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Kgakatsi NA, Majinda RRT, Masesane IB, Nwamadi MS, Demissie TB, Ombito JO, Gobe I. New isoflavan from Erythrina livingstoniana. Nat Prod Res 2024; 38:493-502. [PMID: 36190792 DOI: 10.1080/14786419.2022.2130300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/21/2022] [Indexed: 10/10/2022]
Abstract
Chemical investigation of the root wood of Erythrina livingstoniana led to the isolation of one previously undescribed isoflavan (3S,3″R)-7-hydroxy-2'-methoxy-[3″-hydroxy-2″,2″-dimethylpyrano (3',4')] isoflavan 1, together with eleven known compounds 2-12. The structure of compound 1 was elucidated on the basis of extensive spectroscopic and spectrometric analyses (1 D and 2 D-NMR and APCI-HRMS), with absolute configurations established by comparison of experimental and DFT calculated ECD data. The assignment of the absolute configurations of C-3 and C-3″ of compounds 2 and 3, respectively, were reported for the first time. Compounds 1 - 4 were evaluated for their antibacterial activities in vitro against E. coli ATCC 25922 and S. aureus ATCC 25923. Compound 1 exhibited moderate antibacterial activity with MIC value of 0.063 mg/mL against the clinically relevant risk-group 2 (RG-2) bacterium S. aureus.
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Affiliation(s)
- Nayang A Kgakatsi
- Department of Chemistry, University of Botswana, Gaborone, Botswana
- Boitekanelo College, Gaborone, Botswana
| | | | | | | | - Taye B Demissie
- Department of Chemistry, University of Botswana, Gaborone, Botswana
| | - Japheth O Ombito
- Department of Chemistry, University of Botswana, Gaborone, Botswana
| | - Irene Gobe
- Department of Medical Laboratory Science, University of Botswana, Gaborone, Botswana
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Kgakatsi NA, Majinda RRT, Masesane IB, Gobe I. Methoxylated bibenzyls and isoflavones from Baphia massaiensis Taub. Nat Prod Res 2023:1-7. [PMID: 36995029 DOI: 10.1080/14786419.2023.2196076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Chemical investigation of the stem bark of Baphia massaiensis Taub. led to the isolation of two new natural compounds named 3-hydroxy-2,5,2'-trimethoxybibenzyl (1) and 2'-hydroxy-2,3,5,6-tetramethoxybibenzyl (2), the latter has been previously reported as a synthetic compound, together with twelve known compounds 3-14. The chemical structures of the isolated compounds were elucidated by using NMR analysis and mass spectrometry, as well as comparisons with the reported data in the literature. Known bibenzyls 3-5, bauhinoxepin J (6), and isoflavones 7-10 and 12-14, were reported from genus Baphia for the first time. The isolated compounds were evaluated for their antibacterial activities in-vitro against Staphylococcus aureus and Escherichia coli. The bioactivity evaluation revealed that bibenzyls 1 and 2 showed weak inhibitory activity with MIC values of 1000 µg/mL against S. aureus and bauhinoxepin J (6) showed moderate inhibitory activity with MIC value of 63 µg/mL against S. aureus.
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Affiliation(s)
- Nayang A Kgakatsi
- Department of Chemistry, University of Botswana, Gaborone, Botswana
- Boitekanelo College, Gaborone, Botswana
| | | | | | - Irene Gobe
- Department of Medical Laboratory Science, University of Botswana, Gaborone, Botswana
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Umoh SD, Bojase G, Masesane IB, Majinda RT, Sichilongo KF. Untargeted GC-MS metabolomics to identify and classify bioactive compounds in Combretum platypetalum subsp. oatesii (Rolfe) Exell (Combretaceae). Phytochem Anal 2023; 34:127-138. [PMID: 36377224 DOI: 10.1002/pca.3184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/02/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
INTRODUCTION Combretum platypetalum is used in traditional African healing practices against different infections. Unfortunately, no scientific knowledge of its phytochemical composition exists, except for the isolation of two compounds from the leaves. Scientific study has been limited to the leaves only, despite the applications of stems and roots in traditional medicine practice and natural product drug discovery programs. OBJECTIVE Omics was applied to identify and classify different volatile and semivolatile bioactive compounds in the leaf, stem, and root parts of C. platypetalum. The thermal stability of the plant constituents at 60-65°C extraction temperature by Soxhlet and maceration at room temperature on the type, class, and concentration of compounds in the leaf was further investigated. METHOD A GC-MS untargeted metabolomics approach, automated deconvolution by the Automated Mass Spectral Deconvolution and Identification System (AMDIS) for GC-MS data, preprocessing by Metab R, and multivariate statistical data analysis were employed in this study. RESULTS A total of 97 phytoconstituents, including 17 bioactive compounds belonging to the terpenoids, flavonoids, long-chain fatty acids, and other unclassified structural arrangements distributed across C. platypetalum, were identified for the first time. A correlation (r = 0.782; P = 0.000) between Soxhlet and maceration extraction methods relative to resolved chromatographic peak areas of metabolites was established. CONCLUSION Findings corroborate the reported bio-investigation of its leaf extracts, its traditional uses, and previous findings from the Combretum genus. The results substantiate the possible applications of C. platypetalum in natural product drug discovery and provide a guide for future investigations.
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Affiliation(s)
- Sampson D Umoh
- Department of Chemistry, Faculty of Science, University of Botswana, Gaborone, Botswana
- Department of Chemistry, Joseph Sarwuan Tarka University, Makurdi, formerly known as University of Agriculture, Makurdi Nigeria PMB, Makurdi, Nigeria
| | - Gomotsang Bojase
- Department of Chemistry, Faculty of Science, University of Botswana, Gaborone, Botswana
| | - Ishmael B Masesane
- Department of Chemistry, Faculty of Science, University of Botswana, Gaborone, Botswana
| | - Runner T Majinda
- Department of Chemistry, Faculty of Science, University of Botswana, Gaborone, Botswana
| | - Kwenga F Sichilongo
- Department of Chemistry, Faculty of Science, University of Botswana, Gaborone, Botswana
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Majinda RRT, Masesane IB, Singh GS. An account of organic chemistry research in Botswana. ARKIVOC 2022. [DOI: 10.24820/ark.5550190.p011.780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Kgakatsi N, Majinda RRT, Masesane IB. BF3OEt2 and MeSO3H-Promoted reactions of phenols and ethyl phenylpropiolate as a synthetic routes to neoflavones and a potential route to flavones. ARKIVOC 2022. [DOI: 10.24820/ark.5550190.p011.774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Ombito JO, Bojase G, Majinda RR, Masesane IB, Schüffler A, Opatz T. Erysacleuxins C and D, new isoflavones from the twigs of Erythrina sacleuxii Hua and their cytotoxic activity. ARAB J CHEM 2020. [DOI: 10.1016/j.arabjc.2019.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Keroletswe N, Majinda RRT, Masesane IB. A New 3-Prenyl-2-flavene and Other Extractives from Baphia massaiensis and Their Antimicrobial Activities. Nat Prod Commun 2018. [DOI: 10.1177/1934578x1801300414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
One new 3-prenyl-2-flavene, named baphiflavene A, 1, and eleven known compounds, 2-12, were isolated and reported for the first time from Baphia massaiensis using several chromatographic techniques. Their structures were elucidated using different spectroscopic techniques; 1D and 2D-NMR, HRMS, GC-MS, UV/Vis, FTIR and by comparison with literature data. The isolates were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans to establish their preliminary antimicrobial activities. The results revealed that compound 1 had moderate activities against both Gram positive ( B. subtilis and S. aureus) and Gram negative ( E. coli and P. aeruginosa) bacteria, and good activity against C. albicans with inhibition zones of 10–23 mm (compared to 19 mm for chloramphenicol and miconazole standards). To the best of our knowledge, this is the first phytochemical work reported on Baphia massaiensis.
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Affiliation(s)
- Ngonye Keroletswe
- Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana
- Botswana Institute for Technology Research and Innovation, Private Bag 0082, Gaborone, Botswana
| | - Runner R. T. Majinda
- Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana
| | - Ishmael B. Masesane
- Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana
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Masesane IB, Mihigo SO. Efficient and Green Preparation of 2-Amino-4H-chromenes by a Room-Temperature, Na2CO3-Catalyzed, Three-Component Reaction of Malononitrile, Benzaldehydes, and Phloroglucinol or Resorcinol in Aqueous Medium. SYNTHETIC COMMUN 2015. [DOI: 10.1080/00397911.2015.1031249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Masesane IB, Desta ZY. Reactions of salicylaldehyde and enolates or their equivalents: versatile synthetic routes to chromane derivatives. Beilstein J Org Chem 2012; 8:2166-75. [PMID: 23365628 PMCID: PMC3554813 DOI: 10.3762/bjoc.8.244] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/23/2012] [Indexed: 11/24/2022] Open
Abstract
The reported methodologies for the synthesis of chromane derivatives through the reaction of salicylaldehyde and enolates are discussed. The enolates and their equivalents involved in the reactions discussed in this article were derived from ketones, nitroalkanes, malononitrile and α,β-unsaturated compounds.
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Affiliation(s)
- Ishmael B Masesane
- Department of Chemistry, University of Botswana, Private Bag 00704, Gaborone, Botswana
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Mazimba O, Masesane IB, Majinda RR. A flavanone and antimicrobial activities of the constituents of extracts fromMundulea sericea. Nat Prod Res 2012; 26:1817-23. [DOI: 10.1080/14786419.2011.616504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Mazimba O, Majinda RR, Modibedi C, Masesane IB, Cencič A, Chingwaru W. Tylosema esculentum extractives and their bioactivity. Bioorg Med Chem 2011; 19:5225-30. [DOI: 10.1016/j.bmc.2011.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/29/2011] [Accepted: 07/04/2011] [Indexed: 11/16/2022]
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B. Masesane I, N. Bwire R, R. T. Majinda R. FACILE ENANTIOSELECTIVE PALLADIUM CATALYSED TRANSFER HYDROGENATION OF α-METHYLCINNAMIC ACID IN THE PRESENCE OF OPTICAL PURE ORGANIC ACIDS. B CHEM SOC ETHIOPIA 2007. [DOI: 10.4314/bcse.v21i3.21229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Masesane IB, Batsanov AS, Howard JAK, Mondal R, Steel PG. The oxanorbornene approach to 3-hydroxy, 3,4-dihydroxy and 3,4,5-trihydroxy derivatives of 2-aminocyclohexanecarboxylic acid. Beilstein J Org Chem 2006; 2:9. [PMID: 16674802 PMCID: PMC1524792 DOI: 10.1186/1860-5397-2-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 05/04/2006] [Indexed: 11/10/2022] Open
Abstract
The nitro oxanorbornene adduct derived from the Diels-Alder reaction of ethyl (E)-3-nitroacrylate and furan provides a versatile template for the stereoselective synthesis of hydroxylated derivatives of 2-aminocyclohexanecarboxylic acid (ACHC).
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Affiliation(s)
- Ishmael B Masesane
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK
- Department of Chemistry, University of Botswana, P/bag 00704, Gaborone, Botswana
| | - Andrei S Batsanov
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK
| | - Judith A K Howard
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK
| | - Raju Mondal
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK
| | - Patrick G Steel
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK
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Abstract
[reaction: see text] A short asymmetric synthesis of (2'S,5R,6R)-2'-[6-amino-5-hydroxy-1,3-cyclohexadiene-1-carbonyloxy]propionic acid, the enantiomer of the reported structure of (+)-oryzoxymycin is described. The reported spectral data does not match that obtained for synthetic "oryzoxymycin".
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Affiliation(s)
- Mark E Bunnage
- Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, UK
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Steel PG, Masesane IB. Stereoselective Routes to PolyhydroxylatedCyclohexyl-β-amino Acids. Synlett 2003. [DOI: 10.1055/s-2003-38346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
The twigs of Rhus pyroides yielded a novel bichalcone 2',4",2"'-trihydroxy-4',4"'-dimethoxy-4-O-5"'-bichalcone. It was identified on the basis of spectroscopic data including 1D and 2D NMR spectroscopy. The name rhuschalcone-1 is proposed.
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Affiliation(s)
- I B Masesane
- Department of Chemistry, University of Botswana, Gaborone, Botswana
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