ASYMMETRICA-VELUTINA 353 



Hetherington and Raistrick (1931b) reported the production from glucose 

 of a yellow coloring matter, citrinin, by strains of Penicillium citrinum 

 Thom. Cultures were grown in Czapek-Dox nutrient broth and the mate- 

 rial obtained in crystalline form by acidification and subsequent cooling of 

 the metabolism solution. Citrinin, C13H14O5, was found to be a laevorota- 

 tory (in alcohol) monobasic acid which melted at 166-170°C., was virtually 

 insoluble in water, but readily soluble as the sodium salt. Coyne, Rais- 

 trick, and Robinson (1931) made a detailed study of the chemistry of citri- 

 nin and proposed a structural formula. The validity of this formula was 

 subsequently questioned by Gore, Pause, and Venkataraman (1946) and 

 by Sprenger and Ruoff (1946), who presented experimental evidence in 

 support of their conclusions. 



Raistrick and Smith (1941) reported metabolism solutions of Penicillium 

 citrinum to have antibiotic properties and attributed this to their citrinin 

 content. Oxford (1942a) mvestigated this more carefully and found citri- 

 nin to have a selective action against Gram-positive bacteria, although 

 some Gram-negative forms were inhibited in low dilutions. The antibiotic 

 is too toxic to be of wide usefulness. Ambrose and De Eds (1945) found 

 doses of 50 mg./kg. of body weight to be toxic to mice, rats, and guinea 

 pigs when administered parenterally. Chu (1946), however, reported the 

 sodium salt of citrinin to produce little irritation when applied to the skin 

 or mucous membranes of animals and man. 



The production of citrinin is typical of Penicillium citrinum Thom, and 

 this biochemical characteristic can be advantageously used in identifying 

 miscellaneous isolates or accessions as already noted (see p. 69). The pro- 

 duction of citrinin is not, however, limited to this species as Raistrick and 

 Hetherington originally believed (1931). Raistrick and Smith (1935) re- 

 ported citrinin from one of five strains of Aspergillus terreus studied. Timo- 

 nin (1942) and Timonin and Rouatt (1944) employed a white-spored Asper- 

 gillus for citrinin production, and obtained substantially greater yields 

 than with strains of P. citrinum. The culture was reported as belonging 

 to the A. candidus group but was found to represent .4. niveus, one of the 

 .4. terreus group, when examined by us. Using the same culture, Wylie 

 (1945) reported citrinin yields up to 4.5 gm./liter culture solution in 10 days, 

 or 5.5 gm./liter in 15 days. Ewart (1933) had earlier isolated citrinin from 

 Crotalaria crispata, reporting yields of 1-1.2 per cent in the dried leaves of 

 this flowering plant from tropical North Australia. 



Nandi (1945) reported the production of an antibacterial substance from 

 a strain of Penicillium citrinum isolated in Calcutta. Identity with citrinin 

 is possible. 



In a survey of the production of acids from glucose by fungi, May, Her- 



