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Dang PH, Tran TH, Le TH, Do TNV, Nguyen HX, Nguyen MTT, Nguyen NT. A new β-carboline-type alkaloid from the flowers of Calotropis gigantea (L.) W.T.Aiton. Nat Prod Res 2023:1-9. [PMID: 37129020 DOI: 10.1080/14786419.2023.2208259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In our antioxidant screening of some Vietnamese plant extracts, the CHCl3-soluble fraction from Calotropis gigantea (L.) W.T.Aiton flowers showed moderate DPPH free radical scavenging activity with an IC50 value of 55.8 μg/mL. Thus, a further phytochemical study was carried out to obtain five alkaloids, including a new β-carboline-type alkaloid, caloside H (1). These known compounds were identified as 5-hydroxy-(2-methoxymethyl)pyridine (2), nicotinic acid (3), p-(acetylamino)phenol (4), and thymine (5). These structures were determined based on the NMR spectroscopic analysis. In antioxidant assay, caloside H at concentration of 100 μM showed DPPH radical scavenging capacity with a percentage of inhibition of 40.2%. In addition, a plausible biosynthetic pathway for the formation of caloside H was proposed based on the Schiff base formation and Mannich-like reaction.
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Affiliation(s)
- Phu H Dang
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
| | - Tu H Tran
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
| | - Tho H Le
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
| | - Truong N V Do
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
| | - Hai X Nguyen
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
| | - Mai T T Nguyen
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
| | - Nhan T Nguyen
- Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Research Lab for Drug Discovery and Development, University of Science, Ho Chi Minh City, Vietnam
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