3- propionyl acyl group

The 3-(3-pyridyl)propionyl acyl group is a convenient acyi group for protease cataiyzed hydrolj is. This resolution of a chiral sulfur compound uses chymotrypsin, but subtilisin can also be used. 

Consideration of rotatory powers of l,l-bis(acylamido)-l-deoxy-alditols showed79 certain correlations between optical rotation (d line of sodium) and configuration that can be summarized as follows. (a) When the acyl group is aliphatic (for example, acetyl or propionyl), the alditol will be dextrorotatory in water if the configuration of C-2 is S. (The rule does not apply to peracetylated derivatives.) (b) When the two substituents on C-l are benzamido and the configuration at C-2 is S, a solution of the alditol in pyridine will be levorotatory. Peracetylation does not alter applicability of this rule, (c) The abso-... 

While CoA was discovered as the "acetylation coenzyme," it has a far more general function. It is required, in the form of acetyl-CoA, to catalyze the synthesis of citrate in the citric acid cycle. It is essential to the P oxidation of fatty acids and carries propionyl and other acyl groups in a great variety of other metabolic reactions. About 4% of all known enzymes require CoA or one of its esters as a substrate.4... 

Branched carbon skeletons are formed by standard reaction types but sometimes with addition of rearrangement steps. Compare the biosynthetic routes to three different branched five-carbon units (Fig. 17-19) The first is the use of a propionyl group to initiate formation of a branched-chain fatty acid. Propionyl-CoA is carboxylated to methylmalonyl-CoA, whose acyl group is transferred to the acyl carrier protein before condensation. Decarboxylation and reduction yields an acyl-CoA derivative with a methyl group in the 3-position. 

After the challenge of the dynamic thiolester system (CDS-1 A) with acetylcholinesterase, the optimal constituents were immediately identified and hydrolyzed to acid and thiol products. The thiol product formed was simultaneously incorporated in the dynamic system to regenerate the optimal thiolester. During the acetylcholinesterase resolution process, two acid products, acetic and propionic acid, respectively, were mainly detected, with the acetyl ester hydrolyzed more rapidly (tl/2 = 210 min) than the propionyl ester (t1/2 = 270 min) as shown in Fig. 2. Only after significant hydrolysis of these two acyl species did the enzyme start to hydrolyze slowly the butyrate thiolester (t1/2 = 1,100 min), a lag phase possibly caused by inhibitory activities of the present thiolesters [8]. All the other acyl groups remained untouched by enzyme, a result which is in accordance with the known specificity of acetylcholinesterase. 

Acylation of free hydroxyl at C-7 in paclitaxel usually led to the reduction and even loss of cytotoxicity of the derivatives, when steric hindrance of the acyl groups increases. Bhat et al. have used a parallel solution phase synthetic method to construct a 26-membered library of C-7 esters, and concluded that modification at C-7 were detrimental to cytotoxicity against the MCF-7 cell line. Only a few exceptions, including 10-deacetyl-lO-propionyl-7-chloroacetyl... 

Malonyl transacylase is highly specific, whereas acetyl transacylase can transfer acyl groups other than the acetyl unit, though at a much slower rate. Fatty acids with an odd number of carbon atoms are synthesized starting with propionyl ACP, which is formed from propionyl CoA by acetyl transacylase. 

The coenzyme form of pantothenic acid is coenzyme A and is represented as CoASH. The thiol group acts as a carrier of acyl group. It is an important coenzyme involved in fatty acid oxidation, pyruvate oxidation and is also biosynthesis of terpenes. The epsilon amino group of lysine in carboxylase enzymes combines with the carboxyl carrier protein (BCCP or biocytin) and serve as an intermediate carrier of C02. Acetyl CoA pyruvate and propionyl carboxylayse require the participation of BCCP. The coenzyme form of folic acid is tetrahydro folic acid. It is associated with one carbon metabolism. The oxidised and reduced forms of lipoic acid function as coenzyme in pyruvate and a-ketoglutarate dehydrogenase complexes. The 5-deoxy adenosyl and methyl cobalamins function as coenzyme forms of vitamin B12. Methyl cobalamin is involved in the conversion of homocysteine to methionine. 

Acyl groups Formyl Acetyl Propionyl Palmitoyl Oleoyl Stearoyl... 

ACTH adrenocorticotrophic hormone, actin cytoskeletal protein, acyl group such as acetyl, propionyl, etc. acylation addition of an acyl group. 

Efforts to introduce larger acyl groups, such as propionyl and butyryl, into the 3-position of chromium and cobalt acetylacetonates failed, probably because steric hindrance by the 2- and 4-methyl groups allowed the chelate ring to be degraded rather than substituted. On the other hand, the increased stability of the rhodium(III) acetylacetonate permitted the synthesis of monobenzoyl, dibenzoyl, and monobutyryl acetylacetonates under Friedel-Crafts reaction conditions (56). 

Acyl derivatives of perhydro-l,4-dioxopyrrolo[l,2-a]pyrazines are rapidly hydrolyzed to the 2-unsubstituted compounds under very mild conditions. The 2-pyruvoyl compound 86 loses the N-acyl group on boiling in water or methanol, on treatment with ammonia in methylene chloride, on exposure to dilute sodium hydroxide solution, and on treatment with p-toluidine at 50-60° for 30 sec. Similarly the methoxy-propionyl compound 142 is extremely sensitive to alkali, immediately reacting with 0.1 M sodium hydroxide solution at 0°. This compound is also deacylated by ammonium hydroxide solution in a few minutes or by sodium bicarbonate solution after several hours. This behavior contrasts sharply with that of the isomeric oxazolo compound 143 and helps to justify the tricyclic formulation adopted for such compounds. Hydrolysis of the 3S,8aS isomer of compound 142 is accompanied by rapid inversion... 

Both in vitro and in vivo activity is reduced by an increase in the acyl group length in the 2 -0-acyl derivatives. The MIC values of the 2 -0-acetyl and 2 -0-propionyl derivatives are nearly the same as that of the parent antibiotic. Because the 2 -0-acyl is easily hydrolyzed in aqueous solution, the potent antibacterial activity has been explained by the hydrolysis of 2 -0-acyl group during bioassays. For this reason, the 2 -hydroxyl group has been considered to be one of the functional groups essential for the biological activity of the macrolide. 

Verdini and coworkers [122] have introduced the 2-methyl-2-(2 -ni-tro)phenoxy-propionyl (Mnp) group for the preparation of stable monopro-tected gem-diamino alkyl residues 27 via IBTFA treatment of the carboxamide precursor 26. The precursor 26 is prepared by coupling amino a-carboxamide and 2-methyl-2-(2 -nitro)phenoxy-propionic acid as its O-succinimidyl ester 25. Hydrochloride salts, such as 27, are generally stable, crystalline compounds that can be stored at room temperature for several months. Once deprotonated, 27 is stable enough for acylation reactions (Scheme 9) [122]. 

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