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ABSTRACT: 4-Nitrophenyl α-d-galactopyranosyl-(1→3)-6-O-acetyl-α-d-galactopyranoside was prepared in a transglycosylation reaction catalyzed by α-d-galactosidase fromTalaromyces flavus using 4-nitrophenyl α-d-galactopyranoside as a glycosyl donor and 4-nitrophenyl 6-O-acetyl-α-d-galactopyranoside as an acceptor. 4-Nitrophenyl 6-O-acetyl-α-d-galactopyranoside and 4-nitrophenyl 6-O-acetyl-β-d-galactopyranoside were prepared in a regioselective enzymic transesterification in pyridine-acetone catalyzed by the lipase
PS fromBurkholderia cepacia. A series of water-miscible organic solvents (acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, 1,4-dioxane,
2-methoxyethanol, pyridine, 2-methylpropan-2-ol, tetrahydrofuran, propargyl alcohol) were used as co-solvents in this enzymic
reaction. Their influence on the activity and stability of the α-galactosidase fromT. flavus was established. 2-Methylpropan-2-ol and acetone (increasing the solubility of the modified substrate acceptors and displaying
the minimum impairment of the activity and stability of the enzyme) were used as co-solvents in transglycosylation reactions.
Folia Microbiologica 01/2003; 48(3):329-337. · 0.68 Impact Factor
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ABSTRACT: 4-Nitrophenyl alpha-D-galactopyranosyl-(1-->3)-6-O-acetyl-alpha-D-galactopyranoside was prepared in a transglycosylation reaction catalyzed by alpha-D-galactosidase from Talaromyces flavus using 4-nitrophenyl alpha-D-galactopyranoside as a glycosyl donor and 4-nitrophenyl 6-O-acetyl-alpha-D-galactopyranoside as an acceptor. 4-Nitrophenyl 6-O-acetyl-alpha-D-galactopyranoside and 4-nitrophenyl 6-O-acetyl-beta-D-galactopyranoside were prepared in a regioselective enzymic transesterification in pyridine-acetone catalyzed by the lipase PS from Burkholderia cepacia. A series of water-miscible organic solvents (acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, 2-methoxyethanol, pyridine, 2-methylpropan-2-ol, tetrahydrofuran, propargyl alcohol) were used as co-solvents in this enzymic reaction. Their influence on the activity and stability of the alpha-galactosidase from T. flavus was established. 2-Methylpropan-2-ol and acetone (increasing the solubility of the modified substrate acceptors and displaying the minimum impairment of the activity and stability of the enzyme) were used as co-solvents in transglycosylation reactions.
Folia Microbiologica 01/2003; 48(3):329-37. · 0.68 Impact Factor
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ABSTRACT: The article suggests a novel method for quantitative determination of optimal dry weight in dialysis patient based on their extracellular volume (ECV) to total body water (TBW) ratio and its relation to age. Values of ECV and TBW are evaluated by means of whole body multifrequency bioimpedometry. In an effort to find a suitable marker of hydration status in an individual from bioimpedance data, significant correlation has been found between ECV/TBW ratio and age in health. Assuming that all excess fluid in dialysis patients is stored exclusively in ECV and that distribution of their TBW at the state of optimal dry weight corresponds to that of a healthy person of the same age, the pre-dialysis ECV/TBW could be used for quantitative determination of optimal dry weight and/or of the ultrafiltration to reach this weight. Practical bioimpedance measurement of ECV/TBW in a group of dialysis patients both pre- and post-dialysis confirmed both above assumptions, i.e. nearly exclusively extracellular origin of ultrafiltration as well as normalisation of the ECV/TBW ratio towards the end of dialysis. Supporting evidence of increasing ECV/TBW value with age was also found in literature. Although the suggested method needs detailed analysis of possible disturbing factors (ethnic "specificity" of the reference ECV/TBW vs. age characteristics in health, possible difference in "biological" and "physical" age of dialysis patient and others), the article is published at this early stage to enable wider testing of the proposed novel method by different investigators.
The International journal of artificial organs 09/2002; 25(8):762-9. · 1.86 Impact Factor
