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Costa TG, Meurer L, Micke GA, Gonçalves S, Szpoganicz B, Mangrich AS. Potentiometric titration of microhydrolysis products of oils: A new low-cost methodology and investment for the analysis of oil binders present in works of art. Talanta 2020; 212:120736. [PMID: 32113528 DOI: 10.1016/j.talanta.2020.120736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 11/25/2022]
Abstract
The analysis of oil paints present in historical paintings is commonly carried out for research, authenticity and forensic purposes. This paper proposes potentiometric titration and calculation of the fatty acids concentrations with the aid of the Best7 program as an alternative technique to characterize the oil binders used in works of art. The method involves determining the ratio between the levels of palmitic (P) and stearic (S) acids present in the microhydrolysis products of commercial oil binders and paints. The microhydrolysis products were characterized, using FTIR spectroscopy, by displacement of the carbonyl band and the pKa values for the C16 and C18 in the system studied were determined. The P/S ratios found for the microhydrolysis products of linseed, palm and nut oils were 1.65, 5.91 and 2.42, respectively. For the commercial paints analyzed, values ranging from 1.34 to 1.98 were obtained, characterizing the presence of linseed oil. The values were confirmed by GC-MS and are in agreement with those reported in the literature for the oils investigated in this study.
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Affiliation(s)
- Thiago G Costa
- Laboratory of Materials, Atelier for the Conservation-Restoration of Movable Cultural Heritage, FundaçãoCatarinense de Cultura (Santa Catarina Culture Foundation), 88025-200, Florianópolis, SC, Brazil; Department of Chemistry, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil.
| | - Lino Meurer
- Laboratory of Materials, Atelier for the Conservation-Restoration of Movable Cultural Heritage, FundaçãoCatarinense de Cultura (Santa Catarina Culture Foundation), 88025-200, Florianópolis, SC, Brazil; Department of Chemistry, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Gustavo Amadeu Micke
- Department of Chemistry, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Samantha Gonçalves
- Department of Chemistry, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Bruno Szpoganicz
- Department of Chemistry, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Antônio S Mangrich
- Department of Chemistry, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
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Multidentate unsymmetrically-substituted Schiff bases and their metal complexes: Synthesis, functional materials properties, and applications to catalysis. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.11.030] [Citation(s) in RCA: 203] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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García J, González JC, Frascaroli MI, García S, Blanes P, Correia I, Costa Pessoa J, Sala LF. Spectroscopic studies of vanadium biosorption on different types of carbohydrate biomass. CAN J CHEM 2013. [DOI: 10.1139/cjc-2012-0208] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The biosorption potential of different types of carbohydrate biomass is investigated to evaluate their application to purify water contaminated by vanadium in environmentally relevant oxidation states (VIV and VV). Spectroscopic studies were done by electron paramagnetic resonance (EPR), vanadium nuclear magnetic resonance (51V NMR), circular dichroism (CD), and electronic absorption in the visible range (vis). Both d-galacturonic and d-glucuronic acids are major components of plant cellular wall polysaccharides. The interaction of VIV with the model ligands d-galacturonic and d-glucuronic acids showed that complexation starts at low pH values (pH 3) and that carboxylate and sugar–OH groups, as well as water molecules, are involved in the coordination. At pH > 4.5, coordination promotes the sugar–OH deprotonation and new species form with the ligand chelating the metal ion via oxygen atoms of carboxylate and of adjacent sugar–O− donors. The studies with pectin and citric acid show the ability of both compounds to partially reduce VV to VIV in solution and the EPR parameters suggest coordination of carboxylate, sugar–OH, and water molecules. The interaction of VV with biomass from different sources shows that grapefruit, orange peel, and plane tree fruit are the most suitable candidates for the biosorption of vanadium. Studies with VV and grapefruit (or the grainless stalk of corn) indicate that the reduction takes place at the “surface” of the solid. EPR studies on the interaction of VIV with different carbohydrate biomass show their ability to complex high amounts of VIV. We propose that the biosorption mechanism, when the biomass is in contact with VV species, involves sorption, reduction, and retention at the surface level of VIV coordinated by oxygen donors of the biomass. When the interaction starts with VIV, the main process just involves the uptake of the metal ion at the surface level.
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Affiliation(s)
- Jousy García
- Área Química General, Departamento de Químico-Física. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Santa Fe, Argentina
| | - Juan Carlos González
- Área Química General, Departamento de Químico-Física. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Santa Fe, Argentina
| | - María Inés Frascaroli
- Área Química General, Departamento de Químico-Física. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Santa Fe, Argentina
| | - Silvia García
- Área Química General, Departamento de Químico-Física. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Santa Fe, Argentina
| | - Patricia Blanes
- Área Química General, Departamento de Químico-Física. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Santa Fe, Argentina
| | - Isabel Correia
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - João Costa Pessoa
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luis F. Sala
- Área Química General, Departamento de Químico-Física. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (2000) Rosario, Santa Fe, Argentina
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Pereira DF, Kappel VD, Cazarolli LH, Boligon AA, Athayde ML, Guesser SM, Da Silva EL, Silva FRMB. Influence of the traditional Brazilian drink Ilex paraguariensis tea on glucose homeostasis. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2012; 19:868-877. [PMID: 22795927 DOI: 10.1016/j.phymed.2012.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 03/29/2012] [Accepted: 05/14/2012] [Indexed: 06/01/2023]
Abstract
In this study we examined the acute in vivo effect and short- and long-term in vitro effects of samples from native and commercial Ilex paraguariensis on glucose homeostasis. Also, the potential effect of I. paraguariensis on serum insulin secretion was investigated. The chemical identification and quantification of methyl xanthines and polyphenols in CH₂Cl₂, EtOAc and n-BuOH fractions of native I. paraguariensis as well as infusions of green and roasted I. paraguariensis from a commercial source was verified by high-performance liquid chromatography. The results for the serum glucose-lowering indicated that both fractions and both infusions were able to improve significantly the oral glucose tolerance curve. Additionally, both the EtOAc and n-BuOH fractions induced-insulin secretion, but EtOAc induced an early (at 15 min) and late (at 60 min) biphasic peak of insulin secretion similar to glipizide stimulatory effect. Both fractions increased liver glycogen content compared with fasted normal rats. Also, EtOAc and n-BuOH fractions inhibited in vitro disaccharidases activities after an acute treatment. The maximum inhibitory effect of the EtOAc and n-BuOH fractions on maltase activity (at 5 min) was around 35%. The evident reduction of protein glycation by glucose or fructose with EtOAc and n-BuOH fractions increased from 7 to 28 days of in vitro incubation. Inhibition of bovine serum albumin glycation by glucose and fructose, by around 50% and 90%, respectively, was observed. Additionally, the green and roasted mate infusions reduced the formation of AGEs in a characteristic long-term effect. In conclusion, this study shows that I. paraguariensis has an anti-hyperglycemic potential role able to improve the diabetic status and is probably a source of multiple hypoglycemic compounds.
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Affiliation(s)
- D F Pereira
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Cx. Postal 5069, CEP: 88040-970 Florianópolis, SC, Brazil
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Nejo AA, Kolawole GA, Nejo AO, Segapelo TV, Muller CJ. Synthesis, Structural, and Insulin-Enhancing Studies of Oxovanadium(IV) Complexes. Aust J Chem 2011. [DOI: 10.1071/ch11291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Oxovanadium(iv) complexes with Schiff bases derived from substituted salicylaldehyde and diamine have been prepared and characterized. 1H NMR and IR spectral data revealed that the symmetrical Schiff base was isolated, and elemental analysis confirmed the purity of all the compounds as formulated. The room-temperature magnetic moments of 1.6–1.8 Bohr magneton for the complexes confirmed that the complexes are VIV complexes, with d1 configuration. Cyclic voltammetry revealed only one quasi-reversible wave for each complex and they all showed redox couples with peak-to-peak separation values (ΔEp) ranging from 76 to 84 mV, indicating a single-step one-electron transfer process. An oral administration of these complexes supplied at a dose of 0.2 mmol kg–1 to streptozotocin-induced diabetic rats elicited a progressive reduction in plasma glucose over 6-h periods. Two of the complexes produced significant and consistent reduction in fasting blood glucose levels over a 6-h monitoring period.
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Nejo AA, Kolawole GA, Opoku AR, Muller C, Wolowska J. Synthesis, characterization, and insulin-enhancing studies of unsymmetrical tetradentate Schiff-base complexes of oxovanadium(IV). J COORD CHEM 2010. [DOI: 10.1080/00958970903104327] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Adeola A. Nejo
- a Department of Chemistry , University of Zululand , Kwadlangezwa, South Africa
| | - Gabriel A. Kolawole
- a Department of Chemistry , University of Zululand , Kwadlangezwa, South Africa
| | - Andy R. Opoku
- b Department of Biochemistry and Microbiology , University of Zululand , Kwadlangezwa, South Africa
| | - Christo Muller
- c Diabetic Discovery Platform , South African Medical Research Council , Tygerberg, South Africa
| | - Joanna Wolowska
- d School of Chemistry, The University of Manchester , Manchester, UK
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Lezama L, Rojo T, Ferrer EG. Spectroscopic evidence on the interaction of prephenate, a shikimate pathway intermediate, with oxidovanadium(IV) species. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Zhou C, Gan L, Zhang Y, Zhang F, Wang G, Jin L, Geng R. Review on supermolecules as chemical drugs. SCIENCE IN CHINA. SERIES B, CHEMISTRY 2009; 52:415-458. [PMID: 38624300 PMCID: PMC7089408 DOI: 10.1007/s11426-009-0103-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 12/28/2008] [Indexed: 11/01/2022]
Abstract
Supramolecular medicinal chemistry field has been a quite rapidly developing, increasingly active and newly rising interdiscipline which is the new expansion of supramolecular chemistry in pharmaceutical sciences, and is gradually becoming a relatively independent scientific area. Supramolecular drugs could be defined as medicinal supermolecules formed by two or more molecules through non-covalent bonds. So far a lot of supermolecules as chemical drugs have been widely used in clinics. Supermolecules as chemical drugs, i.e. supramolecular chemical drugs or supramolecular drugs, which might have the excellences of lower cost, shorter period, higher potential as clinical drugs for their successful research and development, may possess higher bioavailability, better biocompatibility and drug-targeting, fewer multidrug-resistances, lower toxicity, less adverse effect, and better curative effects as well as safety, and therefore exhibit wide potential application. These overwhelming advantages have drawn enormous special attention. This paper gives the definition of supramolecular drugs, proposes the concept of supramolecular chemical drugs, and systematically reviews the recent advances in the research and development of supermolecules, including organic and inorganic complex ones as chemical drugs in the area of antitumor, anti-inflammatory, analgesic, antimalarial, antibacterial, antifungal, antivirus, anti-epileptic, cardiovascular agents and magnetic resonance imaging agents and so on. The perspectives of the foreseeable future and potential application of supramolecules as chemical drugs are also presented.
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Affiliation(s)
- ChengHe Zhou
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715 China
| | - LinLing Gan
- School of Pharmaceutical Sciences, Southwest University, Chongqing, 400715 China
| | - YiYi Zhang
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715 China
| | - FeiFei Zhang
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715 China
| | - GuangZhou Wang
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715 China
| | - Lei Jin
- School of Pharmaceutical Sciences, Southwest University, Chongqing, 400715 China
| | - RongXia Geng
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715 China
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Baran EJ. Oxovanadium(IV) complexes of carbohydrates: A brief overview. J Inorg Biochem 2009; 103:547-53. [DOI: 10.1016/j.jinorgbio.2008.10.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 09/29/2008] [Accepted: 10/03/2008] [Indexed: 10/21/2022]
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