Pfizer Handbook of Microbial Metabolites 



402 



Formation of the monobenzofuran shown also may in- 

 volve phenol coupling, if not precisely as indicated at least 

 in the same general fashion: 



Apparently, many lichens contain an enzyme system 

 which can promote phenolic coupling of this type. Nei- 

 ther the dibenzofurans nor the depsides and depsidones 

 are produced by molds alone (although some of their 

 resorcinolic precursors are), and the algal partners must 

 be required in the coupling process. 



856 Strepsilin, C15H10O5, colorless crystals, m.p. 324°. 



Cladonia strepsilis Wain. 



Shoji Shibata, 7- Pharm. Soc. Japan 64 20 (1944). 

 ture) 



( Struc- 



