scholarly journals Structural analysis of new ligands against Schistosoma mansoni

2014 ◽  
Vol 70 (a1) ◽  
pp. C972-C972
Author(s):  
Ana Mafud ◽  
Yvonne Mascarenhas

Natural compounds have been an alternative to treat several diseases. In this sense, epiisopiloturine (EPI) [1] is an alkaloid found in Pilocarpus microphyllus (Rutaceae) leaves, with anthelmintic activity in vitro [2] and in vivo (To be publish). Unfortunately, EPI is slightly soluble in water. To solve this question, complexes and new derivatives were synthetized. Here, we present a x-ray structural analysis of the compounds: EPICu (CCDC 947608), C64H42N8O23Cl2Cu, P21, and EPIZn (CCDC 959718) C32H36N4O6Cl2Zn, P212121, both complexes with anthelmintic activity; EpiiHCl (CCDC 945616), C16H18N2O3Cl, P21, a derivative with reduce anthelmintic activity even high solubility; and epiisopilosine, EPIss C16H18N2O3, (CCDC 957103), P212121, a new active compound found in the same leaves but seasonally. The ligands conformational analysis were determined using Density Functional Theory calculations with the operator correlation of Lee–Yang–Parr (B3LYP), 6-31G++ base set, implementing two functions of polarization (d,p), to obtain the molecular electrostatic potential map. X-ray powder diffraction and thermogravimetry analysis were also performed to EPIss. The dihedral angle between the benzene and imidazole rings is feature common to such compounds, which range from 3 to 73 degrees. It is interesting to observe that the dihedral angle may be associated with the activity of these compounds, as well as other factors, since the smaller the dihedral angle, the activity is increased, even taking into consideration the EPI to this study. To compare the structures of the ligands, they were aligned and the overlay optimizer was the augmented Lagrangian method (local, no-derivative), shown in Figure 1, EPICl in green, EPI in blue and EPIss in yellow. Results showed that hydrophobic regions are conservative except for EPIss, due to its larger volume. And it may be understood through the occurrence of the CH/pi intramolecular interactions in the crystal stacking, which guarantee the EPIss larger globularity. Experimental parameters for TGA curve indicates that EPIss degradation occurs in two steps, associated with an endothermic DTA signal. XRD were performed in order to exclude the occurrence of isoforms in the crystalline powder.

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
M Mar Pérez ◽  
Miguel David Ferrer Reynes ◽  
Joaquín Ortega-Castro ◽  
Firas Bassissi ◽  
Joan Perelló ◽  
...  

Abstract Background and Aims Vascular calcification (VC) is a major contributor to increased morbidity and mortality in End Stage Kidney Disease (ESKD) patients undergoing dialysis. SNF472, a salt of inositol hexaphosphate (InsP6), is a selective calcification inhibitor that interferes in the formation and growth of ectopic hydroxyapatite (HAP). SNF472 is currently in Phase 3 clinical trials for the treatment of calciphylaxis in ESKD patients on dialysis. Inositol-1,2,3,5-tetraphosphate-4,6-bisPEG100 (InsP4bisPEG or INS3001) results from the PEGylation of inositol tetraphosphate (InsP4) with polyethylene glycol (PEG) 100. Our aim was to compare the relative bioavailability of SNF472 and InsP4bisPEG and their efficacy in the inhibition of calcification in silico, in vitro and in vivo. Method Subcutaneous (10 mg/kg) pharmacokinetics of InsP4bisPEG and SNF472 were assessed in Sprague Dawley (SD) rats. To evaluate the adsorption binding affinity (Eads) of SNF472, InsP4bisPEG and other inositol phosphates to the HAP crystal surface, computational studies were performed using Density Functional Theory calculations with DMOL3 (MS2016). The in vitro efficacy of the compounds was evaluated using a pharmacodynamic assay to measure the calcification potential of human plasma. An in vivo efficacy study (calcification induced by 3 consecutives daily s.c. administrations of 150 kIU/kg vitamin D3) was performed with SD rats receiving s.c. vehicle, or equimolar doses (36 µmol/kg) of SNF472 or InsP4bisPEG once daily. Results The PEGylation of inositol tetraphosphate in positions 4 and 6 increased the exposure and t1/2 of the compound when given subcutaneously compared to SNF472. Molecular modelling revealed that SNF472 binds to the HAP surface with higher affinity than InsP4bisPEG and INSP4 (ΔEads=-352 kcal/mol for SNF472, ΔEads=-177 kcal/mol for InsP4bisPEG and ΔEads=-146 Kcal/mol for InsP4, taking inositol as reference). These results were correlated with the inhibition of calcium phosphate crystallization in plasma in vitro. SNF472 treated animals presented significantly lower calcium levels in aorta, which were 38% and 55% lower than placebo and InsP4bisPEG treated animals, respectively. Conclusion The differential pharmacokinetic profile of InsP4bisPEG (INS3001) does not translate into higher, but lower, efficacy than SNF472 against vascular calcification when comparing equimolar doses.


Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.


2021 ◽  
Vol 60 (8) ◽  
pp. 6016-6026
Author(s):  
Aydar Rakhmatullin ◽  
Maxim S. Molokeev ◽  
Graham King ◽  
Ilya B. Polovov ◽  
Konstantin V. Maksimtsev ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 817
Author(s):  
Abbas Rahdar ◽  
Mohammad Reza Hajinezhad ◽  
Saman Sargazi ◽  
Maryam Zaboli ◽  
Mahmood Barani ◽  
...  

Curcumin is known to exhibit antioxidant and tissue-healing properties and has recently attracted the attention of the biomedical community for potential use in advanced therapies. This work reports the formulation and characterization of oil-in-water F127 microemulsions to enhance the bioavailability of curcumin Microemulsions showed a high encapsulation efficiency and prolonged release. To investigate the interactions of curcumin with one unit of the polymeric chain of surfactant F127, ethyl butyrate, and sodium octanoate, as well as the interaction between ethyl butyrate and one unit of the F127 polymer chain, the Density Functional Theory (DFT) calculations at the M06-2X level of theory, were performed in water solution. The MTT assay was used to assess the cytotoxicity of free and encapsulated curcumin on non-malignant and malignant cell lines. Combination effects were calculated according to Chou-Talalay’s principles. Results of in vitro studies indicated that MCF7 and HepG2 cells were more sensitive to curcumin microemulsions. Moreover, a synergistic relationship was observed between curcumin microemulsions and cisplatin in all affected fractions of MCF7 and HepG2 cells (CI < 0.9). For in vivo investigation, thioacetamide-intoxicated rats received thioacetamide (100 mg/kg Sc) followed by curcumin microemulsions (30 mg/kg Ip). Thioacetamide-intoxicated rats showed elevated serum liver enzymes, blood urea nitrogen (BUN), and creatinine levels, and a significant reduction in liver superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.05). Curcumin microemulsions reduced liver enzymes and serum creatinine and increased the activity of antioxidant enzymes in thioacetamide-treated rats in comparison to the untreated thioacetamide-intoxicated group. Histopathological investigations confirmed the biochemical findings. Overall, the current results showed the desirable hepatoprotective, nephroprotective, and anti-cancer effects of curcumin microemulsions.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 825
Author(s):  
Saman Sargazi ◽  
Mohammad Reza Hajinezhad ◽  
Abbas Rahdar ◽  
Muhammad Nadeem Zafar ◽  
Aneesa Awan ◽  
...  

In this research, tin ferrite (SnFe2O4) NPs were synthesized via hydrothermal route using ferric chloride and tin chloride as precursors and were then characterized in terms of morphology and structure using Fourier-transform infrared spectroscopy (FTIR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray power diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET) method. The obtained UV-Vis spectra was used to measure band gap energy of as-prepared SnFe2O4 NPs. XRD confirmed the spinel structure of NPs, while SEM and TEM analyses disclosed the size of NPs in the range of 15–50 nm and revealed the spherical shape of NPs. Moreover, energy dispersive X-ray spectroscopy (EDS) and BET analysis was carried out to estimate elemental composition and specific surface area, respectively. In vitro cytotoxicity of the synthesized NPs were studied on normal (HUVEC, HEK293) and cancerous (A549) human cell lines. HUVEC cells were resistant to SnFe2O4 NPs; while a significant decrease in the viability of HEK293 cells was observed when treated with higher concentrations of SnFe2O4 NPs. Furthermore, SnFe2O4 NPs induced dramatic cytotoxicity against A549 cells. For in vivo study, rats received SnFe2O4 NPs at dosages of 0, 0.1, 1, and 10 mg/kg. The 10 mg/kg dose increased serum blood urea nitrogen and creatinine compared to the controls (P < 0.05). The pathology showed necrosis in the liver, heart, and lungs, and the greatest damages were related to the kidneys. Overall, the in vivo and in vitro experiments showed that SnFe2O4 NPs at high doses had toxic effects on lung, liver and kidney cells without inducing toxicity to HUVECs. Further studies are warranted to fully elucidate the side effects of SnFe2O4 NPs for their application in theranostics.


1986 ◽  
Vol 250 (2) ◽  
pp. F302-F307 ◽  
Author(s):  
J. M. Burnell ◽  
C. Liu ◽  
A. G. Miller ◽  
E. Teubner

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.


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