3-Hydroxy-4-methyl valerate

Hydroxybutyrate 3-Hydroxyhexanoate 3-Hydroxy-4-methyl valerate 3-Hydroxyvalerate Infrared... 

Recently, two new beauvericins were discovered [56], These beauvericins are composed of L-phenylalanine, D-2-hydroxy-3-methyl-valerate, and D-2-hydroxyisovalerate, yielding mixed-type structures. 

Fig. 3.22. GC separation of keto and hydroxy acids from the urine of a patient with maple syrup urine disease. Top chromatogram, the patient before dietary treatment middle chromatogram, the same patient after two days on a diet bottom chromatogram, a mixture of reference compounds. Peaks 1, lactic acid 2, 2-hydroxyisobutyric acid 3, 2-hydroxybutyric acid 4, pyruvic acid 5, 3-hydroxyisobutyric acid 6, 3-hydroxybutyric acid 7, 2-hydroxyisovaleric acid 8, 2-ketobutyric acid 9, malonic acid (internal standard) 10, 2-methyl-3-hydroxybutyric acid 11, 2-hydroxy-n-valeric acid 12. methylmalonic acid 13, 3-hydroxyisovaleric acid 14a and b, 2-ketoisovaleric acid IS, acetoacetic add 16, 2-hydroxyisocaproic acid 17, 2-hydroxy-3-methylvaleric acid 18a, L-2-keto-3-methylvaleric add 18b, D-2-keto-3-methyl-valeric acid 19, 2-ketoisocaproic acid. Reproduced from [386],...

Following the ketol condensation to yield a-acetolactate and a-aceto-a-hydroxybutyrate the question arises as to whether the pinacol rearrangement occurs first to form a-keto-jS-hydroxyisovaleric acid and a-keto-i9-hydroxy- 8-methylvaleric acid (Fig. 7, III), or whether there is prior reduction. The evidence favoring pinacol rearrangement followed by reduction of the a-keto- 3-hydroxy acids is that enzymes have been found in Neurospora and E. coli which catalyze the reduction of synthetically prepared a-keto-(8-hydroxyisovaleric acid and a-keto-j8-hydroxy-/3-methyl-valeric acid to the corresponding a,/8-dihydroxy acids (166, 167). 

Figure 1 Urinary organic acid chromatogram of a patient with propionic acidemia. Peak A is 3-hydroxypropionic acid, B is 2-methyl-3-hydroxybutyric acid, C is 3-hydroxy-iso-valeric acid, D is 3-hydroxy-/7-vaieric acid, peaks E represent propionylglycine, peak F is tigiyigiycine, peaks G are methyicitric acid. IS = internal standard (tricarballylic acid).

V-Fmoc-(2S,3S,4/ )-4-amino-3-hydroxy-2-methyl-valerate 117, protected histidine analog 118, and Boc pyrimidoblamic acid 119. Final deprotection and cleavage released bleomycin A5 120 (Scheme 3.23). 

Fig. 10.1 Metabolites in the urine of an untreated patient with branched-chain keto aciduria (maple syrup urine disease). Extracted using ethyl acetate and separated as their trimethylsilyl-oxime derivatives on a 25 m SE-30 capillary column, using temperature programming from 80°C to 110°C at 0.5°C min and an injection split ratio 1 12 at a temperature of 250°C. The peaks marked R are due to solvent and reagents. Peak identifications are 1, lactic 2, 2-hydroxyisobutyric 3, 2-hydroxybutyric 4, pyruvic 5, 3-hydroxybutyric 6, 2-hydroxyisovaleric 7, 2-oxobutyric 8, 2-methyl-3-hydroxy-isovaleric 10, a and b, 2-oxoisovaleric 11, acetoacetic 12, 2-hydroxyisocaproic 13, 2-hydroxy-3-methyl- -valeric 14, 2-oxo-3-methyl-/i-valeric (14a L- 14b D-) 15, 2-oxoisocaproic acids. The internal standard was malonic acid. (Redrawn with modifications from Jellum etal., 1976)...

Hydroxy-n-valeric acid is perhaps the most frequently observed urinary metabolite after methylcitrate and 3-hydroxypropionate, and 3-oxo-/r-valeric acid may also occur during severe ketosis. During non-ketotic periods, when propionyl-CoA accumulation still occurs, two molecules of this substrate may condense via the action of a j3-ketothiolase to form 2-methyl-3-oxovaleryl-CoA, resulting ultimately in the excretion of 2-methyl-3-hydroxyvaleric and 2-methyl-3-oxovaleric acids in the urine (Lehnert et ai, 1978 Truscott et al., 1979). The occurrence of these keto acids explains the presence of long-chain ketones in the urine, formed by decarboxylation in an analogous manner to the formation of acetone from acetoacetate (Fig. 11.6). 

Truscott, R. J.W., Pullin, C.J., Halpern, B., Hammond, J., Haan, E. andDanks, D.M. (1979), The identification of 3-keto-2-methylvaleric acid and 3-hydroxy-2-methyl-valeric acid in a patient with propionic acidemia. Biomed. Mass Spectrom., 6,294. 

CiiHnNO 84080-68-2) see Cefixime 17,21-(l-butyl-l-methoxymcthylenedioxy)-3,20-dioxo-9-fluoro-lip-hydroxy-l(Sa-methyl-l,4-pregnadiene (C2gH3gF06 1062-64-2) see Dexamethasone valerate S-(crt-butyl 3-methyl 2,6-dimethyl-4-(3-nitrophenyl)-l,4-dihydropyridine-3,5-[Pg.2319]

P-METHYL-8-VALEROLACTONE (Valeric acid, 5-hydroxy-3-methyl-, 8-lactone)... 

In 1941 Gakhokidze40 realized a different type of Grignard synthesis on a carbohydrate acid derivative. Methyl L-ery(liro-3,4,5-trimethoxy-2-oxovalerate (XXXII), was treated with one mole of methylmagnesium iodide to produce methyl 2-methyl-2-hydroxy-L-er /(firo-3,4,5-trimethoxy-valerate (XXXIII). The configuration of the second carbon atom in... 

Benzyloxy-3-hydroxy-3-methylpentanoic-2-13C acid Valeric-2-13C acid, 5-benzyloxy-3-hydroxy-3-methyl- (8) Pentanoic-2-,3C acid, 3-hydroxy-3-methyl-5-(phenylmethoxy)- (9) (57830-65-6) Acetic-2-13C acid (8,9) (1563-80-0)... 

Wang used reactive-extrusion polymerization with 2,5-di-methyl-2,5-di-t-bu-tylperoxy hexane to prepared a graft copolymer, (11), by free radically grafting polyethylene-glycol malonic acid onto the biodegradable substrate of poly((3-hydroxybutyrate-co- p-hydroxy valerate). 

Esters.— The simplest class of compounds present in essential oils are the esters or ethereal salts (p. 140). In our early discussion of these compounds in the aliphatic series it was stated that the odor and flavor of common fruits is probably due to ester compounds and that certain empirical mixtures of esters are used as artificial fruit essences. Artificial apple essence, for example, may be prepared by mixing certain proportions of ethyl nitrite, ethyl acetate and amyl valerate with chloroform, aldehyde and alcohol. An example of an essential oil which consists of a single ester is oil of wintergreen. vAdxh is the methyl ester of salicylic acid, ortho-hydroxy benzoic acid (p. 714). 

Valeric acid, a-ACETYL- -CHLORO-7-HYDROXY-, y-LACTONE, 31, 1 5-HYDROXY-3-METHYL, 5-LACTONE,... 

Valeric acid, a-ACETYL-5-CHLORO-y-HYDROXY-, 7-LACTONE, 31, 1 S-HYDROXY-3-METHYL-5-LACTONE, 35, 86... 

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