In steroid transformations some of the advantages of immobilized microorganisms seem to be especially important, since the manufacture of steroid drugs often involves very expensive intermediates and products (1). Therefore, we have been studying two corticosteroid transformations. The first reaction is an 11-β-hydroxylation catalyzed by free or polyacrylamide immobilized Curvularia lunata, pr

The cofactor analogue N6-((6-aminohexyl)-carbamoylmethyl)-NAD was bound to beef heart lactate dehydrogenase by the glutaraldehyde coupling method and the enzyme-coenzyme complex subsequently separated from excess of non-coupled cofactor by gel filtration chromatography. The number of cofactor molecules bound per enzyme molecule could be varied between 0 and 8 by altering the coupling time. The enz

A new AMP derivative substituted with spacer arms both at position N6 and C8 of the adenine moiety was synthesized and immobilized to Sepharose. To the immobilized ligand was subsequently coupled C8-substituted ATP in a solid-phase synthesis fashion yielding the bifunctional general ligand AMP-ATP. This affinity material was used in the separation of two major groups of enzymes, dehydrogenases and

WE describe here the development of a new analytical configuration, called a microbe thermistor, in which immobilised microorganisms are placed in proximity to a thermistor which measures the metabolic heat evolved by them. Many metabolites can thus be analysed, as we show here by the determination of both single components such as glucose and fructose and of more complex mixtures such as casein.

THE marked increase in demand for contraceptives and anti-inflammatory agents such as cortisol and prednisolone, combined with a diminishing supply of steroid raw materials may lead to shortages of steroid drugs1. Thus it is important to develop new sources for steroids as well as to devise more efficient means for steroid conversions. Here we report a new approach to steroid transformation in whi

Phosphorylation of 6‐chloropurine riboside with phosphorus oxychloride and phosphorus trichloride gave a mixture of the two isomers, 6‐chloropurine‐riboside 2′,5′‐bisphosphate and 6‐chloropurine‐riboside 3′,5′‐bisphosphate. Reaction with 1,6‐diaminohexane followed by resolution of the isomeric mixture on a Dowex 1‐X2 column yielded N6‐(6‐aminohexyl)‐adenosine 2′,5′‐bisphosphate and N6‐(6‐amin

Alkylation of NAD+ with iodoacetic acid followed by alkaline rearrangement gave N6-carboxymethyl-NAD+. Condensation of this analogue with 1,6-diaminohexane gave the analogue NAD+- N6-[N-(6-aminohexyl)-acetamide]. The coenzymic activity of the two derivatives was tested with malate dehydrogenase, alcohol dehydrogenase and lactate dehydrogenase. The efficiency relative to unsubstituted NAD+ was i

To a Sepharose gel the pyridine nucleotide NAD(H) has been bound using dicyclohexyl carbodiimide. In order to improve the steric availability of the nucleotide for added soluble enzymes such as dehydrogenases, a spacer molecule, ε-amino caproic acid, was inserted between the carbohydrate matrix and the nucleotide. The obtained preparation contained 56 μmoles NAD+/g dry polymer. The obtained

Superporous particles contain two sets of pores, normal diffusion pores and very large flow pores. If such particles are used chromatographically, part of the flow will pass through each particle. This leads to a rapid equilibration between the stationary and the mobile phases, even if the superporous particle has a large outer diameter. Superporous particles are thus chromatographically efficient

Long-term screening with serum prostate-specific antigen (PSA) and systematic prostate biopsies can reduce prostate cancer mortality but leads to unacceptable overdiagnosis. Over the past decade, diagnostic methods have improved and the indolent nature of low-grade prostate cancer has been established. These advances now enable more selective detection of potentially lethal prostate cancer. This n

This thematic issue of the Journal of Digital History focuses on different digital tools that are used to study, explore, and narrate the past. Our idea has been to collect a broad range of articles that demonstrate and critique new ways of exploring the past through computational means—all in order to open up and problematize the use of digital methods in historical research, including analytical

Mortar extrusion during bricklaying, resulting from suboptimal workmanship, may act as a bridge linking clay brick masonry claddings and adjacent layers (e.g., insulation or weather-resistant barriers), thereby, facilitating water penetration into the adjacent layer owing to wind-driven rain (WDR). Despite the significant effect of water penetration on the hygrothermal performance of building enve

This study presents a state-of-the-art review of the evolution of probabilistic hygrothermal assessments of building envelopes. First, relevant literature was identified by employing a systematic methodology, including scoping and systematic searches, quality assessment, and study analysis. The analysis, based on 143 selected publications, provides statistical insights into uncertainty propagation

Fungal cells from Curvularia lunata were entrapped in a crosslinked polyacrylamide gel. The gel-cells obtained as granules were applied in the microbial transformation of Reichstein compound S leading to cortisol through an 11-β-hydroxylation step. Some kinetic studies of this conversion using gel-cells were carried out. In addition, it was shown that gel-cell granules which had lost part o