The c o n d e n s a t io n o f racemic ly s in e to p o ly -D L ly s in e produces a great number o f d is t in ­ guishable molecules. Following merely statistical reasoning the number o f “pure peptides“ — consisting of only one sort of enantiomers — should be extremely low. The hydrolysis of polyD L -ly s in e by pronase a n d t a k a -d ia s ta s e shows that a content of about 3% “pure“ pol...

An adenosine triphosphate (ATP) analogue modified with two nitroxide radicals is developed and employed to study its enzymatic hydrolysis by electron paramagnetic resonance spectroscopy. For this application, we demonstrate that EPR holds the potential to complement fluorogenic substrate analogues in monitoring enzymatic activity.

Three common pretreatment processes based on dilute sulfuric acid, dilute sodium hydroxide and heat treatment (autoclaving) followed by enzymatic hydrolysis were evaluated to provide comparative performance data. Among them, the best result was obtained when the pretreatment of rice husk was carried out with 3% of NaOH solution. The pretreatment of rice husk with NaOH substantially increased th...

A new enzymatic method for synthesis of enantiomerically enriched δ-hexadecalactone (3) based on the enzymatic kinetic resolution of N-methyl-5-acetoxyhexadecanamide (1) is described. A combination of lipase-catalyzed hydrolysis and amidation improved enantioselectivity. Lipase-catalyzed amidation was also investigated. Detailed screening of solvents and additive amines was performed. The addit...

..A.LMOST ALL the neutral urinary 17-ketosteroids are conjugated with either sulfuric or glucuronic acids. These conjugates can be cleaved by strong acids at elevated temperatures (1), or by solvolysis in either ethyl acetate or tetrahydrohiran, each containing perchioric acid (2). Selective hydrolysis of steroid-glucuronosicles is achieved with $-glucuromi_ idase, although in some 1i1#{149}ill...

The conventional biochemical platform featuring enzymatic hydrolysis involves five key steps: pretreatment, cellulase production, enzymatic hydrolysis, fermentation, and product recovery. Sugars are produced as reactive intermediates for subsequent fermentation to fuels and chemicals. Herein, an alternative biochemical route is proposed. Pretreatment, enzymatic hydrolysis and cellulase producti...

Konjac oligo-glucomannan (KOG) was prepared by degradation of konjac glucomannan (KG) using β-mannanase. The hydrolysis process was monitored by the viscosity of the enzymatic hydrolysates. Factors affecting the enzymatic hydrolysis of KG were investigated, and the optimum hydrolysis conditions were as follows: time 2h; temperature 50°C; pH 6.0; and enzymatic concentration 150 U/g. Under these ...

Acids and alkalis are considered important catalysts in biomass pretreatment, which is essential to overcome the recalcitrance of lignocellulose for sugar release. In this study, the effects of various chemicals and temperatures on the pretreatment and subsequent enzymatic hydrolysis of wheat straw were investigated. The conversions of glucan and xylan during pretreatment and enzymatic hydrolys...

To optimize the enzymatic conversion of widely available lignocellulosic biomass-wheat straw (WS), pretreatment facilitating the enzymatic saccharification process was first performed by alkaline peroxide, resulting in a substrate consisting of 60.17% cellulose, 29.53% hemicelluloses, and 4.59% lignin. Using response surface methodology, the combined effects of enzyme loading, substrate concent...

Screening for benzodiazepines is routinely performed by immunochemical analysis such as enzyme immunoassay. However, the wide range of therapeutic and toxic concentrations of the different benzodiazepines and their extensive metabolisation and conjugation hamper the design of an immunoassay protocol that can detect all benzodiazepines and their corresponding urinary metabolites. Only a few inve...