Ehrlich

Acetarsone. Acetarsone (3-acetamido-4-hydroxyphenyl arsonic acid) (13), also known as acetarsol, stovarsol, and Ehrlich 594, forms white prisms from water. 

Analytical and Test Methods. In addition to the modem spectroscopic methods of detection and identification of pyrroles, there are several chemical tests. The classical Runge test with HCl yields pyrrole red, an amorphous polymer mixture. In addition, all pyrroles with a free a- or P-position or with groups, eg, ester, that can be converted to such pyrroles under acid conditions undergo the Ehrlich reaction with p-(dimethylamino)henzaldehyde to give purple products. 

Mutation. For industrial appHcations, mutations are induced by x-rays, uv irradiation or chemicals (iiitrosoguanidine, EMS, MMS, etc). Mutant selections based on amino acid or nucleotide base analogue resistance or treatment with Nystatin or 2-deoxyglucose to select auxotrophs or temperature-sensitive mutations are easily carried out. Examples of useful mutants are strains of Candida membranefaciens, which produce L-threonine Hansenu/a anomala, which produces tryptophan or strains of Candida lipolytica that produce citric acid. An auxotrophic mutant of S. cerevisiae that requires leucine for growth has been produced for use in wine fermentations (see also Wine). This yeast produces only minimal quantities of isoamyl alcohol, a fusel oil fraction derived from leucine by the Ehrlich reaction (10,11). A mutant strain of bakers yeast with cold-sensitive metaboHsm shows increased stabiUty and has been marketed in Japan for use in doughs stored in the refrigerator (12). 

B. J. Ehrlich and S. E. Spencer, Development of an Automated Mustard S tack Monitor, Edgewood Arsenal Report No. ED-CR-76084, Tracer, Inc., June 1976. L. Schwart2 and co-workers. Evaluation of Ml 5/Ml 8 Enyme Detector Ticket System with Eow Concentration of GB, Edgewood Arsenal Report No. 

By using an aromatic aldehyde carrying an electron-releasing group the intermediate cation can be stabilized. This is the basis of the widely-used Ehrlich colour reaction for pyrroles, indoles and furans which have a free reactive nuclear position (Scheme 21). 

Figure 10 Mean values of bond lengths and bond angles of pyrazole structures (a) Ehrlich (X-ray) (b) Berthou et at. (X-ray) (c) Rasmussen et at. (neutron, corrected for rigid body motion) (d) Rasmussen et at. (X-ray, 295 K) ...

The assignment of bands has been carried out using ab initio calculations, unfortunately using the erroneous Ehrlich geometry (Section 4.04.1.3.1). There is a linear relationship between the calculated energy levels (eigenvalues) and the experimental ones IEexp = 0.37 + 0.75IE<,aic, (c.c.) = 0.994. 

EHRLICH - SACHS Aldehyde Synthesis Formation of o-nitrobenzaldehydes from o-nitrotoluenea. 

P. Bailon, G.K. Ehrlich, W. Fung and W. Berthold (Eds), Affinity Chromatography Methods and Protocols, Humana Press, Totowa, 2000. ISBN 0896036944. 

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