ANTIBIOTICS 161 



wliiuli uii Ircatinciit with dilute alkali or on boiling in 



water gives the acid, ^^'H, C=CHOH. Patulin is toxic 



I I 



CHa CH.COOH 



\o/ 



to mice and rabbits in doses of the oixier of 0-25 to 0-5 

 mg. per 20 g. body weight. In concentrations of 1 in 

 2000 it is inhibitory to phagocytosis. Conflicting reports 

 have been published about its efficacy in curing the com- 

 mon cold. The result probably depends on the particular 

 organisms concerned in the secondary stages of the 

 cold, some being susceptible to patulin and some not. 

 The primary virus stage of the cold appears not to be 

 affected by patulin. 



Since clavacin is inactivated by excess of 8H com- 

 pounds it is possible that it exerts its action by inhibiting 

 SH-containing essential metabolites or bacterial enzymes. 



It has been shown by chemical, biological and X-ray 

 evidence that clavacin, claviformm and patulin are 

 identical compounds. 



Clavatih. — This substance is identical with clavacin. 



Claviformin. — This substance is identical with clavacin. 



Flavacidin. — This substance, produced by A. flavus 

 in deep, agitated, aerated cultures in a modified Czapek- 

 Dox medium, is very probably identical with penicillin. 



Flavicin. — Aspergillus flavus when grown on a modi- 

 fied Czapek-Dox medium containing corn steep liquor 

 gives rise to a bacteriostatic substance which can be 

 extracted with i^opropyl ether. The purified material is 

 active against the Gram -positive organisms, staphylo- 

 cocci, streptococci, C. diphthericE, smd B. aiithracis at con- 

 centrations of 0-006 to 0-008 mg./ml. Gram-negative 

 organisms are much less sensitive, E. typhosa, Shigella 



