212 



R. L. Hijiman and P. Frost 



>■ 

 o 

 z 

 < 



CO 



q: 

 o 



CO 

 CD 



< 



X IN M/i 



Fi<r. 3. I'llraviolcl spectra of various indole-3-alkanoic acids after proloui^cd oxi- 

 dation. 1. lAA + peroxidase, 96 hrs. 2. lAA + H^Oo at pH 1, 72 hrs. 3. IBA + 

 H.Oa at pH 1, 48 hrs. 4. IPA + H,0„ at pH 1, 72 hrs. 5. a.a-Dimethyl-IAA + 

 H.Oo at pH 1, 44 hrs. Continuation of curves 1 and 2 over range 0.8 to 1.8 ab- 

 sorbancy is given in reduced scale at lower left. 



of the nature of the products, the available data suggest areas in 

 which these answers may be found. It should be noted at the outset 

 that we have no idea of the niunber of products formed in any of 

 these reactions. 



The pH dependency of the reaction can be accoimted for in a 

 number of ways. The indole ring may imdergo protonation, produc- 

 ing a reactive species which sidxsequenlly reacts with the oxidizing 

 agent, or the hydrogen peroxide may be protonated to yield a re- 

 active fragment such as H302'^ or +OH. A third possibility is that the 

 carboxyl group is converted to a peracid, since peracids can generally 



