Quantification of diterpene acids in Copaiba oleoresin by UHPLC-ELSD and heteronuclear two-dimensional qNMR
Autor: | Anna Laís Pfeifer Barbosa, Ulrich Girreser, Serhat Sezai Çiçek |
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Rok vydání: | 2018 |
Předmět: |
natural product
Light Calibration curve Clinical Biochemistry Copaifera Pharmaceutical Science polyalthic acid 01 natural sciences Analytical Chemistry chemistry.chemical_compound Chromatography detector Drug Discovery Scattering Radiation Oleoresin quality control kaurenoic acid Nuclear Magnetic Resonance Biomolecular Spectroscopy Chromatography High Pressure Liquid ddc:5 Chromatography biology 010405 organic chemistry 010401 analytical chemistry article diterpenoids Fabaceae Repeatability biology.organism_classification Copaifera reticulata 0104 chemical sciences chemistry Heteronuclear molecule ddc:540 Plant Preparations Diterpene Diterpenes Heteronuclear single quantum coherence spectroscopy |
Zdroj: | Journal of pharmaceutical and biomedical analysis. 160 |
ISSN: | 1873-264X |
Popis: | In this study, we present the quantitation of eight diterpene acids in the oleoresin of Copaifera reticulata Ducke by UHPLC-ELSD and quantitative HSQC (heteronuclear single quantum correlation spectroscopy). UHPLC was performed using reversed phase material and external calibration and showed RSD values of ≤ 3% (repeatability) and ≤ 4% (precision), and mean recovery rates of 91.2–104.8%. LOQs were determined with 10 and 20 μg/mL, and LODs with 4 and 8 μg/mL, respectively. For the qHSQC method, calibration curves of eight different NMR cross-peaks (furylic, endo- and exocyclic methine signals, exocyclic methylene and methyl signals) were established and normalized with dimethyl terephthalate, which served as internal standard. This approach allowed the direct quantification of four major and one minor diterpene, whereas simple calculation procedures led to the contents of the remaining minor compounds. Comparison with the results of the UHPLC assay showed good agreement for seven of the eight diterpene acids. In terms of precision, the qHSQC method was advantageous for the quantification of the three main compounds, whereas UHPLC-ELSD was superior in the determination of the minor components. In contrast to previous reports, kolavenic acid was identified as a major diterpene acid in the oleoresin of Copaifera reticulata, with amounts of 4.0 ± 0.3%. |
Databáze: | OpenAIRE |
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