SEARCH · PubMed Health

Results for “PROPANEDIOLS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed2002

A quantitative model for predicting enzyme enantioselectivity: application to Burkholderia cepacia lipase and 3-(aryloxy)-1,2-propanediol derivatives.

We describe a new approach for predicting the enantioselectivity of enzymes towards racemic compounds. It is based on comparative binding energy (COMBINE) analysis. The approach is used to rationalise the enantioselectivity of Burkholderia cepacia lipase (BCL) towards thirteen racemic 3-(aryloxy)-1,2-propanediols in the process of acylation. According to our molecular modelling study the two 3-(aryloxy)-1,2-propanediols enantiomers bind in the BCL active site in different orientations. To derive a quantitative structure-activity relationship (QSAR), the difference in the interaction energy between two enantiomers with each amino acid residue was computed. These residue-based energy differences were then subjected to chemometric analysis and 3D QSAR models were derived. The models were able to unambiguously predict the fast-reacting enantiomer and the approximate magnitude of the enantioselectivity. The study enabled identification of interactions between the substrate and the lipase amino acid residues that play key roles in secondary alcohol enantiodifferentiation. From the results, it was possible to propose modifications of both, substrate and protein, which would directionally modify enantioselectivity of BCL towards secondary aryl-alcohols.

Acetylation↗

PubMed1999

Asymmetric reduction of hydroxyacetone to propanediol in immobilized halotolerant microalga Dunaliella parva.

Cells of the halotolerant microalga Dunaliella parva immobilized in calcium-alginate gel showed morphological characteristics and photosynthetic activity similar to those of free cells. The photosynthetic activity in immobilized cells fell only about 20% during 2 weeks incubation at 5 degrees C in the light. The asymmetric reduction of hydroxyacetone to (R)-propanediol was first examined in batch reactions with both free and immobilized cells. Since the activity of immobilized cells was as high as that of free cells, the optimum conditions for the column reactor were investigated using immobilized cells. The productivity of propanediol in immobilized cells increased in proportion to increases in the light intensity, suggesting that NADPH regenerated through photosynthesis was used for the asymmetric reduction. Electron microscopic observation of thin sections of immobilized cells after the reaction suggested that NADPH used for asymmetric reduction in the dark was produced through the metabolism of starch granules. The use of a CaCO3-free medium in the column reactor markedly prolonged the period of reductive activity and photosynthesis.

Journal Article↗

PubMed1975

Diol lipids of rat liver. Quantitation and structural characteristics of neutral lipids and phospholipids derived from ethanediol, propanediols, and butanediols.

Specific enzymatic and chemical degradation of neutral lipid and phospholipid fractions from rat liver revealed the presence of novel types of lipid metabolites bearing a short-chain diol backbone. Diol-derived lecithin and cephalin analogs were readily cleaved by phospholipase C (EC 3.1.4.3) from Bacillus cereus, although the cephalin analogs required "carrier" lecithin to sustain hydrolysis. The products of phosphilipase hydrolyses as well as the neutral lipid fractions were subjected to alkaline and acidic methanolysis, and constituent short-chain diols were analyzed as long-chain cyclic acetals. Gas chromatographymass spectrometry confirmed that 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, and 1,3 butanediol can form the polyol backbone of neutral lipids and phospholipids. [1,1,2,2-2H]Ethanediol monohexadecanoate, dihexadecanoate, hexadecanoylphosphorylcholine, hexadecanoylphosphorylethanolamine were synthesized chemically and served as internal standards to assure accurate quantitation of the low levels of diol lipids (350 mug/g ot total lipid) present in rat liver.

Animals↗

PubMed1979

Antiestrogens and antiestrogen metabolites: preparation of tritium-labeled (+/-)-cis-3-[p-(1,2,3,4-tetrahydro-6-methoxy-2-phenyl-1-naphthyl)phenoxyl]-1,2-propanediol (U-23469) and characterization and synthesis of a biologically important metabolite.

The Upjohn antiestrogen (+/-)-cis-3-[p-(1,2,3,4-tetrahydro-6-methoxy-2-phenyl-1-naphthyl)phenoxy]-1,2-propanediol (2b, U 23469) has been prepared in tritium-labeled form by reduction of an unsaturated dihydronaphthalene precursor with carrier-free tritium gas over a palladium catalyst followed by alkylation with 3-iodo-1,2-propanediol. After extensive chromatographic purification, the final material was obtained with a specific activity of 13 Ci/mmol and a radiochemical purity of 94%. In vivo studies with immature rats show that [3H]2b is slowly converted to a more polar metabolite that is selectively accumulated in the nuclear fraction of the uterus where it is bound to the estrogen receptor. Chromatographic comparisons indicate that this metabolite is the demethylated analogue 2c, a compound that has an affinity for estrogen receptor more than 300 times greater than that of 2b. These studies suggest that the demethylated analogue 2c may be a biologically important metabolite of 2b that is involved in the action of this antiestrogen.

Animals↗

PubMed2004

Selective oxidation of polyfunctional 2-amino-1,3-propanediol derivatives.

Oxidation of polyfunctional threo-(1S,2S)-2-amino-1,3-propanediol derivatives with a 717 anion-exchange resin-supported bromine has been investigated. The result showed that oxidized products were in close relationship with the substituents at nitrogen in the starting materials. Its primary and secondary amine derivatives were oxidized in the presence of Na(2)HPO(4) to give essentially a substituted chiral oxazoline or C(3)-O acylated product in high yield, while oxidation of its N,N-dimethyl derivative mainly gave a chiral N-methyl oxidation-formylation product. This selective oxidation was first observed in 2-amino-1,3-propanediol chemistry.

Journal Article↗

PubMed2001

The first bovine beta 1,4-galactosyltransferase reaction with an acyclic acceptor substrate, 3-acetamido-1,2-propanediol, to yield a 3-O-beta-D-galactopyranosyl-sn-glycerol skeleton.

[figure: see text] Reactivity of bovine beta 1,4-galactosyltransferase was examined for a series of acyclic acceptor substrates both in the presence and the absence of alpha-lactalbumin (alpha-La). It was found that this enzyme could utilize (R)-3-acetamido-1,2-propanediol (1) as an acceptor substrate regardless of the cofactor protein. The product was determined to be 1-O-beta-D-galactopyranosyl-(R)-3-acetamido-1,2-propanediol (2). Glycerol without the acetamido group was inactive, indicating that this functional group plays a key role in the enzyme reaction.

Animals↗

PubMed2004

1,3-Propanediol production by Klebsiella pneumoniae under different aeration strategies.

1,3-Propanediol production by Klebsiella pneumoniae was studied in batch cultures under N2 flow and four airflow systems. Different byproducts were formed under different aeration conditions. An anaerobic/aerobic combined fed-batch culture was developed giving 70 g 1,3-propanediol l(-1) and 16 g 2,3-butanediol l(-1) with total diol yield of 0.6 mol(-1) glycerol.

Aerobiosis↗

PubMed1998

Site-directed mutagenesis studies of the metal-binding center of the iron-dependent propanediol oxidoreductase from Escherichia coli.

The amino acid residues involved in the metal-binding site in the iron-containing dehydrogenase family were characterized by the site-directed mutagenesis of selected candidate residues of propanediol oxidoreductase from Escherichia coli. Based on the findings that mutations H263R, H267A and H277A resulted in iron-deficient propanediol oxidoreductases without catalytic activity, we identified three conserved His residues as iron ligands, which also bind zinc. The Cys362, a residue highly conserved among these dehydrogenases, was considered another possible ligand by comparison with the sequences of the medium-chain dehydrogenases. Mutation of Cys362 to Ile, resulted in an active enzyme that was still able to bind iron, with minor changes in the Km values and decreased thermal stability. Furthermore, in an attempt to produce an enzyme specific only for the zinc ion, three mutations were designed to mimic the catalytic zinc-binding site of the medium-chain dehydrogenases: (1) V262C produced an enzyme with altered kinetic parameters which nevertheless retained a significant ability to bind both metals, (2) the double mutant V262C-M265D was inactive and too unstable to allow purification, and (3) the insertion of a cysteine at position 263 resulted in a catalytically inactive enzyme without iron-binding capacity, while retaining the ability to bind zinc. This mutation could represent a conceivable model of one of the steps in the evolution from iron to zinc-dependent dehydrogenases.

Alcohol Oxidoreductases↗

PubMed1992

Oligonucleotide labeling methods. 3. Direct labeling of oligonucleotides employing a novel, non-nucleosidic, 2-aminobutyl-1,3-propanediol backbone.

Novel CE-phosphoramidite (7a-e) and CPG (8a, c, d, e) reagents have been prepared from a unique 2-aminobutyl-1,3-propanediol backbone. The reagents have been used to directly label oligonucleotides with fluorescein, acridine, and biotin via automated DNA synthesis. The versatile 2-aminobutyl-1,3-propanediol backbone allows for labeling at any position (5', internal, and 3') during solid phase oligonucleotide synthesis. Multiple labels can be achieved by repetitive coupling cycles. Furthermore, the 3-carbon atom internucleotide phosphate distance is retained when inserted internally. Using this method, individual oligonucleotides possessing two and three different reporter molecules have been prepared.

Automation↗

PubMed2002

Lactobacillus diolivorans sp. nov., a 1,2-propanediol-degrading bacterium isolated from aerobically stable maize silage.

Inoculation of maize silage with Lactobacillus buchneri (5 x 10(5) c.f.u. g(-1) of maize silage) prior to ensiling results in the formation of aerobically stable silage. After 9 months, lactic acid bacterium counts are approximately 10(10) c.f.u. g(-1) in these treated silages. An important subpopulation (5.9 x 10(7) c.f.u. g(-1)) is able to degrade 1,2-propanediol, a fermentation product of L. buchneri, under anoxic conditions to 1-propanol and propionic acid. From this group of 1,2-propanediol-fermenting, facultatively anaerobic, heterofermentative lactobacilli, two rod-shaped isolates were purified and characterized. Comparative 16S rDNA sequence analysis revealed that the newly isolated bacteria have identical 16S rDNA sequences and belong phylogenetically to the L. buchneri group. DNA-DNA hybridizations, whole-cell protein fingerprinting and examination of phenotypic properties indicated that these two isolates represent a novel species, for which the name Lactobacillus diolivorans sp. nov. is proposed. The type strain is LMG 19667T (= DSM 14421T).

1-Propanol↗

PubMed1980

The isolation and characterization of a 1,2-propanediol oxidoreductase from Neisseria gonorrhoeae.

An enzyme which oxidizes 1,2-propanediol in the presence of NAD+ has been purified from lysates of Neisseria gonorrhoeae. The enzyme was activated by monovalent cations, had a pH optimum between 9 and 10, and showed a substrate specificity unlike any known alcohol or glycerol dehydrogenase. The enzyme had an apparent Km of 17 mM for 1,2-propanediol and 0 . 37 mM for NAD+. When chromatographed on a Sephadex G-150 column, the enzyme eluted as a single peak in the molecular weight region of a bovine serum albumin marker. An antibody to the purified enzyme was prepared in goats. When antiserum was reacted with the enzyme in immunodiffusion experiments, a single precipitin band was detected. When the enzyme was mixed with an excess of antibody and then reacted with substrate, enzyme activity was completely inhibited.

Alcohol Oxidoreductases↗

PubMed1980

The occurrence of 1,2-propanediol oxidoreductase in micro-organisms and its use as a possible diagnostic marker for Neisseria gonorrhoeae.

The cervical microbial flora of 25 females and stock cultures of various micro-organisms which may be present in the human female cervix were examined using a fluorimetric assay for 1,2-propanediol oxidoreductase. Results indicated that only members of the genera Neisseria and Acinetobacter possess appreciable activities of the enzyme, whose physiological function is not yet known. The activity of this enzyme in N. gonorrhoeae appeared to be significantly higher than the activities observed in mot of the other Neisseria species and in the Acinetobacter species. These results indicated that it may be possible to utilize this enzyme as a presumptive diagnostic marker for N. gonorrhoeae in cervical secretions. 1,2-Propanediol oxidoreductase may also be of taxonomic significance for the classification of various bacterial species.

Acinetobacter↗

PubMed1976

Growth on D-arabitol of a mutant strain of Escherichia coli K12 using a novel dehydrogenase and enzymes related to L-1,2-propanediol and D-xylose metabolism.

Escherichia coli K12 cannot grow on D-arabitol, L-arabitol, ribitol or xylitol (Reiner, 1975). Using a mutant of E. coli K12 (strain 3; Sridhara et al., 1969) that can grow on L-1,2-propanediol, a second-stage mutant was isolated which can utilize D-arabitol as sole source of carbon and energy for growth. D-Arabitol is probably transported into the bacteria by the same system as that used for the transport of L-1,2-propanediol. The second-stage mutant constitutively synthesizes a new dehydrogenase, which is not present in the parent strain 3. This enzyme, whose native substrate may be D-galactose, apparently dehydrogenates D-arabitol to D-xylulose, and its structural gene is located at 68.5 +/- 1 min on the E. coli genetic map. D-Xylulose is subsequently catabolized by the enzymes of the D-xylose metabolic pathway.

Carbohydrate Epimerases↗

PubMed2006

2,3-Diaryl-3-hydroxypropionic acid intermediates in the synthesis of threo forms of 1,2-diaryl-1,3-propanediols.

Racemic threo-3-hydroxy-2,3-diphenylpropionic acid, C15H14O3, (I), crystallizes from ethyl acetate as a conglomerate of separate (+)- and (-)-crystals. The geometries of (I) and its methyl ester are compared. Reduction of (I) gives threo-1,2-diphenyl-1,3-propanediol. The synthesis of threo forms of 1,2-diaryl-1,3-propanediols via 2,3-diaryl-3-hydroxypropionic acids is discussed.

Journal Article↗

PubMed1994

(S)-2-amino-1,3-propanediol-3-phosphate-carrying diradylglyceroglycolipids. Novel major membrane lipids of Clostridium innocuum.

Two novel aminophosphoglycolipids (I, II) were isolated from Clostridium innocuum which constitute 51% (I) and 15% (II) of total polar membrane lipids. The structures, established by quantitative and methylation analyses, fast-atom-bombardment mass spectrometry, and one- and two-dimensional NMR spectroscopy, are (I) S-2-amino-1,3-propanediol-3-phospho-6-alpha-D-galactopyranosyl(1-2)alpha -D- glucopyranosyl(1-3)diradylglycerol and (II) an acylated derivative of (I) that carries an additional fatty acid ester on O6 of the glucosyl moiety. The stereochemical configuration of the 2-amino-1,3-propanediol 3-phosphate residue was elucidated by conversion to N-acetylserine 3-phosphate, with subsequent release and identification of L-serine by HPLC. In addition to diacylglycerol species, both aminophosphoglycolipids contain 15-32% 1-O-(alk-1-enyl)-2-O-acyl-glycerol species in which C14, C16, and C18 vinyl ether are combined predominantly with unsaturated C16 and C18 fatty acid ester. Hydrogenation of the vinyl ether was required to desorb the alkyl, acyl-substituted species in fast-atom-bombardment mass spectrometry. Hydrogenation made it further possible to release the alkyl glycerols by acid hydrolysis and to locate the ether bond at O1 of the glycerol moiety. In contrast to the glycerophosphoglycolipids of other Gram-positive bacteria, the aminophosphoglycolipids are metabolically not related to the lipoteichoic acid of C. innocuum and serve, therefore, exclusively as major membrane components. Their large abundance among membrane lipids suggests bilayer-forming physicochemical properties.

Carbohydrate Sequence↗

PubMed1978

Extracellular accumulation of a new amino acid, O-2-hydroxypropylhomoserine, from 1,2-propanediol by flavobacterium rigense.

During an investigation of microorganisms utilizing petrochemicals, a strain identified as Flavobacterium rigense was found to accumulate a new amino acid in a medium containing 1,2-propanediol as the sole carbon source. Cultural conditions for the accumulation of the product were investigated, and as a result, the yield was increased to 2.8 mg/ml after a 5-day incubation in a medium containing 8% 1,2-propanediol. The pure amino acid was isolated, and its structure was investigated. Elemental analysis and infrared, nuclear magnetic resonance, and mass spectral analyses indicated that the amino acids is O-2-hydroxypropylhomoserine.

Culture Media↗

PubMed2001

Anaerobic conversion of lactic acid to acetic acid and 1, 2-propanediol by Lactobacillus buchneri.

The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and traces of ethanol. Based on stoichiometry studies and the high levels of NAD-linked 1, 2-propanediol-dependent oxidoreductase (530 to 790 nmol min(-1) mg of protein(-1)), a novel pathway for anaerobic lactic acid degradation is proposed. The anaerobic degradation of lactic acid by L. buchneri does not support cell growth and is pH dependent. Acidic conditions are needed to induce the lactic-acid-degrading capacity of the cells and to maintain the lactic-acid-degrading activity. At a pH above 5.8 hardly any lactic acid degradation was observed. The exact function of anaerobic lactic acid degradation by L. buchneri is not certain, but some results indicate that it plays a role in maintaining cell viability.

Acetic Acid↗

PubMed1985

Identity of Escherichia coli D-1-amino-2-propanol:NAD+ oxidoreductase with E. coli glycerol dehydrogenase but not with Neisseria gonorrhoeae 1,2-propanediol:NAD+ oxidoreductase.

The properties of D-1-amino-2-propanol oxidoreductase from wild-type Escherichia coli have been compared with those of a glycerol dehydrogenase from mutant E. coli 424 and of a 1,2-propanediol oxidoreductase from Neisseria gonorrhoeae. Several independent lines of evidence indicate that the former two enzymes are identical. (i) Both enzymatic activities purified to virtual homogeneity in an identical manner, and the ratio of specific activities (glycerol/aminopropanol) remained constant at all stages. (ii) When electrophoresed, both purified enzymes showed a major as well as a minor band of protein coincident with activity, and these two bands from each enzyme had the same mobility. (iii) The subunit molecular weights and isoelectric points were identical for each enzyme, and (iv) kinetic constants (Km and Vmax values) determined with three different substrates were the same. The somewhat greater stability of the glycerol dehydrogenase to controlled heat denaturation at 74 degrees C was the only difference observed between these two enzymes. In contrast, D-1-amino-2-propanol oxidoreductase was found to be immunochemically and kinetically distinct from the 1,2-propanediol oxidoreductase from N. gonorrhoeae.

Alcohol Oxidoreductases↗