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17 pages, 5049 KiB

Open AccessArticle

Molecular Recognition of Imidazole-Based Drug Molecules by Cobalt(III)- and Zinc(II)-Coproporphyrins in Aqueous Media

by Galina Mamardashvili, Elena Kaigorodova, Ivan Lebedev and Nugzar Mamardashvili

Molecules 2023, 28(3), 964; https://doi.org/10.3390/molecules28030964 - 18 Jan 2023

Cited by 3 | Viewed by 1769

Abstract

The methods of ¹H NMR, spectrophotometric titration, mass spectrometry and elemental analysis are applied to determine the selective binding ability of Co(III)- and Zn(II)-coproporphyrins I towards a series of imidazole-based drug molecules with a wide spectrum of pharmacological activity (metronidazole, histamine, histidine, [...] Read more.

The methods of ¹H NMR, spectrophotometric titration, mass spectrometry and elemental analysis are applied to determine the selective binding ability of Co(III)- and Zn(II)-coproporphyrins I towards a series of imidazole-based drug molecules with a wide spectrum of pharmacological activity (metronidazole, histamine, histidine, tinidazole, mercazolil, and pilocarpine) in phosphate buffer (pH 7.4) simulating the blood plasma environment. It is shown that in aqueous buffer media, Co(III)-coproporphyrin I, unlike Zn(II)-coproporphyrin I, binds two imidazole derivatives, and the stability of mono-axial Co-coproporphyrin imidazole complexes is two to three orders of magnitude higher than that of similar complexes of Zn-coproporphyrin I. The studied porphyrinates are found to have the highest binding ability to histamine and histidine due to the formation of two additional hydrogen bonds between the carboxyl groups of the porphyrinate side chains and the binding sites of the ligands in the case of histidine and a hydrogen bond between the amino group of the ligand and the carbonyl oxygen atom of the carboxyl group of the porphyrinate in the case of histamine. The structures of the resulting complexes are optimized by DFT quantum chemical calculations. The results of these studies may be of use in the design of biosensors, including those for the detection, control and verification of various veterinary drug residues in human food samples. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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18 pages, 6143 KiB

Open AccessArticle

Oxyethylated Fluoresceine—(thia)calix[4]arene Conjugates: Synthesis and Visible-Light Photoredox Catalysis in Water–Organic Media

by Vladimir Burilov, Aigul Fatykhova, Diana Mironova, Elza Sultanova, Ramil Nugmanov, Alina Artemenko, Anastasia Volodina, Amina Daminova, Vladimir Evtugyn, Svetlana Solovieva and Igor Antipin

Molecules 2023, 28(1), 261; https://doi.org/10.3390/molecules28010261 - 28 Dec 2022

Cited by 4 | Viewed by 2136

Abstract

Fluorescent derivatives attract the attention of researchers for their use as sensors, photocatalysts and for the creation of functional materials. In order to create amphiphilic fluorescent derivatives of calixarenes, a fluorescein derivative containing oligoethylene glycol and propargyl groups was obtained. The resulting fluorescein [...] Read more.

Fluorescent derivatives attract the attention of researchers for their use as sensors, photocatalysts and for the creation of functional materials. In order to create amphiphilic fluorescent derivatives of calixarenes, a fluorescein derivative containing oligoethylene glycol and propargyl groups was obtained. The resulting fluorescein derivative was introduced into three different (thia)calix[4]arene azide derivatives. For all synthesized compounds, the luminescence quantum yields have been established in different solvents. Using UV-visible spectroscopy, dynamic light scattering, as well as transmission and confocal microscopy, aggregation of macrocycles was studied. It was evaluated that calixarene derivatives with alkyl substituents form spherical aggregates, while symmetrical tetrafluorescein-containing thiacalix[4]arene forms extended worm-like aggregates. The macrocycle containing tetradecyl fragments was found to be the most efficient in photoredox ipso-oxidation of phenylboronic acid. In addition, it was shown that in a number of different electron donors (NEt₃, DABCO and iPr₂EtN), the photoredox ipso-oxidation proceeds best with triethylamine. It has been shown that a low molecular weight surfactant Triton-X100 can also improve the photocatalytic abilities of an oligoethylene glycol fluorescein derivative, thus showing the importance of a combination of micellar and photoredox catalysis. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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18 pages, 4568 KiB

Open AccessArticle

Donor–Acceptor Complexes of (5,10,15,20-Tetra(4-methylphenyl)porphyrinato)cobalt(II) with Fullerenes C₆₀: Self-Assembly, Spectral, Electrochemical and Photophysical Properties

by Nataliya G. Bichan, Ekaterina N. Ovchenkova, Varvara A. Mozgova, Alexander A. Ksenofontov, Nadezhda O. Kudryakova, Ivan V. Shelaev, Fedor E. Gostev and Tatyana N. Lomova

Molecules 2022, 27(24), 8900; https://doi.org/10.3390/molecules27248900 - 14 Dec 2022

Cited by 9 | Viewed by 1982

Abstract

The noncovalent interactions of (5,10,15,20-tetra(4-methylphenyl)porphinato)cobalt(II) (CoTTP) with C₆₀ and 1-N-methyl-2-(pyridin-4-yl)-3,4-fullero[60]pyrrolidine (PyC₆₀) were studied in toluene using absorption and fluorescence titration methods. The self-assembly in the 2:1 complexes (the triads) (C₆₀)₂CoTTP and (PyC₆₀)₂CoTTP [...] Read more.

The noncovalent interactions of (5,10,15,20-tetra(4-methylphenyl)porphinato)cobalt(II) (CoTTP) with C₆₀ and 1-N-methyl-2-(pyridin-4-yl)-3,4-fullero[60]pyrrolidine (PyC₆₀) were studied in toluene using absorption and fluorescence titration methods. The self-assembly in the 2:1 complexes (the triads) (C₆₀)₂CoTTP and (PyC₆₀)₂CoTTP was established. The bonding constants for (C₆₀)₂CoTTP and (PyC₆₀)₂CoTTP are defined to be (3.47 ± 0.69) × 10⁹ and (1.47 ± 0.28) × 10¹⁰ M⁻², respectively. ¹H NMR, IR spectroscopy, thermogravimetric analysis and cyclic voltammetry data have provided very good support in favor of efficient complex formation in the ground state between fullerenes and CoTTP. PyC₆₀/C₆₀ fluorescence quenching in the PyC₆₀/C₆₀–CoTTP systems was studied and the fluorescence lifetime with various CoTTP additions was determined. The singlet oxygen quantum yield was determined for PyC₆₀ and the intensity decrease in the ¹O₂ phosphorescence for C₆₀ and PyC₆₀ with the CoTTP addition leading to the low efficiency of intercombination conversion for the formation of the ³C₆₀* triplet excited state was found. Using femtosecond transient absorption measurements in toluene, the photoinduced electron transfer from the CoTTP in the excited singlet state to fullerene moiety was established. Quantum chemical calculations were used for the determination of molecular structure, stability and the HOMO/LUMO energy levels of the triads as well as to predict the localization of frontier orbitals in the triads. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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20 pages, 5254 KiB

Open AccessArticle

Amine-Reactive BODIPY Dye: Spectral Properties and Application for Protein Labeling

by Ksenia V. Ksenofontova, Anastasia A. Kerner, Alexander A. Ksenofontov, Artyom Yu. Shagurin, Pavel S. Bocharov, Michael M. Lukanov, Airat R. Kayumov, Darya E. Zhuravleva, Zalina I. Iskhakova, Evgeniy E. Molchanov, Dmitriy A. Merkushev, Ilya A. Khodov and Yuriy S. Marfin

Molecules 2022, 27(22), 7911; https://doi.org/10.3390/molecules27227911 - 16 Nov 2022

Cited by 7 | Viewed by 2609

Abstract

A boron-dipyrromethene (BODIPY) derivative reactive towards amino groups of proteins (NHS-Ph-BODIPY) was synthesized. Spectroscopic and photophysical properties of amine-reactive NHS-Ph-BODIPY and its non-reactive precursor (COOH-Ph-BODIPY) in a number of organic solvents were investigated. Both fluorescent dyes were characterized by [...] Read more.

A boron-dipyrromethene (BODIPY) derivative reactive towards amino groups of proteins (NHS-Ph-BODIPY) was synthesized. Spectroscopic and photophysical properties of amine-reactive NHS-Ph-BODIPY and its non-reactive precursor (COOH-Ph-BODIPY) in a number of organic solvents were investigated. Both fluorescent dyes were characterized by green absorption (521–532 nm) and fluorescence (538–552 nm) and medium molar absorption coefficients (46,500–118,500 M⁻¹·cm⁻¹) and fluorescence quantum yields (0.32 – 0.73). Solvent polarizability and dipolarity were found to play a crucial role in solvent effects on COOH-Ph-BODIPY and NHS-Ph-BODIPY absorption and emission bands maxima. Quantum-chemical calculations were used to show why solvent polarizability and dipolarity are important as well as to understand how the nature of the substituent affects spectroscopic properties of the fluorescent dyes. NHS-Ph-BODIPY was used for fluorescent labeling of a number of proteins. Conjugation of NHS-Ph-BODIPY with bovine serum albumin (BSA) resulted in bathochromic shifts of absorption and emission bands and noticeable fluorescence quenching (about 1.5 times). It was demonstrated that the sensitivity of BSA detection with NHS-Ph-BODIPY was up to eight times higher than with Coomassie brilliant blue while the sensitivity of PII-like protein PotN (PotN) detection with NHS-Ph-BODIPY and Coomassie brilliant blue was almost the same. On the basis of the molecular docking results, the most probable binding sites of NHS-Ph-BODIPY in BSA and PotN and the corresponding binding free energies were estimated. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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13 pages, 4052 KiB

Open AccessArticle

Azocalix[4]arene-Rhodamine Supramolecular Hypoxia-Sensitive Systems: A Search for the Best Calixarene Hosts and Rhodamine Guests

by Diana Mironova, Vladimir Burilov, Farida Galieva, Mohamed Ali Mohamed Khalifa, Sofia Kleshnina, Alsu Gazalieva, Ramil Nugmanov, Svetlana Solovieva and Igor Antipin

Molecules 2021, 26(18), 5451; https://doi.org/10.3390/molecules26185451 - 7 Sep 2021

Cited by 10 | Viewed by 2741

Abstract

A potential hypoxia-sensitive system host-guest complex of three calixarenes (including two with four anionic carboxyl and sulphonate azo fragments on the upper rim and a newly synthesized bis-azo adduct of calixarene in the cone configuration with azo fragments on the lower rim with [...] Read more.

A potential hypoxia-sensitive system host-guest complex of three calixarenes (including two with four anionic carboxyl and sulphonate azo fragments on the upper rim and a newly synthesized bis-azo adduct of calixarene in the cone configuration with azo fragments on the lower rim with the most widespread cationic and zwitterionic rhodamine dyes (123, 6G and B)) was studied using UV-VIS spectrometry and fluorescence as well as 1D and 2D NMR techniques. It was found that all three calixarenes form a complex with rhodamine dyes with a 1:1 composition. The association constants of calixarene-dye complexes with sulfonate calixarenes, especially in the case of tetra-anionic calixarene, turned out to be higher compared with carboxyl calixarene due to the more intense electrostatic interactions. For the first time using an HRESI MS technique, it was shown that the treatment of rhodamine 6G and 123 with sodium dithionite (SDT) produces a non-fluorescent leuco form of the dye, and only rhodamine B can be used with SDT without the occurrence of a side reduction. Moreover, it was identified that in addition to the reduction in the azo groups, SDT causes partial cleavage of the aryl ether bonds. The found features of SDT should be taken into account when SDT is used as an azoreductase mimic. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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22 pages, 6120 KiB

Open AccessArticle

Molecular Recognition of Imidazole Derivatives by Co(III)-Porphyrins in Phosphate Buffer (pH = 7.4) and Cetylpyridinium Chloride Containing Solutions

by Galina Mamardashvili, Elena Kaigorodova, Olga Dmitrieva, Oscar Koifman and Nugzar Mamardashvili

Molecules 2021, 26(4), 868; https://doi.org/10.3390/molecules26040868 - 6 Feb 2021

Cited by 10 | Viewed by 3164

Abstract

By means of spectrophotometric titration and NMR spectroscopy, the selective binding ability of the Co(III)-5,15-bis-(3-hydroxyphenyl)-10,20-bis-(4-sulfophenyl)porphyrin (Co(III)P1) and Co(III)-5,15-bis-(2-hydroxyphenyl)-10,20-bis-(4-sulfophenyl)porphyrin (Co(III)P2) towards imidazole derivatives of various nature (imidazole (L1), metronidazole (L2), and histamine (L3)) in phosphate buffer (pH 7.4) has been studied. It was found [...] Read more.

By means of spectrophotometric titration and NMR spectroscopy, the selective binding ability of the Co(III)-5,15-bis-(3-hydroxyphenyl)-10,20-bis-(4-sulfophenyl)porphyrin (Co(III)P1) and Co(III)-5,15-bis-(2-hydroxyphenyl)-10,20-bis-(4-sulfophenyl)porphyrin (Co(III)P2) towards imidazole derivatives of various nature (imidazole (L1), metronidazole (L2), and histamine (L3)) in phosphate buffer (pH 7.4) has been studied. It was found that in the case of L2, L3 the binding of the “first” ligand molecule by porphyrinates Co(III)P1 and Co(III)P2 occurs with the formation of complexes with two binding sites (donor–acceptor bond at the center and hydrogen bond at the periphery of the macrocycle), while the “second” ligand molecule is added to the metalloporphyrin only due to the formation of the donor–acceptor bond at the macrocycle coordination center. The formation of stable complexes with two binding sites has been confirmed by density functional theory method (DFT) quantum chemical calculations and two-dimensional NMR experiments. It was shown that among the studied porphyrinates, Co(III)P2 is more selective towards to L1-L3 ligands, and localization of cobalt porphyrinates in cetylpyridinium chloride (CPC) micelles does not prevent the studied imidazole derivatives reversible binding. The obtained materials can be used to develop effective receptors for recognition, delivery, and prolonged release of drug compounds to the sites of their functioning. Considering that cetylpyridinium chloride is a widely used cationic biocide as a disinfectant, the designed materials may also prove to be effective antimicrobial agents. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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Review

Jump to: Research

40 pages, 22129 KiB

Open AccessReview

Macrocyclic Receptors for Identification and Selective Binding of Substrates of Different Nature

by Galina Mamardashvili, Nugzar Mamardashvili and Oscar Koifman

Molecules 2021, 26(17), 5292; https://doi.org/10.3390/molecules26175292 - 31 Aug 2021

Cited by 10 | Viewed by 2739

Abstract

Molecular recognition of host/guest molecules represents the basis of many biological processes and phenomena. Enzymatic catalysis and inhibition, immunological response, reproduction of genetic information, biological regulatory functions, the effects of drugs, and ion transfer—all these processes include the stage of structure recognition during [...] Read more.

Molecular recognition of host/guest molecules represents the basis of many biological processes and phenomena. Enzymatic catalysis and inhibition, immunological response, reproduction of genetic information, biological regulatory functions, the effects of drugs, and ion transfer—all these processes include the stage of structure recognition during complexation. The goal of this review is to solicit and publish the latest advances in the design and sensing and binding abilities of porphyrin-based heterotopic receptors with well-defined geometries, the recognition ability of which is realized due to ionic, H-bridge, charge transfer, hydrophobic, and hydrophilic interactions. The dissection of the considered low-energy processes at the molecular scale expands our capabilities in the development of effective systems for controlled recognition, selective delivery, and prolonged release of substrates of different natures (including drugs) to their sites of functioning. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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18 pages, 5702 KiB

Open AccessFeature PaperReview

Fluorescent Probes for Selective Recognition of Hypobromous Acid: Achievements and Future Perspectives

by Yuyu Fang and Wim Dehaen

Molecules 2021, 26(2), 363; https://doi.org/10.3390/molecules26020363 - 12 Jan 2021

Cited by 26 | Viewed by 3943

Abstract

Reactive oxygen species (ROS) have been implicated in numerous pathological processes and their homeostasis facilitates the dynamic balance of intracellular redox states. Among ROS, hypobromous acid (HOBr) has a high similarity to hypochlorous acid (HOCl) in both chemical and physical properties, whereas it [...] Read more.

Reactive oxygen species (ROS) have been implicated in numerous pathological processes and their homeostasis facilitates the dynamic balance of intracellular redox states. Among ROS, hypobromous acid (HOBr) has a high similarity to hypochlorous acid (HOCl) in both chemical and physical properties, whereas it has received relatively little attention. Meanwhile, selective recognition of endogenous HOBr suffers great challenges due to the fact that the concentration of this molecule is much lower than that of HOCl. Fluorescence-based detection systems have emerged as very important tools to monitor biomolecules in living cells and organisms owing to distinct advantages, particularly the temporal and spatial sampling for in vivo imaging applications. To date, the development of HOBr-specific fluorescent probes is still proceeding quite slowly, and the research related to this area has not been systematically summarized. In this review, we are the first to review the progress made so far in fluorescent probes for selective recognition and detection of HOBr. The molecular structures, sensing mechanisms, and their successful applications of these probes as bioimaging agents are discussed here in detail. Importantly, we hope this review will call for more attention to this rising field, and that this could stimulate new future achievements. Full article

(This article belongs to the Special Issue Molecular Recognition of Host/Guest Molecules)

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