Effect of the Harvest Season of Anthyllis henoniana Stems on Antioxidant and Antimicrobial Activities: Phytochemical Profiling of Their Ethyl Acetate Extracts.

Anthyllis henoniana stems were harvested in two seasons: winter and spring (February and May 2021). In this study, we investigated the antioxidant (DPPH, ABTS, FRAP and TAC) and antimicrobial activities, total phenolic contents and total flavonoid contents of the obtained extracts (hexane, ethyl acetate and methanol). The results showed that ethyl acetate extract from stems harvested in winter exhibited the highest antioxidant activity, while ethyl acetate extract from the stems harvested in spring showed the most potent antibacterial and antifungal activities. To explain these differences, we investigated the phytochemical composition of these two extracts using liquid chromatography coupled with mass spectrometry. Therefore, 45 compounds were detected, from which we identified 20 compounds (flavonoids, triterpenoids, chalcones and phenolic acids); some were specific to the harvest month while others were common for both periods. Some of the major compounds detected in ethyl acetate (spring) were dihydrochalcone (Kanzonol Y, 8.2%) and flavanone (sophoraflavanone G, 5.9%), previously recognized for their antimicrobial effects. We therefore concluded that the difference in activities observed for the two harvest periods depends on the chemical composition of the extracts and the relative abundance of each compound.

Chemical Composition and In Vitro Antioxidant and Antimicrobial Activities of the Marine Cyanolichen Lichina pygmaea Volatile Compounds.

Volatile compounds from the marine cyanolichen Lichina pygmaea, collected from the Moroccan Atlantic coast, were extracted by hydrodistillation and their putative chemical composition was investigated by gas chromatography coupled to mass spectrometry (GC/MS). Based on the obtained results, Lichina pygmaea volatile compounds (LPVCs) were mainly dominated by sesquiterpenes compounds, where γ-himachalene, ß-himachalene, (2E,4E)-2,4 decadienal and α-himachalene were assumed to be the most abundant constituents, with percentage of 37.51%, 11.71%, 8.59% and 7.62%, respectively. LPVCs depicted significant antimicrobial activity against all tested strains (Staphylococcus aureus CCMM B3, Pseudomonas aeruginosa DSM 50090, Escherichia coli ATCC 8739 and Candida albicans CCMM-L4) with minimum inhibitory concentration (MIC) values within the range of 1.69-13.5 mg/mL. Moreover, this LPVC showed interesting scavenging effects on the 2,2-diphenyl-1-picrylhydrazyl radical with an IC50 of 0.21 mg/mL. LPVCs could be an approving resource with moderate antimicrobial potential and interesting antioxidant activity for cosmetics and pharmaceutical applications.

New insight into antimicrobial activities of Linaria ventricosa essential oil and its synergetic effect with conventional antibiotics.

The purpose of the present study was to determine for the first time the volatile constituents, the antioxidant and antimicrobial activities of the essential oil (EO) of the endemic Moroccan Linaria ventricosa, alone or in combination with four known antibiotics. The major constituents were 2-methoxy-4-vinylphenol (17.4%), α-terpinene (13.64%) and 3,5-dimethylphenyl isocyanate (12.21%). The EO had moderate antioxidant potency, as measured by DPPH free radical scavenging (1.233 ± 0.031 mg/mL), ferric reducing antioxidant power assay (0.373 ± 0.019 mg/mL) and ß-carotene/linoleic acid (0.922 ± 0.026 mg/mL). EO showed microbicidal activity against all microorganisms tested. The highest effectiveness was recorded against Candida albicans (IZ = 24 mm, MIC = 4.87 mg/mL and MMC = 9.75 mg/mL) and Candida glabrata (IZ = 22 mm, MIC = MMC = 4.87 mg/mL). Gram negative bacteria were the most resistant (MIC = MMC = 39 mg/mL). The combination of EO at sub-inhibitory concentrations with antibiotics showed a significant decrease in their individual MICs from 2 to 128 fold, being the best for ciprofloxacin and fluconazole against E. coli and C. albicans and C. glabrata, respectively.

Sources for developing new medicinal products: biochemical investigations on alcoholic extracts obtained from aerial parts of some Romanian Amaryllidaceae species.

BACKGROUND: Although Galanthus nivalis L. (snowdrop) is known for the galanthamine content, used in the treatment of Alzheimer disease, the polyphenolic compounds of Amaryllidaceae species are less studied. Proper understanding of the polyphenolics in these extracts and of their antioxidant and antimicrobial properties may allow a reconsideration of their medicinal uses. METHODS: The polyphenolic content of four selected Amaryllidaceae species harvested from Romania (Galanthus nivalis L., Narcissus pseudonarcissus L., N. poeticus L. and Leucojum vernum L.) was determined by spectrophotometric methods; the identification of phenolic compounds was performed by a HPLC-MS method, in order to establish their polyphenolic fingerprints. For the evaluation of the antioxidant potential the following methods were employed: DPPH radical scavenging, FRAP, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c, and electron paramagnetic resonance (EPR) spectroscopy assays. Antimicrobial activity was assessed using the disc diffusion method. RESULTS: Qualitative and quantitative analyses highlight important amount of polyphenols (over 15 mg/g); the main identified compounds are chlorogenic and p-coumaric acids in all species. Only G. nivalis shows antioxidant activity by all the used methods. G. nivalis and L. vernum strongly inhibits the growth of S. aureus, while N. poeticus shows a very good antifungal activity. CONCLUSIONS: The results of this study provide a new approach to the properties and therapeutic uses of some Romanian widespread Amaryllidaceae species that could be considered sources of developing new medicinal products with anti anti-staphylococcal and antifungal activity.

A new acylated flavone glycoside, in vitro antioxidant and antimicrobial activities from Saudi Diospyros mespiliformis Hochst. ex A. DC (Ebenaceae) leaves.

Phytochemical investigation of Diospyros mespiliformis leaves resulted in the isolation of new acylated flavone isoscutellarein 7-O-(4'''-O-acetyl)-ß-allopyranosyl(1''' â†’ 2'')-ß-glucopyranoside (1), along with eight known flavonoid metabolites, luteolin 3',4',6,8-tetramethyl ether (2), luteolin 4'-O-ß-neohesperidoside (3), luteolin 7-O-ß-glucoside (4), luteolin (5), quercetin (6), quercetin 3-O-ß-glucoside (7), quercetin 3-O-α-rhamnoside (8), and rutin (9). Their structures were identified by analysis of spectroscopic (UV, NMR, and MS) data, as well as by acid hydrolysis for the isolated glycosides. The antioxidant activity of D. mespiliformis metabolites was determined by the DPPH radical-scavenging assay. The new acylated flavone (1) and flavonol O-rhamnoside (8) displayed the highest antioxidant activities with IC50 values 15.46 and 12.32 µg/mL, respectively, with respect to the antioxidant ascorbic acid (IC50 value 10.62 µg/mL). In addition, the isolated flavonoids were evaluated against four human pathogenic bacteria where the methylated flavone (2) exhibited potent activity against Escherichia coli with inhibition zone 34 mm, and mild activity of flavonol O-rhamnoside (8) against Staphylococcus aureus with MIC value 9.77 µg/mL. According to the MBC/MIC ratio, the antibacterial activity of the isolated flavonoids was considered flavonoid 2 is bactericidal nature against S. aureus, and flavonoids 3 and 4 are bactericidal against E. coli.

Response surface methodology-optimized extraction of flavonoids with antioxidant and antimicrobial activities from the exocarp of three genera of coconut and characterization by HPLC-IT-TOF-MS/MS.

Response surface methodology optimization based on central composite design was applied to extract flavonoids from the exocarp of three coconut genera. The antioxidant and antimicrobial activities and structures of the flavonoids were determined. The results indicated that the optimal extraction conditions were ethanol concentration, 60%; temperature, 50 ℃; time, 90 min; liquid/material ratio, 40 mL/g; ultrasonic power, 150 W. Under these conditions, the yields of green, red and yellow coconut exocarp were 366.03 ± 7.57, 596.38 ± 10.32, and 403.78 ± 5.56 mg rutin/g powder, respectively. The flavonoids exhibited eminent DPPH and ABTS radical scavenging activities with IC50 values of 0.01-0.02 mg/mL. At a concentration of 2 mg/mL, they exhibited antimicrobial activity against Vibrio parahaemolyticus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa. In total, 17 flavonoids and 5 phenolic acids were characterized by UPLC-IT-TOF-MS/MS; among them, catechin, kaempferol, and quercetin were abundant. Yellow coconut had a distinct flavonoid spectrogram from other genera and contained more methoxy flavonoids.

Citrus By-Products: Valuable Source of Bioactive Compounds for Food Applications.

Citrus production produces about 15 million tons of by-products/waste worldwide every year. Due to their high content of bioactive compounds, several extraction techniques can be applied to obtain extracts rich in valuable compounds and further application into food applications. Distillation and solvent extraction continues to be the most used and applied extraction techniques, followed by newer techniques such as microwave-assisted extraction and pulsed electric field extraction. Although the composition of these extracts and essential oils directly depends on the edaphoclimatic conditions to which the fruit/plant was exposed, the main active compounds are D-limonene, carotenoids, and carbohydrates. Pectin, one of the most abundant carbohydrates present in Citrus peels, can be used as a biodegradable polymer to develop new food packaging, and the extracted bioactive compounds can be easily added directly or indirectly to foods to increase their shelf-life. One of the applications is their incorporation in active food packaging for microbiological and/or oxidation inhibition, prolonging foods' shelf-life and, consequently, contributing to reducing food spoilage. This review highlights some of the most used and effective extraction techniques and the application of the obtained essential oils and extracts directly or indirectly (through active packaging) to foods.

Hydrolysis of Edible Oils by Fungal Lipases: An Effective Tool to Produce Bioactive Extracts with Antioxidant and Antimicrobial Potential.

Hydrolysis of olive, rapeseed, linseed, almond, peanut, grape seed and menhaden oils was performed with commercial lipases of Aspergillus niger, Rhizopus oryzae, Rhizopus niveus, Rhizomucor miehei and Candida rugosa. In chromogenic plate tests, olive, rapeseed, peanut and linseed oils degraded well even after 2 h of incubation, and the R. miehei, A. niger and R. oryzae lipases exhibited the highest overall action against the oils. Gas chromatography analysis of vegetable oils hydrolyzed by R. miehei lipase revealed about 1.1 to 38.4-fold increases in the concentrations of palmitic, stearic, oleic, linoleic and α-linolenic acids after the treatment, depending on the fatty acids and the oil. The major polyunsaturated fatty acids produced by R. miehei lipase treatment from menhaden oil were linoleic, α-linolenic, hexadecanedioic, eicosapentaenoic, docosapentaenoic and docosahexaenoic acids, with yields from 12.02 to 52.85 µg/mL reaction mixture. Folin-Ciocalteu and ferric reducing power assays demonstrated improved antioxidant capacity for most tested oils after the lipase treatment in relation to the concentrations of some fatty acids. Some lipase-treated and untreated samples of oils, at 1.25 mg/mL lipid concentration, inhibited the growth of food-contaminating bacteria. The lipid mixtures obtained can be reliable sources of extractable fatty acids with health benefits.

Development of pullulan/carboxylated cellulose nanocrystal/tea polyphenol bionanocomposite films for active food packaging.

In this study, novel active films based on pullulan and carboxylated cellulose nanocrystal (C-CNC) incorporated with tea polyphenol (TP) was prepared by solution casting method. The effect of TP addition on the microstructural, mechanical, barrier, optical, functional properties of the resultant pullulan/C-CNC/TP (PC-TP) bionanocomposite films was systematically evaluated. Scanning electron microscopy showed that an appropriate TP adding was well distributed within the PC-TP bionanocomposite matrix. Fourier-transform infrared further revealed that new hydrogen bond was formed among the pullulan, C-CNC, TP. Addition of TP at an appropriate level (3%, w/w, on a dry basis of the weight of pullulan and C-CNC) led to stronger intermolecular interactions and more compact microstructure, and thus enhanced the water barrier properties, thermal stability and tensile strength of the resultant bionanocomposite films. Nevertheless, overloading of TP in the bionanocomposite films might produce some aggregations and thus have negative effects on their performance. In addition, the incorporation of TP significantly improved the UV-barrier properties, antioxidant activity and antimicrobial activity of PC-TP bionanocomposite films, while induced a decrease in the transmittance. These results revealed that PC-TP bionanocomposite films with TP at appropriate levels had potential to be used as active food packaging.

Physicochemical Properties and Shelf-Life of Regular-Fat Sausages with Various Levels of Grape Tomato Powder Prepared by Different Drying Methods.

This study was aimed to investigate the physicochemical properties, texture, and antioxidant, and antimicrobial activities of regular-fat sausages (RFSs) mixed with 0.25 and 0.5% of oven-dried and freeze-dried grape tomato powder (GTP, 150 µm) during storage at 4°C. RFSs were made by six treatments that included: control (CTL), REF (sausages with 0.1% ascorbic acid alone), F1GTPSs (F1) and F2GTPSs (F2) (sausages with 0.25% and 0.5% freeze-dried GTP), and O1GTPSs (O1) and O2GTPSs (O2) (sausages with 0.25% and 0.5% GTP oven-dried at 100°C). Sausages with added oven-dried grape tomato powders (OGTPs) showed decreased pH, lightness (L*), total plate count (TPC), and thiobarbituric acid-reactive substances (TBARS) compared to the sausages mixed with freeze-dried GTP (FGTPSs), but also had the highest redness (a*) and yellowness (b*) values among the treatments. With increasing levels of GTP, the hardness and chewiness of the sausages gradually decreased and these were decreased more in the FGTPSs (F) than in the OGTPSs (O). Compared to the FGTPSs, OGTPSs had higher antioxidant and antimicrobial activities, which extend the shelf-life of meat products. Application of OGTP to RFSs resulted in higher lipid antioxidant, antimicrobial activities, improving physicochemical properties and extended the shelf-life.

Improvement of oxidative stability and textural properties of fermented sausage via addition of pistachio hull extract.

The purpose of this study was to evaluate the effectiveness of pistachio hull extract (PHE) as an antioxidant and antimicrobial agent for preservation of dry fermented sausages during fermentation and storage period. Sausages were prepared using starter culture (Biobak K) and treated with three levels of PHE (500, 750 and 1,000 ppm). The results showed that PHE at concentrations of 500 ppm and 750 ppm decreased significantly (p < .05) the TBARS content of the sausage samples compared to control (without PHE). Moreover, PHE increased L* and a* value of samples during fermentation period but did not affect the color of samples during storage period. The PHE was also able to improve the chewiness and gumminess of the fermented sausage. Evaluation of microbial properties (total viable count, yeast and molds, lactic acid bacteria, staphylococci and Enterobacteriaceae) also showed that antimicrobial activity of PHE in fermented sausage.

Stress associated protein from Lobularia maritima: Heterologous expression, antioxidant and antimicrobial activities with its preservative effect against Listeria monocytogenes inoculated in beef meat.

Stress associated Protein from Lobularia maritima (LmSAP) transcripts showed up-regulation in response to wounding, Methyl-jasmonate acid, Picolinic acid, and ethephon treatments. The antioxidant activities of the purified LmSAP protein were evaluated using various in vitro and in vivo assays. LmSAP has an excellent DPPH scavenging ability and exhibits notable reducing power capacity and led to a decrease in TBARS values. The LmSAP showed an important antimicrobial activity against different pathogenic strains tested. In fact, the Inhibition Zone (IZ), Minimal Inhibitory Concentration (MIC) and The Minimum Bactericidal Concentration (MCB) recorded were in the range of 14-22 mm, 62-250 µg/ml and 125-250 µg/ml, respectively. The LmSAP protein successfully inhibited the growth of L. monocytogenes in minced beef meat. Furthermore, the LmSAP enhanced the sensory acceptability extending the shelf life of minced beef meat. Overall, the finding demonstrates that the application of LmSAP may open new promising opportunities for the prevention of bacterial contamination, particularly L. monocytogenes, during minced beef meat storage.

Synergistic effect of polysaccharides, betalain pigment and phenolic compounds of red prickly pear (Opuntia stricta) in the stabilization of salami.

The aim of this work is to try to substitute some synthetic additives by a natural extract from red prickly pear (Opuntia stricta) which known by its richness on bioactive polysaccharides mainly consisting of galactose, rhamnose and galacturonic acid. This natural fruit has a high content of carbohydrates above 18.81% FM. It contains also a high level of polyphenols 152.25 ±â€¯0.26 µg QE/mg PPE and flavonoids about 370.60 ±â€¯0.12 µg GAE/mg of PPE. In addition, prickly pear extract (PPE) displayed a strong antioxidant and antimicrobial activities. These activities are likely due to its phenolic, flavonoid and carbohydrate contents. Moreover, the addition of 2.5% of PPE, as a natural colorant and antimicrobial agent in salami formulation, causes a decrease in hardness and chewiness of the formulated salami. Interestingly, PPE inhibited bacterial growth in salami stored at 4 °C over 30 days. Sensorial analysis shows that the color, taste and texture of salami prepared with 2.5% of PPE are markedly more appreciated by panelists. Our results suggest that the betalain pigment, carbohydrate and phenolic compounds present in PPE could be used as a natural colorant, antioxidant and antimicrobial agent without change of the sensory characteristics.

Nutritional constituents, phytochemical profiles, in vitro antioxidant and antimicrobial properties, and gas chromatography-mass spectrometry analysis of various solvent extracts from grape seeds (Vitis vinifera L.).

The present study revealed that the nutritive value of grape seeds (Vitis vinifera L.) was 383.55±0.13 Kcal/100 g, with magnesium as the most abundant mineral element (70.44±0.88 mg/L). The maximum phenolic (392.58±1.70mg of GAE/g), flavonoid (256.16±1.60 mg of QE/g), and tannin (30.95±0.17mg of CE/g) contents were also found in the ethanol, dichloromethane, and hexane extracts, respectively. The major phytochemical compounds in the ethyl acetate extract were identified via gas chromatography-mass spectrometry (GC-MS) analysis. The ethanol extract has the highest antioxidant activity (IC50=140±1.20 µg/mL for DPPH, 145.28±0.45mg α-tocopherol/g for total antioxidant capacity, and EC50=80±1.41 µg/mL for ferric-reducing power assays). For ß-carotene test, the highest antioxidant activity was obtained in the hexane extract. A satisfactory antimicrobial activity was found against a panel of microorganisms with the ethyl acetate extract as the best antimicrobial agent. Additionally, it was found that the bactericidal concentration required for the grape seed extract to kill Listeria monocytogenes should be less than 12.50 mg/mL (minimum inhibitory concentration=4).

Chitin extraction from crab shells by Bacillus bacteria. Biological activities of fermented crab supernatants.

Crab shells waste were fermented using six protease-producing Bacillus species (Bacillus subtilis A26, Bacillus mojavensis A21, Bacillus pumilus A1, Bacillus amyloliquefaciens An6, Bacillus licheniformis NH1 and Bacillus cereus BG1) for the production of chitin and fermented-crab supernatants (FCSs). In medium containing only crab shells, the highest demineralization DM was obtained with B. licheniformis NH1 (83±0.5%) and B. pumilus A1 (80±0.6%), while the highest deproteinization (DP) was achieved with A1 (94±1%) followed by NH1 (90±1.5%) strains. Cultures conducted in medium containing crab shells waste supplemented with 5% (w/v) glucose, were found to remarkably promote demineralization efficiency, and enhance slightly deproteinization rates. FTIR spectra of chitins showed the characteristics bands of α-chitin. FCSs showed varying degrees of antioxidant activities which were in a dose-dependent manner (p<0.01). In fact, FCS produced by B. amyloliquefaciens An6 exhibited the highest DPPH free radical-scavenging activity (92% at 4 mg/ml), while the lowest hydroxyl radical-scavenging activity (60% at 4 mg/ml) was obtained with B. subtilis A26 hydrolysates. However, the highest reducing power (OD700nm=2 at 0.5 mg/ml) was obtained by B.amyloliquefaciens An6 hydrolysates. These results suggest that crab hydrolysates are good sources of natural antioxidants. Further, FCSs were found to exhibit antibacterial activity against Gram-positive and Gram-negative bacteria.

New screw lactam and two new carbohydrate derivatives from the methanol extract of rice bran.

A new screw lactam and two new carbohydrate derivatives, oryzalactam (1), oryzasaccharide A (2), and oryzasaccharide B (3), have been isolated from the methanol extract of rice bran together with four other known compounds, including momilactone A (4), butyl ß-d-xylopyranose (5), ethyl ß-d-xylopyranose (6), and methyl ß-d-xylopyranose (7). The structures of these compounds were determined using a combination of spectroscopic methods and chemical analysis. This work represents the first recorded example of the isolation of compounds 1, 2, 3, 5, 6, and 7 from rice bran. The antioxidant experiments revealed that compound 1 possessed strong ABTS(+) (ABTS = 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)) and DPPH (DPPH = diphenyl(2,4,6-trinitrophenyl) iminoazanium) radical scavenging with IC50 values of 33.38 ± 1.58 and 40.20 ± 1.34 µM, respectively. Antimicrobial assays revealed that compound 4 showed high levels of selectivity toward Escherichia coli with a minimal inhibitory concentration value of 5 µM.