant Physiology. 14. Springer-Verlag. Heidelberg. (In preparation.") 



3 Bentley, Joyce A., and Bickle, ,'\. S. Studies on plant growth hormones. II. 

 Further biological properties of 3-indolylacetoniirile. Jour. Exper. Bot. 3: 406- 

 423. 1952. 



4. Bentley, Joyce A., and Housley, S. Studies on plant growth hormones. I. Bio- 

 logical activities of 3-indolylacetaldehyde and 3-indolylacetonitrile. Jour. Exper. 

 Bot. 3: 393-405. 1952. 



5. Blommaert, K. L. J. Growth promoting and inliiljiting substances in relation to 

 the rest period of the potato tuber. Nature. 171: 970-973. 1951. 



6. Brown, J. B., Henbest, H. B., and Jones, E. R. H. 3-Indolylacetaldehvde and 3- 

 indolylacetone. Jour. Chem. Soc. London. 3167-3172. 1952. 



