This review highlights the biosynthesis of heterocycles in polyketide natural products with a focus on oxygen and nitrogen-containing heterocycles with ring sizes between 3 and 6 atoms. Heterocycles are abundant structural elements of natural products from all classes and they often contribute significantly to their biological activity. Progress in recent years has led to a much better understa...

Molecular Enzymology Group Colloquium Organized by D. Fell (School of Biological and Molecular Sciences, Oxford Brooke University) and D. Kell (Department of Biological Sciences, University College, Wales, Aberystwyth), Edited by D. Fell and Sponsored by Xenova Ltd, Zeneca Bioproducts, Glaxo Research and Development Ltd and SmithKline Beecham Pharmaceuticals. 653rd Meeting held at the Universit...

Accurate, economical and high-throughput gene and genome synthesis is essential to the development of synthetic biology and biotechnology. New large-scale gene synthesis methods harnessing the power of DNA microchips have recently been demonstrated. Yet, the technology is still compromised by a high occurrence of errors in the synthesized products. These errors still require substantial effort ...

Introd u ction Clinical chemistry, for decades restricted to a limited number of chemical tests, has, in recent years, through an increasing awareness of the value of the laboratory investigation of disease, and the introduc­ tion of automation and sophisticated instru­ mentation, expanded its field of operations to include a bewildering variety of tests. Advances in biochemical knowledge have ...

We developed an enzymatic method for determination of 5-fluorocytosine in serum, using creatine iminohydrolase (EC 3.5.4.21), the Cobas-Bio analyzer, and an extant ammonia method. Analytical recovery (y) of drug added to serum (x) was good, with y = 0.97x-0.7, Sy.x = 3.6, r = 0.997 (n = 65) over the range 6.25 to 150 mg/L. Comparison with an HPLC method (x) showed good agreement: y = 0.98x + 1....

Creatinine amidohydrolase is used to measure serum creatinine in a totally enzymatic procedure. Creatine, produced by hydrolysis, is acted upon by creatine kinase, and then by pyruvate kinase and lactate dehydrogenase, to result in a change in absorbance at 340 nm. The amount of creatinine present is related to the rate of change in A340 and is determined from a standard curve. Absorbance and c...

l-asparaginase has remarkable properties which make it useful in dual pharmaceutical and food industries.in this study, simple and advantageous method has been validated for rapid and precise determination of intracellular l-asparaginasein bacterial species. a suspension of bacterial cells was used instead ofcell extract and incubated by substrate (asparagine) after simple wash and centrifugati...

We evaluated a new, simple, enzymatic kinetic method from Wako Chemicals GmbH in comparison with a kinetic Jaffé method by using isotope dilution-mass spectrometry (ID-MS) as a reference method. An ID-MS-calibrated serum standard was used. Both the enzymatic and the Jaffé method correlated well with ID-MS, except for sera with high concentrations of bilirubin. Ethyl acetoacetate, acetone, and g...