1
|
Tong G, Baker MA, Shenvi RA. Change the channel: CysLoop receptor antagonists from nature. PEST MANAGEMENT SCIENCE 2021; 77:3650-3662. [PMID: 33135373 PMCID: PMC8087819 DOI: 10.1002/ps.6166] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/27/2020] [Accepted: 11/01/2020] [Indexed: 05/04/2023]
Abstract
Vertebrate and invertebrate ligand-gated ion channels (LGICs) exhibit significant structural homology and often share ligands. As a result, ligands with activity against one class can be brought to bear against another, including for development as insecticides. Receptor selectivity, metabolism and distribution must then be optimized using chemical synthesis. Here we review natural products (NPs) that ligate and inhibit the Cys-loop family of LGICs, which benefit from the unique physicochemical properties of natural product space but often present a high synthetic burden. Recent advances in chemical synthesis, however, have opened practical entries into these complex structures, several of which are highlighted. © 2020 Society of Chemical Industry.
Collapse
Affiliation(s)
- Guanghu Tong
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Meghan A Baker
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Ryan A Shenvi
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| |
Collapse
|
2
|
Romanelli MN, Gratteri P, Guandalini L, Martini E, Bonaccini C, Gualtieri F. Central Nicotinic Receptors: Structure, Function, Ligands, and Therapeutic Potential. ChemMedChem 2007; 2:746-67. [PMID: 17295372 DOI: 10.1002/cmdc.200600207] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The growing interest in nicotinic receptors, because of their wide expression in neuronal and non-neuronal tissues and their involvement in several important CNS pathologies, has stimulated the synthesis of a high number of ligands able to modulate their function. These membrane proteins appear to be highly heterogeneous, and still only incomplete information is available on their structure, subunit composition, and stoichiometry. This is due to the lack of selective ligands to study the role of nAChR under physiological or pathological conditions; so far, only compounds showing selectivity between alpha4beta2 and alpha7 receptors have been obtained. The nicotinic receptor ligands have been designed starting from lead compounds from natural sources such as nicotine, cytisine, or epibatidine, and, more recently, through the high-throughput screening of chemical libraries. This review focuses on the structure of the new agonists, antagonists, and allosteric ligands of nicotinic receptors, it highlights the current knowledge on the binding site models as a molecular modeling approach to design new compounds, and it discusses the nAChR modulators which have entered clinical trials.
Collapse
Affiliation(s)
- M Novella Romanelli
- Laboratory of Design, Synthesis, and Study of Biologically Active Heterocycles (HeteroBioLab), Department of Pharmaceutical Sciences, University of Florence, via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
| | | | | | | | | | | |
Collapse
|
3
|
Exley R, Iturriaga-Vásquez P, Lukas RJ, Sher E, Cassels BK, Bermudez I. Evaluation of benzyltetrahydroisoquinolines as ligands for neuronal nicotinic acetylcholine receptors. Br J Pharmacol 2005; 146:15-24. [PMID: 15980871 PMCID: PMC1576253 DOI: 10.1038/sj.bjp.0706307] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Effects of derivatives of coclaurine (C), which mimic the 'eastern' or the nonquaternary halves of the alkaloids tetrandrine or d-tubocurarine, respectively, both of which are inhibitors of nicotinic acetylcholine receptors (nACh), were examined on recombinant, human alpha7, alpha4beta2 and alpha4beta4 nACh receptors expressed in Xenopus oocytes and clonal cell lines using two-electrode voltage clamping and radioligand binding techniques. In this limited series, Cs have higher affinity and are most potent at alpha4 subunit-containing-nACh receptors and least potent at homomeric alpha7 receptors, and this trend is very marked for the N-unsubstituted C and its O,O'-bisbenzyl derivative. 7-O-Benzyl-N-methylcoclaurine (BBCM) and its 12-O-methyl derivative showed the highest affinities and potencies at all three receptor subtypes, and this suggests that lipophilicity at C7 and/or C12 increases potency. Laudanosine and armepavine (A) were noncompetitive and voltage-dependent inhibitors of alpha7, alpha4beta2 or alpha4beta4 receptors, but the bulkier C7-benzylated 7BNMC (7-O-benzyl-N-methylcoclaurine) and 7B12MNMC (7-O-benzyl-N,12-O-dimethyl coclaurine) were voltage-independent, noncompetitive inhibitors of nACh receptors. Voltage-dependence was also lost on going from A to its N-ethyl analogue. These studies suggest that C derivatives may be useful tools for studies characterising the antagonist and ion channel sites on human alpha7, alpha4beta2 or alpha4beta4 nACh receptors and for revealing structure-function relationships for nACh receptor antagonists.
Collapse
Affiliation(s)
- Richard Exley
- School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP
| | - Patricio Iturriaga-Vásquez
- Millennium Institute for Advanced Studies in Cell Biology and Biotechnology and Department of Chemistry, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Ronald J Lukas
- Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, U.S.A
| | - Emanuele Sher
- Eli Lilly and Co. Lilly Research Centre, Erl Wood Manor, Windlesham, Surrey
| | - Bruce K Cassels
- Millennium Institute for Advanced Studies in Cell Biology and Biotechnology and Department of Chemistry, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Isabel Bermudez
- School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP
- Author for correspondence:
| |
Collapse
|
4
|
Virginio C, Graziani F, Terstappen GC. Differential inhibition of rat α3* and α7 nicotinic acetylcholine receptors by tetrandrine and closely related bis-benzylisoquinoline derivatives. Neurosci Lett 2005; 381:299-304. [PMID: 15896488 DOI: 10.1016/j.neulet.2005.02.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 01/25/2005] [Accepted: 02/11/2005] [Indexed: 10/25/2022]
Abstract
The patch-clamp technique was used to investigate the effects of bis-benzylisoquinoline alkaloids on two of the major neuronal nicotinic acetylcholine receptors (nAChRs), the alpha3-containing nAChR (alpha3*nAChR) endogenously expressed in PC12 cells and the rat alpha7-nAChR heterologously expressed in GH4C1 cells. Tetrandrine and hernandezine reversibly inhibited both receptors displaying half-maximal inhibitory concentrations (IC50) of 8.1 microM and 5.8 microM for alpha3*nAChR and 407.4 nM and 372.2 nM, respectively, for alpha7-nAChR. E6-berbamine completely inhibited the alpha3*nAChR with an IC50 of 5.1 microM, but only partially inhibited the alpha7-nAChR at concentrations up to 30 microM. Tetrandrine inhibition of alpha3*nAChR was functionally non-competitive. All three compounds displaced radiolabelled methyllycaconitine ([3H]-MLA) binding to alpha7-nAChR providing some evidence of competitive antagonism. The results demonstrate that these alkaloids are nAChRs antagonists, with tetrandrine and hernandezine displaying selectivity for one of the major neuronal subtype, the alpha7 nAChR. The different potencies and multiple modes of action on nAChRs may help to better understand the pharmacology of these receptors and to aid in novel drug design.
Collapse
Affiliation(s)
- Caterina Virginio
- GlaxoSmithKline Medicines Research Centre, Assay Development and Compound Profiling, Via A. Fleming 4, 37135 Verona, Italy.
| | | | | |
Collapse
|
5
|
Zhao X, Cui XY, Chen BQ, Chu QP, Yao HY, Ku BS, Zhang YH. Tetrandrine, a bisbenzylisoquinoline alkaloid from Chinese herb Radix, augmented the hypnotic effect of pentobarbital through serotonergic system. Eur J Pharmacol 2004; 506:101-5. [PMID: 15588729 DOI: 10.1016/j.ejphar.2004.10.046] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Accepted: 10/20/2004] [Indexed: 11/18/2022]
Abstract
This is the first study of hypnotic activity of tetrandrine (a major component of Stephania tetrandrae) in mice by using synergism with pentobarbital as an index for the hypnotic effect. The results showed that tetrandrine potentiated pentobarbital (45 mg/kg, i.p.)-induced hypnosis significantly by reducing sleep latency and increasing sleeping time in a dose-dependent manner, and this effect was potentiated by 5-hydroxytryptophan (5-HTP). In the subhypnotic dosage of pentobarbital (28 mg/kg, i.p.)-treated mice, tetrandrine (60 and 30 mg/kg, p.o.) significantly increased the rate of sleep onset and also showed synergic effect with 5-HTP. Pretreatment of p-chlorophenylalanine (PCPA, 300 mg/kg, s.c.), an inhibitor of tryptophan hydroxylase, significantly decreased pentobarbital-induced sleeping time and tetrandrine abolished this effect. From these results, it should be presumed that serotonergic system may be involved in the augmentative effect of tetrandrine on pentobarbital-induced sleep.
Collapse
Affiliation(s)
- Xin Zhao
- Department of Pharmacology, Peking University, School of Basic Medical Science, 38 Xueyuan Lu, Beijing 100083, PR China
| | | | | | | | | | | | | |
Collapse
|
6
|
Maskell PD, Speder P, Newberry NR, Bermudez I. Inhibition of human alpha 7 nicotinic acetylcholine receptors by open channel blockers of N-methyl-D-aspartate receptors. Br J Pharmacol 2004; 140:1313-9. [PMID: 14645141 PMCID: PMC1574144 DOI: 10.1038/sj.bjp.0705559] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Human alpha 7 nicotinic acetylcholine (ACh) receptors were expressed in Xenopus oocytes and the effects of the N-methyl-D-aspartate (NMDA) receptor open channel blockers memantine and cerestat on this receptor were examined using two-electrode voltage-clamp recordings and 125I-alpha-bungarotoxin (125I-alpha-bgtx) binding. 2. Memantine and cerestat produced complete inhibition of ACh-induced inward currents with affinities similar to that reported for native NMDA receptors. Cerestat, IC50 1.7 (-1; +2) microm, was more potent than memantine, IC50 5 (-3;+8) microM, and the effects of both drugs were fully and rapidly reversible. 3. Inhibition of alpha 7 receptor function was voltage-independent, and it occurred at concentrations far lower than those needed to inhibit (never completely) binding of 125I-alpha-bgtx to alpha 7 receptors, suggesting that the effects of memantine or cerestat are noncompetitive. 4. These results provide evidence that human alpha 7 receptors are inhibited by memantine and cerestat and suggest that caution should be applied when using these compounds to study systems in which NMDA and nACh receptors co-exist.
Collapse
Affiliation(s)
- Peter D Maskell
- School of Biological and Molecular Sciences, Oxford Brookes University, Oxford OX3 0BP
| | - Pauline Speder
- School of Biological and Molecular Sciences, Oxford Brookes University, Oxford OX3 0BP
| | | | - Isabel Bermudez
- School of Biological and Molecular Sciences, Oxford Brookes University, Oxford OX3 0BP
- Author for correspondence:
| |
Collapse
|
7
|
Abstract
This review covers beta-phenylethylamines and isoquinoline alkaloids derived from them, including further products of oxidation. condensation with formaldehyde and rearrangement, some of which do not contain an isoquinoline system, together with naphthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids, with the structures of new bases, together with their reactions, syntheses and biological activities are reported. The literature from July 2002 to June 2003 is reviewed, with 568 references cited.
Collapse
|