A one-pot synthesis of 1,4-naphthoquinone-2,3-bis-sulfides catalysed by a commercial laccase

Wellington, Kevin W.; Bokako, Refiloe; Raseroka, Nelly; Steenkamp, Paul A.

doi:10.1039/c2gc35926j

Cited by 50 publications

(28 citation statements)

References 48 publications

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“…The synthesis of the 1,4-naphthoquinone-2,3-bis-sulfides 2-10 shown in Figure 1 (Wellington, Bokako, Raseroka, & Steenkamp, 2012), the 1,4-naphthohydroquinone 11 and the 1,4-naphthoquinoe sulfides 12-20 (Wellington, Gordon, Ndlovu, Kolesnikova, & Steenkamp, 2013) shown in Figure 2, have been reported previously.…”

Section: Synthesissupporting

confidence: 58%

Investigation of the antibacterial and antifungal activity of thiolated naphthoquinones

Wellington

Nyoka

McGaw

2019

Drug Development Research

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The WHO has stated that antibiotic resistance is escalating to perilously high levels globally and that traditional therapies of antimicrobial drugs are futile against infections caused by resistant microorganisms. Novel antimicrobial drugs are therefore required. We report in this study on the inhibitory activity of the 1,4‐naphthoquinone‐2,3‐bis‐sulfides and 1,4‐naphthoquinone sulfides against two bacteria and a fungus to determine their antimicrobial properties. The 1,4‐naphthoquinone sulfides have potent activity with a minimum inhibitory concentration (MIC) of 7.8 μg/mL against Staphylococcus aureus (Gram +ve), an MIC of 23.4 μg/mL against the fungus, Candida albicans, which was better than that of Amphotericin B (MIC = 31.3 μg/mL), and against Escherichia coli (Gram −ve) an MIC of 31.3 μg/mL was obtained. The 1,4‐naphthoquinone had an MIC of 11.7 μg/mL against S. aureus and the 1,4‐naphthohydroquinone also had the same activity against E. coli. Hit, Lead & Candidate Discovery

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Section: Synthesissupporting

confidence: 58%

Investigation of the antibacterial and antifungal activity of thiolated naphthoquinones

Wellington

Nyoka

McGaw

2019

Drug Development Research

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“…Prior research has suggested that small sulfhydryl compounds, such as cysteine, are potent inhibitors of some fungal laccases . Thus, the few reported laccase‐catalyzed reactions involving sulfur nucleophiles have employed aromatic, benzylic, or cyclic sulfhydryl compounds and coupled them with catechols and naphthohydroquinones for the synthesis of catechol thioethers and 1,4‐naphthoquinone‐2,3‐bis‐sulfides, respectively . In spite of the aforementioned finding, we were able to successfully perform the laccase‐catalyzed coupling of 1,2‐ethanedithiol to substituted hydroquinones (Scheme ).…”

Section: Applications Of Laccases In Organic Synthesismentioning

confidence: 79%

Two Decades of Laccases: Advancing Sustainability in the Chemical Industry

Cannatelli

Ragauskas

2016

Chem. Rec.

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Given the current state of environmental affairs and that our future on this planet as we know it is in jeopardy, research and development into greener and more sustainable technologies within the chemical and forest products industries is at its peak. Given the global scale of these industries, the need for environmentally benign practices is propelling new green processes. These challenges are also impacting academic research and our reagents of interest are laccases. These enzymes are employed in a variety of biotechnological applications due to their native function as catalytic oxidants. They are about as green as it gets when it comes to chemical processes, requiring O as their only co-substrate and producing H O as the sole by-product. The following account will review our twenty year journey on the use of these enzymes within our research group, from their initial use in biobleaching of kraft pulps and for fiber modification within the pulp and paper industry, to their current application as green catalytic oxidants in the field of synthetic organic chemistry.

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“…Furthermore, the combination of electrochemistry with on‐line mass spectrometry has a great application potential for a wide variety of systems beyond the demonstrated example. We believe that numerous further applications are possible to substantiate enzyme‐catalysed reactions, such as coupling reactions of para ‐hydroquinones with aromatic amines or even a coupling with aryl and alkyl thiols to form C‐S bonds .…”

Section: Discussionmentioning

confidence: 99%

Electrochemical Initiated C‐N Coupling of 3‐Methylcatechol and n‐Hexylamine in a Flow Cell Monitored with ESI‐MS

2016

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The electrochemical initiated heterocoupling of 3‐methylcatechol and n‐hexylamine was investigated. The oxidation of 3‐methylcatechol was performed in an electrochemical flow cell with glassy carbon as the working electrode. As a result, the two‐electron, two‐proton oxidised chinone intermediate undergoes a C‐N coupling reaction in the presence of an amine (Michael addition). This mono coupling product can undergo a second two‐electron, two‐proton oxidation depending on acidic or basic conditions and substrate ratios. This flow cell was coupled on‐line with electrospray ionisation mass spectrometry to identify the possible coupling products. Higher substrate concentrations were performed off‐line as first scale‐up experiments in a two‐step procedure.

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A one-pot synthesis of 1,4-naphthoquinone-2,3-bis-sulfides catalysed by a commercial laccase

Cited by 50 publications

References 48 publications

Investigation of the antibacterial and antifungal activity of thiolated naphthoquinones

Investigation of the antibacterial and antifungal activity of thiolated naphthoquinones

Two Decades of Laccases: Advancing Sustainability in the Chemical Industry

Electrochemical Initiated C‐N Coupling of 3‐Methylcatechol and n‐Hexylamine in a Flow Cell Monitored with ESI‐MS

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