Y-hydroxy butyrate

Water, as a contaminant, is reduced to OH-, which further attacks the y-BL molecules. y-Hydroxy butyrate is thus the final reduction product in wet... 

The most important esters in connection with Li batteries are y-butyrolactone (BL) and methyl formate (MF). Li is apparently stable in both solvents due to passivation. Electrolysis of BL on noble metal electrodes produces a cyclic 0-keto ester anion which is a product of a nucleophilic reaction between a y-butyrolactone anion (produced by deprotonation in position a to the carbonyl) and another y-BL molecule. FTIR spectra measured from Li electrodes stored in y-BL indicate the formation of two major surface species the Li butyrate and the dilithium cyclic P-keto ester dianion. The identification of these products and related experimental work is described in detail in Refs. 150 and 189. Scheme 3 shows the reduction patterns of y-BL on lithium surfaces (also see product distribution in Table 3). In the presence of water, the LiOH formed on the Li surfaces due to H20 reduction attacks the y-BL nucleophilically to form derivatives of y-hydroxy butyrate as the major surface species [18] [e.g., LiO(CH2COOLi)]. We have evidence that y-BL may be nucleophilically attacked by surface Li20, thus forming LiO(CH2)3COOLi, which substitutes for part of the surface Li oxide [18]. MF is reduced on Li surfaces to form Li formate as the major surface species [4], LiOCH3, which is also an expected reduction product of MF on Li, was not detected as a major component in the surface films formed on Li surfaces in MF solutions [4], The reduction paths of MF on Li and their product analysis are presented in Scheme 3 and Table 3. 

The surface chemistry of Ca in y-BL and MF is very similar to that of Li in these solvents. In y-BL, the surface species include Ca butyrate, derivatives of y-hydroxy butyrate, and a cyclic P-keto ester calcium salt (see Table 3). In MF, calcium formate is the major surface species. 

Problem 16.24 Write the structure for the lactone formed on heating in the presence of acid (a) y-hydroxy-butyric acid, (b) 5-hydroxyvaleric acid. 

Butanediol, an industrial solvent, is metabolized to y-hydroxy-butyrate, a drug of abuse. One report described the potential mortality and psychiatric morbidity from the intentional ingestion of 1,4-butane-diol for bodybuilding or self-treatment of depression or insomnia (Zvosec et al. 2001). 

With the exception of a-keto glutaric acid the acids can be identified after total hydrolysis together with the amino acids. A distinction between succinic acid and its amide is possible by reduction with NaBH4 after esterification Only the ester will be reduced to y hydroxy butyric acid which can be identified as r-butyrolactone (ref. 18). 

Preparation of N-Hydroxysuccinimide Ester of L-(-) y-Benzyloxycarbonylamino-a-Hydroxy-butyric Acid A solution of 10.6 grams (0,042 mol) of L-(-)-7-benzyloxycarbonylamino-o-hydroxybutyric acid and 4.8 grams (0.042 mol) of N-hydroxysuccinimide in 200 ml of... 

Carnitine (p-hydroxy-y-trimethylammonium butyrate), (CHjljN"—CH2—CH(OH)—CH2—COO , is widely distributed and is particularly abundant in muscle. Long-chain acyl-CoA (or FFA) will not penetrate the inner membrane of mitochondria. However, carnitine palmitoyltransferase-I, present in the outer mitochondrial membrane, converts long-chain acyl-CoA to acylcarnitine, which is able to penetrate the inner membrane and gain access to the P-oxidation system of enzymes (Figure 22-1). Carnitine-acylcar-nitine translocase acts as an inner membrane exchange transporter. Acylcarnitine is transported in, coupled with the transport out of one molecule of carnitine. The acylcarnitine then reacts with CoA, cat-... 

C-chiral racemic y-hydroxy sulfides were also resolved using PEL under kinetic resolution conditions. The products were transformed into optically active 3-(alkanesulfonyloxy)thiolane salts (Scheme 1). Similarly, 1,2-cyclic sulfite glycerol derivatives cis and trans) were resolved into enantiomers via a Pseudomonas cepacia-catalysed acylation with vinyl butyrate. The E values depended on the solvent used and varied from 2 to 26. ... 

Carnitine deficiency complicates HMG-CoA lyase deficiency and other inborn errors of metabolism, which results in organic acidemia. L-Camitine or P-hydroxy-y-trimethylammonium butyrate is a carrier molecule that transports long-chain fatty acids across the inner mitochondrial membrane for subsequent P-oxi-dation. L-Carnitine also facilitates removal of toxic metabolic intermediates or xenobiotics via urinary excretion of their acyl carnitine derivatives. Indeed, individuals with HMG-CoA lyase deficiency have been shown to excrete 3-methylgluatarylcamitine (Roe et al., 1986). In the absence of ketogenesis, the formation of the acyl carnitine derivative of 3-hydroxy-3-methylglutarate from HMG-CoA also serves to regenerate free CoA in the mitochondria and permits continued P-oxidation of fatty acids. 

The dependence of CD-IC formation from solution for polymers with different stereosequences was investigated for isotactic (i) and atactic (a) poly(3-hydroxy-butyrates) (i-PHB and a-PHB) [26], i-PHB was found to form an IC with a-CD, but not with 0- or y-CDs, while only y-CD formed an IC with a-PHB. From these observations it was concluded that extended conformations available to i-PHB were too narrow, thin for a tight-packing fit with 0- or y-CDs, while the much wider, thicker extended conformations available to a-PHB chains precluded their inclusion in the narrower a- and 3-CDs, but fit tightly in the more spacious channels of its IC formed with y-CD. 

This transport is accomplished by carnitine (L-jS-hydroxy-y-trimethylammonium butyrate), which is required in catalytic amounts for the oxidation of fatty acids (Figure 18-1). Carnitine also participates in the transport of acetyl-CoA for cytosolic fatty acid synthesis. Two carnitine acyl-transferases are involved in acyl-CoA transport carnitine palmitoyltransferase I (CPTI), located on the outer surface of the inner mitochondrial membrane, and carnitine palmitoyltransferase II (CPTII), located on the inner surface. 

The study and development of microbial methods for the industrial-scale production of C3 and C4 chiral synthetic units such as 2,3-dichloro-l-propanol (DCP), epichloro-hydrin (EP), 3-chloro-l,2-propanediol (CPD), glycidol (GLD), 4-chloro-3-hydroxy-butyrate (CHB), 3-hydroxy-y-butyrolactone (HL) is described. The following points are emphasized overall strategy screening, isolation, and cultivation of bacteria control of fermentation reactions and transfer from lab- to production-scale. 

Production of (R)-4-Chloro-3-hydroxy-butyrate (CHB) and (S)-3-Hydroxy-y-butyro-lactone (HL) by Enterobacter sp. 

Homoserine. 2 -Amino -4-hydroxybutanoic acid 2-amino-4-hydroxybutyric acid < -amino-y-hydroxy-n-butyric acid. C4H,N03 mol wt 119.12. C 40.33%. H 7.62%, N 11.76%, O 40.29%. Principal free amino acid occurring in pea plants A. 1. Virtanen, Acta Chem. Scored. 7, 1423... 

Alimet Butanoic acid, 2-hydroxy-4-(methylthio)- Butyric acid, 2-hydroxy-4-(methyithio)- EINECS 209-523-0 -/-(Methylthiol-a-hydroxybutyric acid a-Hydroxy-y-(methylmercapto)butyric acid a-Hydroxy-y-(methylthio)butyric acid 2-Hydroxy-4-(methylthio)butyric acid 2-Hydroxy-4-(methylthio)butanoic acid HSDB 5700 Methionine hydroxy analog MHA MHA acid MHA-FA. Used as a feed additive for livestock, especially poultry. Monsanto Co. 

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