Determined By The 2,2-diphenyl-1-picrylhydrazyl Research Articles

Antibacterial, antidiabetic and antioxidant bioevaluation of Calamus leptospadix Griff. and isolation of a flavan type compound

The plant based natural products have always been a rich source of bioactive molecules for drug discovery. The tender shoots of Calamus leptospadix Griff., an edible medicinal plant was extracted using methanol, water and ethanol as three different solvents to study the effect of the extracting solvents and temperature on their antioxidant, antidiabetic and antibacterial properties and total phenolic and flavonoid contents. The antioxidant properties were determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assay. The α-glucosidase inhibitory assay was carried out to determine the antidiabetic potential. The antibacterial properties of the extracts were determined against four strains of bacterial species viz. Bacillus subtilis, Streptococcus pneumoniae, Escherichia coli and Citrobacter freundii using Broth macro dilution method.The methanolic extracts of the plant were found to possess the highest total phenolic and total flavonoid contents. In the antioxidant assays, the cold methanolic extract was found to exhibit the highest DDPH radical scavenging activity and ferric-reducing antioxidant power. In the antidiabetic assay, the extract exhibited better α-glucosidase inhibitory potential than that of the positive control acarbose. It was also found to be effective against both gram-positive and gram-negative strains in the antibacterial assay. A flavan-type compound 4-(5,7-dimethoxychroman-2-yl)phenol was isolated from the most bioactive cold methanolic extract of the plant and characterised from its XRD, 1H and 13C NMR, HRMS and IR data.

Comparison of the Antimicrobial and Antioxidant Effects of Oleuropein Extracted from Arbequina Olive Leaves with the Extracts of its Leaf and Fruit

Introduction: Olive leaf is an evergreen plant and enriched in phenolic compounds and antioxidants. Oleuropein is the most common type of phenolic compounds can found in Olive leaves. The aim of this study was to compare the antimicrobial and antioxidant effects of Oleuropein extracted from olive leaf with the extracts from its leaf and fruit.
 Methods: The type of study was experimental and after ethanol extraction from olive leaf and fruit, oleuropein was isolated from the leaf extract. Antimicrobial effects of Oleuropein obtained from olive fruit and leaf extracts against Staphylococcus saprophyticus and Pseudomonas aeruginosa bacteria were determined using minimum inhibitory concentration (MIC) method. Amounts of phenolic compounds were derived by the Folin-Ciocalteu assay and the antioxidant effects were determined by the 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) free radical inhibition method. SPSS version 16 software was used for statistical calculations, Excel program used to draw graphs and one-way ANOVA was used to evaluate the effect of the intervention.
 Results: Oleuropein was extracted from olive leaf in the amount of 14% with a purity of 70%. The highest and lowest amount of phenolic compounds and the antimicrobial and antioxidant effects were observed for Oleuropein obtained from olive leaf and olive fruit extracts, respectively. The amount of oleuropein phenolic compounds was equal to 879.16 (µg GAE/g), its MIC against S. saprophyticus and P.aeruginosa bacteria was equal to 3.25 and 12.5 mg/ml, respectively. Its antioxidant activity was equal to 8.59 µg/ml.
 Conclusion: In the present study, oleuropein was extracted from olive leaves and the study showed that the amount of oleuropein in the Spanish Arbican variety was obtained with the highest value of 14%. According to the results of antimicrobial activity and antioxidant, it can be concluded that olive leaf extract and extracted oleuropein have the potential to increase and improve the performance of preservatives and antioxidants.

Effect of extraction solvents on polyphenol content and antioxidant activity of carob tree (Ceratonia siliqua L.) leaves

Carob tree (Ceratonia siliqua L.) is widely used in traditional medicine and food. The aim of this study was to determine the most appropriate extraction solvent to optimize the extraction of polyphenols and flavonoids from the leaves, in order to obtain the highest antioxidant activity. In this context, the effects of six different solvents (100% methanol, 100% ethanol, 100% acetone, 50% (v/v) aqueous methanol, 50% (v/v) aqueous ethanol and 50% (v/v) aqueous acetone) with different polarities on the polyphenol content and antioxidant activity of carob tree leaf extracts were investigated. The total polyphenol and total flavonoid contents, as well as the antioxidant activity determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method of the extracts were evaluated. The results showed that carob tree leaves extracted with 100% methanol presented the highest values in terms of total polyphenol content (11.33± 0.08 mg EAG/g DM), total flavonoid content (8.55± 0.34 mg EC/g DM) and DPPH inhibition percentage (79.29 ± 3.75%). High positive correlations between total polyphenols, total flavonoids and antioxidant activity of carob tree leaf extracts were also observed. These results indicate that carob tree leaf extract obtained using an appropriate extraction solvent was able to enhance the protective effect against oxidative damage associated with free radicals.

Biological Activities and Polyphenol Content of Qi Cha Tea®, a Functional Beverage of White Tea Containing Botanicals and Dry Botanical Extracts with European Health Claims.

Infusions of Camellia sinensis leaves have been known for their health benefits. The Bio Concentrate Assets® (ABC) method is a method of enriching organic infusion leaves (from Camellia sinensis) with organic dry and concentrated extracts using organic acacia gum, and its application to white tea has provided Qi cha tea®. In the present study, the content of tea polyphenols and caffeine, and the biochemical properties of Qi cha tea® and its botanical constituents (elderberry, tulsi, Echinacea purpurea, orange peel, lemongrass, and acacia gum) were assessed. Antioxidant and cell viability activities were determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and MTT (3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) assay in human Caco-2 and HCT-116 cell lines, and ascorbic acid and tamoxifen, respectively. The caffeine and polyphenol composition of Qi cha tea® was modified with less caffeine and gallic acid and more epigallocatechin gallate (EGCG) than the original white tea. The majority of the tested botanical samples including Qi cha tea® at 50 µg/mL show similar antioxidant activities, with the exception of Echinacea purpurea. The greatest effect was found for white tea. The antioxidant power of the Qi cha tea® (90% at 50 µg/mL for pressurized liquid extraction (PLE) was divided by approximately a factor of two (61% at 50 µg/mL for pressurized liquid extraction products (PLEP)), which corresponds to the 48.3% (mass/mass) white tea original content in the Qi cha tea®. Qi cha tea® shows the lowest cytotoxic activity in the viability of the two cell lines when compared to white tea. The application of the ABC method to Qi cha tea® using various botanicals and dry extract with acacia gum as blinder has allowed the development of a new innovative functional health beverage that complies with European health claims.

Comparison of Composition, Free-Radical-Scavenging Capacity, and Antibiosis of Fresh and Dry Leave Aqueous Extract from Michelia shiluensis.

Numerous plants of medicinal value grow on Hainan Island (China). Given the lack of knowledge on the phytochemical and pharmacological properties of Michelia shiluensis Chun and Y. F. Wu (M. shiluensis), the application of natural antioxidants and antimicrobials in the food industry has attracted increasing interest. This study aimed to compare the chemical composition, free-radical-scavenging capacity, and antibiosis of aqueous extracts of the fresh and dried leaves of M. shiluensis. The aqueous extract of the leaves of M. shiluensis was obtained using steam distillation, and its chemical components were separated and identified via gas chromatography-mass spectrometry (GC-MS). The free-radical-scavenging capacity and antibiosis were determined. Further, 28 and 20 compounds were isolated from the fresh leaf aqueous extract of M. shiluensis (MSFLAE) and dried leaf aqueous extract of M. shiluensis (MSDLAE), respectively. The free-radical-scavenging capacity of MSFLAE and MSDLAE was determined by the 2,2-diphenyl-1 picrylhydrazyl (DPPH) method, which was 43.43% and 38.74%, respectively. The scavenging capacity of MSFLAE and MSDLAE determined by the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS)) method was 46.90% and 25.99%, respectively. The iron ion reduction capacity of MSFLAE and MSDLAE was determined by the ferric-reducing antioxidant power (FRAP) method as 94.7 and 62.9 μmol Fe2⁺/L, respectively. This indicated that the two leaf aqueous extracts had a certain free-radical-scavenging capacity, and the capacity of MSFLAE was higher than that of MSDLAE. The antibiosis of the two leaf aqueous extracts on the three foodborne pathogenic bacteria was low, but the antimicrobial effects on Gram-positive bacteria were better than those on Gram-negative bacteria. The antibiosis of MSFLAE on Escherichia coli and Staphylococcus aureus was greater than that of MSDLAE. Finally, MSFLAE and MSDLAE both had certain free-radical-scavenging capacities and antibiosis, confirming that the use of this plant in the research and development of natural antioxidants and antibacterial agents was reasonable. Plant aqueous extracts are an essential source of related phytochemistry and have immense pharmacological potential.

Screening of Chemical Composition, Antimicrobial and Antioxidant Activities in Pomegranate, Quince, and Persimmon Leaf, Peel, and Seed: Valorization of Autumn Fruits By-Products for a One Health Perspective.

Antimicrobial resistance is increasing globally and is now one of the major public health problems. Therefore, there is a need to search for new antimicrobial agents. The food industry generates large amounts of by-products that are rich in bioactive compounds, such as phenolic compounds, which are known to have several health benefits, including antioxidant and antimicrobial properties. Thus, we aimed to characterize the phenolic compounds present in pomegranate, quince, and persimmon by-products, as well as their antioxidant and antimicrobial activities. Phenolic compounds were extracted from pomegranate, quince, and persimmon leaves, seeds, and peels using a mixture of ethanol/water (80/20). The polyphenol profile of the extracts was determined by high-performance liquid chromatography. The antioxidant activity of the extracts was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) methods. Antimicrobial susceptibility was evaluated using the Kirby-Bauer disk diffusion method. In general, leaves showed higher concentrations of phenolics than the peel and seeds of fruits. In total, 23 phenolic compounds were identified and quantified, with sanguiin and apigenin-3-O-galactoside being present in the highest concentrations. Leaf extracts of pomegranate showed higher antioxidant activities than the other components in all methods used. In general, all extracts had a greater antimicrobial activity against Gram-positive bacteria. Persimmon leaf and seed extracts inhibited a greater number of bacteria, both Gram-positive and -negative. The lowest minimum inhibitory concentration (MIC) detected among Gram-positive and -negative bacteria was 10 mg/mL for pomegranate peel and leaf extracts against Staphylococcus aureus and S. pseudintermedius and for pomegranate leaf extract against Escherichia coli. Our results reinforce the need to value food industry by-products that could be used as food preservatives and antibiotic adjuvants against multiresistant bacteria.

Potential Biochemical Properties of Endemic Onosma mutabilis

The Onosma L. (Lithospermae, Boraginaceae) genus contains many plant species with therapeutic properties due to its rich phytochemicals. Onosma mutabilis Boiss. & Hausskn. ex Boiss. (O. mutabilis) is the species for which there is not enough information on its characteristics. Objective: The total phenolic content, antioxidant activity, possible bioactive compounds, and antibacterial activities of ethanolic extracts of leaf, stem, root, and flower parts of endemic O. mutabilis were investigated. Conclusions: The total phenolic content of all O. mutabilis extracts was in the range of 9.2–31 mg gallic acid equivalent (GAE)/g of extract. According to the results of antioxidant activity, the IC50 antioxidant capacity values determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method were between 4.39–29 μg/mL, while the equivalent trolox antioxidant activity determined by the cupric reducing antioxidant values (CUPRAC) was 0.45–0.78 mmol of trolox equivalents (TE)/g of extract. Bioactive compounds have been analysed using gas chromatography coupled with mass spectrometry (GC/MS) and were found to contain 29 different chemical components. All plant extracts tested showed effective antibacterial activity against A. baumannii (ATCC 02026) (62.5 μg/mL MIC value) when compared to the reference drug Ampicillin (125 μg/mL).

Application of Natural Deep Eutectic Solvents for Extraction of Bioactive Components from Rhodiola rosea (L.).

Rhodiola rosea (L.) is a valuable source of nutrients. Nutrients have adaptogenic, immunostimulating, nootropic, anti-inflammatory and anti-cancer properties. Natural deep eutectic solvents (NADES) consisting of choline chloride and malonic, malic, tartaric or citric acids have been first used to extract biologically active substances from R. rosea. The total content of polyphenols has been determined by the Folin-Ciocalteu method for all extracts. Antioxidant activity has been determined by the phosphomolybdate method, and antiradical activity has been determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Rosavin concentration has been determined by high-performance liquid chromatography (HPLC). Extraction kinetics has been evaluated regarding the effectiveness of NADES with each other and with reference solvents (water and 50% ethanol) has been made. Extraction conditions have been optimized according to the Box-Behnken design of the experiment. The optimal parameters of the extraction process have been established. The antibacterial activity of NADES-based extracts against bacterial cultures of Micrococcus luteus, Pseudomonas fluorescens, and Bacillus subtilis has been studied.

Selective Structural Derivatization of Flavonoid Acetamides Significantly Impacts Their Bioavailability and Antioxidant Properties

Flavonoids show abundant favorable physicochemical and drug related properties, leading to substantial biological applications which are limited by undesirable properties such as poor solubility, high polarity, low bioavailability, and enzymatic degradations. Chemical modification with bioisosteres can be used to address some of these challenges. We report the synthesis and characterization of partial flavonoid acetamide derivatives from quercetin, apigenin and luteolin and the evaluation of their structure-activity relationships based on antioxidant, bioavailability, drug likeness, and toxicity properties. The sequential synthesis was achieved with 76.67-87.23% yield; the structures of the compounds were confirmed using 1H & 13C NMR characterizations. The purity of each compound was determined by HPLC while the molecular weights were determined by mass spectrometry. The % bioavailability was determined using the dialysis tubing procedure and the values were in the range 15.97-38.12%. The antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and expressed as the IC50 values which were in the range 31.52-198.41 µM. The drug likeness and the toxicity properties of compounds 4, 5, 7, 11 and 15 were predicted using computational tools and showed satisfactory results. A structure-activity relationship evaluation reveals that hydroxyl and methylene groups attached on the 2-phenylchromen-4-one structure of the flavonoid play a colossal role in the overall antioxidant and bioavailability properties. The improved bioavailability and excellent drug relevance and toxicity properties present flavonoid acetamide derivatives as prospective drug candidates for further evaluations.

Effect of Grinding Process Parameters and Storage Time on Extraction of Antioxidants from Ginger and Nutmeg.

The aim of this study was to optimize the grinding process parameters (mesh size of grinder sieve (X1), the peripheral velocity of the grinding wheels (X2)), and the storage time (X3) of ground ginger rhizome and nutmeg to obtain ethanol and ethanol-water extracts with improved antioxidant properties. The optimal conditions were estimated using response surface methodology (RSM) based on a three-variable Box-Behnken design (BBD) in order to maximize the antioxidant capacity (AC) determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, and the total phenolic content (TPC) was determined by the Folin-Ciocalteu (F-C) method in spice extracts. Additionally, the phenolic acid profiles in extracts from optimized conditions were analyzed using ultra-performance liquid chromatography (UPLC). It was found that the optimal preparation conditions for antioxidant extraction were dependent on the spice source and solvent type. The best antioxidant properties in nutmeg extracts were achieved for X1 = 1.0 mm, X2 = 40-41 Hz and X3 = 7 days, whereas the optimized parameters for ginger extracts were more varied (1.0-2.0 mm, 43-50 Hz and 1-9 days, respectively). The ginger extracts contained 1.5-1.8 times more phenolic acids, and vanillic, ferulic, gallic, and p-OH-benzoic acids were dominant. In contrast, the nutmeg extracts were rich in protocatechuic, vanillic, and ferulic acids.

Biological activities and structural characterization of sulfated polysaccharide extracted from a newly Mediterranean Sea record Grateloupia gibbesii Harvey

Grateloupia gibbesii Harvey (family; Halymeniaceae) is a newly recorded red alga in the Egyptian Mediterranean Sea. In the present study, Grateloupia gibbesii polysaccharide was isolated by hot aqueous extraction and then precipitated by cold ethanol. The yield of crude polysaccharides was 6.4% (w/w), which increased to 17% (w/w) after deproteinization. Preliminary structural characterization and bioactivity of the deproteinized polysaccharide (DGP) were investigated. The monosaccharides' contents were identified by TLC and HPLC. Preliminary structural estimation was carried out by FT-IR and 1H NMR. Moreover, in-vitro exploration of anticoagulant activity by prothrombin time (PT) and fibrinolytic activity of the polysaccharide was determined. The antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the prebiotic activity was assessed against Lactobacillus spp. bacteria. The molecular weight of DGP was 286 kDa and galactose was the most abundant monomer with traces of xylose and glucuronic acid. Anticoagulant tests of DGP revealed prolonged clotting and prothrombin times (20 &14 s at a concentration of 2 mg/mL), respectively, showing moderate anticoagulant activity. DGP exhibited significant fibrinolytic activity (50%), relatively high antioxidant activity (86% at a concentration of 10 mg/mL) and positive prebiotic activity (2.27–2.67). DGP extracted and purified from Grateloupia gibbesii Harvey can be considered as a natural source contestant in the treatment of thrombosis and as an antioxidant and prebiotic supplement in the drug and food industries.

Biological Activities of Seven Medicinal Plants Used in Chiapas, Mexico.

Seven medicinal plants from Chiapas, Mexico, used by Native Americans were analyzed, aiming to improve the understanding of their medicinal properties through the evaluation of various biological activities, i.e., bactericidal, antioxidant, α-glucosidase inhibition, and toxicity, to provide a scientific basis for the management of infectious and hyperglycemic diseases in the Mexican southeast. Plant extracts were obtained from Cordia dodecandra, Gaultheria odorata, Heliotropium angiospermum, Justicia spicigera, Leucaena collinsii spp. collinsii, Tagetes nelsonii, and Talisia oliviformis through maceration techniques using methanol and chloroform (1:1). Minimum Inhibitory Concentration (MIC) was employed to determine the antibacterial activity against Staphylococcus aureus, Enterobacter faecalis, Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeuroginosa. The antiradical/antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays and antihemolytic activity using the 2,2’-Azobis(2-amidinopropane) dihydrochloride radical (APPH). The anti-α-glucosidase activity was evaluated in vitro through the chromogenic PNPG assay. The toxicity was assessed using the brine shrimp lethality assay. The highest antimicrobial activity was displayed by T. nelsonii, mainly against E. faecalis and P. aeuroginosa. The extracts of L. collinsii, J. spicigera, and T. nelsonii possess antioxidant properties with EC50 < 50 μg/mL. J. spicigera and T. nelsonii extracts showed the highest antihemolytic activity with IC50 < 14 μg/mL. T. nelsonii exhibited a remarkable inhibitor effect on the α-glucosidase enzyme and the greatest toxic effect on Artemia salina with IC50 = 193 ± 20 μg/mL and LD50 = 14 ± 1 μg/mL, respectively. According to our results, G. odorata, J. spicigera, T. nelsonii, and T. oliviformis extracts contained active antimicrobial compounds. At the same time, T. nelsonii stands to be a possible source of effective antineoplastic and antihyperglycemic compounds.

Comparison of Important Quality Characteristics of Some Fungal Disease Resistance/Tolerance Grapes Dried with Energy-Saving Heat Pump Dryer

Raisins have been widely consumed for many years all around the world, and different grape cultivars and drying techniques are used in their production. Recently, mechanical drying systems have been used to overcome any undesirable effects that arise from sun-drying with grape cultivars that require fewer pesticides to minimize the risk of residues. Both seeded and seedless cultivars were preferred for drying in the past; however, seedless grape cultivars have been increasingly preferred for drying purposes in addition to their use as table grapes. For the first time, an alternative processing method (using an energy-saving heat pump dryer) and important quality characteristics (total phenolics, antioxidant activity, brix, colour analyses and sensory evaluation) of disease resistant/tolerant grape cultivars of different species that can be grown in humid regions were investigated in this study. First, the fresh fruits of nine different grape (Vitis spp.) cultivars grown in a humid ecology were analysed, and then so too were the important phytochemical and quality characteristics of raisins dried with an energy-saving heat pump dryer. The water activity of the raisins ranged from 0.71 (Özer Beyazı) to 0.42 (Kay Gray). The total phenolic contents of Muscat Bleu (65.96), Philipp (64.88) and Campbell Early (64.53 g GAE/100 g db) berries were the highest (p &lt; 0.05). The fresh berries of the Kishmish Vatkana cultivar had the lowest antioxidant activity, as determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay (525.81 mmol TE/100 g) (p &lt; 0.05). The total phenolic contents of raisins ranged from 12.76 to 13.58 g GAE/100 g fw. The highest value on a dry weight basis was 19.30 g GAE/100 g for the raisins of the Özer Beyazı cultivar (p &lt; 0.05). The highest antioxidant activity value on a dry weight basis was found for the raisins of Özer Beyazı (991.01 mmol TE/100 g) using the DPPH assay. The raisins of the Philipp cultivar had an antioxidant activity of 7893.51 mmol TE/100 g db, as determined by the ferric reducing antioxidant potential (FRAP) assay, which was significantly higher than those of other cultivars, with the exception of Muscat Bleu (p &lt; 0.05). The range for antioxidant activity values provided by the cupric reducing antioxidant capacity (CUPRAC) assay was high, and the highest value was found for the raisins of the Philipp cultivar (4505.21 mg Trolox/100 g fw) (p &lt; 0.05). The results indicated that the raisins of the seedless Rhea and Kishmish Vatkana cultivars can be appreciated more than those of the other cultivars, both in terms of their bioactive content and sensory scores, and the raisins of these cultivars, which can be grown in humid regions, hold a great deal of potential for grape growers.

Influence of processing methods on the content of polyphenols and anthocyanins and on the antioxidant activity of Rubus brasiliensis Mart. fruits

Abstract Little is known about the phytochemical composition and the influence of different processing methods on the concentration of bioactive compounds and on the antioxidant activity of the fruits of Rubus brasiliensis Mart., a native plant of Brazil. This work aimed to evaluate the influence of different processing methods on the quantification of phenolic and anthocyanin compounds and on the antioxidant activity of R. brasiliensis fruits. The plants were processed by different ways - the extracts of fruits were obtained by Spray Dryer (SD) or Lyophilization (LYO), and the fruits were dried directly in an oven (OD) and were also evaluated after freshly thawed (FT). The processing methods were independent. After processing, the polyphenol and anthocyanin contents and antioxidant activity were evaluated. The Total Phenolic Content (TPC) was assessed using the Folin-Ciocalteu technique. The pH differential method was used for quantification of anthocyanin and the antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. R. brasiliensis fruits have a high content of polyphenols and anthocyanins, and an expressive antioxidant activity that can bring benefits to the population. The FT fruits showed the lowest content of total polyphenols. However, the OD fruits showed the most interesting results, since the total polyphenols and anthocyanins contents and the antioxidant activity were similar to the other processing methods performed in this work and were more economically viable. Obtain a bioactive content and adequate antioxidant activity after simple processing such as drying is very interesting when using these fruits for longer, or even, obtaining pharmaceutical formulations. It could be determined, for the first time, the content of polyphenols and anthocyanins and the antioxidant activity of the fruits of R. brasiliensis, as well as the best way to process these fruits by drying them in an oven.

Evaluation on the physicochemical properties and mineral contents of Averrhoa bilimbi L. leaves dried extract and its antioxidant and antibacterial capacities

This study aimed to evaluate the physicochemical characteristics and mineral contents of dried extract of Averrhoa bilimbi and its antioxidant and antibacterial properties. Dried extracts leaves powder of A. bilimbi were analysed for its physicochemical properties and mineral compositions. The antioxidant and antibacterial capacities of extracts were determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the disc diffusion method respectively. The functional groups from active compounds were identified by Fourier Transforms Infrared Spectrophotometer (FTIR). Physicochemical characteristics of A. bilimbi dried extracts, including pH and total acids dissolved in water and ethanol solvents, showed negligible differences. The dried leaves powder of A. bilimbi was rich in carbohydrate, protein, and ash contents. It also exhibited essential minerals in which potassium was the highest content. Compared to water, ethanol extract showed more scavenging property against DPPH (82.82 mg GAE/ g DW) and gave a more inhibitory effect on the growth of Salmonella sp., Escherichia coli, and Staphylococcus aureus. The FTIR spectra showed phenolic compounds might be associated with the antioxidant and antibacterial activities of this extract. A. Bilimbi leaves are promising a source for the development of functional food to prevent diseases related to stress oxidative and bacterial infections.

Green synthesis, characterization and biological activity of silver nanoparticles from Dicranum majus Turner

The exploitation of various plant compounds for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In the current study, we synthesized and characterized silver nanoparticles from Dicranum majus (Dm) Turner, a moss plant (Bryophyte). The occurrence of the visible color change from red to brown confirmed Dm silver nanoparticles (DmAgNPs). The DmAgNPs were characterized based on Ultraviolet-Visible (UV-Vis) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR). The morphology, size, and elemental analysis of the prepared silver nanoparticles were examined using Transmission Electron Microscope (TEM) and zeta potential (ZP). The distribution pattern of DmAgNPs particle size and stability were determined with the zeta potential analysis by zeta sizer. The maximum absorption of DmAgNPs was obtained at 422 nm by UV-Vis spectrometer. The presence of carbonyl compounds was demonstrated by FTIR, TEM. Zeta sizer analysis revealed the average size of the nanoparticles as 278.7 nm with -16.7 mV zeta potential demonstrates moderate stability. Considering its antibacterial activities, DmAgNP is more effective on Enterococcus faecalis (ATCC 29212), Listeria monocytogenes (ATCC 7644), and Proteus vulgaris (NRRL B-123) bacteria; it has no mutagenic activity; cleaved DNA as a result of gel electrophoresis; Antioxidant activity was determined by the 2,2-Diphenyl-1- picrylhydrazyl (DPPH) method.

Antioxidant Activity of Rosmarinic Acid Extracted and Purified from Mentha piperita.

Rosmarinic acid was obtained from methanolic extract of Mentha piperita L. under a reflux condenser. The current study aimed to evaluate the in vitro antioxidant activities and rosmarinic acid levels of the methanol extracts of M. piperita. The analysis of the sample by high-performance liquid chromatography technique (HPLC) indicated that rosmarinic acid was present in high concentration 1.9 mg/mL in the extract. Purification was carried out by column chromatography to give 0.020 g from 1 g of crude extract, and then the antioxidant activity of purified rosmarinic acid was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), H2O2 scavenging, and REDOX methods. It was revealed that the anti-oxidant potential of the rosmarinic acid extract was greater than 95% (at 100 µg/mL) for DPPH assay and 87.83% (at 100 µg/ml) for H2O2 scavenging assay. This study was performed by using a reflux methanolic extraction of M. piperita. This possible instructional technique proved to be a quick and successful method for retaining the antioxidant properties of rosmarinic acid. The rosmarinic acid content was determined using HPLC.

Antimicrobial and Antioxidant properties of Petiveria alliacea

The leaf, stem and root decoctions of Petiveria alliacea (referred to as Anamu or Apacin (Guatemala), Guinea–Hen weed (English), Awogba or Ojusaju (Yoruba), kanunfari (Hausa) and Akwa-ose (Igbo) have been used as a diuretic, antispasmodic, sedative, analgesic and anti-inflammatory agents in traditional medicine. Cold maceration and Soxhlet extraction techniques were used to obtain oils from the leaf, stem and root of P. alliacea. The oils were analysed for their antimicrobial properties using brothmicrodilution technique while their antioxidant properties were determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests. The antimicrobial tests on the following micro-organisms Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Escherichia coli,as well as the anti-fungi test on Rhizopus sp., and Aspergillus niger, showed that the hexane and ethanol cold leaf extracts were most effective in limiting the growth of Salmonella typhi with minimum inhibitory concentration (MIC)value of 3.125 µg/mL and minimum bactericidal concentration (MBC)value of 6.25 µg/mL. The ethanol leaf extracts using Soxhlet extraction technique were most effective at MIC value of 3.125 µg/mL on Staphylococcus aureus, Escherichia coli. Likewise, the hexane and ethanolcold leaf extracts were most effective in limiting the growth of Rhizopus sp. and Aspergillus niger with MIC value of 3.125 µg/mL and minimum fungicidal concentration (MFC) value of 6.25 µg/mL.

Influence of phenolic acid content on the antioxidant capacity of hemicellulose from sorghum plant fractions

Recovered hemicellulose fractions from biorefineries have the potential to improve overall process economics during the production of biofuels or other high value chemicals. A common hemicellulose found in many agricultural feedstocks is arabinoxylan (AX). This work investigated the influence of ferulic and p-coumaric acids on the antioxidant capability of AX hemicellulose recovered from sorghum bran, biomass, and bagasse. Sorghum bagasse and sorghum biomass AX contained the largest quantities of bound ferulic and p-coumaric acids at 13.1 mg/100 g and 6.3 mg/100 g, respectively. Antioxidant performance showed that sorghum bagasse AX hemicellulose produced the best reducing capability, while sorghum biomass and sorghum bran AX hemicellulose performed better as free radical scavengers. A reduction in free radical scavenging, as determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, occurred for sorghum bagasse and sorghum biomass AX hemicellulose at higher polysaccharide concentrations, which was either caused by the solution properties of the AX hemicelluloses or DPPH reaction reversibility in the presence of phenolic compounds with methoxy content. Alternatively, H2O2 scavenging by the AX hemicellulose revealed a dose-dependent response. Although scavenging effect was reduced at higher concentrations, sorghum bagasse AX hemicellulose functioned as having the best antioxidant capacity with respect to total reducing capability.

Ferulic acid production from brewery spent grains, an agro-industrial waste

This research aims at the utilization of an agro-industrial waste, the brewery spent grains (BSG) for the extraction of a natural antioxidant, the ferulic acid. Brewery spent grain was initially treated with dilute sulfuric acid, and then subjected to alkaline hydrolysis using NaOH, prior to ferulic acid extraction and purification. X-ray diffraction analysis of the raw and hydrolyzed BSG showed the evidence for a possible release of phenolic extractives. The effect of extraction time (100, 120 and 140 min), temperature (60, 90, and 120 °C), and alkali concentration (1, 2 and 3% (w/v) on the ferulic acid yield was optimized by the Box Behnken Design, using Response Surface Methodology. Accordingly, the experimental ferulic acid yield obtained at optimized conditions (90 min, 120 °C and 2% (w/v) NaOH concentration) was determined to be 46.17 mg/100 g BSG. The total phenolic, flavonoid, protein and reducing sugar content of ferulic acid extract were measured. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Fourier Transform Infrared Spectroscopy (FT-IR) and High-Performance Liquid Chromatography (HPLC) analysis confirmed the presence of ferulic acid. Results of this present research provides an alternative insight into the waste management of BSG through ferulic acid extraction.