DL-a-Aminobutyric acid

Cyclic peptide from 11 amino acids. Preparation by fermentation of Tolypocladium inflatum Gams with addition of DL-a-aminobutyric acid to the fermentation medium. Isolation by homogenization of mycelium, extraction with 90 % methanol and column chromatographic purification. 

DL-a-aminobutyric acid DL-a-hydroxybutyric acid DL-a-bromobutyric acid 15.7 184... 

Acetylaminocarboxylic acids. DL-a-Aminobutyric acid refluxed 20 hrs. with acetic acid DL-a-acetylaminobutyric acid. Y 90%.—Racemic derivatives are obtained from optically active compounds. F. e. and limitations (cf. 412) s. E. A. Bell, Soc. 1958, 2423. 

In Reference 55, several positively charged CDs, i.e., 6 mono-6-alkylimidazolium p-CDs, 2 mono-6-aIkylammo-nium p-CDs, mono-6-amino-p-CD hydrochloride, and 2-amino-p-CD hydrochloride, and mono-6-substituted a- and y-CDs with alkylimidazolium, alkylammonium, and amino moieties, were successfully applied for the separation of 14 derivatized AAs, 8 hydroxyl acids, and 14 carboxyl acids. Phosphate buffers and acetate buffers both with a concentration of 50 mM, were used for basic and acidic compounds, respectively. The optimum buffer pH varied for the different CDs. For example, 2-amino-p-CD hydrochloride (20-mM BGE) could baseline resolve a mixture of 8 dansyl (Dns)-amino and hydroxyl acids, i.e., Dns-DL-a-caprylic acid, Dns-DL-a-aminobutyric acid, Dns-oL-glutamic acid,... 

Methyl a-benzalaminocrolonate (1). Mol. wt. 203.34. This SchilT base is obtained as a 60 40 (E)/(Z) mixture from DL-j3-chloro-a-aminobutyric acid methyl ester hydrochloride. It is stable at 0°, but isomerizes slowly to the pure (E)-isomer. 

A strot influence on the biosynthesis of peptide metabolites exerted by exogenously supplied amino acid precursors has been observed earlier both in prokaryotes and eukaryotes (40). In the cyclosporin series, addition of specific amino acids in excess to the fermentation medium effects a shift in the ratio of the various cyclosporins produced, especially by influencing position 2. For example, addition of DL-2-aminobutyric acid suppresses the biosynthesis of the minor congeners, with CyA becoming almost the exclu-... 

Upon incubating rat liver extracts with DL-homoserine-2-C Matsuo et al. (74) demonstrated that the immediate reaction product was butyric acid. This compound was in part transaminated to a-aminobutyric acid and in part reduced to a-hydroxybutyric acid. Further d radation was accomplished by its decarboxylation to propionic acid. The complete oxidation then proceeds through conversion to succinic acid and the operation of the TCA cycle. 

Upon incubating DL-a-aminobutyric-3-O acid with rat liver homogenate, radioactive a-ketobutyric add and propionic acid were isolated by column chromatography on a silica gd colunm (140). The catabolism of this amino acid can be represented by the reactions of Fig. 8. 

Martin DL, Shain W (1979) High affinity transport of taurine and beta-alanine and low affinity transport of gamma-aminobutyric acid by a single transport system in cultured glioma cells. J Biol Chem 254(15) 7076-7084... 

Sanacora G, Mason GE, Rothman DL, Behar K L, Hyder F, Petroff OA, et al. Reduced cortical gamma-aminobutyric acid levels in depressed patients determined by proton magnetic resonance spectroscopy. Arch. Gen. Psychiatry 1999 56 1043-1047. Epperson CN, Haga K, Mason GE, Sellers E, Gueorguieva R, Zhang W, et al. Cortical gamma-aminobutyric acid levels across the menstrual cycle in healthy women and those with premenstrual dysphoric disorder A proton magnetic resonance spectroscopy study. Arch. Gen. Psychiatry 2002 59 851-858. 

Tian J, Lu Y, Zhang H, Chau CH, Dang HN, Kaufman DL (2004) Gamma-aminobutyric acid inliibits T cell autoimmunity and the development of inflammatory responses in a mouse type 1 diabetes model. J Immunol 173 5298—5304. 

Fig. 166. The innervation of the inferior olive of the rat by catecholaminergic, serotoninergic, substance P, and gamma-aminobutyric acid decarboxylase (GAD)-immunoreactive fibers and the distribution of acetylcholinesterase (AChE). a = subnucleus a of the medial accessory olive b = subnucleus b of the medial accessory olive beta = subnucleus beta DAO = dorsal accessory olive dc = dorsal cap dl = dorsal eaf principal olive DM = dorsomedial subnucleus dmcc = dorsomedial cell column MAO = medial accessory olive PO = principal olive vl = ventral leaf principal olive vlo = ventrolateral outgrowth XII = hypoglossal nerve.

A cell suspension culture of Datura ferox, when supplied with dl-[2- C]-ornithine, yielded radioactive putrescine, citrulline, arginosuccinate, arginine, y-aminobutyric acid, glutamic acid, aspartic acid, a-keto-8-guanidovalerate, and a-keto-S-aminovalerate. However, none of the tropane alkaloids produced by this species was radioactive. It was suggested that this in vitro cell culture lacks the enzyme which catalysed the reaction between A -pyrroline-2-carboxylic acid (55) and acetoacetyl coenzyme A. The product of this condensation ultimately yields hygrine (57) and then tropine (56) as illustrated in Scheme 12. 

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