306 BACTERIOLOGICAL CHEMISTRY 



Chlorine containing Products. — Almost all the inor- 

 ganic chlorine of Czapek-Dox medium is removed during 

 the growth of A. terreus and is converted into geodin, 

 C17H12O7CI2, and erdin, C16H10O7CI2. Although the con- 

 stitution of the products themselves is not yet known, 

 dihydroerdin (obtained by catalytic reduction of erdin) 

 is methylated by diazomethane to give 3^ 5'-dichloro- 

 4:6:2': 6'-tetramethoxy-4'-methylbenzophenone-2-car- 

 boxylic acid : — 



OCH3 ^ OCH3 



I II ^ II r^ 



CH3O L IICOOH CHgO'l ICH3 



CI 



Dihydro geodin is the methyl ester of dihydroerdin. 

 Replacement of the potassium chloride in the medium 

 by bromide or iodide did not give rise to the corres- 

 ponding compounds although the organism grew normally. 



The yellow crystalline compound sulochrin, 



COOCH3 ^ OH 



I II ^ !l 



HOL lloCHa HO'I icHg 



which occurs in the mycelium of Oospora sulphur ea- 

 ochracea, has a benzophenone structure very like that of 

 dihydroerdin and dihydrogeodin although it lacks the 

 chlorine atoms. Sulochrin is also related to the pigment 

 ravenelin (see p. 396) since treatment of demethylated 

 sulochrin with concentrated sulphuric acid gives rise to a 

 xanthone derivative having a methyl group, a hydroxyl 

 group and the carbonyl group in the same positions as 

 those in ravenelin. 



