| Full text | |
| Author(s): |
Ccana-Ccapatinta, Gari V.
[1]
;
Sampaio, Bruno L.
[1]
;
dos Santos, Jr., Fernando M.
[2]
;
Batista, Jr., Joao M.
[2]
;
Da Costa, Fernando B.
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, AsterBioChem Res Team, Lab Pharmacognosy, Sch Pharmaceut Sci Ribeirao Preto, Ave Cafe S-N, BR-14040903 Ribeirao Preto, SP - Brazil
[2] Univ Fed Sao Carlos, Dept Chem, Rod Washington Luis Km 235, BR-13565905 Sao Carlos, SP - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | TETRAHEDRON-ASYMMETRY; v. 28, n. 12, p. 1823-1828, DEC 15 2017. |
| Web of Science Citations: | 3 |
| Abstract | |
Recently, it was observed that infrared (IR) and vibrational circular dichroism (VCD) calculations including deuterated hydroxyl groups in phenolic and saccharide moieties improved significantly the agreement with experimental data obtained in methanol-d(4). In the present study, the relative and absolute configurations of three methanol-soluble caffeic acid ester derivatives 1-3, isolated from Tithonia diversifolia, were established by a combined use of experimental and calculated C-13 NMR chemical shifts, as well as electronic circular dichroism (ECD) and VCD spectroscopies. Interestingly, the attempt to reproduce the deuteration pattern arising from possible isotopic exchange in methanol-d(4) solution led to nearly mirror image calculated VCD spectra for 1 when compared to the non-deuterated molecule with the same absolute configuration. This latter fact can potentially lead to absolute configuration misassignments. A closer inspection of the vibrational chiroptical properties of 1 revealed that the deuteration status of the tertiary hydroxyl group at C-2 is critical for the correct reproduction of experimental VCD data in protic solvents. Therefore, in the case of stereochemical analysis of polar chiral natural product molecules, a combination of VCD and ECD is recommended. (C) 2017 Elsevier Ltd. All rights reserved. (AU) | |
| FAPESP's process: | 15/07089-2 - Vibrational chiroptical spectroscopy for stereochemical characterization of small molecules and macromolecules |
| Grantee: | João Marcos Batista Junior |
| Support Opportunities: | Scholarships in Brazil - Young Researchers |
| FAPESP's process: | 11/13361-6 - Evaluation of seasonal variation of the main secondary metabolites and anti-inflammatory activity of extracts of Tithonia diversifolia (Hemsl.) A. Gray (Asteraceae) |
| Grantee: | Bruno Leite Sampaio |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 14/26866-7 - Metabolomics, enzymatic targets and in silico tools in the search of bioactive compounds from plants |
| Grantee: | Fernando Batista da Costa |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 14/25222-9 - Vibrational chiroptical spectroscopy for stereochemical characterization of small molecules and macromolecules |
| Grantee: | João Marcos Batista Junior |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 14/16850-6 - Metabolomic and chemometric approach for the study of chemotaxonomy, authentication and quality control of the species of the subfamily Barnadesioideae (Asteraceae) |
| Grantee: | Gari Vidal Ccana Ccapatinta |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 16/23794-0 - Stereochemistry of complex natural compounds by vibrational optical activity: acetogenins |
| Grantee: | Fernando Martins dos Santos Junior |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |