DL-a-Aminoadipic acid

Other microorganisms, as evidenced by Neurospora, have a different pathw ay of biosynthesis of lysine. The lysine auxotrophs of this organism do not respond to diaminopimelic acid and do respond to such 6-carbon compounds as DL-a-aminoadipic acid or DL-a-amino-6-hydroxy-caproio acid to satisfy their lysine requirement. The latter compounds are inactive for E, coli. Furthermore, diaminopimelic acid could not be detected in Neurospora. 

N-Phthalyl-DL-a-aminoadipic acid dimethyl ester N-Phlhalyl-O-a-aminoadipic acid e-methyl ester... 

Addition of DL-a-aminoadipic acid-2- C to fermentations of the Cephalo-sporium sp. in a complex medium resulted in the production of cephalosporin C with i C localized in the a-aminoadipoyl side-chain (Trown et aL, 1963). Under similar conditions C from dl-valine-1- C was incorporated into the a/8-dehydro-valine fragment of cephalosporin C (Trown et aL, 1963), while acetate-l- C was incorporated, as expected, into the acetoxy group of the molecule and also into the a-aminoadipoyl side-chain (Trown et aL, 1962). The C from L-vahne- C and also from a mixture of dl- and w socystine-3- C was incorporated into cephalosporin C produced by suspensions of washed mycelium with an efficiency similar to that of its incorporation into peniciUin N (Trown et aL, 1963 Abraham et aL, 1964). 

To obtain a maximum yield of dl-lysine, the keto ester is allowed to react with hydrazoic add in the presence of a stream of hydrogen chloride the reaction mixture is then hydrolyzed and evaporated to remove the hydrochloric acid, and the residue is treated with hydrazoic acid and concentrated sulfuric acid. In a similar manner, ethyl cyclopentanone-2-carboxylate yields a-aminoadipic acid and dZ-omithine. 

The cephalosporin produced by Streptomyces clavuligerus, cephamycin C (203), has also been shown to be derived from the amino acids a-aminoadipic acid, cysteine and valine 288), DL-[1- C]-Cysteine, DL-[3- C]-cysteine, DL-[l- " C]-valine and DL-a-amino-[l- C]-adipic acid all labelled cephamycin C. Acid hydrolysis of cephamycin C, followed by separation of the hydrolysis mixture using an amino acid analyser, indicated that DL-a-amino-[l- C]-adipic acid was specifically incorporated into the acylamino side chain. The 7-methoxy group was shown to be derived from L-[me//i> /- C]-methionine. 

Side-chain precursors. The incorporation of isotope from deuterophenylacetyl-valine and from phenylacetic acid-1into benzylpenicilUn by P. chrysogenum showed that added phenylacetic acid and some of its derivatives were direct precursors of the penicillin side-chain (Behrens, 1949 Sebek, 1953 Halliday and Arnstein, 1956). The use of DL-a-amino-adipic acid-2- C and 6- C has indicated that free exogenous a-aminoadipic acid can be incorporated into the side-chain of penicillin N by the Cephalosporium sp. (Abraham et al., 1964). However, the isotope from added L-a-aminoadipic acid-6- C was incorporated into the antibiotic much more efficiently than that from the corresponding D-isomer. 

A few studies on lysine catabolism have been carried out in the Graminae. Nigam and McConnell (1963) infiltrated 3-week-old wheat seedlings with L-[ C]lysine and DL-a-amino[6- C]adipate and after 5 h extracted the tissue with ethanol. [ CJlysine gave rise to large amounts of labeled pipecolic acid and a-aminoadipate with glutamate as the next most labeled amino acid. This appears to imply that if Leistner et al, (1973) are correct, wheat must racemize the L-lysine in the course of metabolism. 

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