Wiesneth, Stefan and Petereit, Frank and Juergenliemk, Guido (2015) Salix daphnoides: A Screening for Oligomeric and Polymeric Proanthocyanidins. MOLECULES, 20 (8). pp. 13764-13779. ISSN 1420-3049,
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In the present study, a qualitative analysis of proanthocyanidins (PAs) from an aqueous-methanolic extract of Salix daphnoides VILL. bark is described. Procyanidin B1 (1), B2 (2), B3 (3), B4 (4), C1 (5), epicatechin-(48)-epicatechin-(48)-catechin (6) and epicatechin-(48)-epicatechin-(48)-epicatechin-(48)-catechin (7) have been isolated by a combination of different chromatographic separations on Sephadex((R)) LH-20-, MCI (R)-, Diol-and RP-18-phases. Mass spectrometry, 1D- and 2D-NMR, circular dichroism and polarimetry were used for their structure elucidation and verification by comparison with the literature. Additionally, two fractions of very polar flavan-3-ols were compared: regular polymeric PAs received at the very end of the Sephadex((R)) LH-20 chromatography showing no mobility on silica TLC and unusual PAs with the same R-F-value but already eluting together with flavonoids in the Sephadex((R)) LH-20 system. These unusual PAs were subsequently enriched by centrifugal partition chromatography (CPC). C-13-NMR, polarimetry, thiolysis, acid hydrolysis and phloroglucinol degradation were used to characterize both fractions. Differences in the composition of different flavan-3-ol units and the middle chain length were observed.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PLANT PROANTHOCYANIDINS; PROCYANIDIN OLIGOMERS; CIRCULAR-DICHROISM; STEREOCHEMISTRY; ELUCIDATION; CATECHIN; BARK; procyanidins; proanthocyanidins; flavan-3-ols; Salix daphnoides; willow bark; low temperature NMR; thiolysis; polarimetry; polymeric proanthocyanidins |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institute of Pharmacy > Pharmaceutical Biology (Prof. Heilmann) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 18 Jun 2019 11:58 |
| Last Modified: | 18 Jun 2019 11:58 |
| URI: | https://pred.uni-regensburg.de/id/eprint/5079 |
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