Isovaleric acid 3 hydroxy

Fig. 8. Stmcture of (a) valinomycin and (J3) and enniatins and beauvericin. Hov = a-hydroxy-isovaleric acid and Lac = lactic acid. The /V-methylamino acid for enniatin A is isoleucine enniatin B, valine enniatin C, leucine and beauvericin, phenylalanine.

Metabolism of the 2,S -isomers proceeds sequentially hydroxylation at the phenoxy group, hydrolysis of the cyano group, and cleavage of the ester linkage (Coats et al. 1989). Fenvalerate and the IS-isomers yield two ester metabolites in feces from hydroxylation at the 4 - and 2 -phenoxy positions. Other significant metabolites were 3-phenoxybenzoic acid and its hydroxy derivatives from the alcohol moiety, 3-(4-chlorophenyl) isovaleric acid and its hydroxy derivatives from the acid moiety, and thiocyanate and carbon dioxide from the cyano moiety (Ohkawa et al. 1979). A slow elimination rate characterizes fenvalerate and other a-cyano pyrethroids when compared with... 

Effect of Cation Used for the Adjustment of Modifying pH on EDA of (S)-2-Hydroxy isovaleric Acid-MRNi°... 

The carbodiimide method has been employed in several syntheses of depsipeptides. However, direct application of DCC for the formation of the ester bond between the amino acid and hydroxy acid components under the usual conditions of amide coupling affords the desired depsipeptides in acceptable yields only in the case of unhindered co-hydroxy units [54] or an active hydroxy group, such as in TV-benzoyl-u-hydroxyglycine benzyl ester. For example, Ravdel et al.[55 have performed the esterification of various benzyloxycarbonyl- and phthalylamino acids with /V-benzoyl-a-hydroxyglycine benzyl ester with DCC in 50-65% yield. On the other hand, Shemyakin et all21 failed to obtain the expected depsipeptide products on condensation of bulky benzyloxycarbonyl- or phthalylvaline with a-hydroxy-isovaleric acid benzyl ester. The main product was acylurea in the first case and phthalylvaline anhydride in the second. Thus, the classical carbodiimide procedure could not be applied in practical depsipeptide preparation. 

Individuals who are deficient in HMG-CoA lyase are unable to complete the metabolism of leucine. The increased urinary excretion of 3-hydroxy-3-methylglutaric acids is the primary biochemical criterion that distinguishes this particular enzymatic defect from other defects in enzymes of leucine catabolism that also result in metabolic acidosis and abnormal organic aciduria. There is also substantial urinary excretion of intermediates of leucine catabolism, such as 3-methylglutaconic acid, and their metabolites, including 3-hydroxy-isovaleric acid produced from isovaleric acid. 

Hydroxy-isovaleric acid (hydration products of 3-methylcrotonic acid) 3-Methylcrotonyl glycine... 

Biotin deficiency in experimental animals is teratogenic, and a number of the resultant birth defects resemble human birth defects. Up to half of pregnant women have elevated excretion of 3-hydroxy-isovaleric acid (Section 11.4), which responds to supplements of biotin, in the first trimester, suggesting that marginal stams may be common in early pregnancy and may be a factor in the etiology of some birth defects. This may be the result of increased catabolism of biotin as a result of steroid induction of biotin catabolic enzymes there is increased excretion of bisnorbiotin and biotin sulfoxide (Zempleni and Mock, 2000a Mock et al., 2002). 

Reduced activity of methylcrotonyl CoA carboxylase (Section 11.2.1.4) results in the formation and excretion of 3-hydroxy-isovaleric acid in experimental biotin depletion, significant amounts of 3-hydroxy-isovaleric acid are excreted at the same time as the excretion of biotin and bisnorbiotin falls, before there is any change in the plasma concentration of biotin (Mock et al., 1997). 

Diazonamide A is a potently antimitotic natural product and its penultimate step involves the coupling of macrocyclic amine 104 with (5)-a-hydroxy isovaleric acid and DEPC in 90% yield.46-41... 

Athamantin. 3-Methyibutanoic acid 8,9-dihydro-8-fl-m ethyl-I-(3-me thy i-I -oxobutoxy)ethylJ-2-oxo-2H-furo[2,3-h]-l. benzopyran-9-yl ester isovaleric acid diester with 8,9-dihydro-9-hydroxy-8-(l-hydroxy-l-methyUihyl)-... 

Several fungal metabolites have been found which enhance the passive uptake of potassium. Some, like nonactin and monactin 14.6), are macro-tetrolides others, like valinomycin, are depsipeptides. Valinomycin 14.7) (from Streptomycesfulvissimus) is a macrocycle composed of three residues of each of L-valine, D-valine, L-lactic acid, and D-a-hydroxy-isovaleric acid, linked alternatively by ester and amide bonds to form a 36-membered ring (Shemyakin... 

A soln. of D-valyl-D-a-hydroxyisovaleryl-D-valyl-D-a-hydroxyisovaleric acid in aq. 50%-alcohol refluxed 20 hrs. D-a-hydroxyisovaleryl-D-valyl-D-a-hydroxy-isovaleric acid. Y 69%. F. e. s. M. M. Shemyakin et al., 34, 1782 (1964) G. A. 61, 10774d. 

The kutzneride cluster encodes three multidomain NRPS proteins, KtzE, KtzG, and KtzH, that make up the six required modules. KtzE activates o-MecPG and catalyzes its condensation with the hydroxy acid, which is activated by the A domain of KtzG. KtzG adenylates 2-keto-isovaleric acid and, after in situ reduction of the keto function by the KR domain, a methyltransferase forms the t-butyl group. Whether the... 

To allow estimation of human biotin requirements and evaluation of potential deleterious efiects of marginal degrees of biotin deficiency, indicators of biotin status need to be determined and validated. Several explored directions include serum concentrations and urinary excretion rates of biotin and biotin metabolites, activities of the biotin-dependent decarboxylases in peripheral blood mononuclear cells, and urinary excretion rates of 3-hydroxy-isovaleric acid 3-methylcrotonyl glycine and 2-methylcitric acid. 

Not only aldehydes are of enormous importance as constituents of flavoring mixtures, but so also are products that can be easily derived from these compounds such as hemiacetals, acetals, or carboxylic acid esters (Scheme 6.1). Noteworthy, lower carboxylic acids (e.g., isovaleric acid [11], 3-hydroxy-3-methylhexanoic acid) [12] emerging from human body or in household have malodourous properties [13]. However, some of them are widely used as... 

Sweaty feet Isovaleric acid Isovaleric acidemia 3-Hydroxy-3-methylglutaric aciduria MAD... 

I sovaleryl glycine Isovaleric add S -Hydroxy isovaleric acid C5-Hydroxyacylcarniti ne... 

Zhang Z, Talleyrand V, Rathmacher J, Nissen S. Change in plasma P-hydroxy-P-methylbutyrate (HMB) by feeding leucine, alpha-ketoisocaporate (KIC) and isovaleric acid (IVA) to pigs. FASEB J 1993 1-.A391 (abstract). 

Onchidin is cyclo(Meval-Amo-Val-Hiv-Hiv-MevabAmo-VabHiv-Hiv). It is the first example of a dimeric depsipeptide isolated from a mollusk. Meval is N-methylvaline and Hiv is 2-hydroxy-isovaleric acid. 

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