Synthesis, structure and in vitro anti-trypanosomal activity of non-toxic Arylpyrrole-Based Chalcone derivatives:
- Zulu, Ayanda I, Oderinlo, Ogunyemi O, Kruger, Cuan, Isaacs, Michelle, Hoppe, Heinrich C, Smith, Vincent J, Veale, Clinton G L, Khanye, Setshaba D
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
Expanding the SAR of Nontoxic Antiplasmodial Indolyl-3-ethanone Ethers and Thioethers:
- Lunga, Mayibongwe J, Chisango, Ruramai L, Weyers, Carli, Isaacs, Michelle, Taylor, Dale, Edkins, Adrienne L, Khanye, Setshaba D, Hoppe, Heinrich C, Veale, Clinton G L
- Authors: Lunga, Mayibongwe J , Chisango, Ruramai L , Weyers, Carli , Isaacs, Michelle , Taylor, Dale , Edkins, Adrienne L , Khanye, Setshaba D , Hoppe, Heinrich C , Veale, Clinton G L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164389 , vital:41114 , DOI: 10.1002/cmdc.201800235
- Description: Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1-(5-chloro-1H-indol-3-yl)-2-[(4-cyanophenyl)thio]ethanone (13) and 1-(5-chloro-1H-indol-3-yl)-2-[(4-nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain.
- Full Text:
- Date Issued: 2018
- Authors: Lunga, Mayibongwe J , Chisango, Ruramai L , Weyers, Carli , Isaacs, Michelle , Taylor, Dale , Edkins, Adrienne L , Khanye, Setshaba D , Hoppe, Heinrich C , Veale, Clinton G L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164389 , vital:41114 , DOI: 10.1002/cmdc.201800235
- Description: Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1-(5-chloro-1H-indol-3-yl)-2-[(4-cyanophenyl)thio]ethanone (13) and 1-(5-chloro-1H-indol-3-yl)-2-[(4-nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain.
- Full Text:
- Date Issued: 2018
Unexpected transformations of 3-(bromoacetyl)coumarin provides new evidence for the mechanism of thiol mediated dehalogenation of α-halocarbonyls
- Magwenzi, Faith N, Khanye, Setshaba D, Veale, Clinton G L
- Authors: Magwenzi, Faith N , Khanye, Setshaba D , Veale, Clinton G L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66200 , vital:28916 , https://doi.org/10.1016/j.tetlet.2017.01.082
- Description: publisher version , The mechanism for the thiol mediated dehalogenation of α-halogenated carbonyls has remained an unresolved problem, despite its ongoing application in synthetic organic chemistry. Nakamura and co-workers first proposed that net dehalogenation occurs via sequential nucleophilic substitutions, while Israel and co-workers concluded that the rate at which dehalogenation occurred suggested that dehalogenation proceeds in a single concerted step. In this study, we investigated the debromination and nucleophilic substitution of 3-(bromoacetyl)coumarin with a variety of thiophenols, whose electron donating or withdrawing natures resulted in large variations in the degree of nucleophilic substitution and dehalogenation products, respectively. Results from these experiments, in addition to an unexpected formation of thioether containing dibenzo[b,d]pyran-6-ones from a Robinson annulation, has provided new evidence for this disputed mechanism.
- Full Text: false
- Date Issued: 2017
- Authors: Magwenzi, Faith N , Khanye, Setshaba D , Veale, Clinton G L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66200 , vital:28916 , https://doi.org/10.1016/j.tetlet.2017.01.082
- Description: publisher version , The mechanism for the thiol mediated dehalogenation of α-halogenated carbonyls has remained an unresolved problem, despite its ongoing application in synthetic organic chemistry. Nakamura and co-workers first proposed that net dehalogenation occurs via sequential nucleophilic substitutions, while Israel and co-workers concluded that the rate at which dehalogenation occurred suggested that dehalogenation proceeds in a single concerted step. In this study, we investigated the debromination and nucleophilic substitution of 3-(bromoacetyl)coumarin with a variety of thiophenols, whose electron donating or withdrawing natures resulted in large variations in the degree of nucleophilic substitution and dehalogenation products, respectively. Results from these experiments, in addition to an unexpected formation of thioether containing dibenzo[b,d]pyran-6-ones from a Robinson annulation, has provided new evidence for this disputed mechanism.
- Full Text: false
- Date Issued: 2017
Indolyl-3-ethanone-α-thioethers: a promising new class of non-toxic antimalarial agents
- Svogie, Archibald L, Isaacs, Michelle, Hoppe, Heinrich C, Khanye, Setshaba D, Veale, Clinton G L
- Authors: Svogie, Archibald L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D , Veale, Clinton G L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66233 , vital:28920 , https://doi.org/10.1016/j.ejmech.2016.02.056
- Description: publisher version , The success of chemotherapeutics in easing the burden of malaria is under continuous threat from ever-evolving parasite resistance, including resistance to artemisinin combination therapies. Therefore, the discovery of new classes of antimalarials which inhibit new biological targets is imperative to controlling malaria. Accordingly, we report here the discovery of indolyl-3-ethanone-α-thioethers, a new class of antimalarial compounds with encouraging activity. Synthesis of a focused library of compounds revealed important insight into the SAR of this class of compounds, including critical information regarding the position and chemical nature of substituents on both the thiophenol and indole rings. This investigation ultimately led to the discovery of two hit compounds (16 and 27) which exhibited nano molar in vitro antimalarial activity coupled to no observable toxicity against a HeLa cell line.
- Full Text: false
- Date Issued: 2016
- Authors: Svogie, Archibald L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D , Veale, Clinton G L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66233 , vital:28920 , https://doi.org/10.1016/j.ejmech.2016.02.056
- Description: publisher version , The success of chemotherapeutics in easing the burden of malaria is under continuous threat from ever-evolving parasite resistance, including resistance to artemisinin combination therapies. Therefore, the discovery of new classes of antimalarials which inhibit new biological targets is imperative to controlling malaria. Accordingly, we report here the discovery of indolyl-3-ethanone-α-thioethers, a new class of antimalarial compounds with encouraging activity. Synthesis of a focused library of compounds revealed important insight into the SAR of this class of compounds, including critical information regarding the position and chemical nature of substituents on both the thiophenol and indole rings. This investigation ultimately led to the discovery of two hit compounds (16 and 27) which exhibited nano molar in vitro antimalarial activity coupled to no observable toxicity against a HeLa cell line.
- Full Text: false
- Date Issued: 2016
Facile synthesis and biological evaluation of assorted indolyl-3-amides and esters from a single, stable carbonyl nitrile intermediate
- Veale, Clinton G L, Edkins, Adrienne L, de la Mare, Jo-Anne, de Kock, Carmen, Smith, Peter J, Khanye, Setshaba D
- Authors: Veale, Clinton G L , Edkins, Adrienne L , de la Mare, Jo-Anne , de Kock, Carmen , Smith, Peter J , Khanye, Setshaba D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66221 , vital:28919 , https://doi.org/10.1016/j.tetlet.2015.02.090
- Description: publisher version , The synthesis of biologically relevant amides and esters is routinely conducted under complex reaction conditions or requires the use of additional catalysts in order to generate sensitive electrophilic species for attack by a nucleophile. Here we present the synthesis of different indolic esters and amides from indolyl-3-carbonyl nitrile, without the requirement of anhydrous reaction conditions or catalysts. Additionally, we screened these compounds for potential in vitro antimalarial and anticancer activity, revealing 1H-indolyl-3-carboxylic acid 3-(indolyl-3-carboxamide)aminobenzyl ester to have moderate activity against both lines.
- Full Text: false
- Date Issued: 2015
- Authors: Veale, Clinton G L , Edkins, Adrienne L , de la Mare, Jo-Anne , de Kock, Carmen , Smith, Peter J , Khanye, Setshaba D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66221 , vital:28919 , https://doi.org/10.1016/j.tetlet.2015.02.090
- Description: publisher version , The synthesis of biologically relevant amides and esters is routinely conducted under complex reaction conditions or requires the use of additional catalysts in order to generate sensitive electrophilic species for attack by a nucleophile. Here we present the synthesis of different indolic esters and amides from indolyl-3-carbonyl nitrile, without the requirement of anhydrous reaction conditions or catalysts. Additionally, we screened these compounds for potential in vitro antimalarial and anticancer activity, revealing 1H-indolyl-3-carboxylic acid 3-(indolyl-3-carboxamide)aminobenzyl ester to have moderate activity against both lines.
- Full Text: false
- Date Issued: 2015
Expanding the SAR of Nontoxic Antiplasmodial Indolyl-3-ethanone Ethers and Thioethers.
- Lunga, Mayibongwe J, Chisango, Ruramai Lissa, Weyers, Carli, Isaacs, Michelle, Taylor, Dale, Edkins, Adrienne L, Khanye, Setshaba D, Hoppe, Heinrich C, Veale, Clinton G L
- Authors: Lunga, Mayibongwe J , Chisango, Ruramai Lissa , Weyers, Carli , Isaacs, Michelle , Taylor, Dale , Edkins, Adrienne L , Khanye, Setshaba D , Hoppe, Heinrich C , Veale, Clinton G L
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122908 , vital:35370 , https://doi.org/10.1002/cmdc.201800235
- Description: Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐cyanophenyl)thio]ethanone (13) and 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain. Furthermore, these compounds were found to be nontoxic to HeLa cells as well as being non‐haemolytic to uninfected red blood cells. Intriguingly, several of our most promising compounds were found to be less active against the isogenic NF54 strain, highlighting possible issues with long‐term dependability of malarial strains. Finally compound 14 displayed similar activity against both the NF54 and K1 strains, suggesting that it inhibits a pathway that is uncompromised by K1 resistance.
- Full Text:
- Authors: Lunga, Mayibongwe J , Chisango, Ruramai Lissa , Weyers, Carli , Isaacs, Michelle , Taylor, Dale , Edkins, Adrienne L , Khanye, Setshaba D , Hoppe, Heinrich C , Veale, Clinton G L
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122908 , vital:35370 , https://doi.org/10.1002/cmdc.201800235
- Description: Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐cyanophenyl)thio]ethanone (13) and 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain. Furthermore, these compounds were found to be nontoxic to HeLa cells as well as being non‐haemolytic to uninfected red blood cells. Intriguingly, several of our most promising compounds were found to be less active against the isogenic NF54 strain, highlighting possible issues with long‐term dependability of malarial strains. Finally compound 14 displayed similar activity against both the NF54 and K1 strains, suggesting that it inhibits a pathway that is uncompromised by K1 resistance.
- Full Text:
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