In vitro antioxidant and free-radical scavenging activities of polar leaf extracts of Vernonia amygdalina.

BACKGROUND: Plants are able to deliver a huge number of differing bioactive compounds which may supplement the requirements of the human body by acting as natural antioxidants. Antioxidants are mindful for the defense component of the life form against the pathologies related to the assault of free radicals. The main purpose of this study was to investigate the qualitative phytochemical composition of Vernonia amygdalina leaf extract and its antioxidant activity. METHOD: The powdered plant sample was successively extracted with aqueous, methanol and ethanol solvents using Soxhlet apparatus. The antioxidant activities of the crude leaf extract were determined using 1, 1- diphenyl-2-picryl hydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical, phosphomolybdate (PM) and hydrogen peroxide (H2O2) scavenging assay. All the examinations were drained triplicates and average values of each test were taken. RESULTS: Phytochemical investigation of the plant revealed that the three solvent extracts contained numerous bioactive compounds namely alkaloids, tannins, saponins, phenols, terpenoids, steroids, glycosides and sugars. The result showed that, the leaf extracts of V. amygdalina obtained from methanol extract exhibit the maximum antioxidant activity compared ethanol and aqueous extracts. The IC50 values of DPPH assay for the H2O, MeOH and EtOH extracts were 111.4, 94.92 and 94.83 µg/ml; of ABTS assay were 334.3, 179.8 and 256.9 µg/ml; of H2O2 assay were 141.6, 156 and 180.6 µg/ml, respectively. The maximum radical scavenging activity was obtained in DPPH assay while the lowest scavenging activity was obtained in ABTS assay method. The data obtained in the in vitro models clearly suggest that methanol extract has higher antioxidant activity due to a higher presence of phenolic constituents in the extract. CONCLUSION: This study revealed that V. amygdalina leaf has a noteworthy antioxidant and free radical scavenging activity mitigating the traditional use of the plant for different aliments.

Antioxidant, Antibacterial, and Anti-diabetic Activity of Green Synthesized Copper Nanoparticles of Cocculus hirsutus (Menispermaceae).

The emergence of new technologies has led to the discovery of the biological properties of nanoparticles through green approach. In the present investigation, we report the potential antibacterial, antioxidant, and anti-diabetic properties of copper nanoparticle (CuNPs) synthesized by reducing 3 mM copper acetate solution with aqueous leaf extract of Cocculus hirsutus. A colour change from deep brown to dark greenish brown indicated the formation of copper nanoparticles. The so-formed CuNPs were characterized by employing UV spectroscopy, FTIR, SEM, and EDX analyses which described sheet-like structure morphology having typical size of 63.46 nm. Later, the synthesized CuNPs efficiency was evaluated against bacterial pathogens, and was found highly toxic to B. subtilis and S. aureus strains. The synthesized CuNPs were examined through H2O2 and PMA assays which demonstrated the highest free radical scavenging activity. Besides, the resulted CuNPs revealed the higher anti-diabetic efficacy in both the [Formula: see text]-amylase and [Formula: see text] -glucosidase inhibition assays (64.5% ± 0.11 and 68.5% ± 0.11, respectively). Finally, our findings report that C. hirsutus can be exploited as a source for green synthesis of CuNPs, having potent in vitro antioxidant, antibacterial, and anti-diabetic properties.

Evaluation of nutritional value and antioxidant activity of Leea macrophylla Roxb. ex Hornem. root and leaf.

Background: Hanshia dabar or hathkan is one of the folklore plant of Odisha, the botanical source of which is Leea macrophylla Roxb. ex Hornem., family Vitaceae. Its root and leaves are eaten as vegetables, and used for Rasayana purpose (tonic and alterative properties). Aim: The aim is to assess the nutritive value and antioxidant potential of the root and leaves of L. macrophylla with compound leaf. Materials and methods: Nutritional parameters such as energy value, carbohydrate, protein, true protein, fat, mineral contents, and Vitamin A, Vitamin C of the root and leaves of the plant were evaluated with standard procedures. The in vitro antioxidant properties of the root and leaf of L. macrophylla were screened through 1,1diphenyl2picrylhydrazyl (DPPH) assay, the ferric reducing antioxidant power (FRAP) assay, and phosphomolybdenum assay. Results: Root is having higher energy value (391.87 Kcal/100 g) as compared to leaf (353.62 Kcal/100 g). L. macrophylla root and leaf showed the presence of carbohydrates (30.65% and 21.72%), protein (8.78% and 9.37%), true protein (6.85% and 7.23%), fat (0.77% and 1.89%), iron (723.80 ppm and 285.07 ppm), zinc (26.51 ppm and 13.75 ppm), manganese (44.88 ppm and 35.00 ppm), phosphorous (0.07 ppm and 0.03 ppm), calcium (7806.90 ppm and 3862.80 ppm), Vitamin A (3.63 mg/g and 2.47 mg/g), and Vitamin C (8.49 mg/g and 6.7 mg/g), respectively. Percentage scavenging of DPPH radical was found to rise with an increase in concentration. IC50 values of root and leaf, by DPPH assay, were 66.46 and 110.68 µg/ml, respectively. In the FRAP assay, the antioxidant activity of the methanolic extract of leaf (507.06 µmol/l) was found to be more than root (455.93 µmol/l). The total antioxidant capacity of root and leaf were 20.15 and 17.90 mg, equivalent to ascorbic acid on a dry weight basis, respectively. Conclusion: Root and leaf of L. macrophylla has the highest energy value, contains carbohydrate, protein, fat, iron, zinc, manganese, phosphorous, calcium, Vitamin A, and Vitamin C, and possesses antioxidant capacity.

Development and validation of the spectrophotometric method of butaphosphan determination in veterinary preparations.

A simple and sensitive method has been developed for the determination of butaphosphan in single- and multi-component veterinary preparations. The method is based on the combustion of organic matter prior to the formation of phosphate and the subsequent formation of the phosphoric­molybdenum complex in the presence of molybdate and ascorbic acid as a reducing agent in the sulfate acid medium. The intensity of light absorption of the colored analytical form of "molybdenum blue" is measured at a wavelength of 830 nm in the range of 0.3-9.0 µg/ml of butaphosphan, where Beer's law is obeyed, has been measured. The reaction conditions and other experimental parameters influencing the reaction transition and the stability of the colored complex have been thoroughly investigated and optimized for the quantitative determination of butaphosphan. Validation of the developed method according to the requirements has been carried out State Pharmacopoeia of Ukraine garmonised with European Pharmacopoeia and its suitability for the analysis of the selected veterinary preparations for the quantitative content of butaphosfan has been confirmed. The results of the determination of butaphosphan in six veterinary preparations of domestic and imported products have been obtained with the help of the developed method. The received results are in agreement with the results obtained by the method of potentiometric titration.

New Chemical Constituents from the Bark of Dendropanax morbifera Leveille and their Evaluation of Antioxidant Activities.

Four new constituents, as cis-6-oxogeran-4-enyl-10-oxy-O-ß-arabinopyranosyl-4'-O-ß-arabinopyranosyl-2''-octadec-9''',12''',15'''-trienoate (1), geran-3(10)-enyl-1-oxy-O-ß-arabinopyranosyl-4'-O-ß-arabinopyranosyl-2''-octadec-9''',12''',15'''-trienoate (2), geranilan-8-oxy-O-α-d-xylopyranosyl-2'-n-octadec-9'',12'',15''-trienoate (3), 1-cyclohex-2', 5'-dienyl 1-cyclohexylethanol-O-ß-d-xylopyranoside (4), along with six known constituents, guaiacol-O-ß-d-arabinopyaranoside (5), n-tetradecanyl oleate (6), oleyl-O-ß-d-xyloside (7), n-octadec-9,12-dienoyl-O-ß-d-arabinopyranoside (8), linolenyl-O-ß-d-arabinofuranoside (9) andglyceryl-1,3-dipalmito-2-olein (10), were isolated and identified from the Dendropanax morbifera bark. The new structures were established by one-and two-dimensional NMR (and in combination with IR, FAB-MSand HR-ESI-FTMS. The comparative evaluation of antioxidant potential by phosphomolybdenum, DPPH, FRAP and the NO assay of four different compounds (1-4), we have found that the compounds 1 and 2 have power as a natural antioxidant, whereas the compound 3 and 4 exhibited mild activity in comparison to compounds 1 and 2.

Biologically active novel N, N, O donor tridentate water soluble hydrazide based O-carboxymethyl chitosan Schiff base Cu (II) metal complexes: Synthesis and characterisation.

Water soluble hydrazide based O-carboxymethyl chitosan Schiff base ligands have been prepared from chitosan and a mixture of benzoic acidhydrazide with ß-diketone by carboxymethylation using mono chloroaceticacid (MCA) through in-situ reaction. The degree of deacetylation of chitosan was determined by elemental analysis and potentiometric titration. Schiff base ligands and the functional groups were characterised by FT-IR, 1H, and 13C NMR spectroscopic techniques. The crystallinity of ligands and complexes was evaluated by X-ray powder diffraction (XRD) studies. Thermal stability of all the synthesized compounds was investigated by thermo gravimetric analysis and differential thermal analysis (TGA-DTA) which revealed the presence of metal oxide (CuO) residue to elevate the temperature to >500 °C. Filed emission scanning electron microscopic (FESEM) analysis revealed that Cu (II) complexes were more amorphous in nature than chitosan and Schiff base ligands. Vibrating sample magnetometer (VSM) studies reported that the d9 configuration of the metal complex was paramagnetic in nature and the geometry of the complex was square pyramidal. The antimicrobial activity of the synthesized hydrazide Cu (II) complexes was characterised by agar plate method, anti-inflammatory study was characterised by egg albumin denaturation technique and total antioxidant activity was characterised by phosphomolybdenum method.

Flow injection programmed to function in batch mode is used to determine molar absorptivity and to investigate the phosphomolybdenum blue method.

The ultimate goal of flow-based analytical techniques is to automate serial assays of a target analyte. However, when developing any reagent-based assay, the underlying chemistry has to be investigated and understood a step, which is almost always the most challenging component of the optimization effort. The difficulty lies in that almost all reagent-based assays were initially developed and optimized in a batch mode, with the aim to perform assays manually, within a time frame of up to 15 min, while flow injection techniques are designed to monitor concentration gradients at times prior to reaching chemical equilibria and while performing up to two assays per minute. This work resolves this discrepancy by using programming Flow Injection (pFI) that operates in a batch mode within a time frame of 1 min or less, with the aim of optimizing an assay under the same conditions and using the same instrument in which the assay will be performed. This novel concept is verified by determining a molar absorptivity of Fe(II) ferrozine complex and by comparing it with literature data. Next, the pFI-batch technique was used to investigate and optimize the phosphate assay, based on formation of phosphomolybdenum blue, with the aim of maximizing sensitivity and improving the limit of detection of this widely used method.

Effects and improvements of different reagents preservation methods on the determination of phosphate in seawater by phosphomolybdenum blue spectrophotometric method.

This work attempted to prolong the validity of the molybdate mixed solution and ascorbic acid solution used in the phosphomolybdenum blue spectrophotometric method by improving their preservation according to the influence factors. The results showed that the molybdate mixed solution can be directly preserved in darkness with validity over half a year. The ascorbic acid solution is influenced by light, temperature, pH, metal ions, oxygen, and bacteria. The validity of ascorbic acid is shortened as the temperature rises. Through keeping in darkness, adding complexing agents, adjusting pH, removing oxygen and sterilization, the validity of ascorbic acid solution was prolonged to over 2.7 times under 4 °C and over 5 times under 25 °C. At the same time, the hybrid solution of ascorbic acid solution and molybdate mixed solution should be preserved separately, otherwise the using effect is poor.

Determination of traces of phosphate in sea water automated by programmable flow injection: Surfactant enhancement of the phosphomolybdenum blue response.

An assay protocol, based on programmable Flow Injection (pFI), is optimized by tailoring flowrates appropriately to the individual steps of an assay, thus allowing sample and reagent metering, mixing, incubation, monitoring and washout to be carried out more efficiently and in different time frames. This novel approach to flow based methods is applied here to optimize the determination of orthophosphate at nanomolar levels. Programmable Flow Injection was also used to facilitate an investigation of the properties of the phosphomolybdenum blue (PMoB) formed during this assay, by using the stop flow technique - an approach that revealed for the first time the influence of surfactants on the kinetics of formation of PMoB and its spectral characteristics. It was discovered that the two most frequently used surfactants (SDS and Brij) have profound and different influences on the spectra and formation of PMoB and this finding was used to enhance the sensitivity of the phosphate assay at nanomolar levels. The method was applied to the assay of trace levels of phosphate in sea water.

Optimization of ultrasound-assisted extraction of antioxidant compounds from Tunisian Zizyphus lotus fruits using response surface methodology.

The optimization of antioxidant extraction conditions from a ripe edible fruits of Zizyphus lotus (L.) with an ultrasound-assisted system was achieved by response surface methodology. The central composite rotatable design was employed for optimization of extraction parameters in terms of total phenolic content and antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and phosphomolybdenum assay. The optimum operating conditions for extraction were as follows: ethanol concentration, 50%; extraction time, 25 min; extraction temperature, 63°C and ratio of solvent to solid, 67 mL/g. Under these conditions, the obtained extract exhibited a high content of phenolic compounds (40.782 mg gallic acid equivalents/g dry matter) with significant antioxidant properties (the total antioxidant activity was 75.981 mg gallic acid equivalents/g dry matter and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was 0.289 mg/mL).