702 ]. P. Nitsch and C. Nitsch 



as those contained in casein hydrolysate, was found to promote the 

 growth of the Jerusalem artichoke tissues also as well as that of crown- 

 gall tissues (Table 2). Thus, it is possible that part of the TJ effect is 

 due to its amino acid content. 



Reducing Compounds 



Tomato juice also contains reducing compounds, such as ascorbic 

 acid, glutathione (40), phytoene (34), etc. Ascorbic acid and glutathi- 

 one were found to enhance the growth of the strains of tissue cultures 

 which we stimulated by TJ (Table 2). Epicatechin'', at the concentra- 

 tion of 10"^ M, also gave some growth stimulation, more than cate- 

 chin.5 



Flavones 



The yellow color of substances I, II, and III, and the fact that 

 these colors deepened markedly under alkaline conditions suggested 

 to us that these compounds could be flavones. Although the precise 

 chemical nature of these three substances has not yet been determined, 

 we suspect that they are glycosides, at least substances I and II. Quer- 

 cetrin was found to stimulate slightly the growth of Jerusalem arti- 

 choke tissues (Table 2). The presence of biologically active glycosides 

 of flavones in TJ would be of special interest in view of the report 

 that a leucoanthocyanin is one of the active components of coconut 

 milk (39). 



Sugars 



The fraction which produced the most intense growth effects upon 

 the growth of Jerusalem artichoke tissues was, when concentrated, 

 of the consistency of a sugar syrup. From this fraction a whitish com- 

 pound could be precipitated out with ether or acetone. This substance, 

 called substance S, was biologically active. 



Auxins 



Methanol extracts of tomatoes at various stages of development 

 yielded several growth substances of the auxin type which were 

 separated by paper chromatography. These substances, with their 

 relative biological importance, Rj values, and color reactions are 

 listed in Table 3. It should be noted that, in addition to biologically 

 active substances, several other spots giving a color with the Ehrlich re- 

 agent for indoles were found to have no growth-promoting effect upon 

 the elongation of Avena first internodes. 



Kiiully sii]>pliccl by Dr. K. Frciulcnlicrg. 



