Win, Thida and Htwe, Thant Thant and Shwe, Htay Htay and Heilmann, Joerg (2012) Lavandulyl Flavanones from the Stems of Hypericum calycinum L. CHEMISTRY & BIODIVERSITY, 9 (6). pp. 1198-1204. ISSN 1612-1872,
Full text not available from this repository. (Request a copy)Abstract
One novel lavandulyl flavanone (=2,3-dihydro-2-phenyl-4H-1-benzopyran-4-one) with an unusual 5,2',4',6'-tetrahydroxy substitution, calycinigin A (1), was isolated from the stems of Hypericum calycinum L. (Hypericaceae). The structure was elucidated on the basis of 1D- and 2D-NMR analysis, as well as mass spectrometry (LR-EI- and HR-EI-MS) and circular dichroism. Three known lavandulyl flavanones with 5,7,2',4',6'-pentahydroxy substitution, i.e., 24, were also isolated. Chemosystematically, this is the first report on the occurrence of prenylated flavanones in the family Hypericaceae. Reduction of cell viability by all compounds was evaluated in a MTT (=3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay using HeLa cells. Compound 1 showed moderate activity with an IC50 value of 9.7 +/- 1.8 mu M, whereas compounds 24 were less active exhibiting IC50 values of 11.6 +/- 0.9, 19.3 +/- 1.5, and 40.7 +/- 2.4 mu M, respectively. The antioxidant activity was evaluated by an ORAC (Oxygen Radical Absorbance Capacity) assay, and calycinigin A (1) was again the most active compound with a Trolox equivalent of 2.3 +/- 0.2. None of the compounds was able to reduce the TNF-a induced ICAM-1 expression in vitro using human microvascular endothelial cells (HMEC-1).
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PHENOLIC-COMPOUNDS; ABSOLUTE-CONFIGURATION; CIRCULAR-DICHROISM; ENDOTHELIAL-CELLS; SOPHORA-EXIGUA; FLAVONOIDS; BARK; CYTOTOXICITY; CONSTITUENTS; GUTTIFERAE; Hypericum calycinum; Flavanones; Lavandulylation; Cell viability; Antioxidant activity |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 500 Science > 570 Life sciences 600 Technology > 615 Pharmacy |
| Divisions: | Chemistry and Pharmacy > Institute of Pharmacy > Pharmaceutical Biology (Prof. Heilmann) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 13 May 2020 05:05 |
| Last Modified: | 13 May 2020 05:05 |
| URI: | https://pred.uni-regensburg.de/id/eprint/18641 |
Actions (login required)
 |
View Item |
