Bioassay- and Chemistry-Guided Isolation of Scalemic Caged Prenylxanthones from the Leaves of Garcinia bracteata
| Autor: | Jiao Bai, Hui-Ming Hua, Yue-Hu Pei, Zhan-Lin Li, Sheng-Li Niu, Yongkui Jing, Yue-Tong Wang, Xin-Yu Li, Sheng-Ge Li, Dahong Li |
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| Rok vydání: | 2018 |
| Předmět: |
Circular dichroism
Xanthones Pharmaceutical Science HL-60 Cells Fractionation Crystallography X-Ray 01 natural sciences High-performance liquid chromatography Analytical Chemistry Structure-Activity Relationship X ray methods Cell Line Tumor Drug Discovery Humans Bioassay Chromatography High Pressure Liquid Cell Proliferation Pharmacology Garcibracteatone Chromatography 010405 organic chemistry Chemistry Circular Dichroism Organic Chemistry Garcinia bracteata Antineoplastic Agents Phytogenic 0104 chemical sciences Plant Leaves 010404 medicinal & biomolecular chemistry Complementary and alternative medicine Molecular Medicine Biological Assay Enantiomer Garcinia K562 Cells |
| Zdroj: | Journal of Natural Products. 81:749-757 |
| ISSN: | 1520-6025 0163-3864 |
| DOI: | 10.1021/acs.jnatprod.7b00454 |
| Popis: | With bioassay- and chemistry-guided fractionation, seven new caged prenylxanthones including two scalemic mixtures, epiisobractatin (1), 13-hydroxyisobractatin (2), 13-hydroxyepiisobractatin (3), 8-methoxy-8,8a-dihydrobractatin (4), 8-ethoxy-8,8a-dihydrobractatin (5), garcibracteatone (6), and 8-methoxy-8,8a-dihydroneobractiatin (7), and the eight known compounds 8-15 were isolated from the leaves of Garcinia bracteata. The structures were unambiguously elucidated through analysis of spectroscopic data. The 2D structures and relative configurations of 1 and 5 were confirmed by X-ray crystallographic analysis. The separation of the enantiomers of 1-5 was accomplished by chiral-phase HPLC. The absolute configurations of the enantiomers of 1 and 5 were assigned by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The absolute configurations of the related compounds were determined via comparisons of their ECD data with those of the enantiomers of 1 and 5, respectively. Notably, compound 7, with a neo caged skeleton, is the first representative of a novel type of caged xanthone lacking a Δ |
| Databáze: | OpenAIRE |
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