Synthesis 



benzenesulphonic acid and phenyl-acetic acid, the simple 

 CgHg group having two names while fulfilling similar func- 

 tions. The Chemical Society appear to prefer the form 

 indole-acetic to indolylacetic, but, to the author, the latter 

 seems desirable from the analogy of phenyl-acetic. Jackson 

 and Manske (1935) have introduced the term indylene to 

 indicate at least some di-substituted derivatives of indole, in 

 analogy with phenylene. 



Typical Formulae of Growth-regulating and Allied 

 Substances of Physiological Importance. 



CH(4) 



C3)HC 



(6)HC 



CM (5) 



CH(2) 



/\ 



CH3 



\y\/^"'" \/\y 



CH 

 (7) 



NH 



Indole; 



henz-pyrrole. 



CH : OH: NH 



6 4 2 2 



N 



Skatole; 



S-methyl-indole; 



Pr-S-methyl-indole; 



fi-methyl-indole. 



/\ 



1/3) 



C«) 



/\ 



N-CH3 



1-methyl-indole; 

 N-methyl-indole. 



TyQ) (of) 



ch2.chCnHj)cooh 



N 



Tryptophan; 



a- {3-indole)-amino-propionic acid 



(optically active). 



101 



