n 



Phenolic Substances 



a. PHENOLS AND PHENOL ETHERS (GENERAL) 



Phenolic substances are commonly encountered as microor- 

 ganism metabolites. Besides the compounds listed in this chap- 

 ter phenolic moieties are present in other structures such as the 

 xanthones, altemariol, blastmycin, hygromycin, fulvic acid, cit- 

 romycetin, atrovenetin, the tetracyclines, mycobactin, anthra- 

 quinones and naphthoquinones. Benzoquinones are undoubt- 

 edly oxidation products of phenolic precursors. 



Practically all of the phenolic materials in this section are 

 mold metabolites. Perhaps that is because more isolation work 

 has been done with fungi than with bacteria. It is evident that 

 similar compounds are produced by bacteria, since 6-methyl- 

 salicylic acid, a typical penicillium metabolite, also occurs as a 

 moiety of mycobactin from Mycobacterium phlei. Also, 2,3- 

 dihydroxybenzoic acid occurs as a moiety of a metabolite from 

 Bacillus subtilis, and 2,6-dihydroxybenzoic acid as a part of 

 pyoluteorin from Pseudomonas aeruginosa. It is interesting 

 that these bacterial phenolic acids are conjugates of nitrogen- 

 containing substances. 



The phenolic acid production of certain cultures has been 

 studied in depth. Penicillium brevi-compactum, for example, 

 has been found to produce the following: 

 3,5-Dihydroxyphthalic Acid CsHgOg 

 l-Carboxy-2,5-dioxyphenyl Acetyl Carbinol CioHioOg 

 2,4-Dioxy-6-pyruvylbenzoic Acid CioHgOg 



