Butyryl-/isobutyryl

Exceptions formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, oxalyl, malonyl, succinyl, glutaryl, furoyl, and thenoyl. 

C4 Butyryl-/ Isobutyryl- SCAD deficiency, IBDH deficiency, GA-2, EE... 

N. glutinosa L. Leaf (cuticular com- 2,3,4 and 2,3,4,3 ponents) Acetyl, propionyl, n-butyryl, isobutyryl, 2-methylbutyryl, 3-methylbutyryl, valeroyl, 3-methylvaleroyl, 4-methylva-leroyl, hexrmoyl, 4-methylhexanoyl, 5-methylhexanoyl, heptanoyl, 6-methylheptanoyl, octanoyl Arrendale et al. 1990... 

The commercially important normal to branched aldehyde isomer ratio is critically dependent on CO partial pressure which, in propylene hydroformylation, determines the rate of interconversion of the -butyryl and isobutyryl cobalt tetracarbonyl intermediates (11). 

In contrast to triphenylphosphine-modified rhodium catalysis, a high aldehyde product isomer ratio via cobalt-catalyzed hydroformylation requires high CO partial pressures, eg, 9 MPa (1305 psi) and 110°C. Under such conditions alkyl isomerization is almost completely suppressed, and the 4.4 1 isomer ratio reflects the precursor mixture which contains principally the kinetically favored -butyryl to isobutyryl cobalt tetracarbonyl. At lower CO partial pressures, eg, 0.25 MPa (36.25 psi) and 110°C, the rate of isomerization of the -butyryl cobalt intermediate is competitive with butyryl reductive elimination to aldehyde. The product n/iso ratio of 1.6 1 obtained under these conditions reflects the equihbrium isomer ratio of the precursor butyryl cobalt tetracarbonyls (11). 

Koeberl DD, Young SP, Gregersen NS, Voddey J, Smith WE, Benjamin DK Jr, An Y, Weavil SD, Chaing SH, Bah D, McDonald MT, Kishnani PS, Chen YT, Millington DS. Rare disorders of metabolism with elevated butyryl- and isobutyryl-carnitine detected... 

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

Acylcobalt carbonyls formed from acyl halides appear to isomerize less readily. No isomerization was found using isobutyryl bromide or n-butyryl chloride in nonpolar solvents such as hexane or benzene. Some isomerization was found with diethyl ether and ethyl acetate as solvents, again promoted by absence of carbon monoxide. Curiously, no isomerization... 

The DEBS 1-TE multienzyme was purified to 90-95% homogeneity and then used in another series of experiments to establish the extent to which alternative starter units could be used by the polyketide synthase [36], Substantial amounts of lactones were obtained in the presence of acetyl-, n-butyryl-, and isobutyryl-CoA, illustrating that the loading didomain exhibits a relaxed specificity for the starter unit (Fig. 10). The utilization of acetyl-CoA and -butyryl-CoA by DEBS 1 + TE was demonstrated in a cell-free system [39], Additionally, in the absence of the reducing cofactor NADPH, cell-free DEBS 1+TE converted... 

Figure 10 Biosynthesis of triketide lactones in vitro by DEBS 1-TE. Incubation of propionyl-CoA or acetyl-CoA with methylmalonyl-CoA and NADPH in vitro resulted in synthesis of the appropriate lactones. The mini-PKS also accepted the unnatural starter units ra-butyryl-CoA and isobutyryl-CoA.

Figure 3.2 Extent of binding of methyl orange at pH 7.0 and 25 °C as a function of free (nonbound) dye concentration. (1) Polyethylenimine (PEI) with 8.4% of residues acylated by lauroyl groups. (2) PEI with 11.5% of residues acylated by hexanoyl groups. (3) PEI with 10% of residues acylated by butyryl or isobutyryl groups. (4) PEI-600. (5) Bovine serum albumin.

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... 

Palladium acyl complexes such as [Pd(COR)(MeCN)L2] BF4 or [Pd(COR)ClL2]/ AICI3 (L = PPh3) catalyze the isomerization of isobutyryl chloride to an equilibrium mixture with -butyryl chloride. The reaction probably proceeds via a palladium hydride intermediate which was not observed (Scheme 10). The turnover is slow up to 12.9 in 7 days. " Palladium cyclopropenylidene pyridine complexes (21) catalyze the isomerization of quadricyclane to norbomadiene at... 

Besides MMCM and GM, two other coenzyme B -dependent carbon skeleton mutases are known. These are (1) methylene glutarate mutase (MGM) from the anaerobe Eubacterium (Clostridium) barkeri, which catalyzes the equilibration of 2-methylene-glutarate with (R)-3-methylitaconate as part of a degradative path of nicotinic acid [175,199] and (2) isobutyryl-CoA mutase (ICM), which is observed in species of gram-positive bacteria Strep-tomyces and catalyzes the reversible rearrangement of iso-butyryl-CoA and n-butyryl-CoA [177]. The isomerization of iso-butyryl-CoA and n-butyryl-CoA in ICM is relevant in the biosynthesis of polyketide antibiotics [177]. 

The role of valine as a precursor to butyrate units in streptomycete metabolism has been observed in the biosynthesis of many secondary metabolites, such as tylosin and monensin (36,37). In these pathways, the valine is thought to be degraded to isobutyryl CoA, which is then isomerized to n-butyryl CoA. The stereochemistry of this latter isomerization has been investigated in vivo in Snreptomyces ctniurnionemis, the producer of the antibiotic monensin A (38). 

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