scholarly journals Determination of chemical structure and anti-Trypanosoma cruzi activity of extracts from the roots of Lonchocarpus cultratus (Vell.) A.M.G. Azevedo & H.C. Lima

2021 ◽  
Vol 28 (1) ◽  
pp. 99-108
Author(s):  
Aline Antunes Maciel Bortoluzzi ◽  
Izabela Virginia Staffen ◽  
Fernanda Weyand Banhuk ◽  
Aline Griebler ◽  
Patricia Karoline Matos ◽  
...  
2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Imad Tarek Hanoon ◽  
Abed Mohammed Daheir AL-Joubory 2 ◽  
Marwa Mohamed Saied 3

A simple , specific, accurate and precise RP-HPLC method was developed for determination of Irbesartan (IRB) in pharmaceutical dosage forms in tablets products and sachet using symmetry (L 1 ) column at 30°C . The signal was detected at 225 nm. A mobile phase dissolve 0.5 g of buffer potassium phosphate in 100 ml distilled water and adjust pH 2.7 , methanol and acetonitrile at ratio (40 :30 :30 ) . and flow rate 1.2ml/min -1 at pH=7.2 a mobile phase The percent recovery was detected 101 % and the linearity of concentration was 10-50 µg.ml -1 and supported this method by using (FT.I.R.) spectrum method for organic spectrophotometer to prove the chemical structure of this drug and some physical properties . we are obtained the result is identical of other literature . The proposed method was applied successfully for determination of the IRB in tablets products.


2013 ◽  
Vol 62 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Gabriela Ibáñez-Cervantes ◽  
Alejandro Martínez-Ibarra ◽  
Benjamín Nogueda-Torres ◽  
Eduardo López-Orduña ◽  
Ana L. Alonso ◽  
...  
Keyword(s):  

2021 ◽  
Vol 17 ◽  
Author(s):  
Ke Huan ◽  
Li Tang ◽  
Dongmei Deng ◽  
Huan Wang ◽  
Xiaojing Si ◽  
...  

Background: Hydrogen peroxide (H2O2) is a common reagent in the production and living, but excessive H2O2 may enhance the danger to the human body. Consequently, it is very important to develop economical, fast and accurate techniques for detecting H2O2. Methods: A simple two-step electrodeposition process was applied to synthesize Pd-Cu/Cu2O nanocomposite for non-enzymatic H2O2 sensor. Cu/Cu2O nanomaterial was firstly electrodeposited on FTO by potential oscillation technique, and then Pd nanoparticles were electrodeposited on Cu/Cu2O nanomaterial by cyclic voltammetry. The chemical structure, component, and morphology of the synthesized Pd-Cu/Cu2O nanocomposite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of Pd-Cu/Cu2O nanocomposite were studied by cyclic voltammetry and amperometry. Results: Under optimal conditions, the as-fabricated sensor displayed a broad linear range (5-4000 µM) and low detection limit (1.8 µM) for the determination of H2O2. The proposed sensor showed good selectivity and reproducibility. Meanwhile, the proposed sensor has been successfully applied to detect H2O2 in milk. Conclusion: The Pd-Cu/Cu2O/FTO biosensor exhibits excellent electrochemical activity for H2O2 reduction, which has great potential application in the field of food safety.


2017 ◽  
Vol 12 (5) ◽  
pp. 1934578X1701200
Author(s):  
Ahmed A. Hussein ◽  
Luz Romero ◽  
Jose Luis López-Pérez ◽  
Mahabir P. Gupta

Mikania guaco Bonpl. methanol extract showed an interesting activity against Trypanosoma cruzi with an IC50 of 4 μg/mL. Bioassay-guided fractionation of the methanol extract resulted in the isolation of a new sesquiterpene lactone, 2α-acetoxy, 15-acetylartemisiifolin (1), which was shown to be active (IC50 = 25 μM) against the amastigote form of T. cruzi,. The chemical structure of 1 was elucidated using 2-D NMR techniques and mass spectrometry.


2016 ◽  
Vol 88 (3) ◽  
pp. 1519-1529 ◽  
Author(s):  
LEONARDO M. FONSECA ◽  
TATIANA C. GARCEZ ◽  
LUCIANA PENHA ◽  
LEONARDO FREIRE-DE-LIMA ◽  
EMMANUEL MAES ◽  
...  

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1779 ◽  
Author(s):  
Sapia Murgolo ◽  
Irina Moreira ◽  
Clara Piccirillo ◽  
Paula Castro ◽  
Gianrocco Ventrella ◽  
...  

Diclofenac (DCF) is one of the most detected pharmaceuticals in environmental water matrices and is known to be recalcitrant to conventional wastewater treatment plants. In this study, degradation of DCF was performed in water by photolysis and photocatalysis using a new synthetized photocatalyst based on hydroxyapatite and TiO2 (HApTi). A degradation of 95% of the target compound was achieved in 24 h by a photocatalytic treatment employing the HApTi catalyst in comparison to only 60% removal by the photolytic process. The investigation of photo-transformation products was performed by means of UPLC-QTOF/MS/MS, and for 14 detected compounds in samples collected during treatment with HApTi, the chemical structure was proposed. The determination of transformation product (TP) toxicity was performed by using different assays: Daphnia magna acute toxicity test, Toxi-ChromoTest, and Lactuca sativa and Solanum lycopersicum germination inhibition test. Overall, the toxicity of the samples obtained from the photocatalytic experiment with HApTi decreased at the end of the treatment, showing the potential applicability of the catalyst for the removal of diclofenac and the detoxification of water matrices.


1987 ◽  
Vol 243 (2) ◽  
pp. 481-485 ◽  
Author(s):  
Y Tanaka ◽  
H Sato ◽  
A Kageyu ◽  
T Tomita

The arrangement of isoprene units in pig liver dolichol-18, -19 and -20 was determined by 1H- and 13C-n.m.r. spectroscopies. The alignment of trans and cis isoprene units was found to be in the order: dimethylallyl unit, two trans units, a sequence of 14-16 cis units, and a saturated isoprene unit terminated with a hydroxyl group, which verified the presumed chemical structure of dolichol. The absence of geometric isomers was confirmed. A slight amount of impurity was detected in each reversed-phase h.p.l.c. fraction of dolichol obtained by a conventional method. Detailed assignments of the 13C-n.m.r. spectrum were given for these dolichols by using model compounds and INEPT (insensitive nuclei enhanced by polarization transfer) measurement. The chemical structure of synthetic dolichol-19, which was prepared by the addition of a saturated isoprene unit to the polyprenol-18 isolated from Ginkgo biloba, was confirmed to be identical with that of pig liver dolichol-19.


2020 ◽  
Vol 27 (12) ◽  
Author(s):  
Zbigniew Grobelny ◽  
Justyna Jurek-Suliga ◽  
Sylwia Golba

Abstract Poly(ε-caprolactone)-block-poly(β-butyrolactone) copolymers were prepared in two-step synthesis. Firstly, poly(ε-caprolactone) (PCL) was obtained by anionic ring-opening polymerization of CL initiated with anhydrous KOH activated 12-crown-4 cation complexing agent. Reaction was carried out in tetrahydrofuran solution and argon atmosphere at room temperature. Then, β-butyrolactone (BL) and 18-crown-6 were added to the system, resulting in PCL-block-PBL copolymer, which contains after methylation hydroxyl starting group and methyl ester end group. The main product was contaminated with PCL and PBL homopolymers formed in a side reactions. 13C NMR technique was used for determination of chemical structure of polymers obtained. The course of the studied processes was proposed. MALDI-TOF technique was used to reveal the macromolecules’ architecture where several series were found. The identified series shown that mainly copolymeric macromolecules were formed with scare contribution of homopolymeric polybutyrolactone with trans-crotonate starting groups and polycaprolactone, which is congruent with the proposed reaction mechanism. Moreover, critical approach concerning previously reported PCL-block-PBL copolymer synthesis by use of NaH as initiator was also presented.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4057 ◽  
Author(s):  
Izabela Maria Barszczewska-Rybarek

Material characterization by the determination of relationships between structure and properties at different scales is essential for contemporary material engineering. This review article provides a summary of such studies on dimethacrylate polymer networks. These polymers serve as photocuring organic matrices in the composite dental restorative materials. The polymer network structure was discussed from the perspective of the following three aspects: the chemical structure, molecular structure (characterized by the degree of conversion and crosslink density (chemical as well as physical)), and supramolecular structure (characterized by the microgel agglomerate dimensions). Instrumental techniques and methodologies currently used for the determination of particular structural parameters were summarized. The influence of those parameters as well as the role of hydrogen bonding on basic mechanical properties of dimethacrylate polymer networks were finally demonstrated. Mechanical strength, modulus of elasticity, hardness, and impact resistance were discussed. The issue of the relationship between chemical structure and water sorption was also addressed.


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