Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses
NMR fingerprints are valuable tools for analyzing complex natural product mixtures and identifying incorrectly assigned structures in the literature. Our diagnostic NMR fingerprints for formyl phloroglucinol meroterpenoids revealed discrepancies in the structures reported for eucalyprobusal C (<b...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-01-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/29/3/594 |
| _version_ | 1797318442279239680 |
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| author | Darren C. Holland Anthony R. Carroll |
| author_facet | Darren C. Holland Anthony R. Carroll |
| author_sort | Darren C. Holland |
| collection | DOAJ |
| description | NMR fingerprints are valuable tools for analyzing complex natural product mixtures and identifying incorrectly assigned structures in the literature. Our diagnostic NMR fingerprints for formyl phloroglucinol meroterpenoids revealed discrepancies in the structures reported for eucalyprobusal C (<b>1a</b>) and eucalypcamal K (<b>2a</b>). NMR fingerprinting PCA analyses identified <b>1a</b> as an oxepine-diformyl phloroglucinol and <b>2a</b> as an oxepine 3-acyl-1-formyl phloroglucinol, contrary to their initial assignments as pyrano-diformyl and pyrano 3-acyl-1-formyl phloroglucinols, respectively. Extensive reinterpretation of their reported one- and two-dimensional NMR data, coupled with GIAO DFT-calculated <sup>1</sup>H and <sup>13</sup>C NMR chemical shift and DP4+ analyses, supported the unequivocal reassignment of eucalyprobusal C to <b>1b</b> and eucalypcamal K to <b>2b</b>. The absolute configurations of the revised oxepine-containing phloroglucinol meroterpenoids were confirmed via the reinterpretation of their reported ROESY and NOESY NMR data, along with comparative TDDFT-calculated and experimental ECD spectra. |
| first_indexed | 2024-03-08T03:52:28Z |
| format | Article |
| id | doaj.art-2af981a502794a91a449e1bd1178c8d4 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-08T03:52:28Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-2af981a502794a91a449e1bd1178c8d42024-02-09T15:18:45ZengMDPI AGMolecules1420-30492024-01-0129359410.3390/molecules29030594Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD AnalysesDarren C. Holland0Anthony R. Carroll1School of Environment and Science, Griffith University, Nathan, QLD 4111, AustraliaSchool of Environment and Science, Griffith University, Nathan, QLD 4111, AustraliaNMR fingerprints are valuable tools for analyzing complex natural product mixtures and identifying incorrectly assigned structures in the literature. Our diagnostic NMR fingerprints for formyl phloroglucinol meroterpenoids revealed discrepancies in the structures reported for eucalyprobusal C (<b>1a</b>) and eucalypcamal K (<b>2a</b>). NMR fingerprinting PCA analyses identified <b>1a</b> as an oxepine-diformyl phloroglucinol and <b>2a</b> as an oxepine 3-acyl-1-formyl phloroglucinol, contrary to their initial assignments as pyrano-diformyl and pyrano 3-acyl-1-formyl phloroglucinols, respectively. Extensive reinterpretation of their reported one- and two-dimensional NMR data, coupled with GIAO DFT-calculated <sup>1</sup>H and <sup>13</sup>C NMR chemical shift and DP4+ analyses, supported the unequivocal reassignment of eucalyprobusal C to <b>1b</b> and eucalypcamal K to <b>2b</b>. The absolute configurations of the revised oxepine-containing phloroglucinol meroterpenoids were confirmed via the reinterpretation of their reported ROESY and NOESY NMR data, along with comparative TDDFT-calculated and experimental ECD spectra.https://www.mdpi.com/1420-3049/29/3/594structure revisionformylated phloroglucinolsNMR fingerprintingDFTDP4+ |
| spellingShingle | Darren C. Holland Anthony R. Carroll Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses Molecules structure revision formylated phloroglucinols NMR fingerprinting DFT DP4+ |
| title | Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses |
| title_full | Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses |
| title_fullStr | Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses |
| title_full_unstemmed | Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses |
| title_short | Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses |
| title_sort | structure revision of formyl phloroglucinol meroterpenoids a unified approach using nmr fingerprinting and dft nmr and ecd analyses |
| topic | structure revision formylated phloroglucinols NMR fingerprinting DFT DP4+ |
| url | https://www.mdpi.com/1420-3049/29/3/594 |
| work_keys_str_mv | AT darrencholland structurerevisionofformylphloroglucinolmeroterpenoidsaunifiedapproachusingnmrfingerprintinganddftnmrandecdanalyses AT anthonyrcarroll structurerevisionofformylphloroglucinolmeroterpenoidsaunifiedapproachusingnmrfingerprintinganddftnmrandecdanalyses |