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1.
Biofouling ; 39(5): 537-554, 2023.
Article in English | MEDLINE | ID: mdl-37477240

ABSTRACT

In the heritage field, the microbial adhesion on wood, and consequently the formation of biofilm led to inestimable losses of historical and cultural monuments. Thereby, this study aimed to examine the combined effect of Thymus vulgaris, Myrtus communis, and Mentha pulegium essential oils on wood surface physico-chemical properties, and to elaborate the optimal mixture using the mixture design approach coupled to the contact angle method. It was found that both wood hydrophobicity and electron donor character increased significantly after treatment using an optimal mixture containing 57% and 43% of M. pulegium and M. communis essential oils, respectively. The theoretical and experimental fungal adhesion on untreated and treated wood were also investigated. The results showed that the adhesion was favorable on untreated wood and reduced using the optimal mixture. Moreover, the experimental data demonstrated that the same mixture exhibited an antiadhesive efficacy effect with a reduction of 36-75% in adhesion.


Subject(s)
Oils, Volatile , Oils, Volatile/pharmacology , Wood , Biofilms , Fungi
2.
Heliyon ; 9(6): e16625, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37292271

ABSTRACT

The primary objective of the present inquiry was to assess the impact of gamma irradiation on the chemical composition and antibacterial potential of the essential oil extracted from the aerial parts of Moroccan Tanacetum annuum L. to this end, two distinct irradiation doses of 5 kGy and 10 kGy were administered to the essential oil, and the resultant effects were evaluated via analysis of the oil's chemical composition and antibacterial activity. The study findings have revealed that irradiation technology possesses the remarkable ability to modulate the concentrations of specific chemical constituents in a manner that effectively amplifies the antibacterial activity of the essential oil. Moreover, the technology has evinced the generation of novel compounds while also demonstrating the eradication of certain pre-existing ones upon the oil's exposure to irradiation. These discoveries have emphasized the potential of irradiation technology for augmenting the chemical profile of essential oils, thereby mitigating the risk of contamination via microbiological, physical, or chemical means, ultimately enhancing the therapeutic efficacy of the plant and its essential oil. Furthermore, the results of this study signify the possibility of harnessing irradiation technology in the production of various natural products and essential oils. The present research has thus broadened the horizons for the application of irradiation technology in advancing the potency and safety of essential oils, paving the way for a diverse range of applications in different fields, such as medicine.

3.
Arch Microbiol ; 205(6): 243, 2023 May 20.
Article in English | MEDLINE | ID: mdl-37209212

ABSTRACT

Recent improvements in 3D printing technology have increased the usage of 3D printed materials in several areas. An exciting and emerging area of applying these next-generation manufacturing strategies is the development of devices for biomedical applications. The main aim of this work was to investigate the effect of tannic acid, gallic acid, and epicatechin gallate on the physicochemical characteristics of acrylonitrile butadiene-styrene (ABS) and Nylon 3D printing materials using the contact angle method. The adhesion of Staphylococcus aureus on untreated and treated materials was evaluated by scanning electron microscopy (SEM) analysis and the images were treated by MATLAB software. The results of the contact angle measurements showed a significant change in the physicochemical properties of both surfaces, indicated an increase in the electron donor character of 3D printing materials following treatment. Thus, the ABS surfaces treated with tannic acid, gallic acid, and epicatechin gallate have become more electron donating. Furthermore, our results proved the ability of S. aureus to adhere on all materials with a percentage of 77.86% for ABS and 91.62% for nylon. The SEM has shown that all actives molecules were sufficient to obtain better inhibition of bacterial adhesion, which tannic acid has shown a total inhibition of S. aureus on ABS. From these results, our treatment presents a high potential for utilization as an active coating to prevent bacterial attachment and the eventual biofilm development in medical field.


Subject(s)
Staphylococcal Infections , Staphylococcus aureus , Humans , Nylons/pharmacology , Printing, Three-Dimensional , Styrene/chemistry , Styrene/pharmacology , Tannins/pharmacology , Gallic Acid/pharmacology
4.
Folia Microbiol (Praha) ; 68(4): 627-632, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36807129

ABSTRACT

Microbial infections and nosocomial diseases associated with biomaterial have become a major problem of public health and largely lead to revision surgery, which is painful and quite expensive for patients. These infections are caused by formation of biofilm, which present a difficulty of treatment with conventional antibiotics. The aim of our study is to investigate the theoretical adhesion of Staphylococcus aureus and Pseudomonas aeruginosa on four 3-dimensional printing filament materials used in the manufacture of medical equipment. Thus, the physicochemical properties of these microorganisms and all filament materials were determined using the contact angle measurements. Our results indicated that bacterial surfaces were hydrophilic, strongly electron donating and weakly electron accepting. In contrast, nylon, acrylonitrile butadiene-styrene, polyethylene terephthalate, and polylactic acid surfaces were hydrophobic and more electron-donor than electron-acceptor. In addition, according to the values of total free interaction energy ΔGTotal, Staphylococcus aureus was found unable to adhere to the filament materials except polyethylene terephthalate surface. However, Pseudomonas aeruginosa showed adhesion capacity only for acrylonitrile butadiene-styrene and polyethylene terephthalate surfaces. These findings imply that the usage of these 3D printed materials in the medical area necessitates more research into enhancing their resistance to bacterial adherence.


Subject(s)
Acrylonitrile , Cross Infection , Staphylococcal Infections , Humans , Bacterial Adhesion , Pseudomonas aeruginosa , Staphylococcus aureus , Butadienes/pharmacology , Polyethylene Terephthalates/chemistry , Biofilms , Styrenes
5.
Brain Sci ; 12(12)2022 Dec 03.
Article in English | MEDLINE | ID: mdl-36552121

ABSTRACT

Background:Ceratonia siliqua L. (Carob tree) is a Mediterranean evergreen, well known for its medicinal properties. The different parts of Carob were proven to exert antidiabetic, antibacterial, antifungal, and antiproliferative effects. Hence, the present paper aims to validate the positive correlation between the high antioxidant activity of carob seed peels and the improvement of negative symptoms of schizophrenia. Materials & Methods: The antioxidant activity was carried out using the ß-carotene test. Methionine and carob seed peels (CSP) extracts (50 and 100 mg/kg) were orally administrated to mice for a week. After administration, behavioral tests were assessed using the Y-maze, elevated plus maze, and forced swimming tests, as well as the novel object recognition task. Furthermore, the oxidative stress status was evaluated by analyzing the levels of the antioxidant enzymes: Superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde levels (MDA). Results: Both extracts exhibited remarkable antioxidant activity and showed antibacterial effect against Gram-positive bacteria tested (Bacillus subtilis and Staphylococcus aureus) and against Pseudomonas aeruginosa (Gram-negative). Therefore, Escherichia coli was very resistant. The behavioral tests proved the efficacy of CSP in enhancing the cognitive impairment of animal models of schizophrenia. Hence, the stated correlation between oxidative stress and schizophrenia was confirmed by the increased SOD and GPx activities and the decreased MDA level. Conclusions: The present study gave further confirmation of the potential correlation between oxidative stress and the development of psychiatric disorders and highlighted the use of natural antioxidants, especially Ceratonia siliqua L. in the improvement of cognitive impairment in the dementia of schizophrenia.

6.
Phytochemistry ; 202: 113291, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35787353

ABSTRACT

The Monimiaceae, Siparunaceae, and Atherospermataceae, formerly included in the broad ''old'' Monimiaceae family, have long been known for their uses in traditional medicine and have proven to be rich sources of chemically diverse specialized metabolites with numerous potent biological and therapeutical properties. The progress made recently has expanded their phytochemistry and pharmacology albeit to different extents. This review focuses on the non-volatile constituents isolated from the three plant families during the last two decades and their emerging therapeutic potential. Based on the data collected from multiple databases without statistical analysis, approximately 93 components, of which 35 undescribed compounds including γ-lactones, alkaloids, terpenoids, flavonoids, and homogentisic acid derivatives, have been reported. Moreover, diverse biological activities of pure isolated compounds such as anticancer, antioxidant, antiparasitic, antiviral, and antibacterial activities have been evidenced. Besides offering new important perspectives for different diseases' management, the chemical and biological diversities among the isolated compounds, open promising avenues of research and contribute to renewed interest in these families needing further studies. This review provides an updated overview of their potential as sources of leads for drug discovery, while also highlighting ongoing challenges and future research opportunities.


Subject(s)
Monimiaceae , Antioxidants , Ethnopharmacology , Medicine, Traditional , Phytochemicals/chemistry , Plant Extracts/pharmacology
7.
Int J Biomater ; 2022: 9923079, 2022.
Article in English | MEDLINE | ID: mdl-35069743

ABSTRACT

Despite having been used for ages to preserve wood against several effects (biological attack and moisture effects) that cause its degradation, the effect of vegetable oils on the cedar wood physicochemical properties is poorly known. Thus, in this study, the hydrophobicity, electron-acceptor (γ +), and electron-donor (γ -) properties of cedar wood before and after treatment with vegetable oils have been determined using contact angle measurement. The cedar wood has kept its hydrophobic character after treatment with the different vegetable oils. It has become more hydrophobic quantitatively with values of surface energy ranged from -25.84 to -43.45 mJ/m2 and more electron donors compared to the untreated sample. Moreover, the adhesion of four fungal strains (Penicillium commune (PDLd"), Thielavia hyalocarpa, Penicillium commune (PDLd10), and Aspergillus niger) on untreated and treated cedar wood was examined theoretically and experimentally. For untreated wood, the experimental adhesion showed a positive relationship with the results obtained by the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) approach which found that all fungal strains could adhere strongly to the cedar wood material. In contrast, this relationship was not always positive after treatment. The Environmental Scanning Electron Microscopy (ESEM) has shown that P. commune (PDLd10) and A. niger were found unable to adhere to the wood surface after treatment with sunflower and rapeseed oils. In addition, the results showed that the four fungal strains' adhesion was decreased with olive and linseed oils treatment except that of P. commune (PDLd10) treated with linseed oil.

8.
J Complement Integr Med ; 15(4)2018 May 29.
Article in English | MEDLINE | ID: mdl-29813031

ABSTRACT

Carob tree (Ceratonia siliqua L.) is one of the most widespread medicinal plants in the Mediterranean area. Traditionally, it was cultivated for its ethnopharmacological benefits and, more especially, for the seeds, which served as unit of measurement of jewelers "carat." Hence, in the last half-century, numerous studies reported a wide range of phytoconstituents contained in all parts of Ceratonia siliqua such as phenolic compounds, flavonoids, tannins, anthocyanins, alkaloids, glycosides, proteins and minerals. This review article unveils the phytochemical constituents, bioactivity and pharmacological studies of Ceratonia siliqua. Recent studies have shown that the extracts of this plant exhibit an antioxidant, antidiarrheal, antibacterial, antifungal, anti-inflammatory, antidiabetic activities and also hepatoprotective and antiproliferative effects. In this review, we provide a summary of the most interesting data related to bioactivity and therapeutic potential of Ceratonia siliqua in a way to suggest possible future studies that may use Ceratonia siliqua as an undeniable natural alternative for neurodegenerative diseases treatment.


Subject(s)
Fabaceae/chemistry , Neurodegenerative Diseases/drug therapy , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Animals , Humans , Seeds/chemistry
9.
Med Chem ; 13(6): 585-591, 2017.
Article in English | MEDLINE | ID: mdl-28290251

ABSTRACT

BACKGROUND: Uric acid is the end product of purine metabolism in humans and its increased level in serum leads to hyperuricemia. Among the different regulatory factors to control the level of uric acid in humans, xanthine oxidase (XO) is a well-established pharmacological target, as it is directly involved in uric acid production. METHODS: The aim of the study was to present a systematic approach to analyze the xanthine oxidase inhibition studies from in vitro leading to in vivo. RESULTS: Initially, dinuclear cyclam complex 1 was evaluated for in-vitro XO inhibitory activity using a spectrophotometric assay. Significant results were obtained in XO inhibition assay (IC50 = 3.70 ± 0.07 µM), in comparison to the standard drug, allopurinol (IC50 = 2.00 ± 0.01 µM). Complex 1 showed a non-competitive type of inhibition in kinetic studies. Complex 1 was also found to be non-cytotoxic in MTT assay, as it did not affect the viability of 3T3-cell line. Based on these results, compound 1 was further evaluated for the in-vivo xanthine oxidase inhibitory activity. An in-vivo model was used to evaluate the XO inhibitory activity in plasma samples of male Wistar rats. Complex 1 showed a significant inhibition of xanthine oxidase activity (50%), in comparison to the standard inhibitor allopurinol (100%). Therefore, non-cytotoxic compound 1 could be considered as an anti-hyperurecemic lead for further studies. CONCLUSION: Our studies concluded that complex 1 is a non-cytotoxic inhibitor that decreases the activity of XO in a non-competitive manner. It can serve as a potential anti-hyperurecemic lead after further pre-clinical and clinical studies.


Subject(s)
Heterocyclic Compounds/chemistry , Heterocyclic Compounds/pharmacology , Hyperuricemia/drug therapy , 3T3 Cells , Animals , Cattle , Drug Design , Heterocyclic Compounds/therapeutic use , Heterocyclic Compounds/toxicity , Hyperuricemia/enzymology , Kinetics , Male , Mice , Rats , Rats, Wistar , Xanthine Oxidase/antagonists & inhibitors
10.
Am J Ther ; 24(6): e706-e712, 2017.
Article in English | MEDLINE | ID: mdl-27058575

ABSTRACT

In this work, we characterized by high-performance liquid chromatography, the γ-tocopherol (573.66 µg/g), and by gas chromatography-mass spectrometry, the linoleic acid (62.05%) as major components from Peganum harmala L. seeds oil and evaluated their potential in vivo acute antiinflammatory, analgesic activities, and in vitro antioxidative capacity. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay showed an important antioxidant activity (62.50% with an IC50 of 4.8 mg/mL). In addition, the antiinflammatory effect of the formulation cream at 20% caused a reduction in inflammation at 5 hours after carrageenan application compared with diclofenac at 1% (60.4%; 45.65%; respectively). A slight potential peripheral analgesia was noted in plantar test in treated rats with cream (20 s). Therefore, our findings demonstrate that formulation cream of P. harmala seeds oil has an interesting antiinflammatory activity with a slight peripheral analgesic effect due mainly to its richness on linoleic acid, γ-tocopherol, and polyphenols and to its important antioxidant capacity.


Subject(s)
Dermatitis, Atopic/drug therapy , Peganum/chemistry , Plant Extracts/pharmacology , Plant Oils/chemistry , Seeds/chemistry , Analgesics/pharmacology , Analgesics/therapeutic use , Animals , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antioxidants/pharmacology , Antioxidants/therapeutic use , Carrageenan/toxicity , Chromatography, High Pressure Liquid/methods , Dermatitis, Atopic/chemically induced , Disease Models, Animal , Gas Chromatography-Mass Spectrometry/methods , Humans , Linoleic Acid/pharmacology , Male , Plant Extracts/therapeutic use , Rats , Rats, Wistar , Skin Cream/pharmacology , gamma-Tocopherol/pharmacology
11.
Article in English | MEDLINE | ID: mdl-24098252

ABSTRACT

The asymmetric unit of the title mol-ecular salt [systematic name: 1,4,8,11-tetraazacyclotetradecane-1,8-diium bis(3-carboxy-prop-2-enoate)], C10H26N4 (2+)·2C4H3O4 (-), contains two half-cations (both completed by crystallographic inversion symmetry) and two maleate anions. The cyclam macrocycles adopt trans-III conformations, supported by two intra-molecular N-H⋯O hydrogen bonds. The O-bonded H atom of each maleate ion is disordered over two positions with an occupancy ratio of 0.61 (5):0.39 (5): each one generates an intra-molecular O-H⋯O hydrogen bond. In the crystal, the cations are linked to the anions by N-H⋯O hydrogen bonds, generating [001] chains.

12.
Dalton Trans ; 41(47): 14369-80, 2012 Dec 21.
Article in English | MEDLINE | ID: mdl-23047805

ABSTRACT

The complexation of Fe(SO(3)CF(3))(2) to the series of fluoro α-substituted tris-(2-aminomethylpyridyl)amine tripods F(1-3)TPA yields the triflato F(1-3)TPAFe(SO(3)CF(3))(2) complexes which have firstly been characterized in solution. As expected, bis-acetonitrile charged species are present in CH(3)CN, and neutral bis-triflato complexes in CH(2)Cl(2). The X-ray diffraction analyses of F(1)TPAFe(SO(3)CF(3))(2) and F(2)TPAFe(SO(3)CF(3))(2) crystallized from CH(2)Cl(2) solutions show that their structure in solution is retained in the solid state, with coordination of both triflate ions and the κ(4) coordination mode of the tripod in each complex. The solid state structure of the [F(2)TPAFe(NCMe)(SO(3)CF(3))](SO(3)CF(3)) complex obtained from crystallization in acetonitrile of the bis-triflato precursor is also reported. The presence of a bound triflate in the solid state is unexpected and interpreted as the result of solid-state stabilization by a metal center which displays some Lewis acidity character because of its coordination to an electron-deficient tripod. The fourth compound whose solid state structure is reported is [F(2)TPAFe(H(2)O)(2)](SO(3)CF(3))(2), fortuitously obtained after the bis-triflato precursor was handled under aerobic conditions. In CH(3)CN, all complexes are oxygen stable. The gain in stability of the bis-acetonitrile adducts is certainly responsible for the lack of reactivity of all complexes in this solvent. In CH(2)Cl(2), the parent TPAFe(SO(3)CF(3))(2) complex reacts with O(2) to yield a compound belonging to the well-known class of µ-oxo diferric compounds. Whereas F(1)TPAFe(SO(3)CF(3))(2) is poorly reactive, F(2)TPAFe(SO(3)CF(3))(2) and F(3)TPAFe(SO(3)CF(3))(2) turn out to be completely inert. This strongly contrasts with the behavior of the known F(1-3)TPAFeCl(2) complexes for which an increased reactivity is observed upon ligand substitution. In CH(2)Cl(2), conductimetry measurements indicate extremely weak (if any!) dissociation of the ancillary ligands in all complexes. Comparative analysis of the structures reveals relatively invariant structural parameters within the series of Fe(SO(3)CF(3))(2) complexes, whereas FeCl(2) complexes display important metal to ligand elongations upon tripod substitution. The reactivity increase upon fluorination of the ligand in the FeCl(2) complexes is interpreted as resulting from sterically-induced pyridine flexibility. The opposite situation with Fe(SO(3)CF(3))(2) complexes is due to the lock of the coordination polyhedron in the absence of important steric stress, especially when the metal center becomes electron-deficient.


Subject(s)
Ferrous Compounds/chemistry , Lewis Acids/chemistry , Oxygen/chemistry , Crystallization , Ligands , Models, Molecular , Stereoisomerism
13.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): o1734-5, 2011 Jul 01.
Article in English | MEDLINE | ID: mdl-21837123

ABSTRACT

The asymmetric unit of the title compound, C(12)H(17)NO(3), contains two mol-ecules with different conformations. It is a polymorph of the monoclinic form [El Antri et al. (2004 ▶). Mol-ecules, 9, 650-657]; the samples were crystallized at different temperatures from the same solvent. In both structures, mol-ecules are linked by O-H⋯N hydrogen bonds, forming chains. The conformations of the chains and their packing differ markedly in the two polymorphs.

14.
Chem Commun (Camb) ; 47(30): 8554-6, 2011 Aug 14.
Article in English | MEDLINE | ID: mdl-21709892

ABSTRACT

For the first time, α-emitter radioisotope (213)Bi has been incorporated into porphyrin chelates, with rates matching with the short period of the radionuclide. An in situ transmetalation mechanism involving the daughter isotope (209)Pb is expected to boost the (213)Bi radiolabeling process.


Subject(s)
Bismuth/chemistry , Chelating Agents/chemistry , Porphyrins/chemistry , Alpha Particles , Cell Line, Tumor , Coordination Complexes/chemistry , Coordination Complexes/toxicity , Crystallography, X-Ray , Humans , Hydrogen-Ion Concentration , Lead Radioisotopes/chemistry , Molecular Conformation , Radioisotopes/chemistry
15.
J Am Chem Soc ; 132(12): 4477-89, 2010 Mar 31.
Article in English | MEDLINE | ID: mdl-20201539

ABSTRACT

A novel porphyrin tripod (TPZn(3)) was synthesized via "click chemistry". Three porphyrin moieties of TPZn(3) are geometrically close and linked by a flexible linker. The electron-transfer oxidation of TPZn(3) results in intramolecular pi-dimer formation between porphyrin moieties as indicated by electrochemical, vis-NIR, and ESR measurements. The cyclic voltammogram of TPZn(3) exhibited stepwise one-electron oxidation processes of three porphyrin moieties in the range from 0.58 to 0.73 V (vs SCE in CH(2)Cl(2)). When TPZn(3) was oxidized by tris(2,2'-bipyridyl)-ruthenium(III) ([Ru(bpy)(3)](3+)), the oxidized species (TPZn(3))(n+) (0 < n

Subject(s)
Fullerenes/chemistry , Macromolecular Substances/chemistry , Porphyrins/chemistry , Quantum Theory , Molecular Structure , Oxidation-Reduction , Photochemistry , Zinc/chemistry
16.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 6): o1391, 2010 May 19.
Article in English | MEDLINE | ID: mdl-21579471

ABSTRACT

The crystal structure of the title compound, C(7)H(10)N(+)·H(2)PO(3) (-), has been reported previously by Sabounchei & Naghipour [Asian J. Chem. (2003) ▶, 15, 1677-1686]. A new look at this compound has revealed doubling of the unit cell. The asymmetric unit consists of two 4-methyl-anilinium cations and two dihydrogen phosphite anions. The crystal structure is built upon alternating layers of organic cations and dihydrogen phosphite anions stacked along c. The organic layer is stabilized by C-H⋯π interactions. Weak aromatic π-π stacking interactions with centroid-centroid distances of 4.6147 (12), 4.6917 (12), 4.6932 (13) and 4.8366 (13) Šare also observed in the structure. The dihydrogen phosphite anions are linked by O-H⋯O hydrogen bonds into chains running parallel to the a-axis direction. These chains are connected to the cation layer by N-H⋯O hydrogen bonds.

17.
Inorg Chem ; 48(11): 4777-86, 2009 Jun 01.
Article in English | MEDLINE | ID: mdl-19371064

ABSTRACT

We report in this article one of the first examples of a reaction of O-demethylation carried out at a Fe(II) center by molecular dioxygen, in the homogeneous phase in non-porphyrinic chemistry. This reaction parallels at the intramolecular level a very important process found in biology leading to the derivatization and elimination of drugs by oxygen-dependent enzymes that contain nonheme iron centers. To get insight into some reactivity aspects of this reaction, we have used dioxygen and iron complexes coordinated to ligands that are substituted by methoxy groups. We detail in this work the coordination chemistry of FeCl(2) to the series of mono- (L(1)), di- (L(2)), and tris(2,3-dimethoxyphenyl) (L(3)) alpha-substituted ligands in the tris(2-pyridylmethyl)amine series and the behavior of the complexes upon reaction with molecular dioxygen. As main outcomes of this study, we demonstrate that the methoxy group does not need to be coordinated to the metal center to undergo O-demethylation, but needs to be properly orientated close to an oxygenated form of the metal. We also demonstrate the importance of the environment in the reactivity with molecular dioxygen: whereas a regular 18-electron Fe(II) reacts with O(2), a five- coordinate, 16-electron center may be oxygen-stable, if the access of dioxygen to the reaction site is locked.


Subject(s)
Ferrous Compounds/chemistry , Oxygen/chemistry , Pyridines/chemistry , Crystallography, X-Ray , Ferrous Compounds/chemical synthesis , Ligands , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure , Stereoisomerism
18.
Biochimie ; 91(10): 1318-20, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19285538

ABSTRACT

In order to investigate the possible coordination of both bismuth(III) and lead(II) by porphyrins for an application in alpha-radioimmunotherapy, several series of functionalized bismuth porphyrins have been synthesized and their stabilities in acidic medium were compared. Where unfunctionalized porphyrins are not suitable for such a purpose, strapped hanging carboxylate porphyrins are stable and allow a rapid coordination of both bismuth and lead. This property could lead to the preparation of an in-situ generator of alpha particles by a pre-complexation of (212)lead, the radioactive parent of (212)bismuth, in the ligand.


Subject(s)
Bismuth/chemistry , Lead/chemistry , Porphyrins/chemistry , Radioimmunotherapy/methods , Magnetic Resonance Spectroscopy , Models, Molecular
19.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 5): i35, 2009 Apr 25.
Article in English | MEDLINE | ID: mdl-21583727

ABSTRACT

In the title compound, Pb(2)(HPO(3))(NO(3))(2), the two distinct Pb(2+) ions (both with site symmetry m) adopt irregular PbO(10) coordination polyhedra. The structure is completed by two distinct nitrate groups (in which one O atom and the N atom have m site symmetry for both ions) and an HPO(3) (2-) anion (in which one O atom and the P and H atoms have m site symmetry). The connectivity of the PbO(10), NO(3) and HPO(3) units in the crystal structure results in a three-dimensional network.

20.
Dalton Trans ; (48): 6996-7003, 2008 Dec 28.
Article in English | MEDLINE | ID: mdl-19050786

ABSTRACT

Reaction of FeCl(2) with the mono-, bis- and tris-alpha-methyl substituted tripods of tris(2-pyridylmethyl)amine (TPA) structure (L(1-3)) affords stable complexes that have been fully characterized in solid state and in solution. Whereas L(1) and L(2) coordinate in the tetradentate mode yielding complexes with pseudo-octahedral geometry, L(3) adopts the hypodentate coordination mode with one dangling pyridine, providing a trigonal bipyramidal environment around the metal. Instead of lowering the redox potential, methyl substitution increases the Fe((II))/Fe((III)) value. Being firmly bound in the parent unsubstituted TPA complex, the chloride anions become labile when alpha-substituted tripods are used as ligands, because of steric constraints at the coordination site. With L(2) and L(3), in acetonitrile and in the presence of supporting electrolyte, exchange reactions rapidly take place yielding cationic species that are more difficult to oxidize. Thus, what could at first be described in electrolytic medium as "stabilization of ferrous state", corresponds in fact to the formation of different species stabilized by (a) positive charge(s).


Subject(s)
Ferrous Compounds/chemistry , Pyridines/chemistry , Electrochemistry , Ligands , Magnetic Resonance Spectroscopy , Nitrogen/chemistry , Oxidation-Reduction , Solutions
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