Selective biotransformation reactions on (±)-aryl alkyl ketones, (±)-benzoxazines, and d-arabino- and d-threo-hydroxyalkyltriazoles

2001 ◽  
Vol 73 (1) ◽  
pp. 167-174 ◽  
Author(s):  
◽  
Ashok K. Prasad ◽  
Najam A. Shakil ◽  
Virinder S. Parmar ◽  
Keyword(s):  
Carbonyl Group ◽  
Organic Solvents ◽  
Pancreatic Lipase ◽  
Candida Rugosa ◽  
Candida Antarctica ◽  
Diisopropyl Ether ◽  
Hydroxyl Group ◽  
Porcine Pancreatic Lipase ◽  
Secondary Hydroxyl ◽  
Primary Hydroxyl

The capabilities of porcine pancreatic lipase (PPL), Candida antarctica lipase (CAL), and Candida rugosa lipase (CRL) were evaluated for enantio- and/or regioselective acetylation/deacetylation of (±)-2,4-diacetoxyphenyl alkyl ketones, (±)-4-alkyl-3,4-dihydro-3-hydroxyalkyl-2H-1,3-benzoxazines, and d-arabino and d-threo-polyhydroxyalkyltriazoles in organic solvents. PPL in tetrahydrofuran (THF) exhibited high to moderate enantioselectivity during the deacetylation of (±)-2,4-diacetoxyaryl alkyl ketones and acetylation of (±)-3-hydroxyalkyl-2H-1,3-benzoxazines. Together with enantioselectivity, PPL in THF also showed exclusive regioselectivity for the deacetylation of para-acetoxy over the ortho-acetoxy function, with respect to the nuclear carbonyl group in 2,4-diacetoxyphenyl alkyl ketones. CAL in diisopropyl ether (DIPE) and PPL in THF exhibited exclusive selectivity for the acetylation of primary hydroxyl over secondary hydroxyl group(s) of d-arabino- and d-threo-polyhydroxyalkyltriazoles.

Recent Studies on the Application of Enzymes in the Synthesis of Polyesters

1990 ◽  
Vol 218 ◽  
Author(s):  
Cary J. Morrow ◽  
Eugenia M. Brazwell ◽  
Dianela Filos ◽  
Juanita Mercure ◽  
Rosemary Romero ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ambient Temperature ◽  
Organic Solvents ◽  
Pancreatic Lipase ◽  
Bound Water ◽  
Optically Active ◽  
Porcine Pancreatic Lipase ◽  
Dibenzyl Ether ◽  
High Boiling Solvent ◽  
Hydrolysis Of

AbstractEnzyme-catalyzed preparation of polymers offers several potentially valuable advantages over the usual polymerization procedures. This paper summarizes our successful use of lipase-catalyzed polycondensations to prepare both a series of achiral [AA-BB]x polyesters from bis(2,2,2- trichloroethyl) alkanedioates and diols and of an optically active, epoxy-substituted polyester having a stereochemical purity estimated to be greater than 96%, from racemic bis(2,2,2-trichloroethyl) trans-3,4-epoxyhexanedioate and 1,4-butanediol. All of the reactions were carried out at ambient temperature in anhydrous, low to intermediate polarity, organic solvents such as ether, THF, 2-ethoxyethyl ether, dibenzyl ether, o-dichlorobenzene, or methylene choride, using porcine pancreatic lipase (PPL) as the catalyst. The molecular weight achieved by the polycondensation is limited by accumulation of the trihaloethanol that forms as the reaction progresses, probably because it frees enzyme-bound water permitting hydrolysis of the polymer to occur. This problem has been alleviated by using a high boiling solvent and removing the alcohol by placing the re'action mixture under vacuum.

scholarly journals SYNTHESIS OF 1,2;3,4-DI-O-ISOPROPYLIDENE-6- O-[4-(1H-AZOL-1-YLMETHYL) PHENYL]- ¯-D-GALACTOPYRANOSE AND 1,2,3,4-TETRA-O-ACETYL-6- O-[4-(1H-AZOL-1- YLMETHYL)PHENYL]-¯-D-GLUCOPYRANOSE

2017 ◽  
Vol 17 (5) ◽  
pp. 122-128
Author(s):  
Z.P. Belousova ◽  
P.P. Purygin ◽  
A.P. Tyurin
Keyword(s):  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Secondary Hydroxyl ◽  
Primary Hydroxyl ◽  
Derivatives Of

Derivatives of D-galactose and D-glucose substituted for the primary hydroxyl group, which contain an aglycone azolylmethylphenyl fragments (for imidazole, 1,2,4-triazole, benzimidazole and benzotriazole) has been synthesized. Toprotect the secondary hydroxyl groups of monosaccharides acetyl and isopropylidene groups were used.

scholarly journals XIX. Polyhydroxylic Acceptors for the . ? -Glucosidase of Staohybotrys Atra

1966 ◽  
Vol 19 (6) ◽  
pp. 1153 ◽  
Author(s):  
MAJ ermyn
Keyword(s):  
Hydroxyl Group ◽  
Transfer Product ◽  
Group Transfer ◽  
Secondary Hydroxyl ◽  
Primary Hydroxyl ◽  
Order Of Magnitude

Transfer to polyols appears to take place principally to the terminal primary hydroxyl group. Transfer to the penultimate secondary hydroxyl group in any amount was only demonstrated for the pentitols, adonitol, and L-arabitol. Where the concentrations of the acceptor and the initial transfer product are of the same order of magnitude, there is measurable transfer to the initial transfer product to give molecules containing two glucosyl residues. Where all hydroxyls are secondary, as in myoinositol, no one transfer product predominates.

Porcine pancreatic lipase mediated selective acylation of primary alcohols in organic solvents

1990 ◽  
Vol 31 (24) ◽  
pp. 3405-3408 ◽  
Author(s):  
Sowmianarayanan Ramaswamy ◽  
Brian Morgan ◽  
Allan.C. Oehlschlager
Keyword(s):  
Organic Solvents ◽  
Pancreatic Lipase ◽  
Porcine Pancreatic Lipase ◽  
Primary Alcohols ◽  
Selective Acylation

Effect of Organic Solvents on Porcine Pancreatic Lipase Thermal Aggregation

2018 ◽  
Vol 24 (10) ◽  
Author(s):  
Mahsa Vaezzadeh ◽  
Marjan Sabbaghian ◽  
Parichehreh Yaghmaei ◽  
Azadeh Ebrahim-Habibi
Keyword(s):  
Organic Solvents ◽  
Pancreatic Lipase ◽  
Porcine Pancreatic Lipase ◽  
Thermal Aggregation

Biocatalytic Synthesis of Polyesters by Enzyme-Catalyzed Transesterification in Organic Media

1989 ◽  
Vol 174 ◽  
Author(s):  
Cary J. Morrow ◽  
J. Shield Wallace ◽  
Gregory M. Bybee ◽  
Kristin B. Reda ◽  
Mark E. Williams
Keyword(s):  
Ambient Temperature ◽  
Organic Solvents ◽  
Pancreatic Lipase ◽  
Optically Active ◽  
Organic Media ◽  
Porcine Pancreatic Lipase ◽  
Nmr Analysis ◽  
The Difference

AbstractEnzyme-catalyzed preparation of polymers offers several potentially valuable advantages over the usual polymerization procedures. This paper summarizes our successful use of lipase-catalyzed polycondensations to prepare both a series of achiral [AA-BBJx polyesters from simple bis(2,2,2- trichloroethyl) alkanedioates and diols and of an optically active, epoxy-substituted polyester having a stereochemical purity estimated to be greater than 96%, from racemic bis(2,2,2-trichloroethyl) trans- 3,4-epoxyhexanedioate and 1,4-butanediol. The somewhat less successful polycondensation of a series of A-B monomers is also described. All of the reactions were carried out at ambient temperature in anhydrous, low to intermediate polarity, organic solvents such as ether, THF, and methylene choride, using porcine pancreatic lipase (PPL) as the catalyst. Possible explanations for the difference between the A-B and AA + BB cases, based on NMR analysis of the reactions' progress are considered.

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