Showing papers on "DPPH published in 2020"

Antioxidants and antioxidant methods: an updated overview

Abstract: Antioxidants had a growing interest owing to their protective roles in food and pharmaceutical products against oxidative deterioration and in the body and against oxidative stress-mediated pathological processes. Screening of antioxidant properties of plants and plant-derived compounds requires appropriate methods, which address the mechanism of antioxidant activity and focus on the kinetics of the reactions including the antioxidants. Many studies evaluating the antioxidant activity of various samples of research interest using different methods in food and human health have been conducted. These methods are classified, described, and discussed in this review. Methods based on inhibited autoxidation are the most suited for termination-enhancing antioxidants and for chain-breaking antioxidants, while different specific studies are needed for preventive antioxidants. For this purpose, the most common methods used in vitro determination of antioxidant capacity of food constituents were examined. Also, a selection of chemical testing methods was critically reviewed and highlighted. In addition, their advantages, disadvantages, limitations and usefulness were discussed and investigated for pure molecules and raw extracts. The effect and influence of the reaction medium on the performance of antioxidants are also addressed. Hence, this overview provides a basis and rationale for developing standardized antioxidant methods for the food, nutraceuticals, and dietary supplement industries. In addition, the most important advantages and shortcomings of each method were detected and highlighted. The chemical principles of these methods are outlined and critically discussed. The chemical principles of methods of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS·+) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, Fe3+-Fe2+ transformation assay, ferric reducing antioxidant power (FRAP) assay, cupric ions (Cu2+) reducing power assay (Cuprac), Folin-Ciocalteu reducing capacity (FCR assay), peroxyl radical (ROO·), superoxide radical anion (O2·-), hydrogen peroxide (H2O2) scavenging assay, hydroxyl radical (OH·) scavenging assay, singlet oxygen (1O2) quenching assay, nitric oxide radical (NO·) scavenging assay and chemiluminescence assay are outlined and critically discussed. Also, the general antioxidant aspects of main food components were discussed by a number of methods, which are currently used for the detection of antioxidant properties of food components. This review consists of two main sections. The first section is devoted to the main components in the food and pharmaceutical applications. The second general section comprises some definitions of the main antioxidant methods commonly used for the determination of the antioxidant activity of components. In addition, some chemical, mechanistic and kinetic basis, and technical details of the used methods are given.

Structure-antioxidant activity relationship of methoxy, phenolic hydroxyl, and carboxylic acid groups of phenolic acids.

Abstract: The antioxidant activities of 18 typical phenolic acids were investigated using 2, 2′-diphenyl-1-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP) assays. Five thermodynamic parameters involving hydrogen atom transfer (HAT), single-electron transfer followed by proton transfer (SET-PT), and sequential proton-loss electron transfer (SPLET) mechanisms were calculated using density functional theory with the B3LYP/UB3LYP functional and 6–311++G (d, p) basis set and compared in the phenolic acids. Based on the same substituents on the benzene ring, -CH2COOH and -CH = CHCOOH can enhance the antioxidant activities of phenolic acids, compared with -COOH. Methoxyl (-OCH3) and phenolic hydroxyl (-OH) groups can also promote the antioxidant activities of phenolic acids. These results relate to the O-H bond dissociation enthalpy of the phenolic hydroxyl group in phenolic acids and the values of proton affinity and electron transfer enthalpy (ETE) involved in the electron donation ability of functional groups. In addition, we speculated that HAT, SET-PT, and SPLET mechanisms may occur in the DPPH reaction system. Whereas SPLET was the main reaction mechanism in the FRAP system, because, except for 4-hydroxyphenyl acid, the ETE values of the phenolic acids in water were consistent with the experimental results.

ABTS/PP Decolorization Assay of Antioxidant Capacity Reaction Pathways.

Abstract: The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical cation-based assays are among the most abundant antioxidant capacity assays, together with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-based assays according to the Scopus citation rates. The main objective of this review was to elucidate the reaction pathways that underlie the ABTS/potassium persulfate decolorization assay of antioxidant capacity. Comparative analysis of the literature data showed that there are two principal reaction pathways. Some antioxidants, at least of phenolic nature, can form coupling adducts with ABTS•+, whereas others can undergo oxidation without coupling, thus the coupling is a specific reaction for certain antioxidants. These coupling adducts can undergo further oxidative degradation, leading to hydrazindyilidene-like and/or imine-like adducts with 3-ethyl-2-oxo-1,3-benzothiazoline-6-sulfonate and 3-ethyl-2-imino-1,3-benzothiazoline-6-sulfonate as marker compounds, respectively. The extent to which the coupling reaction contributes to the total antioxidant capacity, as well as the specificity and relevance of oxidation products, requires further in-depth elucidation. Undoubtedly, there are questions as to the overall application of this assay and this review adds to them, as specific reactions such as coupling might bias a comparison between antioxidants. Nevertheless, ABTS-based assays can still be recommended with certain reservations, particularly for tracking changes in the same antioxidant system during storage and processing.

Screening and characterization of phenolic compounds and their antioxidant capacity in different fruit peels

Abstract: Fruit peels have a diverse range of phytochemicals including carotenoids, vitamins, dietary fibres, and phenolic compounds, some with remarkable antioxidant properties. Nevertheless, the comprehensive screening and characterization of the complex array of phenolic compounds in different fruit peels is limited. This study aimed to determine the polyphenol content and their antioxidant potential in twenty different fruit peel samples in an ethanolic extraction, including their comprehensive characterization and quantification using the LC-MS/MS and HPLC. The obtained results showed that the mango peel exhibited the highest phenolic content for TPC (27.51 ± 0.63 mg GAE/g) and TFC (1.75 ± 0.08 mg QE/g), while the TTC (9.01 ± 0.20 mg CE/g) was slightly higher in the avocado peel than mango peel (8.99 ± 0.13 mg CE/g). In terms of antioxidant potential, the grapefruit peel had the highest radical scavenging capacities for the DPPH (9.17 ± 0.19 mg AAE/g), ABTS (10.79 ± 0.56 mg AAE/g), ferric reducing capacity in FRAP (9.22 ± 0.25 mg AA/g), and total antioxidant capacity, TAC (8.77 ± 0.34 mg AAE/g) compared to other fruit peel samples. The application of LC-ESI-QTOF-MS/MS tentatively identified and characterized a total of 176 phenolics, including phenolic acids (49), flavonoids (86), lignans (11), stilbene (5) and other polyphenols (25) in all twenty peel samples. From HPLC-PDA quantification, the mango peel sample showed significantly higher phenolic content, particularly for phenolic acids (gallic acid, 14.5 ± 0.4 mg/g) and flavonoids (quercetin, 11.9 ± 0.4 mg/g), as compared to other fruit peel samples. These results highlight the importance of fruit peels as a potential source of polyphenols. This study provides supportive information for the utilization of different phenolic rich fruit peels as ingredients in food, feed, and nutraceutical products.

Synthesis of copper oxide nanoparticles by chemical and biogenic methods: photocatalytic degradation and in vitro antioxidant activity

Abstract: Copper oxide nanoparticles (CuO-NPs) were synthesized using two different methods (chemical and biosynthesis) to study the influence of the preparation method on the structural, optical, morphological, photocatalyst, antibacterial and in vitro antioxidant of these nanoparticles. The synthesized nanoparticles were analysed by XRD, UV–Vis, HR-TEM, DLS, ZE, PL and FT-IR spectroscopy. The X-ray diffraction spectra showed the single-phase monoclinic structure of copper oxide, with an average crystallite size of 2.05–3.00 nm. HR-TEM analysis confirmed the spherical morphology of the synthesized CuO-NPs using chemical and biological methods with an average size of 32 nm and 25 nm, respectively. The synthesized CuO-NPs exhibited potential photocatalytic activity towards the degradation of methylene blue dye on exposing to sunlight irradiation. The degradation effectiveness against methylene blue dye was found to be 85 and 97% for chemical and biosynthesized CuO-NPs, respectively. Furthermore, antibacterial and antioxidant activities were evaluated. The biogenic method showed a significant antibacterial activity against Gram-negative bacteria E. coli and B. subtilis than Gram-positive bacteria and also DPPH assay.

Quantification of the Antioxidant Activity of Plant Extracts: Analysis of Sensitivity and Hierarchization Based on the Method Used.

Abstract: Plants have a large number of bioactive compounds with high antioxidant activity. Studies for the determination of the antioxidant activity of different plant species could contribute to revealing the value of these species as a source of new antioxidant compounds. There is a large variety of in vitro methods to quantify antioxidant activity, and it is important to select the proper method to determine which species have the highest antioxidant activity. The aim of this work was to verify whether different methods show the same sensitivity and/or capacity to discriminate the antioxidant activity of the extract of different plant species. To that end, we selected 12 species with different content of phenolic compounds. Their extracts were analyzed using the following methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing (FRAP) assay, Trolox equivalent antioxidant capacity (ABTS) assay, and reducing power (RP) assay. The four methods selected could quantify the antioxidant capacity of the 12 study species, although there were differences between them. The antioxidant activity values quantified through DPPH and RP were higher than the ones obtained by ABTS and FRAP, and these values varied among species. Thus, the hierarchization or categorization of these species was different depending on the method used. Another difference established between these methods was the sensitivity obtained with each of them. A cluster revealed that RP established the largest number of groups at the shortest distance from the root. Therefore, as it showed the best discrimination of differences and/or similarities between species, RP is considered in this study as the one with the highest sensitivity among the four studied methods. On the other hand, ABTS showed the lowest sensitivity. These results show the importance of selecting the proper antioxidant activity quantification method for establishing a ranking of species based on this parameter.

Exploiting Fruit Waste Grape Pomace for Silver Nanoparticles Synthesis, Assessing Their Antioxidant, Antidiabetic Potential and Antibacterial Activity Against Human Pathogens: A Novel Approach.

Abstract: Grape pomace, a most abundant and renewable wine industry waste product was utilized as a suitable reducing, capping, and stabilizing biomolecules for green synthesis of silver nanoparticles (AgNPs). The physicochemical properties of biosynthesized grape pomace extract (GPE)-AgNPs were duly appraised via UV-Visible spectroscopy, X-ray diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy. The analytical studies revealed that the GPE-AgNPs were well formed and stable in nature. The functional groups of organic molecules of GPE are present on the surface of AgNPs with average NPs diameter in the range of 20-35 nm. GPE-AgNPs exhibited significant free radical scavenging activity mainly DPPH radical (IC50, 50.0 ± 2.25 μg/mL) and ABTS radical (IC50, 38.46 ± 1.14 μg/mL). Additionally, the synthesized AgNPs showed noticeable inhibition of carbohydrate hydrolyzing enzymes mainly, α-amylase (IC50, 60.2 ± 2.15 μg/mL) and α-glucosidase (IC50, 62.5 ± 2.75 μg/mL). The GPE fabricated AgNPs showed noteworthy antibacterial potential against infectious bacteria viz., Escherichia coli and Staphylococcus aureus. The reaction mechanism of antibacterial activity was studied by measuring the bacterial cell membrane breakage and cytoplasmic contents, mainly, nucleic acid, proteins, and reducing sugar. Therefore, this research attempt illustrated the potential of GPE as a novel source intended for the biosynthesis of AgNPs that may open up new horizons in the field of nanomedicine.

Nutrients, minerals, antioxidant pigments and phytochemicals, and antioxidant capacity of the leaves of stem amaranth.

Abstract: We evaluated 17 genotypes of stem amaranth (Amaranthus lividus) in terms of dietary fiber, moisture, carbohydrates, fat, ash, gross energy, protein, minerals, phytopigments, total antioxidant capacity (TAC), vitamins, total flavonoids (TFC), total polyphenols (TPC) and their variations. Stem amaranth leaves have abundant dietary fiber, moisture, carbohydrates, and protein. We found significant amount of potassium, calcium, magnesium (9.61, 24.40, and 29.77 mg g−1 DW), iron, manganese, copper, zinc, (1131.98, 269.89, 25.03, and 1006.53 µg g−1 DW), phytopigments such as chlorophyll a, chlorophyll ab chlorophyll b, (27.76, 42.06, and 14.30 mg 100 g−1 FW), betalain, betaxanthin, betacyanin (62.92, 31.81, 31.12 µg 100 g−1 FW), total carotenoids, beta-carotene (1675.38, 1289.26 µg g−1 FW), vitamin C (1355.46 µg g−1 FW), TPC, TFC (228.63 GAE and 157.42 RE µg g−1 DW), and TAC (DPPH, ABTS+) (26.61, 51.73 TEAC µg g−1 DW) in the leaves of stem amaranth. Genotypes exhibited a wide range of variations. Three genotypes DS40, DS30, and DS26 could be used as an antioxidant profile enriched stem amaranth. Phenolics, phytopigments, flavonoids, and vitamins of stem amaranth leaves exhibited strong antioxidant activity. Stem amaranth could be a potential source of dietary fiber, moisture, carbohydrates, protein, minerals, phenolics, phytopigments, flavonoids, and vitamins in our daily diet for attaining nutritional and antioxidant sufficiency.

Total Phenolic, Flavonoid Contents, and Antioxidant Activities of Fruit, Seed, and Bark Extracts of Zanthoxylum armatum DC.

Abstract: Natural antioxidants present in several medicinal plants are responsible for inhibiting the harmful effects of oxidative stress. These plants contain polyphenols and flavonoids that act as free radical scavengers and reduce oxidative stress and may be an alternative remedy to cure various harmful human diseases. This study aims to quantify the total phenolic and flavonoid contents (TPC and TFC) and antioxidant properties of methanol extracts of fruits, seeds, and bark of an important medicinal and aromatic plant, Zanthoxylum armatum collected from wild and cultivated populations in Nepal. TPC was determined by Folin–Ciocalteu colorimetric method using gallic acid as standard, and various concentrations of the extract solutions were measured at 760 nm. TFC was calculated by aluminum chloride colorimetric assay. Quercetin was used as standard, and the absorbance was measured at 510 nm. The antioxidant potential of the different extracts was estimated by DPPH free radical scavenging assay, and the absorbance was measured at 517 nm. The highest TPC value was 226.3 ± 1.14 mg GAE/g in wild fruits, and the lowest was 137.72 ± 4.21 mg GAE/g in cultivated seeds. Similarly, the highest TFC value was 135.17 ± 2.02 mg QE/g in cultivated fruits, and the lowest was 76.58 ± 4.18 mg QE/g in cultivated seeds. The extracts showed variable antioxidant properties. The fruits exhibited excellent antioxidant properties with IC50 values of 40.62 μg/mL and 45.62 μg/mL for cultivated and wild fruits, respectively. Similarly, the IC50 values of the bark were 63.39 μg/mL and 67.82 μg/mL, respectively, for cultivated and wild samples. And the least antioxidant capacity was shown by the seeds extract with IC50 values of 86.75 μg/mL and 94.49 μg/mL for wild and cultivated seeds, respectively. The IC50 value of the standard ascorbic acid was 36.22 μg/mL. Different extracts of Z. armatum contain considerable amount of phenols and flavonoids, including antioxidant properties, suggesting the potential use of this species in pharmacy and phytotherapy as a source of natural antioxidants.

Significance of FRAP, DPPH, and CUPRAC assays for antioxidant activity determination in apple fruit extracts

Abstract: Thirteen apple cultivars were analyzed for their total phenolic content, total flavonoids, anthocyanins, ascorbic acid in methanolic extracts of both peel and cortex fractions. Three in vitro assays (FRAP, DPPH, and CUPRAC) were used to determine the antioxidant activity. Concentration of the phytochemicals studied varied greatly between the apple peel and the cortex region. Peels showed ~ 2.8 times higher total phenolic content and ~ 2.68% higher flavonoid content than the cortex. Principal component analysis could successfully explain 76.86% and 84.27% variability in the antioxidant determinants (antioxidants/assays) in the peel and cortex region of apple cultivars, respectively. Major contributor for antioxidant activity in both apple peel and cortex was total flavonoid content. Cultivars ‘Well Spur’ and ‘Oregon Spur II’ were found to be substantially rich in these two antioxidants. The antioxidant activity was best expressed by the in vitro FRAP assay in both the fractions. Non-hierarchical K-medoids clustering reflected the presence of an antioxidant/ assay protocol apart from the antioxidant/assay we considered in this study that needs further exploration to get full spectra of antioxidant profile across apple genotypes. Based on multivariate analysis and the concept of RACI, the FRAP antioxidant assay is recommended for determining antioxidant activity in apples.

Nutrients, minerals, pigments, phytochemicals, and radical scavenging activity in Amaranthus blitum leafy vegetables

Abstract: A. blitum is good sources of abundant natural antioxidant phytopigments such as anthocyanin, betalain, betaxanthin, and betacyanin and antioxidant phytochemicals of interest in the food industry. The chances of utilizing amaranth pigments and phytochemicals had been evaluated for extracting colorful juice as drink purposes. Hence, the presence of nutrients, phytopigments, phytochemicals, and radical scavenging activity of selected A. blitum leafy vegetables were evaluated. Leaves of A. blitum have considerable fiber, moisture, protein, and carbohydrates. It has considerable magnesium, calcium, potassium (30.42, 24.74, 10.24 mg g−1), zinc, iron, copper, manganese, (878.98, 1153.83, 26.13, 207.50 µg g−1), phytopigments such as chlorophyll a, chlorophyll ab, chlorophyll b, (63.69, 90.60, 29.32 mg 100 g−1), betalain, betaxanthin, betacyanin (112.01, 58.38, 53.63 µg 100 g−1), vitamin C (1848.15 µg g−1), total carotenoids, β-carotene (1675.38, 1281.66 µg g−1), TPC, TFC (253.45 GAE and 162.97 RE µg g−1 DW), and TAC (29.46, 55.72 µg g−1 DW in Tolax equivalent DPPH and ABTS+ radical scavenging capacity) in A. blitum. The accessions DS3, DS6, DS8, and DS12 exhibited the highest TAC in Trolox equivalent DPPH and ABTS+ radical scavenging capacity, flavonoids, and considerable phytopigments. These accessions had excellent antioxidant profiles along with high yielding potentiality. Hence, A. blitum provides an excellent source of proximate, phenolics, minerals, flavonoids, vitamins, and phytopigments to address the nutritional and antioxidant deficiency in daily diet.

Anticholinergic, antidiabetic and antioxidant activities of Anatolian pennyroyal (Mentha pulegium)-analysis of its polyphenol contents by LC-MS/MS

Abstract: Methanol and water extracts of pennyroyal (Mentha pulegium) were evaluated for their antioxidant profiles by eight distinguished bioanalytical methods and for their inhibitory effects against enzymes linked to different diseases, namely acetylcholinesterase, butyrylcholinesterase, α-glycosidase and α-amylase. Additionally, the antioxidant properties of both extracts were determined and their polyphenolic compositions were evaluated by LC-MS/MS. For estimation of the antioxidant capacities of methanolic extract of pennyroyal (MEP) and water extract of pennyroyal (WEP); 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS•+), 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH•), and N,N-dimethyl-p-phenylenediamine (DMPD•+) scavenging activities, Fe3+-2,4,6-tris(2-pyridyl)-s-triazine (TPTZ), Fe3+, and Cu2+ reducing assays were studied. The IC50 values of the MEP and WEP indicated that they were potent effective DPPH· (16.92 and 18.52 μg/mL), ABTS•+ (7.92 and 9.37 μg/mL) and DMPD•+ (36.02 and 38.94 μg/mL) scavengers, as well as acetylcholinesterase (AChE) (40.76 and 60 μg/mL), butyrylcholinesterase (BChE) (49.51 and 63.03 μg/mL), α-glycosidase (20.38 and 21.65 μg/mL) and α-amylase (23.11 and 36.47 μg/mL) inhibitors. Plant materials are potential sources for novel products in food and pharmaceutical applications. Also, biologically active compounds from plants have proven to be desirable in cosmetics, foods, and pharmaceuticals. This study clearly showed that both MEP and WEP had a broad screening of active compounds and phytochemicals. As a result of this abundant active ingredient, both extracts possessed antioxidant, anticholinergic and anti-diabetes properties.

Antioxidant activity of high purity blueberry anthocyanins and the effects on human intestinal microbiota

Abstract: The investigation of the composition, antioxidant activity of blueberry anthocyanins (BA) and the effects on human intestinal microbiota were carried out. The separation of anthocyanins from blueberry (Vaccinum sp.) was performed by liquid chromatography-diode array detector-electrospray ionization-tandem mass spectrometry (LC-DAD-ESI-MS2). 14 anthocyanins were tentatively identified and their concentration was determined. Among them, malvidin-3-O-glucoside was the main anthocyanin species, followed by malvidin-3-O-galactoside and petunidin-3-O-glucoside, they accounted for 44.81% of the total anthocyanins in blueberry extract. The antioxidant activities were evaluated by DPPH, ABTS• +, FRAP, reducing power and superoxide anion radical scavenging activity. The result showed that the EC50 value of BA by ABTS•+assay was lower than the data obtained by DPPH assay, which was 14.99 μg/mL and 26.48 μg/mL, respectively. Furthermore, the impact of BA on human intestinal microbiota were analyzed by high throughput sequencing and bioinformatics analysis. The results demonstrated that BA have impact on the microbial diversity. They could increase the relative abundances of some certain communities including Bifidobacterium spp. Our findings suggest that blueberry and blueberry extracts consumption could exert prebiotic activity which are associated with health benefits.

Comparative Analysis of In-Vitro Biological Activities of Methyl Eugenol Rich Cymbopogon khasianus Hack., Leaf Essential Oil with Pure Methyl Eugenol Compound.

Abstract: Background The essential oil of methyl eugenol rich Cymbopogon khasianus Hack. was evaluated and its bioactivities were compared with pure methyl eugenol. So far, methyl eugenol rich essential oil of lemongrass was not studied for any biological activities; hence, the present study was conducted. Objective This study examined the chemical composition of essential oil of methyl eugenol rich Cymbopogon khasianus Hack., and evaluated its antioxidant, anti-inflammatory, antimicrobial, and herbicidal properties and genotoxicity, which were compared with pure compound, methyl eugenol. Material and methods Methyl eugenol rich variety of Cymbopogon khasianus Hack., with registration no. INGR18037 (c.v. Jor Lab L-9) was collected from experimental farm CSIR-NEIST, Jorhat, Assam (26.7378°N, 94.1570°E). The essential oil wasobtained by hydro-distillation using a Clevenger apparatus. The chemical composition of the essential oil was evaluated using GC/MS analysis and its antioxidant (DPPH assay, reducing power assay), anti-inflammatory (Egg albumin denaturation assay), and antimicrobial (Disc diffusion assay, MIC) properties, seed germination effect and genotoxicity (Allium cepa assay) were studied and compared with pure Methyl Eugenol compound (ME). Results Major components detected in the Essential Oil (EO) through Gas chromatography/mass spectroscopy analysis were methyl eugenol (73.17%) and β-myrcene (8.58%). A total of 35components were detected with a total identified area percentage of 98.34%. DPPH assay revealed considerable antioxidant activity of methyl eugenol rich lemongrass essential oil (IC50= 2.263 μg/mL), which is lower than standard ascorbic acid (IC50 2.58 μg/mL), and higher than standard Methyl Eugenol (ME) (IC50 2.253 μg/mL). Methyl eugenol rich lemongrass EO showed IC50 38.00 μg/mL, ME 36.44 μg/mL, and sodium diclofenac 22.76 μg/mL, in in-vitro anti-inflammatory test. Moderate antimicrobial activity towards the 8 tested microbes was shown by methyl eugenol rich lemongrass essential oil whose effectiveness against the microbes was less as compared to pure ME standard. Seed germination assay further revealed the herbicidal properties of methyl eugenol rich essential oil. Moreover, Allium cepa assay revealed moderate genotoxicity of the essential oil. Conclusion This paper compared the antioxidant, anti-inflammatory, antimicrobial, genotoxicity and herbicidal activities of methyl eugenol rich lemongrass with pure methyl eugenol. This methyl eugenol rich lemongrass variety can be used as an alternative of methyl eugenol pure compound. Hence, the essential oil of this variety has the potential of developing cost-effective, easily available antioxidative/ antimicrobial drugs but its use should be under the safety range of methyl eugenol and needs further clinical trials.

GC-MS analysis of phytoconstituents from Amomum nilgiricum and molecular docking interactions of bioactive serverogenin acetate with target proteins.

Abstract: Amomum nilgiricum is one of the plant species reported from Western Ghats of India, belonging to the family Zingiberaceae, with ethno-botanical values, and is well-known for their ethno medicinal applications. In the present investigation, ethyl acetate and methanol extracts of A. nilgiricum were analyzed by Fourier transform infrared spectrometer (FTIR) and gas chromatography-mass spectrometry (GC-MS) to identify the important functional groups and phytochemical constituents. The FTIR spectra revealed the occurrence of functional characteristic peaks of aromatic amines, carboxylic acids, ketones, phenols and alkyl halides group from leaf and rhizome extracts. The GC-MS analysis of ethyl acetate and methanol extracts from leaves, and methanol extract from rhizomes of A. nilgiricum detected the presence of 25 phytochemical compounds. Further, the leaf and rhizome extracts of A. nilgiricum showed remarkable antibacterial and antifungal activities at 100 mg/mL. The results of DPPH and ferric reducing antioxidant power assay recorded maximum antioxidant activity in A. nilgiricum methanolic leaf extract. While, ethyl acetate leaf extract exhibited maximum α-amylase inhibition activity, followed by methanolic leaf extract exhibiting aldose reductase inhibition. Subsequently, these 25 identified compounds were analyzed for their bioactivity through in silico molecular docking studies. Results revealed that among the phytochemical compounds identified, serverogenin acetate might have maximum antibacterial, antifungal, antiviral, antioxidant and antidiabetic properties followed by 2,4-dimethyl-1,3-dioxane and (1,3-13C2)propanedioic acid. To our best knowledge, this is the first description on the phytochemical constituents of the leaves and rhizomes of A. nilgiricum, which show pharmacological significance, as there has been no literature available yet on GC-MS and phytochemical studies of this plant species. The in silico molecular docking of serverogenin acetate was also performed to confirm its broad spectrum activities based on the binding interactions with the antibacterial, antifungal, antiviral, antioxidant and antidiabetic target proteins. The results of the present study will create a way for the invention of herbal medicines for several ailments by using A. nilgiricum plants, which may lead to the development of novel drugs.

Structural characterization and antioxidant activity of polysaccharides extracted from jujube using subcritical water

Abstract: Polysaccharides were extracted from jujube fruit using an efficient, optimized subcritical water extraction process. A maximum crude polysaccharide yield of 7.9% was obtained at an extraction temperature of 140 °C and a time of 60 min. The crude polysaccharides extracted under these conditions were purified. Three polysaccharide fractions, ZP1, ZP2 and ZP3, were obtained and their structures were investigated. The three fractions were mainly composed of arabinose, galactose, glucose, mannose, rhamnose, and galacturonic acid. ZP3 was further investigated using methylation and NMR spectroscopy, and ZP3 comprised a main chain of (1 → 4)-α-D-GalAp, (1 → 2,4)-α-L-Rhap, with a (1 → 4,6)-α-D-Galp branch. Assays of antioxidant activity showed that ZP3 exhibited a remarkable DPPH capacity and moderate hydroxyl radical scavenging ability, suggesting that it has potential applications as a natural antioxidant in foods and pharmaceuticals.

Nutritional and bioactive constituents and scavenging capacity of radicals in Amaranthus hypochondriacus.

Abstract: A. hypochondriacus leaves contained ample phytopigments including betalain, anthocyanin, β-xanthin, β-cyanin, and bioactive phytochemicals of interest in the industry of food. We have been evaluating the possibility of utilizing phytopigments of amaranth and bioactive constituents for making drinks. Therefore, we evaluated bioactive phytopigments and compounds including the potentiality of antioxidants in A. hypochondriacus leaves. A. hypochondriacus leaves have abundant protein, carbohydrates, and dietary fiber. We found considerable levels of inorganic minerals including magnesium, calcium, potassium (3.88, 3.01, 8.56 mg g−1), zinc, manganese, copper, iron (16.23, 15.51, 2.26, 20.57 µg g−1), chlorophyll b, chlorophyll ab chlorophyll a (271.08, 905.21, 636.87 μg g−1), scavenging capacity of radicals (DPPH, ABTS+) (33.46, 62.92 TEAC μg g−1 DW), total polyphenols (29.34 GAE μg g−1 FW), β-xanthin, betalain, β-cyanin (584.71, 1,121.93, 537.21 ng g−1), total flavonoids (170.97 RE μg g−1 DW), vitamin C, β-carotene, carotenoids (184.77, 82.34, 105.08 mg 100 g−1) in A. hypochondriacus leaves. The genotypes AHC6, AHC4, AHC11, AHC5, and AHC10 had a good scavenging capacity of radicals. Polyphenols, phytopigments, flavonoids, and β-carotene of A. hypochondriacus had potential antioxidant activity. Extracted juice of A. hypochondriacus can be an ample source of phytopigments and compounds for detoxification of reactive oxygen species (ROS) and attaining nutritional and antioxidant sufficiency.

Chemical Composition, Antimicrobial, Antioxidant, and Antiproliferative Properties of Grapefruit Essential Oil Prepared by Molecular Distillation

Abstract: Grapefruit essential oil has been proven to have wide range of bioactivities. However, bioactivity of its molecular distillate has not been well studied. In this study, a light phase oil was obtained by molecular distillation from cold-pressed grapefruit essential oil and GC-MS was used to identify its chemical composition. The antimicrobial activity of the light phase oil was tested by filter paper diffusion method, and the anticancer activity was determined by the Cell Counting Kit-8 (CCK-8) assay. Twenty-four components were detected with a total relative content of 99.74%, including 97.48% of terpenes and 1.66% of oxygenated terpenes. The light phase oil had the best antimicrobial effect on Bacillus subtilis, followed by Escherichia coli, Staphylococcus aureus and Salmonellaty phimurium. DPPH and ABTS assays demonstrated that the light phase oil had good antioxidant activity. The CCK-8 assay of cell proliferation showed that the light phase oil had a good inhibitory effect on the proliferation of HepG2 liver cancer cells and HCT116 colon cancer cells.