7-Butyrobetaine

Proline and lysine hydroxylases are required for the postsynthetic modification of collagen, and proline hydroxylase also for the postsynthetic modification of osteocalcin in bone and the Clq component of complement. Aspartate / -hydroxylase is required for the postsynthetic modification of protein C, the vitamin K-dependent protease which hydrolyzes activated factor V in the blood-clotting cascade. Trimethyllysine and 7-butyrobetaine hydroxylases are required for the synthesis of carnitine. 

In a somewhat ambiguous manner crotonbetaine, (CH3)3 N+ CH2 -CH=CH COO- and carnitin, (CH3)3 N+ CH2 CHOH CH2 COO- were hydrogenated to y-butyrobetaine, (CH3)3 N+-CH2-CH2-CH2-COO , by undefined mixtures of bacteria of putrefying pancreas in the presence of D-glucose after the long time of four months. ... 

Carnitine, L-3-hydroxy-4-(trimethylammonium)butyrate, is a water-soluble, tri-methylammonium derivative of y-amino-jS-hydroxybutyric acid, which is formed from trimethyllysine via y-butyrobetaine [40]. About 75% of carnitine is obtained from dietary intake of meat, fish, and dairy products containing proteins with trimethyllysine residues. Under normal conditions, endogenous synthesis from lysine and methionine plays a minor role, but can be stimulated by a diet low in carnitine. Carnitine is not further metabolized and is excreted in urine and bile as free carnitine or as conjugated carnitine esters [1, 41, 42]. Adequate intracellular levels of carnitine are therefore maintained by mechanisms that modulate dietary intake, endogenous synthesis, reabsorption, and cellular uptake. 

The mechanism of a-ketoglutarate participation in the dioxygenase reaction has been proposed by Lindstedt and his co-workers6S,220) as shown in Eq. (27) with y-butyrobetaine hydroxylase. 

L. Boehlen, and I. Psenicka, Process integration aspeds for the production of fine chemicals illustrated with the biotransformation of y-butyrobetaine into L-camitine, Chem. Eng.J. 1996, 63, 53-61. 

The other approach starts from epichlorohydrin and involves a classical resolution of the amide. The wrong amide is also converted to the desired isomer by a dehydration-rehydration sequence that uses hydrolases (Scheme 31.23).238-239 A biological variation is to hydrolyze the 4-butyrobetaine as the stcrcodi I fcrcn liating step.240-241... 

In general, the effects on collagen synthesis are more marked and more important than those of decreased formation of carnitine (as a result of impaired activity of trimethyllysine and y-butyrobetaine hydroxylases Section 14.1.1), impaired xenobiotic metabolism, or hypercholesterolemia (Section 13.3.8). However, depletion of muscle carititine may account for the lassitude and fatigue that precede clinical signs of scurvy. 

In general, the effects on collagen synthesis are more marked and more important than those of decreased formation of carnitine (as a result of impaired activity of trimethyllysine and y-butyrobetaine hydroxylases Section... 

Figure 14.2. Biosynthesis of carnitine. Trimethyllysine hydroxylase, EC 1.14.11.8 aldolase, EC 4.1.2. x aldehyde dehydrogenase, EC 1.2.1.47 y-butyrobetaine hydroxylase, EC 1.14.11.1. Relative molecular mass (Mr) carnitine, 161.2.

An example of a process where the fed-batch mode has a decisive advantage over a continuous operation is the biotransformation of y-butyrobetaine into L-carnitine. This fine chemical has pharmacological, nutritional, and animal-feed applications, making product purification an essential part of the production process. Consequently, process optimization of biotransformation and downstream... 

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