Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i>
The present study aimed to screen plants for bioactive compounds with potential antibacterial activities. In our efforts to evaluate plants from Borneo, we isolated and elucidated the structures of four natural products from the bioactive fraction of a chloroform extract of <i>Goniothalamus lo...
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| Format: | Article |
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MDPI AG
2020-12-01
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| Series: | Antibiotics |
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| Online Access: | https://www.mdpi.com/2079-6382/9/12/913 |
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| author | Stephen P. Teo Sanjib Bhakta Paul Stapleton Simon Gibbons |
| author_facet | Stephen P. Teo Sanjib Bhakta Paul Stapleton Simon Gibbons |
| author_sort | Stephen P. Teo |
| collection | DOAJ |
| description | The present study aimed to screen plants for bioactive compounds with potential antibacterial activities. In our efforts to evaluate plants from Borneo, we isolated and elucidated the structures of four natural products from the bioactive fraction of a chloroform extract of <i>Goniothalamus longistipetes</i> using various chromatographic and spectroscopic techniques. The bioactive compounds were identified as a known styryllactone, (+)-altholactone ((2<i>S</i>,3<i>R</i>,3a<i>S</i>,7a<i>S</i>)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4<i>H</i>)-5-one) (<b>1</b>), a new styryllactone, (2<i>S</i>,3<i>R</i>,3a<i>S</i>,7a<i>S</i>)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4<i>H</i>)-5-one) (<b>2</b>) as well as a new alkaloid, 2,6-dimethoxyisonicotinaldehyde (<b>3</b>) and a new alkenyl-5-hydroxyl-phenyl benzoic acid (<b>4</b>). <b>1</b> and <b>4</b> showed broad-spectrum anti-bacterial activities against Gram-positive and Gram-negative bacteria as well as acid-fast model selected for this study. Compound <b>2</b> only demonstrated activities against Gram-positive bacteria whilst <b>3</b> displayed selective inhibitory activities against Gram-positive bacterial strains. Additionally, their mechanisms of anti-bacterial action were also investigated. Using <i>Mycobacterium smegmatis</i> as a fast-growing model of tubercle bacilli, compounds <b>1</b>, <b>2</b> and <b>4</b> demonstrated inhibitory activities against whole-cell drug efflux and biofilm formation; two key intrinsic mechanisms of antibiotic resistance. Interestingly, the amphiphilic compound <b>4</b> exhibited inhibitory activity against the conjugation of plasmid pKM101 in <i>Escherichia coli</i> using a plate conjugation assay. Plasmid conjugation is a mechanism by which Gram-positive and Gram-negative-bacteria acquire drug resistance and virulence. These results indicated that bioactive compounds isolated from <i>Goniothalamus longistipetes</i> can be potential candidates as ‘hits’ for further optimisation. |
| first_indexed | 2024-03-10T14:01:57Z |
| format | Article |
| id | doaj.art-4d286d4e2e324eecb3c9330053b66723 |
| institution | Directory Open Access Journal |
| issn | 2079-6382 |
| language | English |
| last_indexed | 2024-03-10T14:01:57Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Antibiotics |
| spelling | doaj.art-4d286d4e2e324eecb3c9330053b667232023-11-21T01:04:34ZengMDPI AGAntibiotics2079-63822020-12-0191291310.3390/antibiotics9120913Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i>Stephen P. Teo0Sanjib Bhakta1Paul Stapleton2Simon Gibbons3Research Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UKDepartment of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, UKResearch Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UKResearch Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UKThe present study aimed to screen plants for bioactive compounds with potential antibacterial activities. In our efforts to evaluate plants from Borneo, we isolated and elucidated the structures of four natural products from the bioactive fraction of a chloroform extract of <i>Goniothalamus longistipetes</i> using various chromatographic and spectroscopic techniques. The bioactive compounds were identified as a known styryllactone, (+)-altholactone ((2<i>S</i>,3<i>R</i>,3a<i>S</i>,7a<i>S</i>)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4<i>H</i>)-5-one) (<b>1</b>), a new styryllactone, (2<i>S</i>,3<i>R</i>,3a<i>S</i>,7a<i>S</i>)-3-hydroxy-2-phenyl-2,3,3a,7a-tetrahydrobenzo-5(4<i>H</i>)-5-one) (<b>2</b>) as well as a new alkaloid, 2,6-dimethoxyisonicotinaldehyde (<b>3</b>) and a new alkenyl-5-hydroxyl-phenyl benzoic acid (<b>4</b>). <b>1</b> and <b>4</b> showed broad-spectrum anti-bacterial activities against Gram-positive and Gram-negative bacteria as well as acid-fast model selected for this study. Compound <b>2</b> only demonstrated activities against Gram-positive bacteria whilst <b>3</b> displayed selective inhibitory activities against Gram-positive bacterial strains. Additionally, their mechanisms of anti-bacterial action were also investigated. Using <i>Mycobacterium smegmatis</i> as a fast-growing model of tubercle bacilli, compounds <b>1</b>, <b>2</b> and <b>4</b> demonstrated inhibitory activities against whole-cell drug efflux and biofilm formation; two key intrinsic mechanisms of antibiotic resistance. Interestingly, the amphiphilic compound <b>4</b> exhibited inhibitory activity against the conjugation of plasmid pKM101 in <i>Escherichia coli</i> using a plate conjugation assay. Plasmid conjugation is a mechanism by which Gram-positive and Gram-negative-bacteria acquire drug resistance and virulence. These results indicated that bioactive compounds isolated from <i>Goniothalamus longistipetes</i> can be potential candidates as ‘hits’ for further optimisation.https://www.mdpi.com/2079-6382/9/12/913<i>Goniothalamus longistipetes</i>Annonaceaeantibacterialefflux pumpsbiofilm formationbacterial conjugation |
| spellingShingle | Stephen P. Teo Sanjib Bhakta Paul Stapleton Simon Gibbons Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i> Antibiotics <i>Goniothalamus longistipetes</i> Annonaceae antibacterial efflux pumps biofilm formation bacterial conjugation |
| title | Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i> |
| title_full | Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i> |
| title_fullStr | Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i> |
| title_full_unstemmed | Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i> |
| title_short | Bioactive Compounds from the Bornean Endemic Plant <i>Goniothalamus longistipetes</i> |
| title_sort | bioactive compounds from the bornean endemic plant i goniothalamus longistipetes i |
| topic | <i>Goniothalamus longistipetes</i> Annonaceae antibacterial efflux pumps biofilm formation bacterial conjugation |
| url | https://www.mdpi.com/2079-6382/9/12/913 |
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