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Todorov P, Georgieva S, Peneva P, Nikolov S, Rangelov M, Todorova N, Pechlivanova D, Tchekalarova J. Synthesis, molecular docking, electrochemical and fluorimetric analysis of new caffeic and cinnamic acid-conjugated hemorphin derivatives designed as potential anticonvulsant and antinociceptive agents. Bioorg Chem 2024; 143:107063. [PMID: 38150935 DOI: 10.1016/j.bioorg.2023.107063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/17/2023] [Accepted: 12/23/2023] [Indexed: 12/29/2023]
Abstract
Based on the pharmacophore model of opioid receptors, our team recently synthesized a series of short-chain hemorphin peptide analogs containing non-natural amino acids. They demonstrated anticonvulsant and antinociceptive activity with low neurotoxicity. In the present study, a series of novel bioconjugates of N-modified hemorphin analogs containing second pharmacophore cinnamic acids (CA) or caffeic (KA) were synthesized by a traditional solid-phase Fmoc chemistry method for peptide synthesis. Electrochemical and fluorimetric analysis, in vivo anticonvulsant and antinociceptive activity in mice were conducted on the compounds. The three CA acid- (H4-CA, H5-CA, and H7-CA) and three KA acid- (H4-KA, H5-KA, and H7-KA) conjugated hemorphin derivatives exhibited potency at the highest doses of 2 µg/5 µl, administered by intracerebroventricular (icv) mode, against seizure spread in the maximal electroshock test (MES) in mice. The KA-conjugated H5-KA derivate, at the lowest dose, was the only compound that suppressed clonic seizures in the subcutaneous pentylenetetrazol (scPTZ) test. Except for the H5-CA, all tested CA acid- and KA acid-conjugated peptide derivates had the potency to increase the latency for clonic seizures in a dose-dependent mode. The activity against the psychomotor seizures in the 6-Hz test was detected only for the H4-CA (0.5 µg) and H4-KA (0.5 µg and 1 µg), respectively. All investigated peptides showed a more pronounced antinociceptive effect in the "intraplantar formalin" test compared to the "hot plate" test. Shorter chain analogs showed a better antinociceptive profile against tonic pain. The data suggest a DOR and KOR-mediated mechanism of action. According to the docking analysis, H7-CA showed a different antinociceptive profile than other investigated peptides. The novel peptide derivates did not exhibit neurotoxicity in the rotarod test. Our findings suggest that conjugated CA and KA morphine peptides can be used to develop novel morphine-related analogs with anticonvulsant and antinociceptive activity.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria.
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria
| | - Spas Nikolov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria; Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria
| | - Miroslav Rangelov
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Nadezhda Todorova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Daniela Pechlivanova
- Faculty of Medicine, Sofia University "St. Kliment Ohridski", 1407 Sofia, Bulgaria; Institute of Neurobiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Todorov P, Assenov B, Angelov D, Dzhambazova E, Pechlivanova D. Behavioral Effects and Analgesic Profile of Hemoglobin-Derived Valorphin and Its Synthetic Analog in Rodents. Biomedicines 2023; 11:2783. [PMID: 37893157 PMCID: PMC10603931 DOI: 10.3390/biomedicines11102783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/09/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023] Open
Abstract
Valorphin (V1) is a naturally occurring peptide derived from hemoglobin that has been found to have an affinity for opioid receptors and exhibits antinociceptive and anticonvulsant activity. Some of its synthetic analogs containing an aminophosphonate moiety show structure-dependent potent antinociceptive effects. This study aimed to reveal a detailed picture of the antinociceptive mechanisms and behavioral effects of V1 and its recently synthesized phosphopeptide analog V2p in rodents using a range of methods. The studied peptides significantly reduced acute (mean V1-9.0, V2p-5.8 vs. controls-54.1 s) and inflammatory (mean V1-57.9 and V2p-53.3 vs. controls-107.6 s) nociceptive pain in the formalin test, as well as carrageenan-induced hyperalgesia (mean V1-184.7 and V2p-107.3 vs. controls-61.8 g) in the paw pressure test. These effects are mediated by activation of opioid receptors with a predominance of kappa in V1 antinociception and by delta, kappa, and mu receptors in V2p-induced antinociception. Both peptides did not change the levels of TNF-alpha and IL-1-beta in blood serum. V1 induces depression-like behavior, and V2p shows a tendency toward anxiolysis and short-term impairment of motor coordination without affecting exploratory behavior. The results characterize valorphin and its derivative as promising analgesics that exert their effects both centrally and peripherally, without causing severe behavioral changes in experimental animals. These encouraging data are a foundation for future studies focusing on the effects of hemorphins after long-term treatment.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Borislav Assenov
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 23, 1113 Sofia, Bulgaria; (B.A.); (D.A.)
- Faculty of Medicine, Sofia University “St. Kliment Ohridski”, 1 Kozyak Str., 1407 Sofia, Bulgaria;
| | - Dimo Angelov
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 23, 1113 Sofia, Bulgaria; (B.A.); (D.A.)
| | - Elena Dzhambazova
- Faculty of Medicine, Sofia University “St. Kliment Ohridski”, 1 Kozyak Str., 1407 Sofia, Bulgaria;
| | - Daniela Pechlivanova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 23, 1113 Sofia, Bulgaria; (B.A.); (D.A.)
- Faculty of Medicine, Sofia University “St. Kliment Ohridski”, 1 Kozyak Str., 1407 Sofia, Bulgaria;
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Todorov P, Georgieva S, Tchekalarova J, Peneva P, Mateeva P, Assenov B, Dzhambazova E, Pechlivanova D. Synthesis, characterization and evaluation of anti-hyperalgesia, anticonvulsant and antioxidant activity of novel VV-hemorphin-5 analogs. Arch Pharm (Weinheim) 2023; 356:e2300267. [PMID: 37532631 DOI: 10.1002/ardp.202300267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/04/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023]
Abstract
Two series of new VV-hemorphin-5 analogs with structures Val-Val-Tyr-Xxx-Trp-Thr-Gln-NH2 and Adam-Val-Val-Tyr-Xxx-Trp-Thr-Gln-NH2 , where Xxx is Ac5c (1-aminocyclopentane-1-carboxylic acid), Ac6c (1-aminocyclohexane-1-carboxylic acid), Ac7c (1-aminocycloheptane-1-carboxylic acid), and Adam is the low-molecular-weight lipophilic adamantyl building block, were synthesized, characterized electrochemically and evaluated for antioxidant, anti-hyperalgesia, and anticonvulsant activity. The design of the compounds followed the strategy to improve the propensity for aqueous solubility and/or to increase their affinity for the target receptor or enzyme. The partition coefficient value shows that the peptide scaffold goes from hydrophilic to lipophilic with the increasing size of the cycloalkane ring and even more with the introduction of the adamantane. The peptides C5-V and C7-V were the only analogs that provoked an immediate antinociceptive effect changing the mechanical pain threshold. The six new peptide analogs produced a significant and long-lasting carrageenan model of inflammatory pain in rats. While the adamantane hemorphin analog Ad7-V was the only compound with the potency to suppress psychomotor seizures in the 6-Hz test, the C6-V and Ad6-V exhibited protective activity against the seizure spread in the maximal electroshock seizure test in mice. The active analogs did not show neurotoxicity or sedative effects. Our results revealed a structure-related specific activity of a newly designed hemorphin analog that could be used as a template for future modification and preparation of compounds with potential analgesic and anticonvulsant activity.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Jana Tchekalarova
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
- Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Polina Mateeva
- Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Borislav Assenov
- Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
- Faculty of Medicine, Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
| | - Elena Dzhambazova
- Faculty of Medicine, Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
| | - Daniela Pechlivanova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
- Faculty of Medicine, Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
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New N- and C-modified RGD-hemorphins as potential biomedical application on Ti-surface materials: synthesis, characterization and antinociceptive activity. Mol Divers 2023; 27:263-280. [PMID: 35438429 DOI: 10.1007/s11030-022-10428-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/30/2022] [Indexed: 02/08/2023]
Abstract
This manuscript presented the synthesis and characterization of two new N- and C-modified analogues of VV-hemorphin-7 containing RGD (Arg-Gly-Asp) residues as potential nociceptive agents and bioactive materials. It has been shown that the addition of one or two RGD sequences to natural VV-hemorphin-7 increases its effect on acute nociception, but the reduction of the inflammatory phase depends on the concentration of the peptide. The structure-property relationship of the new peptide derivatives was highlighted by electrochemical and FT-IR methods of analysis. Because of the proven bone-structural bonds of hydroxyapatite, the simultaneous deposition of peptide/hydroxyapatite on the surface of a titanium surface was investigated. The deposition was performed in a medium of gelatin solution containing dissolved amounts of peptide and hydroxyapatite using ultrasound. SEM-EDS analyzes confirmed the presence of a layer of the studied system.
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Interaction of new VV-hemorphin-5 analogues with cell membrane models. Colloids Surf B Biointerfaces 2022; 220:112896. [DOI: 10.1016/j.colsurfb.2022.112896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 09/23/2022] [Accepted: 10/01/2022] [Indexed: 11/05/2022]
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Valorphins alter physicochemical characteristics of phosphatidylcholine membranes: datasets on lipid packing, bending rigidity, specific electrical capacitance, dipole potential, vesicle size. Data Brief 2022; 45:108716. [DOI: 10.1016/j.dib.2022.108716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
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Todorov P, Georgieva S, Staneva D, Peneva P, Grozdanov P, Nikolova I, Vasileva-Tonkova E, Grabchev I. Study of Novel Peptides for Antimicrobial Protection in Solution and on Cotton Fabric. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27154770. [PMID: 35897948 PMCID: PMC9332204 DOI: 10.3390/molecules27154770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/14/2022] [Accepted: 07/22/2022] [Indexed: 11/16/2022]
Abstract
Some new N- and C-modified biomolecular peptide analogues of both VV-hemorphin-5 and VV-hemorphin-7 with varied amino acids (Cys, Glu, His), 1-adamantanecarboxylic acid, and niacin (nicotinic acid) were synthesized by solid-phase peptide synthesis-Fmoc (9-fluorenylmethoxy-carbonyl) chemistry and were characterized in water solutions with different pH using spectroscopic and electrochemical techniques. Basic physicochemical properties related to the elucidation of the peptide structure at physiological pH have been also studied. The results showed that the interaction of peptide compounds with light and electricity preserves the structural and conformational integrity of the compounds in the solutions. Moreover, textile cotton fibers were modified with the new compounds and the binding of the peptides to the surface of the material was proved by FTIR and SEM analysis. Washing the material with an alkaline soap solution did not show a violation of the modified structure of the cotton. Antiviral activity against the human respiratory syncytial virus (HRSV-S2) and human adenovirus serotype 5 (HAdV-5), the antimicrobial activity against B. cereus and P. aeruginosa used as model bacterial strains and cytotoxic effect of the peptide derivatives and modified cotton textile material has been evaluated. Antimicrobial tests showed promising activity of the newly synthesized compounds against the used Gram-positive and Gram-negative bacteria. The compounds C-V, H-V, AC-V, and AH-V were found slightly more active than NH7C and NCH7. The activity has been retained after the deposition of the compounds on cotton fibers.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
- Correspondence: ; Tel.: +359-2-8163423
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Desislava Staneva
- Department of Textile and Leathers, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Petar Grozdanov
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (P.G.); (I.N.); (E.V.-T.)
| | - Ivanka Nikolova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (P.G.); (I.N.); (E.V.-T.)
| | - Evgenia Vasileva-Tonkova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (P.G.); (I.N.); (E.V.-T.)
| | - Ivo Grabchev
- Faculty of Medicine, Sofia University “St. Kl. Ohridski”, 1407 Sofia, Bulgaria;
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Investigation of the structure–activity relationship in a series of new LVV- and VV-hemorphin-7 analogues designed as potential anticonvulsant agents. Amino Acids 2022; 54:261-275. [DOI: 10.1007/s00726-021-03112-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 11/24/2021] [Indexed: 11/27/2022]
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Todorov P, Peneva P, Georgieva S, Tchekalarova J, Rangelov M, Todorova N. Synthesis and characterization of new 5,5′-dimethyl- and 5,5′-diphenylhydantoin-conjugated hemorphin derivatives designed as potential anticonvulsant agents. NEW J CHEM 2022. [DOI: 10.1039/d1nj05235g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, the synthesis and characterization of some novel N-modified hybrid analogues of hemorphins containing a C-5 substituted hydantoin residue as potential anticonvulsants and for the blockade of sodium channels are presented.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia 1756, Bulgaria
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia 1756, Bulgaria
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, Sofia 1756, Bulgaria
| | - Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Miroslav Rangelov
- Institute of Organic Chemistry with centre of phytochemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Nadezhda Todorova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
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Todorov P, Georgieva S, Staneva D, Peneva P, Grozdanov P, Nikolova I, Grabchev I. Synthesis of New Modified with Rhodamine B Peptides for Antiviral Protection of Textile Materials. Molecules 2021; 26:molecules26216608. [PMID: 34771015 PMCID: PMC8587962 DOI: 10.3390/molecules26216608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 01/11/2023] Open
Abstract
Here we report on the synthesis and characterization of three new N-modified analogues of hemorphin-4 with rhodamine B. Modified with chloroacetyl, chloride cotton fabric has been dyed and color coordinates of the obtained textile materials were determined. Antiviral and virucidal activities of both the peptide-rhodamine B compounds and the dyed textile material were studied. Basic physicochemical properties (acid-base behavior, solvent influence, kinetics) related to the elucidation of structural activity of the new modified peptides based on their steric open/closed ring effect were studied. The obtained results lead to the conclusion that in protic solvent with change in pH of the environment, direct control over the dyeing of textiles can be achieved. Both the new hybrid peptide compounds and the modification of functionalized textile materials with these bioactive hemorphins showed virucidal activity against the human respiratory syncytial virus (HRSV-S2) and human adenovirus serotype 5 (HAdV-5) for different time intervals (30 and 60 min) and the most active compound was Rh-3.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
- Correspondence: ; Tel.: +359-2-8163423
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Desislava Staneva
- Department of Textile and Leathers, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Petar Grozdanov
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (P.G.); (I.N.)
| | - Ivanka Nikolova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (P.G.); (I.N.)
| | - Ivo Grabchev
- Faculty of Medicine, Sofia University “St. Kl. Ohridski”, 1407 Sofia, Bulgaria;
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Hemorphins-From Discovery to Functions and Pharmacology. Molecules 2021; 26:molecules26133879. [PMID: 34201982 PMCID: PMC8270332 DOI: 10.3390/molecules26133879] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 01/31/2023] Open
Abstract
During the last three decades, a variety of different studies on bioactive peptides that are opioid receptor ligands, have been carried out, with regard to their isolation and identification, as well as their molecular functions in living organisms. Thus, in this review, we would like to summarize the present state-of-the art concerning hemorphins, methodological aspects of their identification, and their potential role as therapeutic agents. We have collected and discussed articles describing hemorphins, from their discovery up until now, thus presenting a very wide spectrum of their characteristic and applications. One of the major assets of the present paper is a combination of analytical and pharmacological aspects of peptides described by a team who participated in the initial research on hemorphins. This review is, in part, focused on the analysis of endogenous opioid peptides in biological samples using advanced techniques, description of the identification of synthetic/endogenous hemorphins, their involvement in pharmacology, learning, pain and other function. Finally, the part regarding hemorphin analogues and their synthesis, has been added.
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Assenov B, Pechlivanova D, Dzhambazova E, Peneva P, Todorov P. Antinociceptive Effects of VV-Hemorphin-5 Peptide Analogues Containing Amino phosphonate Moiety in Mouse Formalin Model of Pain. Protein Pept Lett 2021; 28:442-449. [PMID: 32798365 DOI: 10.2174/0929866527666200813200714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/19/2020] [Accepted: 06/21/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Hemorphins are endogenous hemoglobin-derived peptides that belong to the family of "atypical" opioid peptides with both affinities to opioid receptors and ability to release other endogenous opioid peptides. OBJECTIVE In the present study, peptide analogues of Valorphin (VV-hemorphin-5) containing amino phosphonate moiety synthesized by solid-phase peptide synthesis (Fmoc-strategy) were investigated for their potential antinociceptive activities and compared to the reference VV-H in formalin- induced model of acute and inflammatory pain in mice. METHODS The hemorphin analogues were prepared by replacement of the one and/or two N-terminal Val in VV-hemorphin5 (VV-H) with ((dimethoxy phosphoryl) methyl)-L-valine and ((dimethoxy phosphoryl) methyl)-L-leucine to obtain the compounds pVV-H, pL-H, and pLV-H. Aiming to additionally prove the importance of amino acid valine, we introduced the ((dimethoxy phosphoryl) methyl)-L-leucine to the N-side of VV-hemorphin-5 (pLVV-H). The experiments were carried out on adult male ICR mice. All peptides were administered intracerebroventricularly at three doses (50, 25 and 12,5 μg/mouse). We have studied the effects of the peptides on acute (1st phase) and inflammatory (2nd phase) pain reaction using un experimental model with intraplantar formalin injection. RESULTS VV-H showed a significant antinociceptive effect both in the acute and inflammatory phases of the test. Although Valorphin hexa-, hepta-, and octapeptide analogs demonstrated a significant antinociceptive effect, they showed substantial differences considering their effective dose and the phase of the test as compared to the Valorphin. DISCUSSION Data showed that modified heptapeptides pVV-H and pLV-H exerted the same or better antinociception in acute and inflammatory pain, in comparison to the reference peptide, while pL-H and pLVV-H analogues were less effective. CONCLUSION Our study contributes to the elucidation of the role of Valine and the number of amino acid residues in the structure of hemorphin peptide analogs in their effectiveness in suppressing both acute and inflammatory experimental pain.
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Affiliation(s)
- Borislav Assenov
- Sofia University "St. Kliment Ohridski", Medical Faculty, Sofia 1407, Bulgaria
| | | | - Elena Dzhambazova
- Sofia University "St. Kliment Ohridski", Medical Faculty, Sofia 1407, Bulgaria
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia 1756, Bulgaria
| | - Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia 1756, Bulgaria
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Todorov P, Peneva P, Tchekalarova J, Georgieva S, Rangelov M, Todorova N. Structure-activity relationship study on new hemorphin-4 analogues containing steric restricted amino acids moiety for evaluation of their anticonvulsant activity. Amino Acids 2020; 52:1375-1390. [PMID: 33011823 DOI: 10.1007/s00726-020-02898-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/28/2020] [Indexed: 12/31/2022]
Abstract
In the present study, several new analogues of hemorphin-4, modified with unnatural conformationally restricted amino acids followed the structure Aaa-Tyr-Xxx-Trp-Thr-NH2, where Aaa is the low-molecular-weight lipophilic adamantyl building block, and Xxx is Ac5c (1-aminocyclopentanecarboxylic acid) or Ac6c (1-aminocyclohexane carboxylic acid) was synthesized, characterized and investigated for anticonvulsant activity in three seizure tests, the maximal electroshock test (MES), 6-Hz psychomotor seizure test and timed intravenous pentylenetetrazole infusion (ivPTZ) test. The acute neurological toxicity was determined using the rota-rod test. The new synthetic neuropeptide analogues were prepared by solid-phase peptide synthesis-Fmoc chemistry and were evaluated in three doses of 1, 3 and 5 µg, respectively, administered intracerebroventricularly in male ICR mice. The physicochemical properties of these peptide analogues were evaluated as pKa and pI values were calculated using potentiometry. The IR spectrum of the compounds was recorded and the characteristic lines of both adamantane moiety and the peptide backbone were registered in the wavelength range from 4000 to 400 cm-1. The hexapeptide Ang IV was used as a positive control. From the six synthesized peptide analogues, the P4-5 was the most active at doses of 1 and 3 µg in the three seizure tests. The order of potency of other peptides was as follows: P4 > P4-3 = P4-4 > P4-2 > Ang IV in MES, P4-4 ≥ P4-1 > P4-3 > P4-2 > P4 > Ang IV in 6-Hz test and P4-4 = P4-3 > P4-2 = P4 > Ang IV in ivPTZ test. None of the peptides displayed neurotoxicity in the rota-rod test. Docking study results suggest that direct H-bonding and ionic interactions between our synthetic ligands and residues, responsible for coordination of Zn2+ along with hydrophobic interactions between our ligands and IRAP active site are the most important for the ligand binding. The results propose that incorporation of adamantane and cycloalkane building blocks in the peptide chain of the hemorphin-4 scaffold is important for the potential high biological activity.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria.
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria
| | - Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria
| | - Miroslav Rangelov
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Nadezhda Todorova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
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Ali A, Alzeyoudi SAR, Almutawa SA, Alnajjar AN, Vijayan R. Molecular basis of the therapeutic properties of hemorphins. Pharmacol Res 2020; 158:104855. [PMID: 32438036 DOI: 10.1016/j.phrs.2020.104855] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/09/2020] [Accepted: 04/20/2020] [Indexed: 12/26/2022]
Abstract
Hemorphins are endogenous peptides, 4-10 amino acids long, belonging to the family of atypical opioid peptides released during the sequential cleavage of hemoglobin protein. Hemorphins have been shown to exhibit diverse therapeutic effects in both human and animal models. However, the precise cellular and molecular mechanisms involved in such effects remain elusive. In this review, we summarize and propose potential mechanisms based on studies that investigated the biological activity of hemorphins of different lengths on multiple therapeutic targets. Special emphasis is given to molecular events related to renin-angiotensin system (RAS), opioid receptors and insulin-regulated aminopeptidase receptor (IRAP). This review provides a comprehensive coverage of the molecular mechanisms that underpin the therapeutic potential of hemorphins. Furthermore, it highlights the role of various hemorphin residues in pathological conditions, which could be explored further for therapeutic purposes.
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Affiliation(s)
- Amanat Ali
- Department of Biology, College of Science, United Arab Emirates University, PO Box 15551, Al Ain, United Arab Emirates
| | | | - Shamma Abdulla Almutawa
- Department of Biology, College of Science, United Arab Emirates University, PO Box 15551, Al Ain, United Arab Emirates
| | - Alya Nasir Alnajjar
- Department of Biology, College of Science, United Arab Emirates University, PO Box 15551, Al Ain, United Arab Emirates
| | - Ranjit Vijayan
- Department of Biology, College of Science, United Arab Emirates University, PO Box 15551, Al Ain, United Arab Emirates.
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15
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Potential anticonvulsant activity of novel VV-hemorphin-7 analogues containing unnatural amino acids: synthesis and characterization. Amino Acids 2020; 52:567-585. [PMID: 32206933 DOI: 10.1007/s00726-020-02836-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/04/2020] [Indexed: 10/24/2022]
Abstract
Herein, some new analogues of VV-hemorphin-7, modified at position 4 and 7 by the unnatural amino acids followed the structure Val-Val-Tyr-Xxx-Trp-Thr-Yyy-Arg-Phe-NH2, where Xxx is Ac5c (1-aminocyclopentanecarboxylic acid) or Ac6c (1-aminocyclohexane carboxylic acid) and Yyy is Dap (diaminopropanoic acid) or Dab (diaminobutanoic acid), were synthesized, characterized and investigated for anticonvulsant activity. The new synthetic peptide analogues were prepared by standard solid-phase peptide synthesis-Fmoc chemistry. A single intracerebroventricular (i.c.v.) injection at doses of 5, 10, and 20 µg/10 µl, respectively, was given before evaluation with timed intravenous pentylenetetrazole (ivPTZ) infusion test and 6-Hz psychomotor seizure test in mice. The acute neurological toxicity was determined using the rotarod test. To explain the structure-active properties of the modified peptides, some physicochemical characteristic was obtained. The FT-IR spectra and their second derivatives of the amide I, II, and III bands of the peptides show ß-sheet structure conformation. The calculation of isoelectric points, by potentiometric determination of dissociated constants, is in the range from 9.79 to 10.84. This study, for the first time, also reported on the reduction-oxidative potentials of the guanidine at Arg-moiety on such kind of peptides containing arginine and tyrosine residues in different medium and electrode surface. The VV-hemorphin-7 analogues 4 and 5 were the most active against the ivPTZ test, with the effect comparable to that of peptide 1 used as a positive control. Except compound 8, all other tested peptide analogues were ineffective to raise the threshold for the clonic seizures. The peptide analogue 5 showed 100% protection in the 6-Hz test, while the other seven VV-hemorphin-7 analogues have dose-dependent activity against psychomotor seizures comparable to 1. The novel peptides did not show neurotoxicity in the rotarod test.
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16
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Todorov P, Peneva P, Tchekalarova J, Rangelov M, Georgieva S, Todorova N. Synthesis, characterization and anticonvulsant activity of new series of N-modified analogues of VV-hemorphin-5 with aminophosphonate moiety. Amino Acids 2019; 51:1527-1545. [PMID: 31576456 DOI: 10.1007/s00726-019-02789-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 09/17/2019] [Indexed: 12/29/2022]
Abstract
A new series of N-modified analogues of the VV-hemorphin-5 with aminophosphonate moiety have been synthesized, characterized and investigated for anticonvulsant activity. The novel peptide analogues were prepared by solid-phase peptide synthesis-Fmoc-strategy and were evaluated in the timed intravenous pentylenetetrazole infusion test (ivPTZ) and 6-Hz psychomotor seizure test in mice. The acute neurological toxicity was determined using the rotarod test. The redox potentials at glass carbonic electrode (GC) and the acid/base properties as pKa values of these peptide analogues were compared with the electrochemical behaviour of tyrosine- and tryptophan-containing peptides using different voltamperometric modes. Among the five tested peptide analogues, V3p was the most active against the ivPTZ test with effect comparable to that of the VV-hemorphin-5 (V1) used as a positive control. Dose-dependent elevation of the seizure threshold for myoclonic twitch and generalized clonic seizures was observed after i.c.v. administration of V2p, V4p and V5p as well as for forelimbs tonus in V4p peptides. The peptide analogues V2p-V5p were able to suppress dose-dependent psychomotor seizures in the 6-Hz test. In contrast, the V6p peptide showed either a pro-convulsant effect in the iv PTZ test or was inactive in the 6-Hz test. No changes in motor coordination were noted with the novel peptides. Docking study results suggest that kappa opioid receptor binding could be the mechanism of action of peptide derivatives with anticonvulsant activity. The results suggest that incorporation of aminophosphonate moiety at position 1 of the VV-hemorphin-5 scaffold deserve further evaluation in models of epilepsy and derivatization.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria.
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria.,Institute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Miroslav Rangelov
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Stela Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria
| | - Nadezhda Todorova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
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17
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Todorov P, Rangelov M, Peneva P, Todorova N, Tchekalarova J. Anticonvulsant evaluation and docking analysis of VV-Hemorphin-5 analogues. Drug Dev Res 2019; 80:425-437. [PMID: 30681179 DOI: 10.1002/ddr.21514] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/06/2019] [Accepted: 01/08/2019] [Indexed: 12/25/2022]
Abstract
VV-Hemorphin-5 is an endogenous opioid peptide of the Hemorphin family with affinity at opioid receptors. A series of C-amide analogues have been synthesized, based on the structure of VV-Hemorphin-5, modified at position 1 and 7 by the un/natural amino acids (Aa8-Val-Val-Tyr-Pro-Trp-Thr-Gln-NH2 and Val-Val-Tyr-Pro-Trp-Thr-Aa1-NH2 ) using SPPS, Fmoc-chemistry. The peptide derivatives were evaluated for their anticonvulsant activity in three acute seizure tests in male ICR mice, the maximal electroshock (MES), the 6 Hz psychomotor seizure test, and the timed intravenous pentylenetetrazole (ivPTZ) infusion test. Their neurotoxicity was assessed in the rotarod test. Among the tested peptide analogues, V4 showed anticonvulsant activity in the three seizure tests that was comparable to the VV-Hemorphin-5 (V1) used as a positive control. While V5, V6, and V7 peptide derivatives exhibited anticonvulsant activity in the MES and 6 Hz test, they were inactive (V7) or showed pro-convulsant effect (V5 and V6) in the i.v. PTZ test. At a dose of 10 μg/mouse the peptide V2 was effective against clonic seizures induced by PTZ. Motor coordination was not affected by newly developed analogues of VV-Hemorphin-5. Docking study results suggest that kappa opioid receptor binding could be the mechanism of action of peptide derivatives with anticonvulsant activity. The results suggest that incorporation of nonproteinogenic and/or natural amino acids at position 1 and 7 of the VV-Hemorphin-5 scaffold deserve further evaluation in models of epilepsy and derivatization.
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Affiliation(s)
- Petar Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Miroslav Rangelov
- Laboratory Chemistry and Biophysics of Proteins and Enzymes, Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Petia Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Nadezhda Todorova
- Department of Ecosystem Research, Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Jana Tchekalarova
- Department of Behavioral Neurobiology, Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
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18
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Todorov PT, Peneva PN, Georgieva SI, Tchekalarova J, Vitkova V, Antonova K, Georgiev A. Synthesis, characterization and anticonvulsant activity of new azobenzene-containing VV-hemorphin-5 bio photoswitch. Amino Acids 2019; 51:549-563. [PMID: 30604096 DOI: 10.1007/s00726-018-02691-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/20/2018] [Indexed: 11/30/2022]
Abstract
A novel analog of VV-hemorphin-5 containing azobenzene moiety has been synthesized and investigated for anticonvulsant activity in relation to its E → Z photophysical properties activated by long wavelength light at 365 nm. The synthesis was achieved by a modified SPPS by Fmoc-dimerization strategy. The electrochemical behavior before and after UV illumination was investigated using different voltammetric modes. The number of electrons transferred, heterogenic rate constant and diffusion coefficient for E- and Z-isomers were also evaluated. Revealing the governing principles involved in signaling and nerve pulse propagation requires the detailed characterization of the electrical properties of cell membranes. For probing the effect of synthesized azo-peptide on the membrane electrical properties, we measured the specific capacitance of lipid bilayers, representing a basic physical model of biomembranes with their simple reproducibility in laboratory conditions at controlled membrane composition and physicochemical parameters of the surrounding aqueous medium. Our results have shown reduced membrane capacitance in the presence of the azo-peptide, thus providing evidences for possible alterations in the dielectric permittivity of the bilayer. The (Val-Val-Tyr-Pro-Trp-Thr-Gln)2Azo peptide was explored also in vivo for preliminary anticonvulsant activity by using the 6-Hz seizure test and pentylenetetrazol (PTZ) seizure test in mice. The Z-isomer has exhibited higher potency compared to E-isomer most pronouncedly in the 6 Hz test for psychomotor seizures where the compound had activity at all three tested doses. It was found that the Z-isomer decrease the latency for onset of clonic seizures induced by PTZ. These results demonstrate that the Z-isomer deserves further evaluation in other screening tests for anticonvulsant activity.
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Affiliation(s)
- Petar T Todorov
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria.
| | - Petia N Peneva
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria
| | - Stela I Georgieva
- Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria
| | - Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
| | - Victoria Vitkova
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 1784, Sofia, Bulgaria
| | - Krassimira Antonova
- Institute of Solid State Physics, Bulgarian Academy of Sciences, 1784, Sofia, Bulgaria
| | - Anton Georgiev
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, 1756, Sofia, Bulgaria.,Department of Optical Metrology and Holography, Institute of Optical Materials and Technologies, Bulgarian Academy of Science, 1113, Sofia, Bulgaria
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