1. Pratt, J. J., Steroid immunoassay in clinical chemistry. Clin. Chem. 24, 1869 (1978). 2. Shackleton, C. H. L., and Whitney, J. 0., Use of Sep-pak cartridges for urinary steroid extraction: Evaluation of the method for use prior to gas chromatographic analysis. Clin. Chim. Acta (in press). 3. Thenot, J.-P., and Horning, E. C., MOTMS derivatives of human steroids for GC and GC-MS studies. Anal...

Previous studies of the physiology of an aromatic-deficient mutant strain of Neurospora crassa, Y7655a (1, 2), have led to the following conclusions: (a) The biosynthesis of the aromatic rings of phenylalanine, tyrosine, tryptophan and p-aminobenzoic acid proceeds in Neurospora as it does in Escherichia coli (3) via 5-dehydroshikimic acid and shikimic acid. (b) Protocatechuic acid, the major co...