O-isobutyrylation

IbOpamine, 2 Methylpropanoic acid 4-[2-(methyf-amino)ethyl]-l,2-phenylene ester 4-[2-(methylammo)ethylj-ophenylene diisobutyrate N-methyldopamine diisobutyric ester 3,4-di-o-isobutyryl epinine, C H NO mol wt... 

Methylpropanoyl) 4-O-Isobutyryl-L-oUvomycose C11H20O5 232.276 Glycoside residue from Olivomycin A. 

FIGURE 24.26 Branched-chain fatty acids are oxidized by o -oxidation, as shown for phytanic acid. The product of the phytanic acid oxidase, pristanic acid, is a suitable substrate for normal /3-oxidation. Isobutyryl-CoA and propionyl-CoA can both be converted to suc-cinyl-CoA, which can enter the TCA cycle. 

Polyethylenimine with 10% of residues acylated by butyryl (O) or isobutyryl ( ) groups. 

An, Angeloyl BAn, 3-bromoangeloyl DMB, 2,3-dihydroxy-2-methylbutyryl eDMB, (+)-e,o,JliTO-2,3-dihydroxy-2-methylbutyryl HMB, 2-hydroxy-2-methylbutyryl iB, isobutyryl K, ketone MB (-)-2-methylbutyryl Py, pyridine tDMB, (+ )-riireo-2,3-dihydroxy-2-methylbutyryl TDMB, 2-hydroxy-2-methyl-3-p-toluenesulfonylbutyryl Ts, p-toluenesulfonyl. b Attached carbon epimerized. c Cf, Chloroform. 

Di-iso-butyryl Peroxide (called Diisobutyryl-peroxyd in Ger), (CH3)2CH.CO.OO.CO.CH(CH3)2 mw 174.19, O 36.74% gas, dec vigorously at 110-20° (20° higher than the n-butytyl deriv) when heated in a tube (Ref 2) was prepd by reacting isobutyryl chloride with Na peroxide in cold eth or petr eth (Ref 1). Smid Szwarc (Ref 3) studied its kinetics of decompn Refs 1) Beil 2, 653l 2) A.E. Oxford, JCS... 

Poston (1984) showed that, in isolated rat tissues, about 5% of the catabolic flux of leucine was by way of timinomutase action to yield / -leucine, and then isobutyryl CoA, with the remainder provided by the more conventional O -transamination pathway leading to the formation of isoveileryl CoA. In patients suffering from vittimin B12 deficiency, there is an elevation of plasma / -leucine, suggesting that the aminomutase may act to metabolize / -leucine arising from intestinal bacteria, rather than as a pathway for leucine catabolism. 

Figure 2 HPLC elution profile of I and d-amino acids from freshly prepared apple juice (Golden Delicious) derivatized as the isoindoles with (A) o-phthaldialdehyde-W-isobutyryl-l-cysteine (B) o-phthaldialdehyde-Af-isobutyryl-d-cysteine Column Hypersil ODS (250 X 4 mm 5 pm mobile phase, gradient elution (A) = 23 mmol I" sodium acetate (pH 5.95) (B) methanol-acetonitrile (600 50 v/v), linear gradient from 0% B to 53.5% B in 75min flow rate 1 ml min"fluorescence detection (230nm excitation, 445nm emission). (Reprinted with permission from Bruckner H, Haasmann S, Langer M, Westhauser T, and Wittner R (1994). Journal of Chromatography A 666 259-273 Elsevier.)...

This is the indirect approach for the chromatographic separation of enantiomers. The reaction of the two forms of an enantiomer with an optically pure chiral reagent gives a mixture of diastereoisomers that are not mirror images of each other and therefore can be separated on a nonchiral, common LC phase. This is shown in Figure 4 where amino acids have been derivatized with o-phthaldialdehyde and N-isobutyryl-... 

Also obtained by reaction of isobutyryl chloride with o-cresol in the presence of aluminium chloride [8107],... 

Synthesis of the oligo(nucleoside O-isopropyl phosphates) required preparation of 5 -DMT-nucleoside (N-protected with standard conventional groups) 3 -0- (0- isopropyl )M iV-diisopropylphosphoramidites. They appeared to be easily incorporable into the growing oligonucleotide chain at preselected position(s), and conditions required for the removal of / -protective groups (N -benzoyl of adenosine, N -ben-zoyl of cytidine, and N -isobutyryl of guanosine), and (9-methyl or 0-2-... 

Felix L, Hernandez J, Arguelles-Monal WM et al (2005) Kinetics of gelation and thermal sensitivity of N-isobutyryl chitosan hydrogels. Biomacromolecules 6 2408-2415 Zhang J, Chen XG, Li YY et al (2007) Self-assembled nanoparticles based on hydrophobi-cally modified chitosan as carriers for doxorubicin. Nanomed Nanotechnol 3 258-265 Tong YJ, Wang SF, Xu JW et al (2005) Synthesis of O, O -dipahnitoyl chitosan and its amphiphilic properties and capability of cholesterol absorption. Carbohyd Poiym 60 229-233... 

Bruckner, H., Wittner, R., and Godel, H., FuUy automated HPLC separation of DL-amino acids derivatized with O-phthaldialdehyde together with A-isobutyryl-cysteine Application to food samples, Chromatographia, 32, 383, 1991. 

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