High‐Field FT NMR Application of Mosher′s Method. The Absolute Configurations of Marine Terpenoids.
About: This article is published in ChemInform.The article was published on 1991-08-27. It has received 182 citations till now.
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TL;DR: In this paper, the application of (S)-1,10-binaphthyl-2,20-diol as NMR chiral solvating agent (CSA) for omeprazole, and three of its analogs (lanso-, panto-, and rabe-prazole) was investigated.
Abstract: The application of (S)-1,10-binaphthyl-2,20-diol as NMR chiral solvating agent (CSA) for omeprazole, and three of its analogs (lanso-, panto-, and rabe-prazole) was investigated. The formation of diastereomeric host–guest complexes in solution between the CSA and the racemic substrates produced sufficient NMR signal splitting for the determination of enantiomeric excesses by Hor F-NMR spectroscopy. Using of hydrophobic deuterated solvents was mandatory for obtaining good enantiodiscrimination, thus suggesting the importance of intermolecular hydrogen bonds in the stabilization of the complexes. The method was applied to the fast quantification of the enantiomeric purity of in-process samples of S-omeprazole. Chirality 00:000–000, 2009. VC 2009
885 citations
TL;DR: Fifteen flavonoids and a polyacetylene, 8, were isolated from the ethanol extract of the dried whole plant of Bidens parviflora Willd and their structures have been elucidated on the basis of spectroscopic analyses and chemical studies.
Abstract: Fifteen flavonoids, 1-7 and 9-16, and a polyacetylene, 8, were isolated from the ethanol extract of the dried whole plant of Bidens parviflora Willd. by various chromatographic techniques. Their structures have been elucidated on the basis of spectroscopic analyses and chemical studies. Compound 8 is new and was identified as 3-(R),8(E)-decene-4,6-diyne-1,3,10-triol. All the flavonoid compounds were isolated for the first time from this plant species.
147 citations
Cites background from "High‐Field FT NMR Application of Mo..."
...In the (1)H-NMR spectrum of the R-(+)-MTPA ester, the H-1 and H-2 protons appeared upfield, suggesting an effect of the MTPA pheyl ring [19]....
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TL;DR: An overview of chiral reagents that are used to assign the absolute configuration of particular classes of compounds using NMR spectroscopy is presented.
135 citations
TL;DR: Four alkaloids named piperumbellactams A-D were isolated from branches of Piper umbellatum together with known N-hydroxyaristolam II (5), N-p-coumaroyl tyramine (6), 4-nerolidylcatechol (7) and E-3-(3,4-dihydroxyphenyl)-N-2-propenamide, beta-amyrin, friedelin.
82 citations
Cites methods from "High‐Field FT NMR Application of Mo..."
...In vitro antifungal Bioassay was performed using agar tube dilution method (Ohtani et al., 1991; Kusumi, 1993; Brass et al., 1979)....
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TL;DR: The skeletal structure and the relative stereochemistry of fusarielin A were determined mainly on the basis of its NMR data, and the absolute structure was elucidated by using the exciton chirality method and the modified Mosher method.
Abstract: A new antifungal antibiotic, fusarielin A, and three related compounds, fusarielins B, C and D, were obtained from a culture of a Fusarium sp. The skeletal structure and the relative stereochemistry of fusarielin A were determined mainly on the basis of its NMR data, and the absolute structure was elucidated by using the exciton chirality method and the modified Mosher method. The structures of the other homologues were determined by comparison of their spectral data with those of fusarielin A.
72 citations
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