^-AMINOBENZOIC ACID 



II. p-AMINOBENZOIC ACID REQUIREMENTS OF 

 INSECTS 



_^-Aminobenzoic acid may have some effect on the growth of the 

 larvae of Triholium confusum and Ptinus tectus, but it is not essential 

 in the same way as are other members of the vitamin B complex.^ 



. Reference to Section ii 

 I. G. Fraenkel and M. Blewett, Nature, 1942, 150, 177 ; 1943, 161, 

 703. 



12. ANALOGUES OF p-A2VIINOBENZOIC ACID 



Very few compounds related to _^-aminobenzoic acid have growth- 

 promoting properties. Thus, the methyl and ethyl esters were 

 reported to have only o-i % of the activity of the acid against CI. 

 acetohutylicum i' ^ and Streptobacterium plantarum, whilst procaine had 

 10 to 20 % of the activity against the former organism/' ^ \y■^^l only 

 I % of the activity against the latter.^ Tutocaine also had about i % 

 of the activity of ^-aminobenzoic acid against 5. plantarum, whilst 

 pantocaine was even less effective. i' ^ N-Acyl-_/)-aminobenzoic acids 

 were only slightly active, but ^-nitrobenzoic acid and the N-glycosides 

 were as active as the acid itself towards CI. acetohutylicum.'^ p-Kmmo- 

 phenylacetic acid had only o-i % of the activity of ^-aminobenzoic 

 acid against this organism, whilst o-aminobenzoic acid, isonicotinic acid, 

 ^-hydroxybenzoic acid and folic acid were inactive.^ ^-Amino-, 

 ^-nitro- and ;/)-chloroacetylbenzoylglycine had between 10 and 100 % 

 of the activity of ^-aminobenzoic acid.^ 



^-Nitrobenzoic acid does not invariably stimulate the growth of 

 micro-organisms, however, for, according to Rosenthal et al.,^ it 

 inhibited the growth of certain bacteria. ^-Aminobenzamide ^ and 

 some other sulphur-free analogues of ^-aminobenzoic acid have similar 

 properties. Thus, according to E. Auhagen,^ the growth-promoting 

 effect of ^-aminobenzoic acid on 5. plantarum was counteracted by 

 _^-aminobenzophenone, ;/)-aminoacetophenone and ;/)^'-diaminobenzo- 

 phenone. The last-named was the most active of the three, being 

 one-fifth to one-third as effective as sulphanilamide ; it exhibited a 

 slight antibacterial action in mice infected with streptococci, gonococci 

 and meningococci. 



The bacteriostasis induced by ^-nitrobenzoic acid and ^-amino- 

 benzamide was examined further by Johnson et al.,"^ who found that 

 the compounds were not effective against all bacteria inhibited by the 

 sulphonamides. Thus they inhibited the growth of E. coli but not of 

 5. haemolyticus ; furthermore, with E. coli inhibition lasted only for a 



560 



