160 BACTERIOLOGICAL CHEMISTRY 



Clavacin. — Aspergillvs ciavafus when gn)\Mi on 

 Czapek-Dox medium gives antibacterial filtrates from 

 which clavacin can be isolated by extraction with ether 

 or chloroform or by adsorption on charcoal followed by elu- 

 tion with ether. It is a relatively stable substance even 

 in strongly acid solution. It is bactericidal in concentra- 

 tions of 1 in 10^, to Gram -positive and Gram -negative 

 organisms. It has also been called clavatin. 



At about the same time Penicillimn claviforme was 

 shown to yield an optically inactive, colourless, crystalline 

 substance, m.p. 110°C. which could be extracted from 

 culture filtrates with chloroform. It was stable to boiling 

 dilute acid, but not to alkali, nor to boiling in neutral 

 solution. It was bactericidal to pathogenic Gram-positive 

 and Gram-negative bacteria and killed leucocytes at a 

 dilution of 1 in 800,000. It is lethal to mice (0-25 mg. 

 intravenously, 2 mg. subcutaneously or 2-5 mg. per os). 

 It was given the name claviformin. 



Later Aspergillus gigmiteus, when grown on a medium 

 containing 4 per cent, of glucose, 0-1 per cent, of sodium 

 nitrate and 0-1 per cent, of potassium dihydrogen phos- 

 phate, was also shown to yield claviformin. The substance 

 is also a prduct of the growth of a species of Gymnoascus. 



A fifth mould, Penicillium patidmn, produced a 

 colourless, crystalline substance, given the name patulin, 

 when grown on Raulin-Thom medium, which could 

 be extracted by ether, or ethyl acetate. It was found 

 to be inhibitory to Gram -positive and Gram -negative 

 organisms at concentrations of 1 in 30,000 to 1 in 80,000. 

 It was shown to be anhydro-3-hydroxymethylene- 

 tetrahydro- Y-p3a'one-2-carboxylic acid, 

 o 

 II 



CHa C =CH. 



I I >o . 



CHa CH.CO ^ 



