Synthesis, molecular docking, electrochemical and fluorimetric analysis of new caffeic and cinnamic acid-conjugated hemorphin derivatives designed as potential anticonvulsant and antinociceptive agents.

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.

Synthesis, characterization, and biological study of new synthetic opioid hemorphin-4 peptides containing sterically restricted nonnatural amino acids.

Some new hemorphin-4 analogs with structures of Xxx-Pro-Trp-Thr-NH2 and Tyr-Yyy-Trp-Thr-NH2, where Xxx is 2-amino-3-(4-hydroxy-2,6-dimethylphenyl)propanoic acid or 2-amino-3-(4-dibenzylamino-2,6-dimethylphenyl)propanoic acid, and Yyy is (2S,4S)-4-amino-pyrrolidine-2-carboxylic acid, were synthesized and characterized by electrochemical and spectral analyses. In vivo anticonvulsant and antinociceptive activities of peptide derivatives were studied after intracerebroventricular injection in mice. The therapeutic effects of the modified peptides on seizures and pain in mice were evaluated to provide valuable insights into the potential applications of the novel compounds. Electrochemical characterization showed that the compounds behave as weak protolytes and that they are in a soluble, stable molecular form at physiological pH values. The antioxidant activity of the peptides was evaluated with voltammetric analyses, which were confirmed by applying the 2,2-Diphenyl-1-picrylhydrazyl method. The compounds showed satisfactory results regarding their structural stability, reaching the desired centers for the manifestation of biological activity without hydrolysis processes at 37°C and physiological pH. Dm-H4 and H4-P1 exhibited 100% and 83% potency to suppress the psychomotor seizures in the 6-Hz test compared to 67% activity of H4. Notably, only the H4-P1 had efficacy in blocking the tonic component in the maximal electroshock test with a potency comparable to H4. All investigated peptides containing unnatural conformationally restricted amino acids showed antinociceptive effects. The analogs Db-H4 and H4-P1 showed the most pronounced and long-lasting effect in both experimental models of pain induced by thermal and chemical stimuli. Dm-H4 produced a dose-dependent thermal antinociception and H4-P2 inhibited only formalin-induced pain behavior.

A novel cinnamic and caffeic acid-conjugated peptide analogs with anticonvulsant and analgesic potency: Comparative analyses of trans/cis isomers.

The novel cinnamic acid (CA) (H4-CA, H5-CA, and H7-CA) and caffeic acid (KA) (H4-KA, H5-KA, and H7-KA) hemorphin analogs have recently been synthesized and their trans isomers have been tested for antiseizure and antinociceptive activity. In the present study, the cis forms of these compounds were tested and compared with their trans isomers in seizure and nociception tests in mice. The cis-H5-CA and H7-CA compounds showed efficacy against psychomotor seizures, whereas the trans isomers were ineffective. Both the cis and trans KA isomers were ineffective in the 6-Hz test. In the maximal electroshock (MES) test, the cis isomers showed superior antiseizure activity to the trans forms of CA and KA conjugates, respectively. The suppression of seizure propagation by cis-H5-CA and the cis-H5-KA was reversed by a kappa opioid receptor (KOR) antagonist. Naloxone and naltrindole were not effective. The cis-isomers of CA conjugates and cis-H7-KA produced significantly stronger antinociceptive effects than their trans-isomers. The cis-H5-CA antinociception was blocked by naloxone in the acute phase and by naloxone and KOR antagonists in the inflammatory phase of the formalin test. The antinociception of the KA conjugates was not abolished by opioid receptor blockade. None of the tested conjugates affected the thermal nociceptive threshold. The results of the docking analysis also suggest a model-specific mechanism related to the activity of the cis-isomers of CA and KA conjugates in relation to opioid receptors. Our findings pave the way for the further development of novel opioid-related antiseizure and antinociceptive therapeutics.

New N- and C-modified RGD-hemorphins as potential biomedical application on Ti-surface materials: synthesis, characterization and antinociceptive activity.

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.

Synthesis, characterization and evaluation of anti-hyperalgesia, anticonvulsant and antioxidant activity of novel VV-hemorphin-5 analogs.

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.

Comparative Analysis of Anticonvulsant Activity of Trans and Cis 5,5'-Diphenylhydantoin Schiff Bases.

Recently, the four 5,5'-diphenylhydantoin Schiff bases, possessing different aromatic species (SB1-Ph, SB2-Ph, SB3-Ph and SB4-Ph) were synthesized, characterized, and evaluated for anticonvulsant activity in combination with phenytoin. In the present study, the SB1-Ph and SB4-Ph compounds were selected, based on their anticonvulsant potency, and compared with their cis isomers, prepared after a one-hour exposure to the UV source, for their anticonvulsant potency in the maximal electroshock (MES) test and the kainate (KA)-induced status epilepticus (SE) test in mice. In the MES test, the cisSB1-Ph compound exhibited superior to phenytoin and trans isomer activity in the three tested doses, while the cisSB4-Ph compound entirely suppressed the electroshock-induced seizure spread at the highest dose of 40 mg/kg. Pretreatment with the cisSB1-Ph compound and the cisSB4-Ph at the doses of 40 mg/kg, respectively, for seven days, significantly attenuated the severity of KA SE compared to the matched control group pretreated with a vehicle, while phenytoin was ineffective in this test. The cisSB4-Ph but not the cisSB1-Ph demonstrated an antioxidant effect against the KA-induced SE in the hippocampus. Our results suggest that trans-cis conversion of 5,5'-diphenylhydantoin Schiff bases has potential against seizure spread in the MES test and mitigated the KA-induced SE. The antioxidant potency of cisSB4-Ph might be associated with its efficacy in mitigating the SE.

Investigation of the structure-activity relationship in a series of new LVV- and VV-hemorphin-7 analogues designed as potential anticonvulsant agents.

In the present study, a series of new analogues of both LVV- and VV-hemorphin-7 have been synthesized and characterized. They were modified at the N- and C-terminus with varied amino acids (Ile, D-Leu, D-Val, D-Phe) and enantiopure chiral S- and R- α-aminophosphonic acids ((dimethoxyphosphoryl)methyl)-valine and ((dimethoxyphosphoryl) methyl)-leucine) to optimize the physicochemical properties and to enhance their anticonvulsant potency. The novel peptide analogues were prepared by solid-phase peptide synthesis-Fmoc-strategy. Their structure-property relationship was studied by FT-IR spectroscopy and electrochemical methods. The lipophilicity is also presented. The anticonvulsant activity of peptide analogues, administered intracerebroventricularly, at doses of 1, 2.5, and 5 µg/10 µL, respectively, was explored by 6-Hz psychomotor seizure test, maximal electroshock test (MES) and a timed intravenous pentylenetetrazole (ivPTZ) infusion test in mice. The potential neurological toxicity of the substances was checked by a rotarod test. The H7 was used as a positive control. The H7-1 peptide analogue was the most active molecule against the psychomotor seizures, while H7-6 and H7-7 showed comparable to the positive group H7 potency in the MES test. The H7-5 to H7-8 analogues at the two tested doses of 2.5 and 5 µg/10 µl raised the threshold against ivPTZ-induced myoclonic, clonic, and tonic seizures. None of the hemorphin analogues exhibited neurotoxicity in the rotarod test. In conclusion, our results suggest that modified at N- and C-terminus of certain amino acids in the hemorphin analogues have a crucial role as a basis to design new LVV- and VV-hemorphin-7 analogues for experimental and clinical use.

Study of Novel Peptides for Antimicrobial Protection in Solution and on Cotton Fabric.

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.

Synthesis of New Modified with Rhodamine B Peptides for Antiviral Protection of Textile Materials.

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.

INDRA-IPM: interactive pathway modeling using natural language with automated assembly.

SUMMARY: INDRA-IPM (Interactive Pathway Map) is a web-based pathway map modeling tool that combines natural language processing with automated model assembly and visualization. INDRA-IPM contextualizes models with expression data and exports them to standard formats. AVAILABILITY AND IMPLEMENTATION: INDRA-IPM is available at: http://pathwaymap.indra.bio. Source code is available at http://github.com/sorgerlab/indra_pathway_map. The underlying web service API is available at http://api.indra.bio:8000. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Potential anticonvulsant activity of novel VV-hemorphin-7 analogues containing unnatural amino acids: synthesis and characterization.

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.

Structure-activity relationship study on new hemorphin-4 analogues containing steric restricted amino acids moiety for evaluation of their anticonvulsant activity.

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.

Synthesis, characterization and anticonvulsant activity of new series of N-modified analogues of VV-hemorphin-5 with aminophosphonate moiety.

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.

Synthesis, characterization and anticonvulsant activity of new azobenzene-containing VV-hemorphin-5 bio photoswitch.

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.

Anticonvulsant evaluation and docking analysis of VV-Hemorphin-5 analogues.

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.

Synthesis, characterization and nociceptive screening of new VV-hemorphin-5 analogues.

In the present study, some new analogues of VV-hemorphin-5, modified at position 1 and 7 by the non-proteinogenic and/or natural amino acids followed the structures Xxx-Val-Val-Tyr-Pro-Trp-Thr-Gln-NH2 and Val-Val-Tyr-Pro-Trp-Thr-Yyy-NH2, where Xxx is Ile or Aib and Yyy is Lys/Orn/Dap/Dab were synthesized to investigate their potential antinociceptive activities. We report also the redox potentials and the acid/base properties as pKa values of these peptide analogues which were compared toward electrochemical behaviour of tryptophan containing peptides. All analogues showed a short lasting initial antinociceptive effect, however H2 hemorphin analogue is characterized with prolong and strong antinociceptive effect, while the other peptide analogues exerted more variable effects on the visceral nociception depending on the dose or time after the intracerebral injection.

Chemical Behavior and Bioactive Properties of Spinorphin Conjugated to 5,5'-Dimethyl- and 5,5'-Diphenylhydantoin Analogs.

The discovery of new peptides and their derivatives is an outcome of ongoing efforts to identify a peptide with significant biological activity for effective usage as a possible therapeutic agent. Spinorphin peptides have been documented to exhibit numerous applications and features. In this study, biologically active peptide derivatives based on novel peptide analogues of spinorphin conjugated with 5,5'-dimethyl (Dm) and 5,5'-diphenyl (Ph) hydantoin derivatives have been successfully synthesized and characterized. Scanning electron microscopy (SEM) and spectral methods such as UV-Vis, FT-IR (Fourier Transform Infrared Spectroscopy), CD (Circular Dichroism), and fluorimetry were used to characterize the microstructure of the resulting compounds. The results revealed changes in peptide morphology as a result of the restructuring of the aminoacidic sequences and aromatic bonds, which is related to the formation of intermolecular hydrogen bonds between tyrosyl groups and the hydantoin moiety. Electrochemical and fluorescence approaches were used to determine some physicochemical parameters related to the biological behavior of the compounds. The biological properties of the spinorphin derivatives were evaluated in vivo for anticonvulsant activity against the psychomotor seizures at different doses of the studied peptides. Both spinorphin analog peptides with Ph and Dm groups showed activity against all three phases of the seizure in the intravenous Pentylenetetrazole Seizure (ivPTZ) test. This suggests that hydantoin residues do not play a crucial role in the structure of spinorphin compounds and in determining the potency to raise the seizure threshold. On the other hand, analogs with a phenytoin residue are active against the drug-resistant epilepsy test (6-Hz test). In addition, bioactivity analyses revealed that the new peptide analogues have the potential to be used as antimicrobial and antioxidant compounds. These findings suggest promising avenues for further research that may lead to the development of alternative medicines or applications in various fields beyond epilepsy treatment.

An RNA-seq atlas of mouse brain areas during fasting and diet-induced obesity.

Mammalian energy homeostasis is primarilly regulated by the hypothalamus and hindbrain, with the hippocampus, midbrain nuclei, and other regions implicated by evidence from human genetics studies. To understand how these non-canonical brain regions respond to imbalances in energy homeostasis, we performed two experiments examining the effects of different diets in male C57BL6 mice. In our first study, groups of six pair-housed mice were given access to chow, high-fat diet or fasted for 16 hours. In our subsequent study, two groups of 10 mice were single-housed and given access to chow or fasted for 24 h. We recorded food intake for each cage, the change in body weight for each animal, and collected hypothalamus, hippocampus, superior colliculus, inferior colliculus, frontal cortex, and zona incerta-centric samples. We performed bulk RNA sequencing on 185 samples and validated them by a series of quality control assessments including alignment quality and gene expression profiling. We believe these studies capture the transcriptomic effects of acute fasting and high-fat diet in the rodent brain and provide a valuable reference.

Synthesis and analgesic effects of novel ß2-tryptophan hexapeptide analogs.

Aiming to develop more potent analgesic substances a new series of hexapeptides containing ß(2)-tryptophan analogues was synthesized. The Trp in position 4 and 5, respectively in Ac-Arg-Phe-Met-Trp-Met-Lys-NH2 (opioid receptor antagonist) and Ac-Arg-Tyr-Tyr-Arg-Trp-Lys-NH2 (highly potent and selective NOP-receptor agonist) was substituted by the (S)-2-(1-methyl-1H-indol-3-yl)propionic residue or the (S)-2-(5-methoxy-1H-indol-3-yl)propionic residue. The analgesic effect of the four newly synthesized compounds has been evaluated in male Wistar rats by PP- and HP tests and compared to the native templates. Further estimation of the mechanisms of action of each compound was achieved using specific antagonists-naloxone for opioid and JTC801 for the NOP receptor. Replacement of Trp with ß(2)-tryptophan analogues in 4th position (Ac-Arg-Phe-Met-Trp-Met-Lys-NH2) led to increased and longer lasting analgesic effect. The results obtained permit us to assume that both opioid and NOP receptors take part in the newly synthesized compounds analgesic effects.

Synthesis and changes in affinity for NOP and opioid receptors of novel hexapeptides containing ß(2)-tryptophan analogues.

We report the synthesis and the biological activity of new analogues of Ac-RFMWMK-NH2 and Ac-RYYRWK-NH2, modified in position 4 and 5, respectively, with incorporation of newly synthesized ß(2)-tryptophan analogues. Trp was substituted by the (S)-2-(1-methyl-1H-indol-3-yl)propionic residue or by (S)-2-(5-methoxy-1H-indol-3-yl)propionic residue. The biological activity (pEC50 and Emax) of these compounds was tested on electrically stimulated preparations of rat vas deferens. The 5-methoxy ß-tryptophan group reverses the affinity of the compounds.