scholarly journals New Mixed Ligand Cobalt(II), Nickel(II) and Copper(II) Complexes of 2,2'-Bipyridine-3,3'-Dicarboxylic acid (bpdc) with 2-Mercapto-5-Phenyl-1,3,4-Oxadiazole (phozSH) and Their Antioxidant activity

2020 ◽  
Vol 36 (05) ◽  
pp. 834-842
Author(s):  
Rezan Ali Saleh ◽  
Hikmat Ali Mohammad ◽  
Salim Najm Aldin Saber

The mixing of one mole of 2,2'-bipyridine-3,3'-dicarboxylic acid (bpdc) with two mole of potassium hydroxide (KOH) in methanol were refluxed for (half hour), followed by addition of one mole methanol solution of MCl2.nH2O (where M=Co, Ni or Cu). The mixture was refluxed for (2 hours) to give colored complexes of the metal ions of [M(bpdc)(H2O)4]. The [M(bpdc)(H2O)4] were reacted with one mole of 2-Mercapto-5-phenyl-1,3,4-oxadiazole (phozSH) producing the colored mixed ligand complexes with general formula [M(bpdc)(phozSH)(H2O)3] in which the metal ions coordinated to the ligand through O-atoms of carboxyl group in (bpdc) and N-atom of (phozSH) ligand. The ligands and complexes are well identified by using Furrier transform infrared spectroscopy, 1H-NMR, 13C-NMR, Electronic spectroscopy, CHNS analysis, Melting point, conductivity measurement. The Antioxidant activity were screened for all the complexes by the use of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method.

2019 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Asrul Sani ◽  
Ahyar Ahmad ◽  
Firdaus Zenta

The effect of Cu2+ and Mg2+ metal ions on the antioxidant activity of anthocyanins of ethanol extract from the red dragon skin fruit (Hylocereus polyrhizus) has been done. Anthocyanin pigments from ethanol extract the red dragon skin fruit, content and antioxidant activity of anthocyanins from the red dragon fruit skin with ethanol solvent, and the effect of Cu2+ and Mg2+ metal ions on the antioxidant activity of anthocyanins. Identification of anthocyanin was done by identification of color test, using spectrophotometer analysis of UV-Vis and FTIR. The anthocyanin content was determined using pH difference method, and determined effect of metal ions extract was done by adding 50 ppm, 100 ppm, and 150 ppm of metal ions Cu2+ and Mg2+ into the anthocyanin extract that was been acidified by HCl , using spectrophotometer analysis of FTIR. Antioxidant activity test using DPPH method. The results show that ethanol extracts the red dragon anthocyanin by content is 12.5241 mg / L and antioxidant activity (IC50) is 0.478 μg / mL and with addition of2+ and Mg2+ metal ions can be increased antioxidant activity (IC50) of anthocyanins to be 0.2259 μg / mL for Cu2+ at concentration 50 ppm and 0.3351 μg / mL for Mg2+ at concentration 50 ppm.


Author(s):  
Noorma Rosita ◽  
Dewi Haryadi ◽  
Tristiana Erawati ◽  
Rossa Nanda ◽  
Widji Soeratri

The aim of this study was to investigate the ability of NLC in increasing photostability of tomato extract in term of antioxidant activity. Photostability testing on antioxidant activity of samples were conducted by accelerating method using UVB radiation 32.400 joule for 21 hours radiation. Antioxidant activity was measured by DPPH method. NLC was made by High Shear Homogenization (HPH) method at 24000 rpm for 4 cycles, while conventional creame was made by low speed at 400 rpm. The product were characterized include: pH, viscosity, and particle size. There were had difference characters and physical stability. NLC had smaller size, more homogenous and more stable than conventional creame. It was known that stability of antioxidant activity of tomato extract in NLC system higher than in conventional creame. That was showed with k value, as constanta of rate scavenging activity decreasing in antioxidant power between time (Sigma 2-tail less than 0.005) of NLC and conventional creame were: 2.03x10-2 %/hour ±0.08 (3.94) and 4.71x 10-2 %/ hour ±0.23 (4.88) respectively.


Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.


2019 ◽  
Vol 18 (10) ◽  
pp. 1405-1416 ◽  
Author(s):  
Isabel C.V. da Silva ◽  
Goran N. Kaluđerović ◽  
Pollyana F. de Oliveira ◽  
Denise O. Guimarães ◽  
Carla H. Quaresma ◽  
...  

Background: P. mucronata (Pm) comes from South America, Brazil and is characterized as “Maracujá de Restinga”. It is used in folk medicine for its soothing properties and in treating insomnia. Objective: The present study for the first time analyzed the antioxidant and cytotoxicity of the hydroalcoholic leaves extract and fractions from Pm. Method: The cytotoxicity test will be evaluated by different assays (MTT and CV) against human prostate cancer (PC3) and mouse malignant melanoma (B16F10) cell lines, and the antioxidant test by DPPH method. Results: β-Amyrin, oleanolic acid, β-sitosterol and stigmasterol were isolated of the most active, hexane fraction. These substances were tested against the tumor cell lines: β-sitosterol and stigmasterol showed the most relevant activity to PC3 in CV assay and, oleanolic acid to B16F10 by the MTT assay. In addition, it was possible to indicate that the mode of cell death for stigmasterol, presumably is apoptosis. In terms of antioxidant activity, the hydroalcoholic leaves extract presented higher activity (EC50 133.3 µg/mL) compared to the flower (EC50 152.3 µg/mL) and fruit (EC50 207.9 µg/mL) extracts. By the HPLC-MS, it was possible to identify the presence of flavones in the leaf extract (isoschaftoside, schaftoside, isovitexin, vitexin, isoorientin, orientin). Conclusions: P. mucronata hexane fraction showed promising cytotoxic effect against cancer cell lines, and stigmasterol contributes to this activity, inducing apoptosis of these cells. Furthermore, as other Passiflora species, Pm extract showed antioxidant activity and flavones are its major phenolic compounds.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1255
Author(s):  
Sofia C. Lourenço ◽  
Débora A. Campos ◽  
Ricardo Gómez-García ◽  
Manuela Pintado ◽  
M. Conceição Oliveira ◽  
...  

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80–20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.


2020 ◽  
Vol 5 (1) ◽  
pp. 857-870
Author(s):  
Fernando Gonçalves ◽  
João Carlos Gonçalves ◽  
Ana Cristina Ferrão ◽  
Paula Correia ◽  
Raquel P. F. Guiné

AbstractRecently, edible flowers (EF) have aroused increased interest because of their aesthetic properties as well as potential health benefits related to the occurrence of some bioactive compounds. Therefore, the aim of this work was to evaluate the total phenolics, anthocyanins, flavonoids, and antioxidant activity (AOA) (following DPPH and ABTS methods) in eleven EF. The samples were subjected to three successive extraction steps using methanol, and these extracts were then analysed for the aforementioned properties using spectrophotometric methods. The obtained extracts were used for the quantification of phenolic composition and AOA. The results indicated that, among the flowers analysed in this study, red rose, pink rose, and red carnation possessed the highest total phenolic contents (27.53, 23.30, and 18.17 mg g−1 gallic acid equivalents, respectively), total anthocyanins (3.07, 1.97, and 4.47 mg g−1 catechin equivalents [CE], respectively), and AOA (12.07, 15.77, and 12.93 mg g−1 TE, respectively, as given by the DPPH method or 8.23, 9.27 and 8.00 mg g−1 TE, respectively, as given by the ABTS method). The flowers with highest flavonoids contents were red carnation, Mexican marigold, and pink rose (17.50, 16.90, and 16.57 mg g−1 CE, respectively). Cluster analysis grouped the analysed flowers into two groups, those richest in phenolics with AOA and those not so rich. Finally, some important correlations were observed between the total phenolics and the AOA. In conclusion, these flowers could represent a potential source of natural compounds with antioxidant capacity.


2018 ◽  
Vol 10 (1) ◽  
pp. 407
Author(s):  
Dewi Kumala Putri ◽  
Berna Elya ◽  
Nuraini Puspitasari

Objective: To assess the antioxidant activity from another part of the plant, in this study, leaf extracts in n-hexane were fractionated.Methods: Ten fractions were obtained and tested in vitro for antioxidant activity using two methods, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferricreducing antioxidant power (FRAP), to identify the most active fraction.Results: The IC50 of the most active fraction was 36.24 μg/mL using the DPPH method, and the EC50 was 39.54 μg/mL using the FRAP method. Themost active fraction was also shown to contain terpenoids.Conclusion: The most active fraction of an n-hexane extract of the leaves of Gacinia bancana Miq., which was tested by both DPPH and FRAP methodshad antioxidant activities with IC50 and EC50 values of 36.2482 μg/mL and 39.5442 μg/mL, respectively. Phytochemical screening showed that activefraction contains terpenoids.


2009 ◽  
Vol 64 (9-10) ◽  
pp. 657-663 ◽  
Author(s):  
Jorge Mancini-Filho ◽  
Alexis Vidal Novoa ◽  
Ana Elsa Batista González ◽  
Elma Regina S de Andrade-Wartha ◽  
Dalva Assunção Portari Mancini

Phenolic compounds are found in seaweed species together with other substances presenting antioxidant activity. The objective of this work was to evaluate the antioxidant activity of the free phenolic acids (FPA) fraction from the seaweed Halimeda monile, and its activity to protect the expression of hepatic enzymes in rats, under experimental CCl4 injury. The antioxidant activity was measured by the DPPH method. The FPA fraction (80 mg/kg, p.o.) was administered during 20 consecutive days to rats. The peroxidation was performed by thiobarbituric acid reactive substances (TBARS). The SOD and CAT enzymatic expressions were measured by RT/PCR. The histology technique was used to evaluate liver injuries. The expression of both, CAT and SOD genes, was more preserved by FPA. Only partial injury could be observed by histology in the liver of rats receiving FPA as compared with the control group; and CCl4 administration induced 60% more peroxidation as compared with the rats receiving FPA. These data suggest that FPA could modulate the antioxidant enzymes and oxidative status in the liver through protection against adverse effects induced by chemical agents


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