The Antioxidant Effect of Curcumin and Rutin on Oxidative Stress Biomarkers in Experimentally Induced Periodontitis in Hyperglycemic Wistar Rats

Background: There is a growing interest in the correlation between antioxidants and periodontal disease. In this study, we aimed to investigate the effect of oxidative stress and the impact of two antioxidants, curcumin and rutin, respectively, in the etiopathology of experimentally induced periodontitis in diabetic rats. Methods: Fifty Wistar albino rats were randomly divided into five groups and were induced with diabetes mellitus and periodontitis: (1) (CONTROL)—control group, (2) (DPP)—experimentally induced diabetes mellitus and periodontitis, (3) (DPC)—experimentally induced diabetes mellitus and periodontitis treated with curcumin (C), (4) (DPR)—experimentally induced diabetes mellitus and periodontitis treated with rutin (R) and (5) (DPCR)—experimentally induced diabetes mellitus and periodontitis treated with C and R. We evaluated malondialdehyde (MDA) as a biomarker of oxidative stress and reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG and catalase (CAT) as biomarkers of the antioxidant capacity in blood harvested from the animals we tested. The MDA levels and CAT activities were also evaluated in the gingival tissue. Results: The control group effect was statistically significantly different from any other groups, regardless of whether or not the treatment was applied. There was also a significant difference between the untreated group and the three treatment groups for variables MDA, GSH, GSSG, GSH/GSSG and CAT. There was no significant difference in the mean effect for the MDA, GSH, GSSG, GSH/GSSG and CAT variables in the treated groups of rats with curcumin, rutin and the combination of curcumin and rutin. Conclusions: The oral administration of curcumin and rutin, single or combined, could reduce the oxidative stress and enhance the antioxidant status in hyperglycemic periodontitis rats.     

Molecular orbital calculations of the active site complex of two iron ferredoxins

The results presented here are the first part of a systematic theoretical study of some of the physical and biochemical properties of two iron ferredoxins obtained by the use of an Extended Hückel Self-Consistent Charge iteration method of molecular orbital calculations. In this initial study, attention is focused on the calculation of electronic energies as a function of molecular geometry and the nature of the bonding ligands at the active site in order to determine the most stable form of the active site complex. Included in the active site complex are two iron atoms, two acid labile sulfur atoms of unknown inorganic origin and four sulfur atoms presumably from nearby cysteine residues. Fifteen chemical-conformational variations of this basic active site complex were considered. Among these conformational variations of the sulfur ligands, Fe-Fe distances, bond lengths and angles and chemical variations such as the effect of axial ligands, disulfide bonds and added protons were included. Our results indicate that that with all reasonable variations of the ligands, the preferred molecular geometry about 4-coordinated Fe is tetrahedral rather than planar. The planar conformation is somewhat stabilized by the addition of axial ligands, but is still less favorable than the tetrahedral conformation. In this model, interactions between the two iron atoms occur automatically since they are both part of the same active site complex. Hence the absence of low temperature paramagnetism in the oxidized state is readily explained. Preliminary investigations of the reduced state with one additional electron indicate that the odd electron is delocalized, as observed in both ESR and ENDOR. Its presence apparently substantially destabilizes all of the molecular orbital energies in accord with the observation that only one electron can be added to these proteins without decomposing them.

---

Zusammenfassung Die vorliegenden Ergebnisse stellen den ersten Teil einer systematischen theoretischen Untersuchung einiger physikalischer und biochemischer Eigenschaften des Fe₂-Ferredoxins mit Hilfe einer selbstkonsistenten erweiterten Hückelmethode dar. In diesem ersten Teil wird besonders die elektronische Energie in Abhängigkeit von der Molekülgeometrie und der Art der Liganden an der aktiven Stelle untersucht, um die stabilste Form des Komplexes der aktiven Stelle zu finden. Dieser Komplex enthält zwei Eisenatome, zwei saure, nicht fest gebundene Schwefelatome unbekannter anorganischer Herkunft sowie vier Schwefelatome, vermutlich aus nahegelegenen Cysteinresten. Bei den 15 untersuchten Konformationen der Schwefelliganden wurden Änderungen der Fe-Fe-Abstände, Bindungslängen und -winkel sowie chemische Variationen wie die Einwirkung der axialen Liganden, der Disulfidbindungen und zusätzlicher Protonen berücksichtigt. Es ergibt sich, daß das Eisen vierfach tetraedrisch koordiniert ist und nicht planar, selbst bei der Addition axialer Liganden. In diesem Modell ergeben sich Wechselwirkungen zwischen den beiden Eisenatomen zwanglos, da sie zum gleichen aktiven Komplex gehören. Dadurch wird das Fehlen eines Tieftemperatur-Paramagnetismus im oxydierten Zustand hinreichend erklärt. Eine vorläufige Untersuchung des reduzierten Zustandes mit einem zusätzlichen Elektron zeigt, daß dieses delokalisiert ist, genau wie es mit ESR und ENDOR beobachtet wird. seine Gegenwart destabilisiert offenbar alle MO-Energien, was in Übereinstimmung mit der Beobachtung steht, daß nur ein Elektron von diesen Proteinen addiert werden kann, ohne sie zu zerstören.

     

Characterization of low-energy conformational domains for Met-enkephalin

Summary An extensive exploration of the conformational hypersurface of Met-enkephalin has been carried out, in order to characterize different low-energy conformational domains accessible to this pentapeptide. The search strategy used consisted of two steps. First, systematic nested rotations were performed using the ECEPP potential. Ninety-two low-energy structures were found and minimized using the CHARMm potential. High and low-temperature molecular dynamics trajectories were then computed for the lowest energy structures in an iterative fashion until no lower energy conformers could be found. The same search strategy was used in these studies simulating three different environments, a distance-dependent dielectric =r, and two constant dielectrics =10 and =80. The lowest energy structure found in a distance-dependent dielectric is a Gly-Gly -II-type turn. All other structures found for =r within 10 kcal/mol of this lowest energy structure are also bends. In the more polar environments, the density of conformational states is significantly larger compared to the apolar media. Moreover, fewer hydrogen bonds are formed in the more polar environments, which increases the flexibility of the peptide and results in less structured conformers. Comparisons are made with previous calculations and experimental results.     

Spin-mixing and the different spin states of ferric ion in tetragonal symmetry

We have used the wave functions generated from a strong crystal field model of ferric ion in complexes of tetragonal symmetry with spin-orbit coupling, to calculate the behavior of several localized properties of the ferric ion in parameter regions of different ground and low-lying ferric ion states. In the previous paper of this series we have shown with this model that ferric ion can exist in a doublet, sextet, quartet and substantially spin-mixed ground state. We have delineated such regions and described the changing nature of the wave functions. In the present study, we calculate the effective magnetic moments and their temperature dependence, the first order magnetic field energies, and the electric field gradients of ferric ion in these various spin states. Particular emphasis is placed on the properties of ferric ion in substantially spin-mixed states which have hitherto not been reported. Wherever possible, our results are compared with existing experimental data. In particular, with this model, we have been able to quantitatively account for the continuously varying values of magnetic moment for a series of 12 ferric hemoglobin derivatives, in the region from range of 5.92 to 2.26 Bohr magnetons.     

Calculated properties of the active site of oxidized rubredoxins

For a molecular model of the Fe-S active site complex in oxidized rubredoxin, we have calculated the spin-orbit coupling between the ground sextet state and excited quartet and doublet states which gives rise to the observed zero field splitting of the sextet ground state into three spin-mixed Kramers doublets. Additionally, we have used the six spin-mixed sextet state components to calculate effective magnetic moments, magnetic field energies and nine g values corresponding to transitions between the three pairs of Kramers doublets in applied magnetic fields along three perpendicular axes. We have calculated these properties for eight conformational variations of the ligands around the Fe at the active site. The results of these calculations clearly show the origin of the observed g=4.3 signal previously described only in terms of the phenomenological spin-Hamiltonian formalism. For the eight conformations considered, five have this characteristic signal. Zero field splitting comparable to the observed values could be obtained for all symmetries studied. In addition, the calculated values of magnetic moment in all symmetries correspond to that of high spin ferric ion and do not vary appreciably with temperature above 77° K, in agreement with experimental results. From comparison of all our calculated results with experiment, it appears that the active site in oxidized rubredoxins could have small conformational variations in different rubredoxins and under the various experimental conditions used.     

Thermally inert metal ammines as light-inducible DNA-targeted agents. Synthesis,photochemistry, and photobiology of a prototypical rhodium(III)-intercalator conjugate

The recent discovery of the promising tumor cell kill by a novel platinum-acridine conjugate [Martins, E. T.; et al. J. Med. Chem. 2001, 44, 4492] has prompted us to explore the utility of analogous light-activatable rhodium(III) compounds as photocytotoxic agents. Here, the design and synthesis of [Rh(NH(3))(5)L](n)(+) complexes are described with L = 1,1,3,3-tetramethylthiourea (tmtu) or 1-[2-(acridin-9-ylamino)ethyl]-1,3,3-trimethylthiourea (2). The intercalator-based DNA-affinic carrier ligand 2 was synthesized from N-acridin-9-yl-N'-methylethane-1,2-diamine and dimethylthiocarbamoyl chloride and isolated as the hydrotriflate salt 2(CF(3)SO(3)). [Rh(NH(3))(5)(tmtu)](3+) (1) and [Rh(NH(3))(5)(2)](4+) (3) were obtained from the reactions of the trifluoromethanesulfonato complex [Rh(NH(3))(5)(OSO(2)CF(3))](CF(3)SO(3))(2) with the appropriate thiourea in noncoordinating solvents. All compounds were characterized by (1)H NMR and UV-vis spectroscopies and by elemental analyses. The single-crystal X-ray structures of 1(CF(3)SO(3))(3) x 2MeOH, 2(CF(3)SO(3)), and 3(CF(3)SO(3))(4) x H(2)O have been determined. Ligand-field photolysis of thermally inert 1 (lambda(max) = 378 nm) resulted in the aquation of 2 equiv of ammine ligand without noticeable release of sulfur-bound tmtu ((1)H NMR spectroscopy, NH(3)-sensitive electrode measurements). This was confirmed by (15)N[(1)H] NMR spectroscopy using (15)N-labeled [Rh((15)NH(3))(5)(tmtu)](3+) (1), which also indicated photoisomerization of the [RhN(5)S] moiety. Despite greatly accelerated ligand exchange, rhodium in 1 and 3 did not show light-enhanced formation of covalent adducts in calf thymus DNA. "Dark binding" levels of 3 in native DNA were slightly higher than for nontargeted 1, but significantly lower than those observed for analogous platinum-acridine. Agarose gel electrophoresis revealed photocleavage of supercoiled pUC19 plasmid DNA in the presence of hybrid 3 and its individual constituents 1 and 2. Simple 1 induced single-strand breaks while 3 produced complete degradation of the DNA after 24 h of continuous irradiation. Acridine 2 alone produced double-strand breaks. The extent of DNA damage observed for 1-3 correlates with the photocytotoxicity of the compounds in human leukemia cells, suggesting that DNA might be the cellular target of these agents.     

Über den Nachweis und die Unterscheidung einiger Nicotinsäure-Derivate

Zusammenfassung Es wurden die Reaktionsprodukte des Nicotinsäureamids, des Diäthylamids der Nicotinsäure (Coramin) und des Oxymethylamids der Nicotinsäure (Bilamid) mit Kalium-Wismut-Jodid bzw. -Bromid auf ihre Eignung zum mikroskopischen Nachweis der genannten Basen untersucht. Die unter den angegebenen Verhältnissen erhaltenen Produkte sind homogen, haben eine definierte chemische Zusammensetzung und einen charakteristischen kristallographischen Habitus, der ihre Unterscheidung unter dem Mikroskop ermöglicht.

---

Summary The reaction products of nicotinic amide, of nicotinic dimethylamide (coramine), and of the oxymethylamide (bilamide) with potassium bismuth iodide or bromide have been studied with a view to their suitability for the microscopic detection of these bases. The products obtained under the stated conditions are homogeneous, have a definite chemical composition, and display characteristic crystallographic habits, which makes it possible to distinguish them under the microscope.

---

Résumé On étudie les produits de réaction de l'amide nicotinique, du diéthylamide nicotinique (coramine) et de l'hydroxyméthylamide de l'acide nicotinique (Bilamide) avec le bismuthoiodure ou le bismuthobromure de potassium afin d'examiner leur aptitude à la recherche microscopique des bases nommées ci-dessus. Les produits obtenus suivant des proportions données sont homogènes, ont une composition chimique définie et un aspect cristallographique caractéristique qui rend leur distinction possible sous le microscope.

---

---

Mit 5 Abbildungen.     

Bioassay-Guided Fractionation of Siparuna glycycarpa n-Butanol Extract with Inhibitory Activity against Influenza A(H1N1)pdm09 Virus by Centrifugal Partition Chromatography (CPC)

Siparuna glycycarpa occurs in the Amazon region, and some species of this genus are used in Brazilian folk medicine. A recent study showed the inhibitory effect of this species against influenza A(H1N1)pdm09 virus, and in order to acquire active fractions, a polar solvent system n-butanol-methanol-water (9:1:10, v/v) was selected and used for bioassay-guided fractionation of n-butanol extract by centrifugal partition chromatography (CPC). The upper phase was used as stationary phase and the lower phase as mobile (descending mode). Among the collected fractions, the ones coded SGA, SGC, SGD, and SGO showed the highest antiviral inhibition levels (above 74%) at 100 µg·mL⁻¹ after 24 h of infection. The bioactive fractions chemical profiles were investigated by LC-HRMS/MS data in positive and negative ionization modes exploring the Global Natural Products Social Molecular Networking (GNPS) platform to build a molecular network. Benzylisoquinoline alkaloids were annotated in the fractions coded SGA, SGC, and SGD collected during elution step. Aporphine alkaloids, O-glycosylated flavonoids, and dihydrochalcones in SGO were acquired with the change of mobile phase from lower aqueous to upper organic. Benzylisoquinolinic and aporphine alkaloids as well as glycosylated flavonoids were annotated in the most bioactive fractions suggesting this group of compounds as responsible for antiviral activity.     

Modelling and optimization of least-cost water distribution networks with multiple supply sources and users

The proper allocation of water resources is a very important practical problem in the field of water network planning. Optimization models that are expeditious and easy to use for all stakeholders of the sector play an important role for water resource management. The present work resumes and reviews a least-cost optimization model proposed by our group (Maiolo and Pantusa in Water Sci Tech-W Sup.  https://doi.org/10.2166/ws.2015.114, 2016), able to design a water distribution network with multiple supply sources and multiple users. This approach requires of solving an optimization problem based on a nonlinear objective function which is proportional to the cost of the water distribution network. The cost of pre-existing pipelines is considered null. A more realistic scenario, able to consider the maximum flow rate allowed for existing sources-users connections, is considered here. In order to illustrate the usefulness and flexibility of the proposed approach, an application of the model to the real case of the province of Croton, Southern Italy, is presented.