- Process for preparing hyperpolarized substrates and method for MRI
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The present invention generally relates to a process for the preparation of aqueous solutions of hyperpolarized molecules ready for use in in-vivo MR diagnostic imaging, the use thereof as MRI contrast agent in investigation methods for producing diagnostic MR images of a human or non-human animal body organ, region or tissue.
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Page/Page column 27
(2017/08/01)
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- Enantioselective catabolism of racemic serine: Preparation of d-serine using whole cells of Fusobacterium nucleatum
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Incubation of racemic serine with the anaerobic bacterium Fusobacterium nucleatum yielded d-serine in high enantiomeric excess (>95%). Selective degradation of the l-amino acid was most efficient when F. nucleatum was resuspended in a buffer at high cell densities (ca. 50-100 g damp cells/L); a single incubation effectively removed almost all l-serine from racemic mixtures at initial concentrations up to 800 mM, the solubility limit. The product d-amino acid was separated from the metabolic end-products (acetate, butyrate and lactate) and buffer components by a single cation-exchange step. After recrystallization, 83% of the d-serine in the initial racemate was recovered with >99% ee (HPLC) and 98% purity (HPLC). This anaerobic microbial approach provides a viable complementary method for generating d-serine, a valuable chiral starting material for chemical synthesis.
- Ramezani, Mohammad,White, Robert L.
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experimental part
p. 1473 - 1478
(2011/11/12)
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- Products formed at intermediate stages of electrochemical perfluorination of propionyl and n-butyryl chlorides. Further evidence in support of NiF 3 mediated free radical pathway
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The partially fluorinated HF soluble intermediates formed during the electrochemical perfluorination of propionyl chloride (PC) and n-butyryl chloride (n-BC) were analyzed after passing 0%, 25%, 50%, 75% and 100% of theoretical charge required for the fluorination of PC and n-BC. The acid fluorides formed were converted to their corresponding sodium salt by alkali treatment and were separated by methanol extraction. The methanol was subsequently removed from the extract by vacuum distillation and the residue containing partially fluorinated sodium carboxylates was analyzed using 19F and 1H NMR spectra. Initial perfluorination on activated electrode surface indicates the operation of 'zipper-mechanism'. Formation of partially fluorinated product mixture, initial selectivity towards primary and secondary carbon, carbon chain isomerization and formation of cleaved and coupled products support the general operation of free radical pathway in the overall electrochemical process.
- Rangarajan,Sathyamoorthi,Velayutham,Noel,Singh,Brahma, Raju
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experimental part
p. 107 - 113
(2011/03/23)
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- Acyloxymethyl and 4-acyloxybenzyl diester prodrugs of phosphonoformate
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Sodium pivaloyloxymethyl (pivaloyloxymethoxycarbonyl)phosphonate 4, sodium 4-acyloxybenzyl phenoxycarbonylphosphonates 14a-c and sodium 4-acyloxybenzyl benzyloxycarbonylphosphonates 15a,b have been prepared as bioreversible prodrugs of the antiviral phosphonoformate 1. Their hydrolyses, in vivo systemic bioavailability and antiviral activity are reported. Of the compounds evaluated 4 was the best prodrug.
- Briggs, Andrew D.,Camplo, Michel,Freeman, Sally,Lundstroem, Jan,Pring, Brian G.
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p. 14937 - 14950
(2007/10/03)
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