Date of this Version
Evidence is accumulating that there is a common metabolic precursor to many of the benzene ring derivatives found in living organisms. Recent work by Davis and Tatum indicates that one such precursor is the naturally occurring shikimic acid (Fig. 1) since this compound serves as a growth factor for certain mutants of Escherichia coli and Neurospora which otherwise require a combination of tyrosine, phenylalanine, tryptophan and p-aminobenzoic acid for growth. These mutants cannot utilize the closely related, naturally occurring quinic acid (Fig. 1) as a substitute for any of their requirements.