Chemical structure and biological activity 



All of them are inactive in the pea test and 

 Judged from their effect on the normal geotropic 

 test they possess antagonistic properties. This wi 

 extensively, however (e.g. in Aberg's tests; also 

 ates), before final information can be given. 



We considered it to be of interest to compare 

 acids with the alkyl analogues, also with respect to 

 (Wain, 1953), which in our opinion cannot be 

 reasons given already elsewhere (Veldstra, 1953). 

 COOH COOH 



the straight growth test. 



response in the cress-root 



11 have to be studied more 



after resolving the racem- 



a-alkylidene phenylacetic 

 the a-hydrogen hypothesis 

 of general importance for 



COOH 



y\/v 



CHg 



XIX 



XX 



\ 



c 



CHCH. 



CHCH2CH3 



XXI 



COOH 



C 



y\/v 



C— CH, 



CHo 



XXII 



Figure 7 

 (a) Phenylacetic acid 

 {b) XIX 

 (c) {■D-L)oL-isopropylphenylacetic acid 



{d) XXII 



Pea test. 



100,50, 25, 10.10-5 mo///. 



50,25, 10.10-5 



50, 25, 10, 4.10 



50, 25, 10, 4. 10-5 wo/// 



moljl. 

 5 molll. 



126 



