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Authors: Rasika S. Phansalkar, Charlotte Simmler, Jonathan BissonORCID , Shao-Nong Shen, David C. Lankin, James B. McAlpine, Matthias Niemitz, Guido F. PauliORCID
Journal: Journal of Natural Products (RoMEO status: White)
Subjects: Pharmacognosy Phytochemistry NMR qNMR HiFSA
Chemical standardization, along with morphological and DNA analysis ensures the authenticity and advances the integrity evaluation of botanical preparations. Achievement of a more comprehensive, metabolomic standardization requires simultaneous quantitation of multiple marker compounds. Employing quantitative 1H NMR (qHNMR), this study determined the total isoflavone content (TIfCo; 34.5–36.5% w/w) via multimarker standardization and assessed the stability of a 10-year-old isoflavone-enriched red clover extract (RCE). Eleven markers (nine isoflavones, two flavonols) were targeted simultaneously, and outcomes were compared with LC-based standardization.
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Authors: Thierry Buffeteau, Dominique Cavagnat, Jonathan BissonORCID , Axel Marchal, Gilbert D. Kapche, Ilaria Battistini, Gregory Da Costa, Alain Badoc, Jean-Pierre Monti, Jean-Michel Mérillon, Pierre Waffo-Téguo
Journal: Journal of Natural Products (RoMEO status: White)
Subjects: Pharmacognosy Phytochemistry VCD Stereochemistry
Dimeric stilbene glucosides 1–3 [two diastereomers of (−)-gnemonoside A (1a and 1b), (−)-gnemonoside C (2), and (−)-gnemonoside D (3)] as well as a mixture of the two enantiomers of gnetin C (4) were isolated from the rhizomes of Gnetum africanum. The two enantiomers of gnetin C, (+)-4 and (−)-4, were obtained from the aglycones of 1a and 1b, respectively. The configurations of these stilbenoids were investigated by NMR and vibrational circular dichroism (VCD) experiments.
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Authors: Guido F. PauliORCID , Shao-Nong Chen, David C. Lankin, Jonathan BissonORCID , Ryan J. Case, Lucas R. Chadwick, Tanja Gödecke, Taichi Inui, Aleksej Krunic, Birgit U. Jaki, James B. McAlpine, Shunyan Mo, José G. Napolitano, Jimmy Orjala, Juuso Lehtivarjo, Samuli-Petrus Korhonen, Matthias Niemitz
Journal: Journal of Natural Products (RoMEO status: White)
Subjects: Pharmacognosy Phytochemistry NMR Spin simulation
The present study demonstrates the importance of adequate precision when reporting the δ and J parameters of frequency domain 1H NMR (HNMR) data. Using a variety of structural classes (terpenoids, phenolics, alkaloids) from different taxa (plants, cyanobacteria), this study develops rationales that explain the importance of enhanced precision in NMR spectroscopic analysis and rationalizes the need for reporting Δδ and ΔJ values at the 0.1–1 ppb and 10 mHz level, respectively.
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