138-65-8Relevant articles and documents
Enzymatic synthesis of (-)-6-[18F]-Fluoronorepinephrine from 6- [18F]-Fluorodopamine by dopamine β-hydroxylase
Lui, Eric,Chirakal, Raman,Firnau, Guenter
, p. 503 - 521 (1998)
The visualization and investigation of the sympathetic innervation of the heart with positron emission tomography (PET) has become a new and active area in nuclear cardiology. The radiofluorinated amine (-)-6-[18F]- fluoronorepinephrine ((-)-6-[18F]FNE) has been suggested as a potential radiotracer for imaging the sympathetic nervous system and providing kinetic information regarding the utilization of the native adrenergic neurotransmitter norepinephrine. In this study, it was found that (-)-6- [18F]FNE can be synthesized stereospecifically from 6-[18F]- fluorodopamine (6-[18F]FDA) under in vitro conditions through the catalytic action of the enzyme dopamine β-hydroxylase (DβH), which is responsible for the in vivo biosynthesis of endogenous norepinephrine from dopamine. The estimated K(m) and V(max) values for the enzymatic activity of DβH on 6- [18F]FDA and on dopamine were 0.87 ± 0.07 mM, 0.011 ± 0.001 μmoles/unit/min, and 1.4 ± 0.3 mM, and 0.079 ± 0.017 μmoles/unit/min respectively. The differences between the K(m) and V(max) values of the two substrates were both statistically significant at p18F]FDA with a sufficiently high specific activity is available, results from this study suggests that the enzymatic conversion of 6-[18F]FDA into (-)-6-[18F]FNE by DβH may be used to synthesize (-)-6-[18F]FNE suitable for intravenous administration into humans. Furthermore, this study also opens up the possibility of exploiting the low substrate specificity of DβH for the synthesis of other 11C- or 18F-labeled biogenic phenylethanolamines in their natural enantiomeric form for PET studies.
Design and Use of de novo Cascades for the Biosynthesis of New Benzylisoquinoline Alkaloids
Wang, Yu,Tappertzhofen, Nadine,Méndez-Sánchez, Daniel,Bawn, Maria,Lyu, Boyu,Ward, John M.,Hailes, Helen C.
supporting information, p. 10120 - 10125 (2019/06/27)
The benzylisoquinoline alkaloids (BIAs) are an important group of secondary metabolites from higher plants and have been reported to show significant biological activities. The production of BIAs through synthetic biology approaches provides a higher-yielding strategy than traditional synthetic methods or isolation from plant material. However, the reconstruction of BIA pathways in microorganisms by combining heterologous enzymes can also give access to BIAs through cascade reactions. Most importantly, non-natural BIAs can be generated through such artificial pathways. In the current study, we describe the use of tyrosinases and decarboxylases and combine these with a transaminase enzyme and norcoclaurine synthase for the efficient synthesis of several BIAs, including six non-natural alkaloids, in cascades from l-tyrosine and analogues.
3-methoxy-4-hydroxyphenylglycol fluorescence polarization immunoassay
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, (2008/06/13)
The present invention is directed to a fluoroescence polarization immunoassay for determining the 3-methoxy-4-hydroxyphenylglycol content in body fluids, to the various components needed for preparing and carrying out such an assay, and to methods of making these components. Specifically, tracers, immunogens and antibodies are disclosed, as well as methods for preparing them. The assay is conducted by measuring the degree of polarization of plane polarized light that has been passed through a sample containing antiserum and tracer.
