[Bjonnh.net]# _

Authors: Seon Beom Kim , Jonathan Bisson ORCID , J. Brent Friesen ORCID , Guido F. Pauli ORCID , Charlotte Simmler ORCID
Journal: Journal of Natural Products (RoMEO status: White)
Subjects:
CPC
CCC
Chlorophylls are present in all extracts from the aerial parts of green plant materials. Chlorophylls may act as in vitro bioassay nuisance compounds, possibly preventing the reproducibility and accurate measurement of readouts due to their UV/vis absorbance, fluorescence properties, and tendency to precipitate in aqueous media. Despite the diversity of methods used traditionally to remove chlorophylls, details about their mode of operation, specificity, and reproducibility are scarce. Herein, we report a selective and efficient 45 min liquid–liquid/countercurrent chlorophyll cleanup method using Centrifugal Partition Chromatography (CPC) with a solvent system composed of hexanes–EtOAc–MeOH–water (5:5:5:5, v/v) in elution-extrusion mode.
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categories publications science
Authors: Rasika S. Phansalkar , Charlotte Simmler ORCID , Jonathan Bisson ORCID , Shao-Nong Shen , David C. Lankin ORCID , James B. McAlpine ORCID , Matthias Niemitz ORCID , Guido F. Pauli ORCID
Journal: Journal of Natural Products (RoMEO status: White)
Subjects:
NMR
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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categories publications science
Authors: Thierry Buffeteau , Dominique Cavagnat , Jonathan Bisson ORCID , 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:
VCD
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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categories publications science
Authors: Guido F. Pauli ORCID , Shao-Nong Chen ORCID , David C. Lankin ORCID , Jonathan Bisson ORCID , Ryan J. Case , Lucas R. Chadwick , Tanja Gödecke , Taichi Inui , Aleksej Krunic , Birgit U. Jaki ORCID , James B. McAlpine ORCID , Shunyan Mo , José G. Napolitano , Jimmy Orjala , Juuso Lehtivarjo , Samuli-Petrus Korhonen , Matthias Niemitz ORCID
Journal: Journal of Natural Products (RoMEO status: White)
Subjects:
NMR
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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categories publications science