ABSTRACT
Protecting group-free synthesis of 1,2:5,6-di-anhydro-D-mannitol, followed by ring opening with propargylamine and subsequent ring closure produced a separable mix of piperidine N-propargyl 1,5-dideoxy-1,5-imino-D-gulitol and azepane N-propargyl 1,6-dideoxy-1,6-imino-D-mannitol. In O-acetylated form, these two building blocks were subjected to CuAAC click chemistry with a panel of three differently azide-substituted glucose building blocks, producing iminosugar pseudo-disaccharides in good yield. The overall panel of eight compounds, plus 1-deoxynojirimycin (DNJ) as a benchmark, was evaluated as prospective inhibitors of almond ß-glucosidase, yeast α-glucosidase and barley ß-amylase. The iminosugar pseudo-disaccharides showed no inhibitory activity against almond ß-glucosidase, while the parent N-propargyl 1,5-dideoxy-1,5-imino-D-gulitol and N-propargyl 1,6-dideoxy-1,6-imino-D-mannitol likewise proved to be inactive against yeast α-glucosidase. Inhibitory activity could be reinstated in the former series by appropriate substitution on nitrogen. The greater activity of the piperidine could be rationalized based on docking studies. Further, potent inhibition of ß-amylase was observed with compounds from both the piperidine and azepane series.
Subject(s)
Enzyme Inhibitors/chemical synthesis , Heterocyclic Compounds, 1-Ring/chemical synthesis , Imino Sugars/chemical synthesis , Piperidines/chemical synthesis , Triazoles/chemical synthesis , alpha-Glucosidases/chemistry , beta-Amylase/chemistry , beta-Glucosidase/chemistry , 1-Deoxynojirimycin/chemistry , Azides/chemistry , Click Chemistry/methods , Disaccharides/chemistry , Enzyme Inhibitors/chemistry , Glucose/chemistry , Heterocyclic Compounds, 1-Ring/chemistry , Hordeum/chemistry , Hordeum/enzymology , Imino Sugars/chemistry , Mannitol/chemistry , Pargyline/analogs & derivatives , Pargyline/chemistry , Piperidines/chemistry , Propylamines/chemistry , Prunus dulcis/chemistry , Prunus dulcis/enzymology , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/enzymology , Triazoles/chemistry , beta-Amylase/antagonists & inhibitors , beta-Glucosidase/antagonists & inhibitorsABSTRACT
In the present work, alpha- and beta-amylase enzymes from Zea mays malt were recovered by continuous extraction in a PEG/CaCl2 aqueous two-phase system (ATPS). The influences of the flux rate (RQ), free area of vane (A(free)) and vane rotation (RV) on enzyme recovery were studied by optimization using response surface methodology (RSM). The protein content and enzyme activity were measured from time to time in the extract and refined fluxes. RSM curves showed a squared dependence of recovery index with the RQ, A(free) and RV. The best system for recovering the maize malt enzymes was with low vane rotation and flux rate and high free area of vane. Alpha- and beta-amylases were purified 130-fold in the salt-rich phase.
Subject(s)
Chemical Fractionation/methods , Zea mays/chemistry , alpha-Amylases/isolation & purification , beta-Amylase/isolation & purification , Calcium Chloride/chemistry , Chemical Fractionation/instrumentation , Polyethylene Glycols/chemistry , Reproducibility of Results , alpha-Amylases/chemistry , beta-Amylase/chemistryABSTRACT
Isolation and purification of bioproducts from crude extracts can be obtained by affinity methods based on reversible binding of a specific molecule to ligand immobilized in a porous matrix. In the present work, nicrospheres based on chitosan matrix, which incorporated aminophenylboronic acid as a derivative, were prepared and characterized, aimed at developing a beta-amylase adsorption process. Kinetic curves and adsorption isotheriru of the crude extracts as well as the breakthrough curves for a frontal chromatographic separation method of a commercial sample of beta-amylase from soybean are presented. These results were compared to similar data obtained with a comercial microspheres gel based-on agarose.