Synthesis of lipophilic 1-deoxygalactonojirimycin derivatives as D-galactosidase inhibitors

• Georg Schitter,
• Elisabeth Scheucher,
• Andreas J. Steiner,
• Arnold E. Stütz,
• Martin Thonhofer,
• Chris A. Tarling,
• Stephen G. Withers,
• Jacqueline Wicki,
• Katrin Fantur,
• Eduard Paschke,
• Don J. Mahuran,
• Brigitte A. Rigat,
• Michael Tropak and
• Tanja M. Wrodnigg

Beilstein J. Org. Chem. 2010, 6, No. 21, doi:10.3762/bjoc.6.21

• -galactosidase, exhibiting improvements of the enzyme activity in mutant cell lines [24]. In the course of this work, we became interested in the influence of other lipophilic aromatic substituents on the biological activity of such compounds. Different aromatic acid derivatives were prepared by coupling to the

• preliminary studies compounds 17 as well as 22 served as chemical chaperone and increased the enzyme activity of a β-galactosidase mutant feline fibroblast cell line up to 5.5 fold when applied at a concentration of 100 µM. Compound 18 was a significantly better chemical chaperone for this mutant increasing

• the relative enzyme activity 4.8 fold at a concentration of 2 µM. Conclusion We have synthesised new 1-deoxygalactonojirimycin derivatives 16–20, as well as 22, which feature a C6 chain anchored to the ring nitrogen. Different lipophilic aromatic and aliphatic substituents at the N-alkyl chain were

The development and evaluation of a continuous flow process for the lipase- mediated oxidation of alkenes

• Charlotte Wiles,
• Marcus J. Hammond and
• Paul Watts

Beilstein J. Org. Chem. 2009, 5, No. 27, doi:10.3762/bjoc.5.27

• reagents currently employed, finding use in the synthesis of the aroma linalool oxide and epoxidised soybean oil [16], the reaction times employed for the transformations (< 166 h) and observed reductions in enzyme activity in the presence of H2O2 (2) do not currently make the technique a practical

• heating the bioreactor; confirming enzyme activity was maintained. Effect of oxidant concentration on enzyme stability Although it was pleasing to observe stability of the Novozym® 435 (4) at various reaction temperatures, with literature precedent reporting enzyme deactivation at an oxidant concentration

• conversions ranging from 15% to quantitative depending on the alkene employed. Törnvall et al. [20] subsequently conducted a detailed investigation into the source of enzyme deactivation, concluding that high temperature (60 °C) and high concentrations of H2O2 (2, 6 to 12 M) resulted in rapid loss of enzyme

N-acylation of ethanolamine using lipase: a chemoselective catalyst

• Mazaahir Kidwai,
• Roona Poddar and
• Poonam Mothsra

Beilstein J. Org. Chem. 2009, 5, No. 10, doi:10.3762/bjoc.5.10

• effective [23]. Further, a control set with no Novozym® 435 was also irradiated under microwave irradiation, but no reaction occurred (Table 1 and Table 2). There is remarkable enhancement in reusability of biocatalyst. Conventionally there is a decrease in enzyme activity after run III while in solution

• . Moreover the N-acylation reaction is favoured for mixtures of precursor reagents whose pH values of mixture exceed the pKb of ethanolamine (i.e. 4.5). The case of an equimolar ratio of the substrates provide the best condition in terms of two factors - the enzyme activity (the enzyme is deactivated at very

• economic process. A study was performed to determine enzyme activity in terms of reusability. The reusability of enzyme was checked in all methods, for the synthesis of N-lauroylethanolamine (3b) under optimized conditions as described above. Many experiments were run with the same enzyme, which was

Towards practical biocatalytic Baeyer- Villiger reactions: applying a thermostable enzyme in the gram- scale synthesis of optically- active lactones in a two-liquid- phase system

• Frank Schulz,
• François Leca,
• Frank Hollmann and
• Manfred T. Reetz

Beilstein J. Org. Chem. 2005, 1, No. 10, doi:10.1186/1860-5397-1-10

• after a reaction time of 24 h a conversion of 43% and moderate enantioselectivity for lactones (-)2 and (+)3 (Table 1). Conversion was drastically improved with mutants P1, P2, and P3 to more than 95% under the same whole-cell conditions, which clearly indicates enhanced enzyme activity. Additionally

• cyclohexane, 50% of the initial enzyme activity is lost during the first five minutes of incubation (Figure 2). For the other solvents this effect is even more pronounced. After this initial short period the loss of activity of the enzyme proceeds much slower. The 2°ADH showed less dependency of its activity

• solvent. A reaction temperature of 40°C was chosen as a compromise between enzyme and NADPH-cofactor stability on the one hand, and high enzyme activity on the other. In the reaction we used significantly higher NADPH-regeneration activity (4 U/mL of 2°ADH) than PAMO-activity (0.6 U/mL) to force the