1
|
Egunlusi AO, Malan SF, Palchykov VA, Joubert J. Calcium Modulating Effect of Polycyclic Cages: A Suitable Therapeutic Approach Against Excitotoxic-induced Neurodegeneration. Mini Rev Med Chem 2024; 24:MRMC-EPUB-137761. [PMID: 38275027 DOI: 10.2174/0113895575273868231128104121] [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: 09/06/2023] [Revised: 10/09/2023] [Accepted: 10/23/2023] [Indexed: 01/27/2024]
Abstract
Neurodegenerative disorders pose a significant challenge to global healthcare systems due to their progressive nature and the resulting loss of neuronal cells and functions. Excitotoxicity, characterized by calcium overload, plays a critical role in the pathophysiology of these disorders. In this review article, we explore the involvement of calcium dysregulation in neurodegeneration and neurodegenerative disorders. A promising therapeutic strategy to counter calcium dysregulation involves the use of calcium modulators, particularly polycyclic cage compounds. These compounds, structurally related to amantadine and memantine, exhibit neuroprotective properties by attenuating calcium influx into neuronal cells. Notably, the pentacycloundecylamine NGP1-01, a cage-like structure, has shown efficacy in inhibiting both N-methyl-D-aspartate (NMDA) receptors and voltage-gated calcium channels (VGCCs), making it a potential candidate for neuroprotection against excitotoxic-induced neurodegenerative disorders. The structure-activity relationship of polycyclic cage compounds is discussed in detail, highlighting their calcium-inhibitory activities. Various closed, open, and rearranged cage compounds have demonstrated inhibitory effects on calcium influx through NMDA receptors and VGCCs. Additionally, these compounds have exhibited neuroprotective properties, including free radical scavenging, attenuation of neurotoxicities, and reduction of neuroinflammation. Although the calcium modulatory activities of polycyclic cage compounds have been extensively studied, apart from amantadine and memantine, none have undergone clinical trials. Further in vitro and in vivo studies and subsequent clinical trials are required to establish the efficacy and safety of these compounds. The development of polycyclic cages as potential multifunctional agents for treating complex neurodegenerative diseases holds great promise.
Collapse
Affiliation(s)
- Ayodeji O Egunlusi
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Sarel F Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Vitalii A Palchykov
- Research Institute of Chemistry and Geology, Oles Honchar Dnipro National University, 72 Gagarina Av., Dnipro 49010, Ukraine
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| |
Collapse
|
2
|
Kapp E, Calitz H, Streicher EM, Dippenaar A, Egieyeh S, Jordaan A, Warner DF, Joubert J, Malan SF, Sampson SL. Discovery and biological evaluation of an adamantyl-amide derivative with likely MmpL3 inhibitory activity. Tuberculosis (Edinb) 2023; 141:102350. [PMID: 37244249 DOI: 10.1016/j.tube.2023.102350] [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: 11/01/2022] [Revised: 05/02/2023] [Accepted: 05/07/2023] [Indexed: 05/29/2023]
Abstract
A series of molecules containing bulky lipophilic scaffolds was screened for activity against Mycobacterium tuberculosis and a number of compounds with antimycobacterial activity were identified. The most active compound, (2E)-N-(adamantan-1-yl)-3-phenylprop-2-enamide (C1), has a low micromolar minimum inhibitory concentration, low cytotoxicity (therapeutic index = 32.26), low mutation frequency and is active against intracellular Mycobacterium tuberculosis. Whole genome sequencing of mutants resistant to C1 showed a mutation in mmpL3 which may point to the involvement of MmpL3 in the antimycobacterial activity of the compound. In silico mutagenesis and molecular modelling studies were performed to better understand the binding of C1 within MmpL3 and the role that the specific mutation may play in the interaction at protein level. These analyses revealed that the mutation increases the energy required for binding of C1 within the protein translocation channel of MmpL3. The mutation also decreases the solvation energy of the protein, suggesting that the mutant protein might be more solvent-accessible, thereby restricting its interaction with other molecules. The results reported here describe a new molecule that may interact with the MmpL3 protein, providing insights into the effect of mutations on protein-ligand interactions and enhancing our understanding of this essential protein as a priority drug target.
Collapse
Affiliation(s)
- Erika Kapp
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Hanri Calitz
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.
| | - Elizabeth M Streicher
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.
| | - Anzaan Dippenaar
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa; Global Health Institute, Department of Family Medicine and Population Health, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Gouverneur Kinsbergencentrum, Doornstraat 331, 2610, Wilrijk, Belgium.
| | - Samuel Egieyeh
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Audrey Jordaan
- Molecular Mycobacteriology Research Unit, DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa.
| | - Digby F Warner
- Molecular Mycobacteriology Research Unit, DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa.
| | - Jacques Joubert
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Sarel F Malan
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Samantha L Sampson
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.
| |
Collapse
|
3
|
Joubert J, Malan SF, Geldenhuys WJ. Editorial: Channel Modulation in Neurodegeneration and Neuroprotection. Front Pharmacol 2022; 13:872103. [PMID: 35401197 PMCID: PMC8983928 DOI: 10.3389/fphar.2022.872103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/07/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Jacques Joubert
- Pharmaceutical Sciences, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Sarel F Malan
- Pharmaceutical Sciences, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Werner J Geldenhuys
- Department of Pharmaceutical Science, School of Pharmacy, West Virginia University, Morgantown, WV, United States
| |
Collapse
|
4
|
Zondagh LS, Joubert J, Omoruyi S, Mentor S, Malan SF, Ekpo OE, Fisher D. Multifunctional edaravone‐N‐benzyl pyridinium derivatives: AChE inhibition kinetics,
in vitro
neuroprotective activities and BBB permeability studies. Alzheimers Dement 2021. [DOI: 10.1002/alz.053939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Sarel F Malan
- University of the Western Cape Cape Town South Africa
| | - Okobi E Ekpo
- University of the Western Cape Cape Town South Africa
| | - David Fisher
- University of the Western Cape Cape Town South Africa
| |
Collapse
|
5
|
Mzezewa SC, Omoruyi SI, Zondagh LS, Malan SF, Ekpo OE, Joubert J. Design, synthesis, and evaluation of 3,7-substituted coumarin derivatives as multifunctional Alzheimer's disease agents. J Enzyme Inhib Med Chem 2021; 36:1607-1621. [PMID: 34281458 PMCID: PMC8291583 DOI: 10.1080/14756366.2021.1913137] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Multitarget directed ligands (MTDLs) are emerging as promising treatment options for Alzheimer's disease (AD). Coumarin derivatives serve as a good starting point for designing MTDLs due to their inherent inhibition of monoamine oxidase (MAO) and cholinesterase enzymes, which are complicit in AD's complex pathophysiology. A preliminary series of 3,7-substituted coumarin derivatives were synthesised and evaluated for enzyme inhibitory activity, cytotoxicity as well as neuroprotective ability. The results indicated that the compounds are weak cholinesterase inhibitors with five compounds demonstrating relatively potent inhibition and selectivity towards MAO-B with IC50 values between 0.014 and 0.498 hx00B5;µM. Significant neuroprotective effects towards MPP+-compromised SH-SY5Y neuroblastoma cells were also observed, with no inherent cytotoxicity at 10 µM for all compounds. The overall results demonstrated that substitution of the phenylethyloxy moiety at the 7-position imparted superior general activity to the derivatives, with the propargylamine substitution at the 3-position, in particular, displaying the best MAO-B selectivity and neuroprotection.
Collapse
Affiliation(s)
- Sheunopa C Mzezewa
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Sylvester I Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Luke S Zondagh
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Sarel F Malan
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Okobi E Ekpo
- Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Jacques Joubert
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| |
Collapse
|
6
|
Egieyeh S, Malan SF, Christoffels A. Cheminformatics techniques in antimalarial drug discovery and development from natural products 2: Molecular scaffold and machine learning approaches. Physical Sciences Reviews 2021. [DOI: 10.1515/psr-2019-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A large number of natural products, especially those used in ethnomedicine of malaria, have shown varying in-vitro antiplasmodial activities. Cheminformatics involves the organization, integration, curation, standardization, simulation, mining and transformation of pharmacology data (compounds and bioactivity) into knowledge that can drive rational and viable drug development decisions. This chapter will review the application of two cheminformatics techniques (including molecular scaffold analysis and bioactivity predictive modeling via Machine learning) to natural products with in-vitro and in-vivo antiplasmodial activities in order to facilitate their development into antimalarial drug candidates and design of new potential antimalarial compounds.
Collapse
Affiliation(s)
- Samuel Egieyeh
- School of Pharmacy , University of the Western Cape Faculty of Natural Science , Belville , South Africa
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute , University of the Western Cape Faculty of Natural Science , Belville , South Africa
| | - Sarel F. Malan
- School of Pharmacy , University of the Western Cape Faculty of Natural Science , Belville , South Africa
| | - Alan Christoffels
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute , University of the Western Cape Faculty of Natural Science , Belville , South Africa
| |
Collapse
|
7
|
Kareem AI, Malan SF, Joubert J. Radical Releasing Anti-Tuberculosis Agents and the Treatment of Mycobacterial Tuberculosis Infections - An Overview. Mini Rev Med Chem 2021; 22:387-407. [PMID: 33605858 DOI: 10.2174/1389557521666210219161045] [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: 08/11/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 11/22/2022]
Abstract
The treatment and management of tuberculosis (TB) is a major global concern. Approved drugs for the treatment of TB to date displayed various modes of action which can be grouped into radical releasing and non-radical releasing anti TB agents. Radical releasing agents are of special interest because they diffuse directly into the mycobacterium cell wall, interact with the host cell DNA causing DNA strand breakages and fatal destabilization of the DNA helix inhibiting nucleic acid synthase. As a therapeutic agent with aforementioned activity, nitroimidazoles and most especially bicyclic nitroimidazoles are currently in clinical use for the treatment of tuberculosis. However, the approved drugs, pretomanid (PR) and delamanid (DE) are limited in their nitric oxide radical (NO•) releasing abilities to cause effective bactericidity. It is believed that their bactericidal activity can be improved by harnessing alternative strategies to increase NO• release. The last decade has witness the strategic inclusion of NO-donors into native drugs to improve their activities and/or reverse resistance. The rationale behind this strategy is the targeting of NO• release at specific therapeutic sites. This review therefore aims to highlight various radical releasing agents that may be effective in the treatment of TB. The review also investigates various structural modification to PR and DE and suggests alternative strategies to improve NO• release as well as some applications where NO-donor hybrid drugs have been used with good therapeutic effect.
Collapse
Affiliation(s)
- Afeez I Kareem
- Department of Pharmaceutical Chemistry, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Bellville 7535. South Africa
| | - Sarel F Malan
- Department of Pharmaceutical Chemistry, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Bellville 7535. South Africa
| | - Jacques Joubert
- Department of Pharmaceutical Chemistry, Faculty of Natural Sciences, University of the Western Cape, Private Bag X17, Bellville 7535. South Africa
| |
Collapse
|
8
|
Zondagh LS, Malan SF, Joubert J. Design, synthesis and biological evaluation of edaravone derivatives bearing the N-benzyl pyridinium moiety as multifunctional anti-Alzheimer's agents. J Enzyme Inhib Med Chem 2020; 35:1596-1605. [PMID: 32779503 PMCID: PMC7470113 DOI: 10.1080/14756366.2020.1801673] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/15/2020] [Accepted: 07/18/2020] [Indexed: 12/31/2022] Open
Abstract
A series of multi-target directed edaravone derivatives bearing N-benzyl pyridinium moieties were designed and synthesised. Edaravone is a potent antioxidant with significant neuroprotective effects and N-benzyl pyridinium has previously exhibited positive results as part of a dual-site binding, peripheral anionic site (PAS) and catalytic anionic site (CAS), acetylcholinesterase (AChE) inhibitor. The designed edaravone-N-benzyl pyridinium hybrid compounds were docked within the AChE active site. The results indicated interactions with conserved amino acids (Trp279 in PAS and Trp84 in CAS), suggesting good dual-site inhibitory activity. Significant in vitro AChE inhibitory activities were observed for selected compounds (IC50: 1.2-4.6 µM) with limited butyrylcholinesterase inhibitory activity (IC50's >160 µM), indicating excellent selectivity towards AChE (SI: 46 - >278). The compounds also showed considerable antioxidant ability, similar to edaravone. In silico studies indicated that these compounds should cross the blood-brain barrier, making them promising lead molecules in the development of anti-Alzheimer's agents.
Collapse
Affiliation(s)
- Luke S. Zondagh
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Sarel F. Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| |
Collapse
|
9
|
Egunlusi AO, Malan SF, Omoruyi SI, Ekpo OE, Joubert J. 4-Oxatricyclo[5.2.1.0 2,6]dec-8-ene-3,5-dione Derivatives as NMDA Receptor- and VGCC Blockers with Neuroprotective Potential. Molecules 2020; 25:E4552. [PMID: 33027964 PMCID: PMC7582567 DOI: 10.3390/molecules25194552] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/30/2020] [Indexed: 11/30/2022] Open
Abstract
The impact of excitotoxicity mediated by N-methyl-D-aspartate (NMDA) receptor overactivation and voltage gated calcium channel (VGCC) depolarization is prominent among the postulated processes involved in the development of neurodegenerative disorders. NGP1-01, a polycyclic amine, has been shown to be neuroprotective through modulation of the NMDA receptor and VGCC, and attenuation of MPP+-induced neurotoxicity. Recently, we reported on the calcium modulating effects of tricycloundecene derivatives, structurally similar to NGP1-01, on the NMDA receptor and VGCC of synaptoneurosomes. In the present study, we investigated novel 4-oxatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives for their cytotoxicity, neuroprotective effects via attenuation of MPP+-induced neurotoxicity and calcium influx inhibition abilities through the NMDA receptor and VGCC using neuroblastoma SH-SY5Y cells. All compounds, in general, showed low or no toxicity against neuroblastoma cells at 10-50 µM concentrations. At 10 µM, all compounds significantly attenuated MPP+-induced neurotoxicity as evident by the enhancement in cell viability between 23.05 ± 3.45% to 53.56 ± 9.29%. In comparison to known active compounds, the derivatives demonstrated mono or dual calcium modulating effect on the NMDA receptor and/or VGCC. Molecular docking studies using the NMDA receptor protein structure indicated that the compounds are able to bind in a comparable manner to the crystallographic pose of MK-801 inside the NMDA ion channel. The biological characteristics, together with results from in silico studies, suggest that these compounds could act as neuroprotective agents for the purpose of halting or slowing down the degenerative processes in neuronal cells.
Collapse
Affiliation(s)
- Ayodeji O. Egunlusi
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| | - Sarel F. Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| | - Sylvester I. Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (S.I.O.); (O.E.E.)
| | - Okobi E. Ekpo
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (S.I.O.); (O.E.E.)
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| |
Collapse
|
10
|
Egunlusi AO, Malan SF, Joubert J. Synthesis of 4-oxatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives as lead scaffolds for neuroprotective agents. ARKIVOC 2020. [DOI: 10.24820/ark.5550190.p011.302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
11
|
Robertson JS, Chui WK, Genazzani AA, Malan SF, López de la Rica Manjavacas A, Mignot G, Thorpe R, Balocco R, Rizzi M. The INN global nomenclature of biological medicines: A continuous challenge. Biologicals 2019; 60:15-23. [PMID: 31130314 DOI: 10.1016/j.biologicals.2019.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 02/21/2019] [Revised: 05/07/2019] [Accepted: 05/14/2019] [Indexed: 10/26/2022] Open
Abstract
Medicines are assigned International Nonproprietary Names (INN) by the World Health Organization (WHO), pursuing the aim to increase patient safety. Following scientific developments in drug discovery and biotechnology, the number of biological medicines is constantly growing and a surge in INN applications for them has been observed. Pharmacologically active biological substances have a complex structure and mechanism of action posing new challenges in selecting names that appropriately reflect such properties. As a consequence, existing nomenclature naming schemes may need to be revised and new ones developed. This review reports on the recently implemented policies for naming fusion proteins, monoclonal antibodies, advanced therapy substances that cover gene and cell therapy, virus-based therapies as well as vaccines and vaccine-like substances. Different approaches, based on the use of a one-word versus a two-word naming scheme, have been developed for different categories of biological substances highlighting a major and still not completely resolved issue, i.e. how to assign a name that is both informative, short and euphonic.
Collapse
Affiliation(s)
| | - Wai-Keung Chui
- Department of Pharmacy, National University of Singapore, Singapore
| | - Armando A Genazzani
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Sarel F Malan
- School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | | | | | | | - Raffaella Balocco
- INN Programme, TSN/RHT/MVP, World Health Organization, Geneva, Switzerland
| | - Menico Rizzi
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy.
| |
Collapse
|
12
|
Joubert J, Strydom N, Geldenhuys WJ, Greyling Y, V. Dyk S, Malan SF. Hexacyclododecylamines with Sigma-1 Receptor Affinity and Calcium Channel Modulating Ability. TOMCJ 2019. [DOI: 10.2174/1874104501913010029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Introduction:
Recent research points to the Sigma Receptor (σR) as a possible neuromodulatory system with multi-functional action and σ1Rs have been suggested as a drug target for a number of CNS conditions. Hexacyclododecylamines have shown σ1R activity and provide an advantageous scaffold for drug design that can improve the blood-brain barrier permeability of privileged structures.
Methods and Materials:
A series of oxa- and aza- hexaxcyclododecylamines were synthesised and evaluated for sigma-1 receptor activity and voltage-gated calcium channel blocking ability to determine the effect of inclusion of amine containing heterocycles.
Results & Discussion:
The compounds had promising σ1R activities (Ki = 0.067 – 11.86 µM) with the aza-hexacyclododecylamines 12, 24 and 27 showing some of the highest affinities (Ki = 0.067 µM, 0.215 µM and 0.496 µM respectively). This confirms, as observed in previous studies, that the aza compounds are more favourable for σ1R binding than their oxa counterparts. The addition of the amine heterocycle showed affinities similar to that of related structures with only two lipophilic binding regions. This indicates that the inclusion of an amine heterocycle into these structures is a viable option in the design of new σ1R ligands. Significant voltage-gated calcium channel blocking ability was also observed for 12, 24 and 27, suggesting a link between σ1R activity and intracellular calcium levels.
Conclusion:
The σ1R activity and potential effect on other receptor classes and calcium channels could prove beneficial in pharmacological application.
Collapse
|
13
|
Zindo FT, Malan SF, Omoruyi SI, Enogieru AB, Ekpo OE, Joubert J. Design, synthesis and evaluation of pentacycloundecane and hexacycloundecane propargylamine derivatives as multifunctional neuroprotective agents. Eur J Med Chem 2019; 163:83-94. [DOI: 10.1016/j.ejmech.2018.11.051] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/09/2018] [Accepted: 11/21/2018] [Indexed: 01/15/2023]
|
14
|
Joubert J, Foxen EB, Malan SF. Microwave Optimized Synthesis of N-(adamantan-1-yl)-4-[(adamantan-1-yl)-sulfamoyl]benzamide and Its Derivatives for Anti-Dengue Virus Activity. Molecules 2018; 23:molecules23071678. [PMID: 29996497 PMCID: PMC6099921 DOI: 10.3390/molecules23071678] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 06/25/2018] [Accepted: 06/26/2018] [Indexed: 11/23/2022] Open
Abstract
Dengue fever is a major public health concern in many tropical and sub-tropical regions. The development of agents that are able to inhibit the dengue virus (DENV) is therefore of utmost importance. This study focused on the synthesis of dual acting hybrids comprising structural features of known DENV inhibitors, amantadine (1) and benzsulfonamide derivatives. Hybrid compound 3, N-(adamantan-1-yl)-4-[(adamantan-1-yl)sulfamoyl]benzamide, was synthesized by reacting amantadine (1) with 4-(chlorosulfonyl)benzoic acid (2), after optimization, in a 2:1 ratio under microwave irradiation conditions in a one-pot reaction. Mono-adamantane derivatives 6 and 7 were synthesised via acyl halide formation of benzoic acid (4) and 4-sulfamoyl benzoic acid (5), respectively, followed by conjugation with amantadine (1) through a conventional or microwave irradiation assisted nucleophilic addition/substitution reaction. The use of microwave irradiation lead to significant increases in yields and a reduction in reaction times. Nuclear magnetic resonance, infra-red and mass spectral data confirmed the structures. Compound 3 and 7 showed significant anti-DENV serotype 2 activity (IC50 = 22.2 µM and 42.8 µM) and low cytotoxicity (CC50 < 100 µM). Possible mechanisms of action are also proposed, which are based on the biological results and molecular docking studies.
Collapse
Affiliation(s)
- Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville 7530, South Africa.
| | - Eugene B Foxen
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville 7530, South Africa.
| | - Sarel F Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville 7530, South Africa.
| |
Collapse
|
15
|
Sharma R, Joubert J, Malan SF. Recent Developments in Drug Design of NO-donor Hybrid Compounds. Mini Rev Med Chem 2018; 18:1175-1198. [DOI: 10.2174/1389557518666180416150005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/28/2017] [Accepted: 04/09/2018] [Indexed: 11/22/2022]
Affiliation(s)
- Rajan Sharma
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville, South Africa
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville, South Africa
| | - Sarel F. Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville, South Africa
| |
Collapse
|
16
|
Abstract
INTRODUCTION Indazoles are heterocyclic moieties rarely found in nature. They are nitrogen containing chemical compounds composed of a pyrazole ring condensed with a benzene ring. Various indazole derivatives have been described with a wide variety of biological activities. This has aroused great interest in the development of novel indazole based therapeutic agents. AREAS COVERED Forty-two patents published within the last 5 years (2013-2017) describing derivatives with the indazole scaffold and their therapeutic applications were analysed. EXPERT OPINION The indazole scaffold is of great pharmacological importance as it forms the basic structure of a large number of compounds with potential therapeutic value. Derivatives have been found to possess promising anticancer and anti-inflammatory activity and have also found application in disorders involving protein kinases (aside from cancer) and neurodegeneration. The compounds where mechanism of action is defined can afford new molecules with biological and therapeutic properties.
Collapse
Affiliation(s)
- Ireen Denya
- a Pharmaceutical Chemistry, School of Pharmacy , University of the Western Cape , Bellville , South Africa
| | - Sarel F Malan
- a Pharmaceutical Chemistry, School of Pharmacy , University of the Western Cape , Bellville , South Africa
| | - Jacques Joubert
- a Pharmaceutical Chemistry, School of Pharmacy , University of the Western Cape , Bellville , South Africa
| |
Collapse
|
17
|
Repsold BP, Malan SF, Joubert J, Oliver DW. Multi-targeted directed ligands for Alzheimer's disease: design of novel lead coumarin conjugates. SAR QSAR Environ Res 2018; 29:231-255. [PMID: 29390885 DOI: 10.1080/1062936x.2018.1423641] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [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: 10/30/2017] [Accepted: 01/01/2018] [Indexed: 06/07/2023]
Abstract
Alzheimer's Disease (AD) is a neurodegenerative disease characterized by central nervous system insults with progressive cognitive (memory, attention) and non-cognitive (anxiety, depression) impairments. Pathophysiological events affect predominantly cholinergic neuronal loss and dysfunctions of the dopaminergic system. The aim of the current study was to design multi-targeted directed lead structures based on the coumarin scaffold with inhibitory properties at two key enzymes in disease relevant systems, i.e. acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B). Conventional and microwave synthetic methods were utilized to synthesize coumarin scaffold-based novel morpholino, piperidino, thiophene and erucic acid conjugates. Biological assays indicated that the coumarin-morpholine ether conjugate BPR 10 was the most potent hMAO-B inhibitor. The coumarin-piperidine conjugates BPR 13 and BPR 12 were the most potent inhibitors of eeAChE at 100 μM and 1 μM, respectively. Molecular modelling studies were conducted with Accelrys® Discovery Studio® V3.1.1 utilising the published hMAO-B (2V61) and hAChE (4EY7) crystal structures. Compound BPR 10 occupies both the entrance and substrate cavities of the active site of MAO-B. BPR 13 resides in both the peripheral anionic site (PAS) and the catalytic anionic site (CAS) of hAChE. This study demonstrated that the coumarin scaffold serves as a promising pharmacophore for MTDLs design.
Collapse
Affiliation(s)
- B P Repsold
- a Pharmaceutical Chemistry, School of Pharmacy , North-West University , Potchefstroom , South Africa
| | - S F Malan
- b Pharmaceutical Chemistry, School of Pharmacy , University of the Western Cape , Bellville , South Africa
| | - J Joubert
- b Pharmaceutical Chemistry, School of Pharmacy , University of the Western Cape , Bellville , South Africa
| | - D W Oliver
- a Pharmaceutical Chemistry, School of Pharmacy , North-West University , Potchefstroom , South Africa
| |
Collapse
|
18
|
Denya I, Malan SF, Enogieru AB, Omoruyi SI, Ekpo OE, Kapp E, Zindo FT, Joubert J. Design, synthesis and evaluation of indole derivatives as multifunctional agents against Alzheimer's disease. Medchemcomm 2018; 9:357-370. [PMID: 30108930 DOI: 10.1039/c7md00569e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/14/2018] [Indexed: 12/25/2022]
Abstract
A series of indole derivatives was designed and synthesised to improve on activity and circumvent pharmacokinetic limitations experienced with the structurally related compound, ladostigil. The compounds consisted of a propargylamine moiety (a known MAO inhibitor and neuroprotector) at the N1 position and a ChE inhibiting diethyl-carbamate/urea moiety at the 5 or 6 position of the indole ring. In order to prevent or slow down the in vivo hydrolysis and deactivation associated with the carbamate function of ladostigil, a urea moeity was incorporated into selected compounds to obtain more metabolically stable structures. The majority of the synthesised compounds showed improved MAO-A inhibitory activity compared to ladostigil. The compounds possessing the propargylamine moiety showed good MAO-B inhibitory activity with 6 and 8 portraying IC50 values between 14-20 fold better than ladostigil. The ChE assay results indicated that the compounds have non-selective inhibitory activities on eeAChE and eqBuChE regardless of the type or position of substitution (IC50: 2-5 μM). MAO-A and MAO-B docking results showed that the propargylamine moiety was positioned in close proximity to the FAD cofactor suggesting that the good inhibitory activity may be attributed to the propargylamine moiety and irreversible inhibition as confirmed in the reversibility studies. Docking results also indicated that the compounds have interactions with important amino acids in the AChE and BuChE catalytic sites. Compound 6 was the most potent multifunctional agent showing better inhibitory activity than ladostigil in vitro on all enzymes tested (hMAO-A IC50 = 4.31 μM, hMAO-B IC50 = 2.62 μM, eeAChE IC50 = 3.70 μM, eqBuChE IC50 = 2.82 μM). Chemical stability tests confirmed the diethyl-urea containing compound 6 to be more stable than its diethyl-carbamate containing counterpart compound 8. Compound 6 also exerted significant neuroprotection (52.62% at 1 μM) against MPP+ insult to SH-SY5Y neural cells and has good in silico predicted ADMET properties. The favourable neuronal enzyme inhibitory activity, likely improved pharmacokinetic properties in vivo and the potent neuroprotective ability of compound 6 make it a promising compound for further development.
Collapse
Affiliation(s)
- Ireen Denya
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Sarel F Malan
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Adaze B Enogieru
- Department of Medical Biosciences , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa
| | - Sylvester I Omoruyi
- Department of Medical Biosciences , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa
| | - Okobi E Ekpo
- Department of Medical Biosciences , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa
| | - Erika Kapp
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Frank T Zindo
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Jacques Joubert
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| |
Collapse
|
19
|
Kapp E, Malan SF, Joubert J, Sampson SL. Small Molecule Efflux Pump Inhibitors in Mycobacterium tuberculosis: A Rational Drug Design Perspective. Mini Rev Med Chem 2018; 18:72-86. [PMID: 28494730 DOI: 10.2174/1389557517666170510105506] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 01/11/2017] [Revised: 03/20/2017] [Accepted: 04/26/2017] [Indexed: 11/22/2022]
Abstract
Drug resistance in Mycobacterium tuberculosis (M. tuberculosis) complicates management of tuberculosis. Efflux pumps contribute to low level resistance and acquisition of additional high level resistance mutations through sub-therapeutic concentrations of intracellular antimycobacterials. Various efflux pump inhibitors (EPIs) have been described for M. tuberculosis but little is known regarding the mechanism of efflux inhibition. As knowledge relating to the mechanism of action and drug target is central to the rational drug design of safe and sufficiently selective EPIs, this review aims to examine recent developments in the study of EPIs in M. tuberculosis from a rational drug development perspective and to provide an overview to facilitate systematic development of therapeutically effective EPIs. Review of literature points to a reduction in cellular energy or direct binding to the efflux pump as likely mechanisms for most EPIs described for M. tuberculosis. This review demonstrates that, where a direct interaction with efflux pumps is expected, both molecular structure and general physicochemical properties should be considered to accurately predict efflux pump substrates and inhibitors. Non-competitive EPIs do not necessarily demonstrate the same requirements as competitive inhibitors and it is therefore essential to differentiate between competitive and non-competitive inhibition to accurately determine structure activity relationships for efflux pump inhibition. It is also evident that there are various similarities between inhibitors of prokaryotic and eukaryotic efflux pumps but, depending on the specific chemical scaffolds under investigation, it may be possible to design EPIs that are less prone to inhibition of human P-glycoprotein, thereby reducing side effects and drug-drug interactions.
Collapse
Affiliation(s)
- Erika Kapp
- University of the Western Cape, School of Pharmacy Bellville, Bellville, South Africa
| | - Sarel F Malan
- University of the Western Cape, School of Pharmacy Bellville, Bellville, South Africa
| | - Jacques Joubert
- University of the Western Cape, School of Pharmacy Bellville, Bellville, South Africa
| | - Samantha L Sampson
- University of Stellenbosh, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences Bellville, Bellville, Western Cape, South Africa
| |
Collapse
|
20
|
Kapp E, Visser H, Sampson SL, Malan SF, Streicher EM, Foka GB, Warner DF, Omoruyi SI, Enogieru AB, Ekpo OE, Zindo FT, Joubert J. Versatility of 7-Substituted Coumarin Molecules as Antimycobacterial Agents, Neuronal Enzyme Inhibitors and Neuroprotective Agents. Molecules 2017; 22:molecules22101644. [PMID: 28973990 PMCID: PMC6151660 DOI: 10.3390/molecules22101644] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 09/21/2017] [Accepted: 09/27/2017] [Indexed: 11/16/2022] Open
Abstract
A medium-throughput screen using Mycobacterium tuberculosis H37Rv was employed to screen an in-house library of structurally diverse compounds for antimycobacterial activity. In this initial screen, eleven 7-substituted coumarin derivatives with confirmed monoamine oxidase-B and cholinesterase inhibitory activities, demonstrated growth inhibition of more than 50% at 50 µM. This prompted further exploration of all the 7-substituted coumarins in our library. Four compounds showed promising MIC99 values of 8.31–29.70 µM and 44.15–57.17 µM on M. tuberculosis H37Rv in independent assays using GAST-Fe and 7H9+OADC media, respectively. These compounds were found to bind to albumin, which may explain the variations in MIC between the two assays. Preliminary data showed that they were able to maintain their activity in fluoroquinolone resistant mycobacteria. Structure-activity relationships indicated that structural modification on position 4 and/or 7 of the coumarin scaffold could direct the selectivity towards either the inhibition of neuronal enzymes or the antimycobacterial effect. Moderate cytotoxicities were observed for these compounds and slight selectivity towards mycobacteria was indicated. Further neuroprotective assays showed significant neuroprotection for selected compounds irrespective of their neuronal enzyme inhibitory properties. These coumarin molecules are thus interesting lead compounds that may provide insight into the design of new antimicrobacterial and neuroprotective agents.
Collapse
Affiliation(s)
- Erika Kapp
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Hanri Visser
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, Tygerberg 7505, South Africa.
| | - Samantha L Sampson
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, Tygerberg 7505, South Africa.
| | - Sarel F Malan
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Elizabeth M Streicher
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, Tygerberg 7505, South Africa.
| | - Germaine B Foka
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Digby F Warner
- Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit, Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Institute of Infectious Disease and Molecular Medicine and Department of Clinical Laboratory Sciences, University of Cape Town, Cape Town, Rondebosch 7700, South Africa.
| | - Sylvester I Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Adaze B Enogieru
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Okobi E Ekpo
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Frank T Zindo
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Jacques Joubert
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| |
Collapse
|
21
|
Teponnou GAK, Joubert J, Malan SF. Tacrine, Trolox and Tryptoline as Lead Compounds for the Design and Synthesis of Multi-target Agents for Alzheimer's Disease Therapy. Open Med Chem J 2017; 11:24-37. [PMID: 28567126 PMCID: PMC5418947 DOI: 10.2174/1874104501711010024] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 12/19/2016] [Accepted: 12/21/2016] [Indexed: 11/22/2022]
Abstract
The versatile biological activities of tacrine, trolox and β-carboline derivatives make them promising lead structures for the development of multifunctional Alzheimer’s disease (AD) agents. Based on the topology of the active site of cholinesterases and other target proteins involved in the pathogenesis of AD, we have designed and synthesized tacrine-trolox and tacrine-tryptoline hybrids with various linker chain lengths. The hybrids containing the trolox moiety (8a-8d) showed moderate to high TcAChE inhibition (IC50: 17.37 - 2200 nM), eqBuChE inhibition (IC50: 3.16 – 128.82 nM) and free radical scavenging activities (IC50: 11.48 – 49.23 µM). The hybrids with longer linker chain lengths in general showed better ChE inhibitory activity. As expected, free radical scavenging activities were not significantly affected by varying linker chain lengths. The hybrid compound containing the tryptoline moiety linked with a 7 carbon spacer to tacrine (14) displayed the best AChE and BuChE inhibitory activity (IC50 = 17.37 and 3.16 nM). Docking experiments exhibited that compounds 8d and 14 were able to bind to both the CAS and PAS of TcAChE and eqBuChE, suggesting that they will be able to inhibit ChE induced Aβ aggregation. Novel multi-target agents that exhibit good ChE inhibition (8d and 14) and anti-oxidant (8d) activity were identified as suitable candidates for further investigation.
Collapse
Affiliation(s)
- Gerard A K Teponnou
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Sarel F Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| |
Collapse
|
22
|
Young LM, Geldenhuys WJ, Domingo OC, Malan SF, Van der Schyf CJ. Synthesis and Biological Evaluation of Pentacycloundecylamines and Triquinylamines as Voltage-Gated Calcium Channel Blockers. Arch Pharm (Weinheim) 2016; 349:252-67. [PMID: 26892182 PMCID: PMC5482218 DOI: 10.1002/ardp.201500293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 01/27/2016] [Accepted: 01/27/2016] [Indexed: 01/21/2023]
Abstract
Preclinical studies for neurodegenerative diseases have shown a multi-targeted approach to be successful in the treatment of these complex disorders with several pathoetiological pathways. Polycyclic compounds, such as NGP1-01 (7a), have demonstrated the ability to target multiple mechanisms of the complex etiology and are referred to as multifunctional compounds. These compounds have served as scaffolds with the ability to attenuate Ca(2+) overload and excitotoxicity through several pathways. In this study, our focus was on mitigating Ca(2+) overload through the L-type calcium channels (LTCC). Here, we report the synthesis and biological evaluation of several novel polycyclic compounds. We determined the IC50 values for both the pentacycloundecylamines and the triquinylamines by means of a high-throughput fluorescence calcium flux assay utilizing Fura-2/AM. The potential of these compounds to offer protection against hydrogen peroxide-induced cell death was also evaluated. Overall, 8-benzylamino-8,11-oxapentacyclo[5.4.0.0(2,6) .0(3,10) .0(5,9) ]undecane (NGP1-01, 7a) had the most favorable pharmacological profile with an IC50 value of 86 µM for LTCC inhibition and significant reduction of hydrogen peroxide-induced cell death. In general, the triquinylamines were more active as LTCC blockers than the oxa-pentacycloundecylamines. The aza-pentacycloundecylamines were potent LTCC inhibitors, with 8-hydroxy-N-phenylethyl-8,11-azapentacyclo[5.4.0.0(2,6) .0(3,10) .0(5,9) ]undecane (8b) also able to offer significant protection in the cell viability assays.
Collapse
Affiliation(s)
- Lois-May Young
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Potchefstroom, South Africa
| | - Werner J. Geldenhuys
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Olwen C. Domingo
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Potchefstroom, South Africa
| | - Sarel F. Malan
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Potchefstroom, South Africa
- School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Cornelis J. Van der Schyf
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, ID, USA
| |
Collapse
|
23
|
Joubert J, Kapp E, Taylor D, Smith PJ, Malan SF. Polycyclic amines as chloroquine resistance modulating agents in Plasmodium falciparum. Bioorg Med Chem Lett 2016; 26:1151-5. [DOI: 10.1016/j.bmcl.2016.01.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 10/22/2022]
|
24
|
Egieyeh SA, Syce J, Malan SF, Christoffels A. Prioritization of anti-malarial hits from nature: chemo-informatic profiling of natural products with in vitro antiplasmodial activities and currently registered anti-malarial drugs. Malar J 2016; 15:50. [PMID: 26823078 PMCID: PMC4731946 DOI: 10.1186/s12936-016-1087-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [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: 08/22/2015] [Accepted: 01/09/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND A large number of natural products have shown in vitro antiplasmodial activities. Early identification and prioritization of these natural products with potential for novel mechanism of action, desirable pharmacokinetics and likelihood for development into drugs is advantageous. Chemo-informatic profiling of these natural products were conducted and compared to currently registered anti-malarial drugs (CRAD). METHODS Natural products with in vitro antiplasmodial activities (NAA) were compiled from various sources. These natural products were sub-divided into four groups based on inhibitory concentration (IC50). Key molecular descriptors and physicochemical properties were computed for these compounds and analysis of variance used to assess statistical significance amongst the sets of compounds. Molecular similarity analysis, estimation of drug-likeness, in silico pharmacokinetic profiling, and exploration of structure-activity landscape were also carried out on these sets of compounds. RESULTS A total of 1040 natural products were selected and a total of 13 molecular descriptors were analysed. Significant differences were observed among the sub-groups of NAA and CRAD for at least 11 of the molecular descriptors, including number of hydrogen bond donors and acceptors, molecular weight, polar and hydrophobic surface areas, chiral centres, oxygen and nitrogen atoms, and shape index. The remaining molecular descriptors, including clogP, number of rotatable bonds and number of aromatic rings, did not show any significant difference when comparing the two compound sets. Molecular similarity and chemical space analysis identified natural products that were structurally diverse from CRAD. Prediction of the pharmacokinetic properties and drug-likeness of these natural products identified over 50% with desirable drug-like properties. Nearly 70% of all natural products were identified as potentially promiscuous compounds. Structure-activity landscape analysis highlighted compound pairs that form 'activity cliffs'. In all, prioritization strategies for the NAA were proposed. CONCLUSIONS Chemo-informatic profiling of NAA and CRAD have produced a wealth of information that may guide decisions and facilitate anti-malarial drug development from natural products. Articulation of the information provided within an interactive data-mining environment led to a prioritized list of NAA.
Collapse
Affiliation(s)
- Samuel Ayodele Egieyeh
- South African Medial Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, Cape Town, South Africa. .,School of Pharmacy, University of the Western Cape, Bellville, Cape Town, South Africa.
| | - James Syce
- School of Pharmacy, University of the Western Cape, Bellville, Cape Town, South Africa.
| | - Sarel F Malan
- School of Pharmacy, University of the Western Cape, Bellville, Cape Town, South Africa.
| | - Alan Christoffels
- South African Medial Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, Cape Town, South Africa.
| |
Collapse
|
25
|
Tavari M, Malan SF, Joubert J. Design, synthesis, biological evaluation and docking studies of sulfonyl isatin derivatives as monoamine oxidase and caspase-3 inhibitors. Med Chem Commun 2016. [DOI: 10.1039/c6md00228e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sulfonyl isatin derivatives as multifunctional agents showing monoamine oxidase and caspase-3 inhibitory activities in the low micromolar range.
Collapse
Affiliation(s)
- Mohsen Tavari
- Pharmaceutical Chemistry
- School of Pharmacy
- University of the Western Cape
- Bellville
- South Africa
| | - Sarel F. Malan
- Pharmaceutical Chemistry
- School of Pharmacy
- University of the Western Cape
- Bellville
- South Africa
| | - Jacques Joubert
- Pharmaceutical Chemistry
- School of Pharmacy
- University of the Western Cape
- Bellville
- South Africa
| |
Collapse
|
26
|
Egunlusi AO, Malan SF, Joubert J. Tricycloundecane Derivatives as PotentialN-Methyl-D-aspartate (NMDA) Receptor and Voltage-Gated Calcium Channel Modulators. ChemMedChem 2015; 10:1259-66. [DOI: 10.1002/cmdc.201500072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 04/16/2015] [Indexed: 01/06/2023]
|
27
|
Kadernani YE, Zindo FT, Kapp E, Malan SF, Joubert J. Adamantane amine derivatives as dual acting NMDA receptor and voltage-gated calcium channel inhibitors for neuroprotection. Med Chem Commun 2014. [DOI: 10.1039/c4md00244j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of adamantane-derived compounds, structurally similar to NGP1-01, were synthesised and showed significant dual NMDA receptor and VGCC inhibitory activities.
Collapse
Affiliation(s)
- Yakub E. Kadernani
- Pharmaceutical Chemistry
- School of Pharmacy
- University of The Western Cape
- Bellville 7535
- South Africa
| | - Frank T. Zindo
- Pharmaceutical Chemistry
- School of Pharmacy
- University of The Western Cape
- Bellville 7535
- South Africa
| | - Erika Kapp
- Pharmaceutical Chemistry
- School of Pharmacy
- University of The Western Cape
- Bellville 7535
- South Africa
| | - Sarel F. Malan
- Pharmaceutical Chemistry
- School of Pharmacy
- University of The Western Cape
- Bellville 7535
- South Africa
| | - Jacques Joubert
- Pharmaceutical Chemistry
- School of Pharmacy
- University of The Western Cape
- Bellville 7535
- South Africa
| |
Collapse
|
28
|
Joubert J, Sharma R, Onani M, Malan SF. Microwave-assisted methods for the synthesis of pentacyclo[5.4.0.02,6.03,10.05,9]undecylamines. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.10.047] [Citation(s) in RCA: 10] [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] [Indexed: 11/15/2022]
|
29
|
Young LM, Zeller M, Geldenhuys WJ, Malan SF, Van der Schyf CJ. Triquinane scaffolds: Shape and geometry as a function of saturation and bridgehead groups. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.04.030] [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]
|
30
|
Geldenhuys WJ, Novotny N, Malan SF, Van der Schyf CJ. 3D-QSAR and docking studies of pentacycloundecylamines at the sigma-1 (σ1) receptor. Bioorg Med Chem Lett 2013; 23:1707-11. [PMID: 23414839 DOI: 10.1016/j.bmcl.2013.01.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/09/2013] [Accepted: 01/16/2013] [Indexed: 11/26/2022]
Abstract
Pentacycloundecylamine (PCU) derived compounds have been shown to be promising lead structures for the development of novel drug candidates aimed at a variety of neurodegenerative and psychiatric diseases. Here we show for the first time a 3D quantitative structure-activity relationship (3D-QSAR) for a series of aza-PCU-derived compounds with activity at the sigma-1 (σ1) receptor. A comparative molecular field analysis (CoMFA) model was developed with a partial least squares cross validated (q(2)) regression value of 0.6, and a non-cross validated r(2) of 0.9. The CoMFA model was effective at predicting the sigma-1 activities of a test set with an r(2) >0.7. We also describe here the docking of the PCU-derived compounds into a homology model of the sigma-1 (σ1) receptor, which was developed to gain insight into binding of these cage compounds to the receptor. Based on docking studies we evaluated in a [(3)H]pentazocine binding assay an oxa-PCU, NGP1-01 (IC50=1.78μM) and its phenethyl derivative (IC50=1.54μM). Results from these studies can be used to develop new compounds with specific affinity for the sigma-1(σ1) receptor.
Collapse
Affiliation(s)
- Werner J Geldenhuys
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University (NEOMED), Rootstown, OH 44272, USA.
| | | | | | | |
Collapse
|
31
|
Joubert J, V. Dyk S, F. Malan S. Small Molecule Fluorescent Ligands as Central Nervous System Imaging Probes. Mini Rev Med Chem 2013; 13:682-96. [DOI: 10.2174/1389557511313050005] [Citation(s) in RCA: 10] [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: 02/17/2012] [Revised: 06/06/2012] [Accepted: 06/14/2012] [Indexed: 11/22/2022]
|
32
|
Malan SF, van Marle A, Menge WM, Zuliani V, Hoffman M, Timmerman H, Leurs R. Corrigendum to “Fluorescent ligands for the histamine H2 receptor: Synthesis and preliminary characterization” [Bioorg. Med. Chem. 12 (2004) 6495–6503. Bioorg Med Chem 2012. [DOI: 10.1016/j.bmc.2012.03.053] [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: 11/26/2022]
|
33
|
Lemmer HJR, Joubert J, van Dyk S, van der Westhuizen FH, Malan SF. S-nitrosylation and attenuation of excessive calcium flux by pentacycloundecane derivatives. Med Chem 2012; 8:361-371. [PMID: 22530904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 06/12/2011] [Accepted: 06/21/2011] [Indexed: 05/31/2023]
Abstract
A novel series of polycyclic amines, containing nitrogen monoxide donating moieties, were synthesised and tested for calcium channel and N-methyl-D-aspartate receptor modulating activity. The synthesised compounds were classified into two groups, based on their nitrogen monoxide donating moieties: unsaturated nitro compounds (1, 2 and 3) and nitro esters, or nitrates (4, 5 and 6). The nitrates were obtained via the reaction of hydroxyl functionalities with thionylchloride nitrate. All of the compounds synthesised exhibited significant (p<0.01) S-nitrosylation capacity. The calcium channel activity of the polycyclic amines was evaluated using a KCl mediated fluorescent calcium flux assay. All the compounds exhibited better calcium channel antagonism than the lead structure, NGP1-01, with compound 1 exhibiting calcium channel blockade comparable to the commercially available nimodipine at concentrations of 10 μM and 1 μM. Compounds 3 and 4 inhibited calcium flux to these levels at 10 μM concentrations. NMDA/glycine mediated N-methyl-D-aspartate receptor (NMDAR) calcium influx inhibition was evaluated at a 100 μM concentration using a fluorescent calcium flux assay. All the compounds exhibited NMDAR antagonism with compounds 1 (25.4%), 2 (20.24%), 3 (33.14%) and 6 (24.55%) showing the most significant NMDAR inhibitory activity (p<0.01). No clear correlation was observed between the S-nitrosylation capabilities of the compounds and their calcium channel activity or NMDAR channel antagonism, indicating that other factors probably play a more decisive role in the mechanism of pentacycloundecylamine channel modulation. This could include the geometric and steric bulk considerations that have been described to contribute to the channel activities of the pentacycloundecylamines. All the compounds synthesised exhibited promising calcium channel and NMDAR channel inhibitory activity and show promise as potential lead compounds for drug development against neurodegeneration.
Collapse
Affiliation(s)
- Hendrik J R Lemmer
- Pharmaceutical Chemistry and Centre for Human Metabonomics, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa
| | | | | | | | | |
Collapse
|
34
|
J.R. Lemmer H, Joubert J, van Dyk S, H. van der Westhuizen F, F. Malan S. S-Nitrosylation and Attenuation of Excessive Calcium Flux by Pentacycloundecane Derivatives. Med Chem 2012. [DOI: 10.2174/157340612800786660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
35
|
J.R. Lemmer H, Joubert J, van Dyk S, H. van der Westhuizen F, F. Malan S. S-Nitrosylation and Attenuation of Excessive Calcium Flux by Pentacycloundecane Derivatives. Med Chem 2012. [DOI: 10.2174/1573406411208030361] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
36
|
Joubert J, Geldenhuys WJ, Van der Schyf CJ, Oliver DW, Kruger HG, Govender T, Malan SF. Polycyclic cage structures as lipophilic scaffolds for neuroactive drugs. ChemMedChem 2012; 7:375-84. [PMID: 22307951 DOI: 10.1002/cmdc.201100559] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Indexed: 11/12/2022]
Abstract
Polycyclic cage scaffolds have been successfully used in the development of numerous lead compounds demonstrating activity in the central nervous system (CNS). Several neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, schizophrenia, and stroke, as well as drug abuse, can be modulated with polycyclic cage derivatives. These cage moieties, including adamantane and pentacycloundecane derivatives, improve the pharmacokinetic and pharmacodynamic properties of conjugated parent drugs and serve as an important scaffold in the design of therapeutically active agents for the treatment of neurological disorders. In this Minireview, we focus on the recent developments in the field of polycyclic cage compounds, as well as the relationship between the lipophilic character of these cage-derived drugs and the ability of such compounds to target and reach the CNS and improve the pharmacodynamic properties of compounds conjugated to it.
Collapse
Affiliation(s)
- Jacques Joubert
- School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | | | | | | | | | | | | |
Collapse
|
37
|
Greeff J, Joubert J, Malan SF, van Dyk S. Antioxidant properties of 4-quinolones and structurally related flavones. Bioorg Med Chem 2012; 20:809-18. [DOI: 10.1016/j.bmc.2011.11.068] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/25/2011] [Accepted: 11/30/2011] [Indexed: 11/15/2022]
|
38
|
Joubert J, Dyk SV, Green IR, Malan SF. Synthesis, evaluation and application of polycyclic fluorescent analogues as N-methyl-d-aspartate receptor and voltage gated calcium channel ligands. Eur J Med Chem 2011; 46:5010-20. [DOI: 10.1016/j.ejmech.2011.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 08/04/2011] [Accepted: 08/05/2011] [Indexed: 11/25/2022]
|
39
|
Joubert J, van Dyk S, Green IR, Malan SF. Synthesis and evaluation of fluorescent heterocyclic aminoadamantanes as multifunctional neuroprotective agents. Bioorg Med Chem 2011; 19:3935-44. [PMID: 21665485 DOI: 10.1016/j.bmc.2011.05.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/12/2011] [Accepted: 05/18/2011] [Indexed: 12/20/2022]
Abstract
A series of fluorescent heterocyclic adamantane amines were synthesised with the goal to develop novel fluorescent ligands for neurological assay development. These derivatives demonstrated multifunctional neuroprotective activity through inhibition of the N-methyl-d-aspartate receptor/ion channel, calcium channels and the enzyme nitric oxide synthase. It also exhibited a high degree of free radical scavenging potential. N-(1-adamantyl)-2-oxo-chromene-3-carboxamide (8), N-adamantan-1-yl-5-dimethyl-amino-1-naphthalenesulfonic acid (11) and N-(1-cyano-2H-isoindol-2-yl) adamantan-1-amine (12) were found to possess a high degree of multifunctionality with favourable physical-chemical properties for bioavailability and blood-brain barrier permeability. The ability of these heterocyclic adamantane amine derivatives as nitric oxide synthase inhibitors, calcium channel modulators, NMDAR inhibitors and effective antioxidants, indicate that they may find application as multifunctional drugs in neuroprotection.
Collapse
Affiliation(s)
- Jacques Joubert
- Department of Pharmaceutical Chemistry, North-West University, Potchefstroom, South Africa
| | | | | | | |
Collapse
|
40
|
Abstract
INTRODUCTION Knowledge of NO and its function in cell signaling has rapidly developed since its biological effects were first described in 1977. It is formed from L-arginine by NOS isoforms (nNOS, iNOS and eNOS). These enzymes are products of separate genes, encoded on three different chromosomes and responsible for regulating a variety of functions within cells and tissues. NOS isoforms are currently under investigation as targets for novel therapeutics in especially neurodegenerative disorders, inflammation and pain. Many important questions regarding these messengers and signaling molecules remain to be answered. AREAS COVERED This review gives an overview of patents covering drug-like inhibitors for the NOS isoforms filed and published within the last 6 years, up to September 2010, as well as insight into recent highlights in this area. EXPERT OPINION The NOS isoforms are attractive targets in drug design for various pathological conditions and have received considerable interest over recent years. With the advances in molecular biology, modeling software, synthesis, bioassays, and our understanding of the NOS enzymes and the function of NO, novel bioavailable and highly selective drug therapies utilizing this mode of action may soon see the light.
Collapse
Affiliation(s)
- Jacques Joubert
- School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | | |
Collapse
|
41
|
Prins LH, Petzer JP, Malan SF. Inhibition of monoamine oxidase by indole and benzofuran derivatives. Eur J Med Chem 2010; 45:4458-66. [DOI: 10.1016/j.ejmech.2010.07.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 06/08/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
|
42
|
Strydom B, Malan SF, Castagnoli N, Bergh JJ, Petzer JP. Inhibition of monoamine oxidase by 8-benzyloxycaffeine analogues. Bioorg Med Chem 2010; 18:1018-28. [DOI: 10.1016/j.bmc.2009.12.064] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/18/2009] [Accepted: 12/28/2009] [Indexed: 10/20/2022]
|
43
|
Prins LH, Petzer JP, Malan SF. Synthesis and in vitro evaluation of pteridine analogues as monoamine oxidase B and nitric oxide synthase inhibitors. Bioorg Med Chem 2009; 17:7523-30. [DOI: 10.1016/j.bmc.2009.09.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/09/2009] [Accepted: 09/10/2009] [Indexed: 11/26/2022]
|
44
|
Van der Walt EM, Milczek EM, Malan SF, Edmondson DE, Castagnoli N, Bergh JJ, Petzer JP. Inhibition of monoamine oxidase by (E)-styrylisatin analogues. Bioorg Med Chem Lett 2009; 19:2509-13. [PMID: 19342233 DOI: 10.1016/j.bmcl.2009.03.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 03/09/2009] [Accepted: 03/10/2009] [Indexed: 01/01/2023]
Abstract
Previous studies have shown that (E)-8-(3-chlorostyryl)caffeine (CSC) is a specific reversible inhibitor of human monoamine oxidase B (MAO-B) and does not bind to human MAO-A. Since the small molecule isatin is a natural reversible inhibitor of both MAO-B and MAO-A, (E)-5-styrylisatin and (E)-6-styrylisatin analogues were synthesized in an attempt to identify inhibitors with enhanced potencies and specificities for MAO-B. The (E)-styrylisatin analogues were found to exhibit higher binding affinities than isatin with the MAO preparations tested. The (E)-5-styrylisatin analogues bound more tightly than the (E)-6 analogue although the latter exhibits the highest MAO-B selectivity. Molecular docking studies with MAO-B indicate that the increased binding affinity exhibited by the (E)-styrylisatin analogues, in comparison to isatin, is best explained by the ability of the styrylisatins to bridge both the entrance cavity and the substrate cavity of the enzyme. Experimental support for this model is shown by the weaker binding of the analogues to the Ile199Ala mutant of human MAO-B. The lower selectivity of the (E)-styrylisatin analogues between MAO-A and MAO-B, in contrast to CSC, is best explained by the differing relative geometries of the aromatic rings for these two classes of inhibitors.
Collapse
Affiliation(s)
- Elizna M Van der Walt
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
| | | | | | | | | | | | | |
Collapse
|
45
|
Wilkes DK, de Vries A, Oliver DW, Malan SF. Nitric Oxide Synthase Inhibition by Pentacycloundecane Conjugates of Aminoguanidine and Tryptamine. Arch Pharm (Weinheim) 2009; 342:73-9. [DOI: 10.1002/ardp.200800198] [Citation(s) in RCA: 14] [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] [Indexed: 11/06/2022]
|
46
|
Joubert J, van Dyk S, Malan SF. Fluorescent polycyclic ligands for nitric oxide synthase (NOS) inhibition. Bioorg Med Chem 2008; 16:8952-8. [DOI: 10.1016/j.bmc.2008.08.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 08/19/2008] [Accepted: 08/22/2008] [Indexed: 11/24/2022]
|
47
|
Pretorius J, Malan SF, Castagnoli N, Bergh JJ, Petzer JP. Dual inhibition of monoamine oxidase B and antagonism of the adenosine A(2A) receptor by (E,E)-8-(4-phenylbutadien-1-yl)caffeine analogues. Bioorg Med Chem 2008; 16:8676-84. [PMID: 18723354 DOI: 10.1016/j.bmc.2008.07.088] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 07/29/2008] [Accepted: 07/30/2008] [Indexed: 12/30/2022]
Abstract
The adenosine A(2A) receptor has emerged as an attractive target for the treatment of Parkinson's disease (PD). Evidence suggests that antagonists of the A(2A) receptor (A(2A) antagonists) may be neuroprotective and may help to alleviate the symptoms of PD. We have reported recently that several members of the (E)-8-styrylcaffeine class of A(2A) antagonists also are potent inhibitors of monoamine oxidase B (MAO-B). Since MAO-B inhibitors are known to possess anti-parkinsonian properties, dual-target-directed drugs that block both MAO-B and A(2A) receptors may have enhanced value in the management of PD. In an attempt to explore this concept further we have prepared three additional classes of C-8 substituted caffeinyl analogues. The 8-phenyl- and 8-benzylcaffeinyl analogues exhibited relatively weak MAO-B inhibition potencies while selected (E,E)-8-(4-phenylbutadien-1-yl)caffeinyl analogues were found to be exceptionally potent reversible MAO-B inhibitors with enzyme-inhibitor dissociation constants (K(i) values) ranging from 17 to 149 nM. Furthermore, these (E,E)-8-(4-phenylbutadien-1-yl)caffeines acted as potent A(2A) antagonists with K(i) values ranging from 59 to 153 nM. We conclude that the (E,E)-8-(4-phenylbutadien-1-yl)caffeines are a promising candidate class of dual-acting compounds.
Collapse
Affiliation(s)
- Judey Pretorius
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
| | | | | | | | | |
Collapse
|
48
|
Ogunrombi MO, Malan SF, Terre'blanche G, Castagnoli N, Bergh JJ, Petzer JP. Structure-activity relationships in the inhibition of monoamine oxidase B by 1-methyl-3-phenylpyrroles. Bioorg Med Chem 2007; 16:2463-72. [PMID: 18065227 DOI: 10.1016/j.bmc.2007.11.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 11/13/2007] [Accepted: 11/21/2007] [Indexed: 11/26/2022]
Abstract
1-Methyl-3-phenyl-3-pyrrolines are structural analogues of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and like MPTP are selective substrates of monoamine oxidase B (MAO-B). As part of an ongoing investigation into the substrate properties of various 1-methyl-3-phenyl-3-pyrrolinyl derivatives, it is shown in the present study that their respective MAO-B catalyzed oxidation products act as reversible competitive inhibitors of the enzyme. The most potent inhibitor among the oxidation products considered was 1-methyl-3-(4-trifluoromethylphenyl)pyrrole with an enzyme-inhibitor dissociation constant (K(i) value) of 1.30 microM. The least potent inhibitor was found to be 1-methyl-3-phenylpyrrole with a K(i) value of 118 microM. The results of an SAR study established that the potency of MAO-B inhibition by the 1-methyl-3-phenylpyrrolyl derivatives examined here is dependent on the Taft steric parameter (E(s)) and Swain-Lupton electronic constant (F) of the substituents attached to C-4 of the phenyl ring. Electron-withdrawing substituents with a large degree of steric bulkiness appear to enhance inhibition potency. Potency was also found to vary with the substituents at C-3, again with E(s) and F being the principal substituent descriptors.
Collapse
Affiliation(s)
- Modupe O Ogunrombi
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
| | | | | | | | | | | |
Collapse
|
49
|
Ogunrombi MO, Malan SF, Terre'Blanche G, Castagnoli K, Castagnoli N, Bergh JJ, Petzer JP. Neurotoxicity studies with the monoamine oxidase B substrate 1-methyl-3-phenyl-3-pyrroline. Life Sci 2007; 81:458-67. [PMID: 17655878 DOI: 10.1016/j.lfs.2007.06.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 05/23/2007] [Accepted: 06/08/2007] [Indexed: 11/30/2022]
Abstract
The neurotoxic properties of the parkinsonian inducing agent 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) are dependent on its metabolic activation in a reaction catalyzed by centrally located monoamine oxidase B (MAO-B). This reaction ultimately leads to the permanently charged 1-methyl-4-phenylpyridinium species MPP(+), a 4-electron oxidation product of MPTP and a potent mitochondrial toxin. The corresponding 5-membered analogue, 1-methyl-3-phenyl-3-pyrroline, is also a selective MAO-B substrate. Unlike MPTP, the MAO-B-catalyzed oxidation of 1-methyl-3-phenyl-3-pyrroline is a 2-electron process that leads to the neutral 1-methyl-3-phenylpyrrole. MPP(+) is thought to exert its toxic effects only after accumulating in the mitochondria, a process driven by the transmembrane electrochemical gradient. Since this energy-dependent accumulation of MPP(+) relies upon its permanent charge, 1-methyl-3-phenyl-3-pyrrolines and their pyrrolyl oxidation products should not be neurotoxic. We have tested this hypothesis by examining the neurotoxic potential of 1-methyl-3-phenyl-3-pyrroline and 1-methyl-3-(4-chlorophenyl)-3-pyrroline in the C57BL/6 mouse model. These pyrrolines did not deplete striatal dopamine while analogous treatment with MPTP resulted in 65-73% depletion. Kinetic studies revealed that both 1-methyl-3-phenyl-3-pyrroline and its pyrrolyl oxidation product were present in the brain in relatively high concentrations. Unlike MPP(+), however, 1-methyl-3-phenylpyrrole was cleared from the brain quickly. These results suggest that the brain MAO-B-catalyzed oxidation of xenobiotic amines is not, in itself, sufficient to account for the neurodegenerative properties of a compound like MPTP. The rapid clearance of 1-methyl-3-phenylpyrroles from the brain may contribute to their lack of neurotoxicity.
Collapse
Affiliation(s)
- Modupe O Ogunrombi
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa
| | | | | | | | | | | | | |
Collapse
|
50
|
van den Berg D, Zoellner KR, Ogunrombi MO, Malan SF, Terre'Blanche G, Castagnoli N, Bergh JJ, Petzer JP. Inhibition of monoamine oxidase B by selected benzimidazole and caffeine analogues. Bioorg Med Chem 2007; 15:3692-702. [PMID: 17416530 DOI: 10.1016/j.bmc.2007.03.046] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/11/2007] [Accepted: 03/14/2007] [Indexed: 11/20/2022]
Abstract
We have recently reported that a series of (E)-8-styrylcaffeines and (E)-2-styrylbenzimidazoles are moderate to very potent competitive inhibitors of monoamine oxidase B (MAO-B). The most potent member of the series was found to be (E)-8-(3-chlorostyryl)caffeine (CSC) with an enzyme-inhibitor dissociation constant (K(i) value) of 128 nM. In the present study, we have prepared additional caffeine and benzimidazole analogues in an attempt to identify compounds with improved MAO-B inhibition potency while still acting reversibly. The most potent inhibitor among the caffeine analogues was (E)-8-(3,4-dichlorostyryl)caffeine with a K(i) value of 36 nM, approximately 3.5 times more potent than CSC. The most potent inhibitor among the benzimidazole analogues was (E)-2-(4-trifluoromethylstyryl)-1-methylbenzimidazole with a K(i) value of 430 nM. An SAR analysis indicated that the potency of MAO-B inhibition by (E)-2-styryl-1-methylbenzimidazole analogues depended upon the Taft steric parameter (E(s)) of the substituents attached to C-4 of the styryl phenyl ring. Substituents with a large degree of steric hindrance appear to enhance inhibition potency. The proposal that potent MAO-B inhibition by (E)-8-styrylcaffeines and (E)-2-styrylbenzimidazoles can be explained by a mode of binding that involves traversing both the entrance and substrate cavities was supported by the finding that 1-methylbenzimidazole only weakly inhibited MAO-B with a K(i) value of 2084 microM. Without the styryl side chain, 1-methylbenzimidazole is not expected to be able to bind simultaneously to both the entrance and substrate cavities.
Collapse
Affiliation(s)
- Deidré van den Berg
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
| | | | | | | | | | | | | | | |
Collapse
|