Phenolic Secondary Metabolites and Antiradical and Antibacterial Activities of Different Extracts of Usnea barbata (L.) Weber ex F.H.Wigg from Calimani Mountains, Romania.

Phenolic compounds represent an essential bioactive metabolites group with numerous pharmaceutical applications. Our study aims to identify and quantify phenolic constituents of various liquid and dry extracts of Usnea barbata (L.) Weber ex F.H. Wigg (U. barbata) from Calimani Mountains, Romania, and investigate their bioactivities. The extracts in acetone, 96% ethanol, and water with the same dried lichen/solvent ratio (w/v) were obtained through two conventional techniques: maceration (mUBA, mUBE, and mUBW) and Soxhlet extraction (dUBA, dUBE, and dUBW). High-performance liquid chromatography with diode-array detection (HPLC-DAD) was performed for usnic acid (UA) and different polyphenols quantification. Then, the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity (AA) were determined through spectrophotometric methods. Using the disc diffusion method (DDM), the antibacterial activity was evaluated against Gram-positive and Gram-negative bacteria known for their pathogenicity: Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 13883). All extracts contain phenolic compounds expressed as TPC values. Five lichen extracts display various UA contents; this significant metabolite was not detected in dUBW. Six polyphenols from the standards mixture were quantified only in ethanol and water extracts; mUBE has all individual polyphenols, while dUBE shows only two. Three polyphenols were detected in mUBW, but none was found in dUBW. All U. barbata extracts had antiradical activity; however, only ethanol and acetone extracts proved inhibitory activity against P. aeruginosa, S. pneumoniae, and S. aureus. In contrast, K. pneumoniae was strongly resistant (IZD = 0). Data analysis evidenced a high positive correlation between the phenolic constituents and bioactivities of each U. barbata extract. Associating these extracts' properties with both conventional techniques used for their preparation revealed the extraction conditions' significant influence on lichen extracts metabolites profiling, with a powerful impact on their pharmacological potential.

Fermentation of soymilk by Lactobacillus acidipiscis isolated from Chinese stinky tofu capable of efficiently biotransforming isoflavone glucosides to dihydrodaidzein and dihydrogenistein.

BACKGROUND: The soy isoflavone microbial metabolites dihydrodaidzein (DHD), dihydrogenistein (DHG), equol and 5-hydroxy-equol are generally more biologically active than their precursors daidzein and genistein. Bacteria responsible for isoflavone metabolism have been isolated and identified. Fermented soymilk is a potential functional food; however, there are few lactic acid bacteria capable of metabolizing soy isoflavones. RESULTS: A newly isolated Gram-positive facultative anaerobic bacterium, which was named Lactobacillus acidipiscis HAU-FR7, was isolated from the traditional Chinese fermented soy product 'stinky tofu'. Bacterium strain HAU-FR7 can grow under aerobic conditions and can also convert most of the daidzin and genistin in soymilk into DHD and DHG, respectively. The concentrations of DHD and DHG produced were 183 and 134 µmol L-1 , respectively, after fermentation for 24 h. Strain HAU-FR7 does not produce the biogenic amines cadaverine, putrescine, histamine or tyramine, and an antibiotic susceptibility test showed that HAU-FR7 is sensitive to nine of the ten tested antibiotics, except for vancomycin. Moreover, the 1,1-diphenyl-2- picrylhydrazyl free radical scavenging capacity of soymilk fermented with HAU-FR7 was significantly higher than that of unfermented soymilk. CONCLUSION: A facultative anaerobic lactic acid bacterium, designated Lactobacillus acidipiscis HAU-FR7, is capable of reducing the soy isoflavone glucosides daidzin and genistin in soymilk to DHD and DHG efficiently, even in the presence of atmospheric oxygen. The biotransformation activity of HAU-FR7 grown in soymilk is higher than that in de Man-Rogosa-Sharpe liquid culture medium. © 2022 Society of Chemical Industry.

Research on the antioxidant activity of metabolites from a sponge-derived fungus Alternaria sp. F49 / 药学学报

To study the chemical constituents from the the deep-sea fungus Alternaria sp. F49. Seven compounds were isolated from the EtOAc extract by using silica gel, Sephadex LH-20, ODS and HPLC methods. Based on the spectroscopic analysis, their structures were identified as (8R)-5-O-methyl-orcinotriol (1), orcinotriol (2), α-acetylorcinol (3), 3'-hydroxyalternariol 5-O-methyl ether (4), altenusiol (5), altenusin (6), and 5'-methoxy-6-methyl-biphenyl-3,4,3'-triol (7). (8R)-5-O-Methyl-orcinotriol (1) is a new phenolic compound which has never been reported in the literature. Compounds 4-7 showed strong DPPH free radical scavenging activity; whereas compounds 1-7 showed strong ABTS free radical scavenging activity.

Physicochemical properties and enzymatic activity of wheat germ extract microencapsulated with spray and freeze drying.

Wheat germ is produced as a by-product during wheat milling operations and is a relatively inexpensive protein source that, in spite of its exclusive nutritional properties, is mostly used for animal feed formulation and has limited use in the food industry. In this study, wheat germ extract (WGE) was microencapsulated by spray and freeze drying and with different ratios of maltodextrin to whey protein concentrate (M-W) as the coating material and then physicochemical properties of the microcapsules were evaluated. Results showed decreased moisture content and increased solubility, lipase activity, acid phosphatase activity, and both lipase and acid phosphatase microencapsulation efficiency with increasing M-W ratios in both drying methods. The M-W ratios had no significant effects on the DPPH free radical scavenging activity in both methods. With increasing M-W ratios, particle size decreased and bulk density increased in the spray drying method, while particle size increased and bulk density decreased in the freeze drying method. Spray drying elevated solubility, DPPH free radical scavenging activity, lipase activity, acid phosphatase activity, and both lipase and acid phosphatase microencapsulation efficiency, in comparison with the freeze drying method.

Quality Evaluation of Brown Rice Sulgidduk Containing Acorn Powder

This study examined the quality characteristics of brown rice Sulgidduk containing acorn powder and the optimal mixing rate (0%, 5%, 10%, and 15%). The moisture contents of brown rice Sulgidduk increased with increasing amount of acorn powder. The DPPH free radical scavenging activities (16.15%~28.06%) and ABTS free radical scavenging activities (22.98%~42.81%) of the brown rice Sulgidduk increased with increasing acorn powder content. The L value of the Hunter's color value decreased with increasing amount of acorn powder. The hardness and chewiness of brown rice Sulgidduk increased with increasing amount of acorn powder. The brown rice Sulgidduk containing 10% acorn powder showed the highest score with regard to the sensory characteristics. These results suggest that the most desirable amount of acorn powder is 10% and the addition of acorn powder could contribute positively toward the quality characteristics of brown rice Sulgidduk.

Exploiting fruit byproducts for eco-friendly nanosynthesis: Citrus × clementina peel extract mediated fabrication of silver nanoparticles with high efficacy against microbial pathogens and rat glial tumor C6 cells.

Process byproducts from the fruit industry may represent a cheap and reliable source of green reducing agents to be used in current bio-nanosynthesis. This study reports the use of orange (Citrus × clementina) peel aqueous extract (OPE) for one-pot green synthesis of silver nanoparticles (AgNPs) with high effectiveness against various microbial pathogens as well as rat glial tumor C6 cells. The effects of various operational parameters on the synthesis of AgNPs were systematically investigated. The morphology, particle size, and properties of synthesized AgNPs were characterized using UV-visible spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, and Fourier transform infrared spectroscopy. High-resolution transmission electron microscopy shows that the nanoparticles are mostly spherical in shape and monodispersed, with an average particle size of 15-20 nm. Notably, the OPE-synthesized AgNPs were stable up to 6 months without change in their properties. Low doses of OPE-AgNPs inhibited the growth of human pathogens Escherichia coli, Bacillus cereus, and Staphylococcus aureus. The minimum inhibitory concentration and minimum bactericidal concentration of AgNPs against selected pathogenic bacteria were determined. OPE-AgNPs exhibited strong antioxidant activity in terms of ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging (IC50 49.6 µg/mL) and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging (IC50 63.4 µg/mL). OPE-AgNPs showed dose-dependent response against rat glial tumor C6 cells (LD50 60 µg/mL) showing a promising potential as anticancer agents. Overall, the current investigation highlighted a cheap green technology route to synthesize AgNPs using OPE byproducts and could potentially be utilized in biomedical, cosmetic, and pharmaceutical industry.

Acylphenols and dimeric acylphenols from Myristica maxima Warb.

Giganteone E (1), a new dimeric acylphenol was isolated as a minor constituent from the bark of Myristica maxima Warb. The structure of 1 was established on the basis of 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Malabaricones A-C (2-4), giganteones A and C (5 and 6), maingayones A and B (7 and 8), maingayic acid B (9) and ß-sitosteryl oleate (10) were also characterized in this plant for the first time. Compound 10 was identified for the first time in the Myristicaceae. Compounds 2 and 5 were active against human prostate cancer cell-lines, thus making this the first report on the prostate cancer inhibiting potential of acylphenols and dimeric acylphenols. Compounds 1, 4, 5, 7 and 8 exhibited potent DPPH free radical scavenging activity. This is the first report on their free radical scavenging capacity.

Optimization protocol for the extraction of antioxidant components from Origanum vulgare leaves using response surface methodology.

In the present work, the response surface methodology (RSM) based on a central composite rotatable design (CCRD), was used to determine optimum conditions for the extraction of antioxidant compounds from Origanum vulgare leaves. Four process variables were evaluated at three levels (31 experimental designs): methanol (70%, 80%, and 90%), the solute:solvent ratio (1:5, 1:12.5, 1:20), the extraction time (4, 10, 16 h), and the solute particle size (20, 65, 110 micron). Using RSM, a quadratic polynomial equation was obtained by multiple regression analysis for predicting optimization of the extraction protocol. Analysis of variance (ANOVA) was applied and the significant effect of the factors and their interactions were tested at 95% confidence interval. The antioxidant extract (AE) yield was significantly influenced by solvent composition, solute to solvent ratio, and time. The maximum AE was obtained at methanol (70%), liquid solid ratio (20), time (16 h), and particle size (20 micron). Predicted values thus obtained were closer to the experimental value indicating suitability of the model. Run 25 (methanol:water 70:30; solute:solvent 1:20; extraction time 16 h and solute particle size 20) showed highest TP contents (18.75 mg/g of dry material, measured as gallic acid equivalents) and DPPH radical scavenging activity (IC50 5.04 µg/mL). Results of the present study indicated good correlation between TP contents and DPPH radical scavenging activity. Results of the study indicated that phenolic compounds are powerful scavengers of free radical as demonstrated by a good correlation between TP contents and DPPH radical scavenging activity.

Determination of DPPH free radical scavenging activity: application of artificial neural networks.

A new computational approach for the determination of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) in food is reported, based on the concept of machine learning. Trolox standard was mix with DPPH at different concentrations to produce different colors from purple to yellow. Artificial neural network (ANN) was trained on a typical set of images of the DPPH radical reacting with different levels of Trolox. This allowed the neural network to classify future images of any sample into the correct class of RSA level. The ANN was then able to determine the DPPH-RSA of cinnamon, clove, mung bean, red bean, red rice, brown rice, black rice and tea extract and the results were compared with data obtained using a spectrophotometer. The application of ANN correlated well to the spectrophotometric classical procedure and thus do not require the use of spectrophotometer, and it could be used to obtain semi-quantitative results of DPPH-RSA.

Screening of Antioxidant Active Components of Schisandra chinensis / 中国药房

OBJECTIVE:To screen antioxidant active components of Schisandra chinensis. METHODS:The orthogonal test was adopted to optimize extraction technology using DPPH free radical scavenging activity(IC50)as index and ethanol volume frac-tion,material-liquid ratio and extraction time as factors,and the verification test were made. The fractions(SC-0,SC-10,SC-30, SC-50,SC-70,SC-95) were made by extracting and purifying S. chinensis with macroporous resin with water and 10%,30%, 50%,70%and 95%ethanol. With IC50 and total antioxidant capacity(determined by ABTS method)as indexes(vitamin C as pos-itive control),the antioxidant active components of S. chinensis were optimized. The contents of 5 kinds of lignan in different posi-tions of S. chinensis were determined by HPLC. RESULTS:The optimal extraction condition of S. chinensis was as follows as 60% ethanol,material-liquid ratio of 1∶14,extracting for 2.0 h. The average IC50 of DPPH free radical scavenging activity was 23.81 mg/ml(RSD=0.52%,n=3)in verification test. SC-0 did not have antioxidant abilities. DPPH free radical scavenging activi-ty of those components (ie. the IC50 value from low to high) were in the following order of positive control>SC-50>SC-30>SC-95>SC-70>SC-10;total antioxidant ability of them were in the following order of SC-50>positive control>SC-30>SC-70>SC-95>SC-10;the contents of 5 types of lignan in different components were in the following order of SC-70>SC-50>SC-95>SC-30. CONCLUSIONS:The antioxidant active component of S. chinensis is 50%ethanol eluate.

Acylated flavonol glycosides from the flower of Elaeagnus angustifolia L.

Seven acylated flavonol glycosides named elaeagnosides A-G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the abilities of these flavonoids to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and to inhibit tyrosinase activity were evaluated. Results revealed that two of these compounds had significant anti-oxidant effect and one compound showed weak tyrosinase-inhibitory activity compared with kojic acid, quercetin, or ascorbic acid, which were used as positive control.