Phenolic Compounds Research Articles

Sustainability‐driven optimization of microwave‐assisted extraction for enhanced corilagin and total phenolic compound yield from Dimocarpus longan

AbstractThe longan fruit, widely grown and consumed in Southeast Asia, contains an abundance of essential natural chemicals present in its flesh and seeds. The microwave‐assisted approach is used to extract these components, which include total phenolic compound and corilagin. The optimization of the extraction process included factors such as the sample ratio (0.5–1.5 g/30 mL), time (10–20 min), and microwave power (600–700 W). These variables were examined using the response surface approach. The statistical analysis revealed that the data was most accurately represented by a quadratic polynomial equation. The decision coefficients for total phenolic compounds and corilagin were found to be 0.9956 and 0.9485, respectively, indicating a high level of accuracy. The result was that the optimal conditions to obtain the highest total phenolic compound and corilagin from longan extract are 22.214 mgGAE/gDW and 55.137 mg/gDW, respectively. The sample was extracted under a ratio of 0.97 g/30 mL set at microwave power at 695.74 W, with an extraction time of 15 min. This study suggests that microwave‐assisted, water‐based extraction can produce healthful, eco‐friendly concentrated longan extracts, yielding high levels of corilagin and phenolic compounds.

Effect of formaldehyde exposure on phytochemical content and functional activity of Agaricus bisporus (Lge.) Sing.

In this study, the effect of formaldehyde on phytochemical content and antioxidant activity of Agaricus bisporus was investigated. Synthetic compost based on wheat straw was prepared by fermentation and disinfection. After steam pasteurization, 5 g of A. bisporus mycelia were inoculated into 1 kg of compost. To determine the effects of formaldehyde, 2, 4, and 6% concentrations were added to the composts, while compost without formaldehyde was used for the control group. The harvesting period was set at 10 weeks. Total phenolic and flavonoid content, macro- and microelement profile, and phenolic content were analyzed in the harvested A. bisporus samples. Macro- and microelement content was determined by ICP-OES, and phenolic compound profile was determined by LC-MS/MS analysis. Formaldehyde levels in A. bisporus samples were determined by the acetylacetone spectrophotometry method. The antioxidant capacity of A. bisporus samples was determined by DPPH scavenging activity; antimutagenic effects of samples were determined by Allium test. Application of 2, 4, and 6% formaldehyde resulted in a 1.12-, 1.19-, and 2.07-fold reduction in total phenolic content, respectively. The total phenolic content was reduced between 34.4% and 71.8%. These changes were confirmed by LC-MS/MS analysis. Compounds such as protocatechuic acid, salicylic acid, ferulic acid, and 4-OH benzoic acid, which were detected in the control group, could not be detected in the samples treated with 6% formaldehyde, and it was found that the application of formaldehyde reduced the phenolic content. Similar changes were also observed in macro- and microelements, and significant changes in elemental contents were observed after formaldehyde application. While the presence of formaldehyde at a low level, which may be due to natural production, was detected in the control group, a residue of 11.41 ± 0.93 mg/kg was determined in the 6% FMD applied group. All these changes resulted in a decrease in the antioxidant activity of A. bisporus. The DPPH scavenging activity, which was determined in the range of 21.6-73.3% in the control samples, decreased to 12.3-56.7% in the samples treated with formaldehyde. These results indicate that the application of formaldehyde at different stages of A. bisporus cultivation leads to significant changes in the nutritional value and biological activity of A. bisporus.

Microwave-assisted extraction of Tiliacora triandra leaves for functional ice cream production

Ice cream is widely enjoyed by consumers of all ages, but its high sugar and fat content may have adverse effects on health. This research aims to develop a functional form of ice cream by incorporating Tiliacora triandra leaves, which are rich in antioxidants. The substances from the leaves were extracted using high-power microwaves at 600 W for 30 sec, repeated three times. These extracts were then incorporated into the ice cream recipe, which utilized skim milk powder instead of fresh milk and stevia syrup instead of sugar. The antioxidant activity was assessed using DPPH and ABTS assays, while the total phenolic compounds were measured using the Folin-Ciocalteu assay. The findings indicated that ice cream supplemented with the extract at a 20% leaf ratio (T20) exhibited the highest antioxidant activity against DPPH and ABTS, with values of 54.30 ± 1.42% and 73.83 ± 1.90%, respectively. Additionally, the highest total phenolic compounds content was observed at 3.48 ± 0.10 mg GAE/g sample. The addition of T. triandra leaf extract resulted in a significantly darker green color and a firmer texture. However, the ice cream’s ability to resist melting showed slight change. Sensory assessment revealed that ice cream enhanced with 5% (T5) and 10% leaf ratios (T10) of the extract received higher scores for taste, color, odor, and overall acceptance compared to T20, and showed no difference from the control (T0). These finding suggest that T10 could serve as a viable alternative for health-conscious consumers seeking functional ice cream options.

Development and validation of a UHPLC-ESI-MS/MS method for the simultaneous determination of organic acids and phenolic compounds in Filipendula vulgaris, Polygonum divaricatum, Hypericum linarioides, and Rheum ribes

This research focused on investigating biologically active and pharmaceutically important phytochemicals using reliable and reproducible analytical techniques specifically designed for traditional medicinal plants. Considering the complex chemical diversity present in plant extracts, reliable identification methods are crucial. The goal of this study was to develop and validate a robust UHPLC-ESI-MS/MS method for the qualitative and quantitative analysis of organic acids (OAs) and phenolic compounds (PCs). With gradient elution of water containing 0.1 % formic acid and acetonitrile containing 0.1 % formic acid as the mobile phase, OAs and PCs were separated chromatographically on a C18 reversed-phase column. Through the use of an electrospray ionization source operating in negative ionization mode, these compounds were identified on a triple quadrupole tandem mass spectrometer. The validation results clearly indicate that the method exhibited linearity with a squared correlation coefficient (R2 ≥ 0.9986), demonstrating sensitivity (LOQ: 1.08 µg/L-10.79 µg/L), precision (RSD%≤2.73), and trueness (RE% ≤ 1.53) for the OAs and PCs found in the plants. The developed UHPLC-ESI-MS/MS method was successfully applied to the qualitative and quantitative analysis of OAs and PCs in Turkish plants, which are commonly used in traditional medicine. Our study identified a total of 12 OAs and PCs in F. vulgaris, 12 in P. divaricatum, 9 in H. linarioides, and 11 in R. ribes. In particular, gallic acid had the highest content in F. vulgaris (925.67 µg/g extract) and R. ribes (1358.78 µg/g extract), while H. linarioides (730.66 µg/g extract) and P. divaricatum (4003.02 µg/g extract) had relatively high levels of quinic acid. In conclusion, the developed UHPLC-ESI-MS/MS method allows the simultaneous analysis and quantification of 2 OAs and 33 PCs in plants and proves to be a valuable tool for evaluating the efficacy of traditional medicinal plants.

Potentially functional lactose-free ice cream with Lacticaseibacillus casei CSL3, ginger, and honey.

To develop and characterize a functional lactose-free ice cream with added ginger and honey, evaluate the survival of Lacticaseibacillus casei CSL3 under frozen storage and the simulated gastrointestinal tract (GIT), as well as antioxidant activity and product acceptability. The survival of Lacticaseibacillus casei CSL3 was evaluated for 180 days, under frozen storage, and GIT at 60 days. At 15 days of storage, proximal composition, antioxidant activity, color, pH, acidity, fusion, density, overrun, and sensory analysis were performed. Ice cream was an effective food matrix for maintaining the viability of CSL3, with concentrations > 7 log CFU g- 1 during storage and GIT. In addition, the analysis showed overrun and prebiotic characteristics through high values of antioxidant activity and phenolic compounds, good acceptability, and purchase intention. The product has satisfactory market potential (acceptance rate of 95.19% and purchase intention rate > 96%), and it could become another means of inserting probiotics in food.

Supplementation with soluble or insoluble rice-bran fibers increases short-chain fatty acid producing bacteria in the gut microbiota in vitro

IntroductionStudies have shown that a diet high in fiber and prebiotics has a positive impact on human health due largely to the fermentation of these compounds by the gut microbiota. One underutilized source of fiber may be rice bran, a waste product of rice processing that is used most frequently as an additive to livestock feed but may be a good source of fibers and other phenolic compounds as a human diet supplement. Previous studies focused on specific compounds extracted from rice bran showed that soluble fibers extracted from rice bran can improve glucose response and reduce weight gain in mouse models. However, less is known about changes in the human gut microbiota in response to regular rice bran consumption.MethodsIn this study, we used a Simulator of the Human Intestinal Microbial Ecology (SHIME®) to cultivate the human gut microbiota of 3 different donors in conditions containing either soluble or insoluble fiber fractions from rice bran. Using 16S rRNA amplicon sequencing and targeted metabolomics via Gas Chromatography-Mass Spectrometry, we explored how gut microbial communities developed provided different supplemental fiber sources.ResultsWe found that insoluble and soluble fiber fractions increased short-chain fatty acid production, indicating that both fractions were fermented. However, there were differences in response between donors, for example the gut microbiota from donor 1 increased acetic acid production with both fiber types compared with control; whereas for donors 2 and 3, butanoic acid production increased with ISF and SF supplementation. Both soluble and insoluble rice bran fractions increased the abundance of Bifidobacterium and Lachnospiraceae taxa.DiscussionOverall, analysis of the effect of soluble and insoluble rice bran fractions on the human in vitro gut microbiota and the metabolites produced revealed individually variant responses to these prebiotics.

Unlocking the potential of spent coffee grounds via a comprehensive biorefinery approach: production of microbial oil and carotenoids under fed-batch fermentation.

The valorization of renewable feedstock to produce a plethora of value-added products could promote the transition towards a circular bioeconomy. This study presents the development of cascade processes to bioconvert spent coffee grounds (SCGs) into microbial oil and carotenoids employing sustainable practices. The stepwise recovery of crude phenolic extract and coffee oil was carried out using green or recyclable solvents, i.e., aqueous ethanol and hexane. Palmitic acid (43.3%) and linoleic acid (38.9%) were the major fatty acids in the oil fraction of SCGs. The LC-MS analysis of crude phenolic extracts revealed that chlorogenic acid dominated (45.7%), while neochlorogenic acid was also detected in substantial amounts (24.0%). SCGs free of coffee oil and phenolic compounds were subjected to microwave-assisted pretreatment under different irradiations and solvents to enhance subsequent enzymatic saccharification. Microwave/water pretreatment at 400 W, followed by enzymatic hydrolysis with proteases, hemicellulases, and cellulases, at 50g/L initial SCGs, led to satisfying overall yields of cellulose (75.4%), hemicellulose (50.3%), and holocellulose (55.3%). Mannan was the most extractable polysaccharide followed by galactan and arabinan. SCGs hydrolysate was used in fed-batch bioreactor fermentations with Rhodosporidium toruloides to produce 24.0g/L microbial oil and carotenoids of 432.9μg/g biomass.

Protective effects of rosmarinic acid against autistic-like behaviors in a mouse model of maternal separation stress: behavioral and molecular amendments.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with worldwide increasing incidence. Maternal separation (MS) stress at the beginning of life with its own neuroendocrine changes can provide the basis for development of ASD. Rosmarinic acid (RA) is a phenolic compound with a protective effect in neurodegenerative diseases. The aim of this study was to determine the effect of RA on autistic-like behaviors in maternally separated mice focusing on its possible effects on neuroimmune response and nitrite levels in the hippocampus. In this study, 40 mice were randomly divided into five groups of control (received normal saline (1 ml/kg)) and MS that were treated with normal saline (1 ml/kg) or doses of 1, 2, and 4 mg/kg RA, respectively, for 14 days. Three-chamber sociability, shuttle box, and marble burying tests were used to investigate autistic-like behaviors. Nitrite level and gene expression of inflammatory cytokines including TNF-α, IL-1β, TLR4, and iNOS were assessed in the hippocampus. The results showed that RA significantly increased the social preference and social novelty indexes, as well as attenuated impaired passive avoidance memory and the occurrence of repetitive and obsessive behaviors in the MS mice. RA reduced the nitrite level and gene expression of inflammatory cytokines in the hippocampus. RA, probably via attenuation of the nitrite level as well as of the neuroimmune response in the hippocampus, mitigated autistic-like behaviors in maternally separated mice.

Optimization studies on laccase activity of Proteus mirabilis isolated from treatment sludge of textile industry factories : Optimization of laccase activity of Proteus mirabilis.

Laccase is an exothermic enzyme with copper in its structure and has an important role in biodegradation by providing oxidation of phenolic compounds and aromatic amines and decomposing lignin. The aim of this study is to reach maximum laccase enzyme activity with minimum cost and energy through optimization studies of Proteusmirabilis isolated from treatment sludge of a textile factory. In order to increase the laccase enzyme activities of the isolates, medium and culture conditions were optimized with the study of carbon (Glucose, Fructose, Sodium Acetate, Carboxymethylcellulose, Xylose) and nitrogen sources (Potassium nitrate, Yeast Extract, Peptone From Soybean, Bacteriological Peptone), incubation time, pH, temperature and Copper(II) sulfate concentration then according to the results obtained. Response Surface Method (RSM) was performed on six different variables with three level. According to the data obtained from the RSM, the maximum laccase enzyme activity is reached at pH 7.77, temperature 30.03oC, 0.5g/L CuSO4, 0.5g/L fructose and 0.082g/L yeast extract conditions. After all, the laccase activity increased 2.7 times. As a result, laccase activity of P. mirabilis can be increased by optimization studies. The information obtained as a result of the literature studies is that the laccase enzymes produced in laboratory and industrial scale are costly and their amounts are low. This study is important in terms of obtaining more laccase activity from P.mirabilis with less cost and energy.

Cornus mas L. Extract-Mediated Modulations of the Redox State Induce Cytotoxicity in Schizosaccharomyces pombe

The Cornus mas L. fruit is well known for having a high presence of bioactive substances that include phenolic compounds, anthocyanins, vitamins, flavonoids, carotenoids, and ursolic acid. The health-promoting effects of those substances are mainly associated with their antimicrobial, anti-inflammatory, and antioxidant properties. In this study, we investigated the role of Cornus mas L. fruit ethanolic extract on the cell vitality of a model eukaryotic organism, the yeast Schizosaccharomyces pombe. The effect of Cornus mas L. fruit ethanolic extract on cell viability was determined by analyses of cell growth and cell doubling time during exposure to the extract. To determine the ability of Cornus mas L. to reduce or induce oxidative stress, quantification of intracellular reactive oxygen species and malondialdehyde levels was performed. Additionally, the enzyme activity of superoxide dismutase and catalase was evaluated together with the determination of changes in the expression of genes related to oxidative stress response. The data suggest a dose-dependent cytotoxic effect of the Cornus mas L. fruit ethanol extract, as a higher concentration (2%) led to increased oxidative stress and reduced cell viability of S. pombe cells, while a lower concentration (0.5%) showed only a subtle effect on the analyzed parameters. This study provides a new perspective on the possible antimicrobial or medicinal properties of Cornus mas L. fruit ethanol extract due to its ability to induce oxidative stress in the cell.

Identification, structure elucidation, and isomer differentiation of phenolic compounds of Chinese pepper cultivars by UPLC-ESI-Q-TOF-MS and their antioxidant activity.

A total of 43 compounds, including phenolic acids, flavonoids, lignans, and diterpene, were identified and characterized using UPLC-ESI-Q-TOF-MS coupled with UNIFI software. The identified flavonoids were mostly isomers of luteolin, apigenin, and quercetin, which were elucidated and distinguished for the first time in pepper cultivars. The use of multivariate data analytics for sample discrimination revealed that luteolin derivatives played the most important role in differentiating pepper cultivars. The content of phenolic acids and flavonoids in immature green peppers was generally higher than that of mature red peppers. The pepper extracts possessed significant antioxidant activities, and the antioxidant activities correlated well with phenolic contents and their molecular structure. In conclusion, the findings expand our understanding of the phytochemical components of the Chinese pepper genotype at two maturity stages. Moreover, a UPLC-ESI-Q-TOF-MS in negative ionization mode rapid methods for characterization and isomers differentiation was described.

Can the galling mite Eriophyes tiliae alter the phenolic profile and antioxidant capacity of Tilia platyphyllos in a high UV radiation environment?

AbstractLeaves of large‐leaved lime, Tilia platyphyllos Scop. (Malvaceae), harbor colonies of Eriophyes tiliae (Pagenstecher) (Acari: Eriophyidae), capable of modifying the leaf structure (inducer of nail‐galls) and physiology. The aerial organs of T. platyphyllos have traditionally been consumed for their high antioxidant capacity, related to the rich polyphenol profile. Here, we investigated the polyphenol profiles and antioxidant activity of T. platyphyllos non‐galled leaves and galls to determine the changes induced by the mite in a Chilean environment with high ultraviolet (UV) radiation. Phenolic compound identification in the methanol extracts of non‐galled leaves and galls was carried out through HPLC. Furthermore, the antioxidant activity of the extracts was quantified through spectrophotometry, and it was compared with the standards of the three major phenolic compounds of both organs. Nine phenolic compounds were detected in non‐galled leaves and galls, with no differences between the two organs, except for the absence of gallic acid in galls. The concentration of phenolic compounds did differ significantly between the two conditions. In leaf galls, epicatechin and cyanidin‐3‐glucoside concentrations and antioxidant capacity increased significantly compared to non‐galled leaves. As chlorogenic acid and cyanidin‐3‐glucoside are active phenols responding to UV radiation stress, their concentration in T. platyphyllos leaves could be a response to the high UV radiation occurring in Chile during spring and summer. The phenolic compounds detected here have been reported to be potent antioxidants, that are probably potentiated by E. tiliae for its own protection against UV‐B radiation, as the two most abundant compounds in the galls exhibited the highest capacity to reduce ABTS and DPPH radicals. However, we do not rule out the participation of phenolics in protection against natural enemies of the gall mite, as chlorogenic acid and epicatechin are powerful antifeedants.

Experimental consideration of the effects of calcium lignosulfonate and tannic acid on the flammability and thermal properties of polylactide composites

The purpose of this study was to determine the quantitative and qualitative effects of the form of natural phenolic compounds (NPCs) on the decomposition of polylactide (PLA) under different measurement conditions. For this purpose, thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), and pyrolysis-combustion flow calorimetry (PCFC) analyses were carried out not only on individual raw materials like calcium lignosulfonate (BX), tannic acid (TA), BX chemically modified with TA (BMT), but also on PLA/BX, PLA/TA, and PLA/BMT composites with 3, 6, and 9 wt.% of filler. Moreover, the work checked whether to obtain satisfactory results it is necessary to carry out chemical modification lasting many hours, or whether simple physical mixing of ingredients (TABX) is enough, e.g. in proportions 1:2, 2:4, 3:6. The results of these analyses showed that TA is neither a good flame retardant nor a highly swelling material, but when combined with BX physically or chemically, it can produce an interesting synergistic effect. This work proves that chemically obtained BMT hybrid material allows to reduce flammability by 30 % compared to PLA which cannot be achieved by physically mixing these components in a polymer melt. On the other hand, the addition of TABX is sufficient to achieve a good thermal stabilization effect under processing conditions.

Evaluation of Anti-Inflammatory Activity in Methanolic Seed Extracts of International Sorghum bicolor L. Resources

Sorghum is an important cereal with high value as a health food ingredient because it contains various phenolic compounds. Anti-inflammatory activity was assessed using 12 sorghum resources collected from various countries to explore their potential as medicinal resources. The findings revealed that, at extract concentrations of 25 µg/mL and 50 µg/mL, cell survival rates were observed to be between 70 and 80% for most varieties, with the exception of K159081. In the analysis of anti-inflammatory activity, measured by the rate of nitric oxide (NO) production, sorghum varieties K159041 and K159081 exhibited NO production rates of 0.46 ± 0.38% and 2.58 ± 0.20%, respectively, indicating significant anti-inflammatory properties. The investigation into anti-inflammatory effects also included examining the expression of the inducible nitric oxide synthase (iNOS) gene, which is related to the inflammatory response triggered by LPS in macrophages. Varieties K159041, K159048, K159077, K159078, K159081, K159089, and K159096 were analyzed for this purpose. Further, an expression test of the cyclooxygenase 2 (COX-2) gene revealed values less than 0.4 in K159077, K159081, and K159089, suggesting these sorghum lines possess higher anti-inflammatory activity compared to others. Additionally, the expression analysis of tumor necrosis factor alpha (TNF-α), a gene identified as an inflammatory cytokine, showed that the mRNA levels in the lines K159048, K159077, K159078, K159088, K159089, K159093, and K159096 were expressed at lower levels relative to other sorghum resources, categorizing them as having high anti-inflammatory activity. Notably, the K159081 line exhibited the lowest expression level of all genes associated with inflammation, marking it as a valuable medicinal resource with potential development as an anti-inflammatory agent.

Enhancing the Extraction of Phenolic Antioxidants from Amazonian Assai (Euterpe oleracea Martius) Fruit Waste through Response Surface Methodology Optimization

Assai (Euterpe oleracea Martius) is a superfruit widely consumed in several countries, mainly produced in the Amazon region. The significant growth of the market for this fruit has raised environmental concerns regarding the disposal of production waste, especially the seeds that are not utilized and represent approximately 80% of the fruit. In the present study, strategies were developed for transforming these seed wastes into new products, using green solvents for extraction under conditions conducive to technology transfer and with feasible quality control through simple bench techniques, which represents an ideal approach for establishing a truly sustainable process. A significant interaction between solvent and extraction method was observed, impacting both yields and total phenols. Phenolic compounds are substances known for their health benefits, functioning as antioxidants and consequently aiding in disease prevention. The phenolic content observed in the extractions increased from 22.68% to 44.74% under optimal conditions during extraction via hot maceration (50 °C) in 100% ethanol for 2 h, which also enhanced yield and increased antioxidant capacity. The extracts displayed remarkable free radical scavenging activities (IC50 = 6.54 μg/mL in ABTS and IC50 = 14.71 μg/mL in DPPH), approaching the Trolox and quercetin standards, respectively. The optimized method paved the way for the industrial-scale utilization of the residues of this valuable Amazonian fruit.

Encapsulation of W/O/W Acerola Emulsion by Spray Drying: Optimization, Release Kinetics, and Storage Stability

Acerola (Malpighia emarginata DC.) is a sub-tropical and tropical fruit renowned for its high levels of vitamin C and phenolic compounds, which offer health benefits. This study aimed to optimize the spray drying process by determining the inlet and outlet temperatures using response surface methodology (RSM) with the central composite design. Additionally, it aimed to evaluate the release kinetics in the hydrophilic food simulation environment and the stability of the resulting powder under various storage temperatures. The RSM method determined the optimal inlet and outlet temperatures as 157 °C and 91 °C, respectively. High-accuracy prediction equations (R2 ≥ 0.88) were developed for moisture content (3.02%), process yield (91.15%), and the encapsulation yield of total polyphenol content (61.44%), total flavonoid content (37.42%), and vitamin C (27.19%), with a predicted monolayer moisture content below 4.01%, according to the BET equation. The powder exhibited good dissolution characteristics in the acidic hydrophilic food simulation environment and showed greater stability when stored at 10 °C for 30 days, compared to storage at 35 °C and 45 °C.

Maximizing the value of liquid products and minimizing carbon loss in hydrothermal processing of biomass: an evolution from carbonization to humification

Hydrothermal carbonization (HTC) converts wet biomass into hydrochar and a process liquid, but aromatic compounds in the products have been reported as a roadblock for soil applications as they can inhibit germination, plant growth, and soil microbial activity. Here, we compared HTC and hydrothermal humification (HTH) of cow manure digestate while varying the initial alkaline content by adding KOH. HTH converted 37.5 wt% of the feedstock to artificial humic acids (A-HAs) found in both solid and liquid, twice that of HTC. HTH reduced phenolic and furanic aromatic compounds by over 70% in solids and 90% in liquids. The A-HAs in HTH resemble natural humic acids (N-HA), based on FTIR, UV–vis spectra, and CHN and XRD analysis. The HTH liquid possesses 60% higher total organic carbon (TOC) than HTC. Although one-third of TOC can be precipitated as A-HA, a high TOC concentration remains in the liquid, which is shown to be mainly organic acids. Therefore, we also evaluated the HTC and HTH liquids for anaerobic biomethane production, and found that compared to the original cow manure digestate, the HTH liquids increased methane yield by 110.3 to 158.6%, a significant enhancement relative to the 17.2% increase seen with HTC liquid. The strong reduction in organic acids during biogas production from HTH liquid indicates the potential for converting soluble byproducts into methane, while maintaining high A-HAs levels in the solid product.Graphical

A novel green reducing agent for the synthesis of chromium oxide nanoparticles (Cr2O3 NPs) based on saffron by-products: Characterization and antioxidant activity

The production of nanomaterials using safe, biological and environmentally friendly methods is attracting increasing attention. In the present study, aqueous extracts of Moroccan saffron (Crocus sativus L) by-products were used for the first time as a green stabilizer and reductant agent to synthesize chromium oxide nanoparticles (Cr2O3NPs). The aqueous extract of saffron by-products was analyzed for phytochemical screening, while the green synthesized Cr2O3NPs were analyzed using high-resolution scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antioxidant activity of Cr2O3NPs, aqueous chromium nitrate solution (Cr (NO3)), and aqueous extract of saffron by-products have been also investigated using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) method. The results showed that the aqueous extract of saffron by-products used for the synthesis of Cr2O3NPs appeared to be rich in phenolic (2.32 mg GA / g dry weight), flavonoid (2.28 mg RE / g dry weight), and anthocyanin compounds (33.67 mg Delphinidin / L extract). The XRD analysis confirmed that the Cr2O3NPs have a particle size of 31 nm with a hexagonal crystal structure. SEM micrographs of Cr2O3NPs showed a homogenous distribution and spherical shape, while the EDX spectrum confirmed that Cr2O3NPs contain significant amount of Chromium (61,90 %), and oxygen atoms (36,55 %). Moreover, the presence of absorption bands characteristic of the alcohol group (3451 cm−1) and the aromatic rings (1639 cm−1) in the infrared spectrum of Cr2O3NPs, indicates that the secondary metabolites of the saffron plant were successfully active in reducing chromium ions to Cr2O3NPs. Besides, the antioxidant activity results showed that the biosynthesized Cr2O3NPs exhibited strong inhibition percentages (63 %) compared to the aqueous extract of saffron by-products (74 %), and the aqueous solution of chromium nitrate (30 %) at 1,30 mg/mL. The study suggests that saffron by-products extract can be used as a natural reducing agent in the synthesis of Cr2O3NPs. Furthermore, the environmentally friendly synthesis process for Cr2O3NPs and their antioxidant effect make them suitable for use in various fields.

Sustainable Utilization of Food Biowaste (Papaya Peel) Extract for Gold Nanoparticle Biosynthesis and Investigation of Its Multi-Functional Potentials

Papaya contains high amounts of vitamins A, C, riboflavin, thiamine, niacin, ascorbic acid, potassium, and carotenoids. It is confirmed by several studies that all food waste parts such as the fruit peels, seeds, and leaves of papaya are potential sources of phenolic compounds, particularly in the peel. Considering the presence of numerous bioactive compounds in papaya fruit peels, the current study reports a rapid, cheap, and environmentally friendly method for the production of gold nanoparticles (AuNPs) employing food biowaste (vegetable papaya peel extract (VPPE)) and investigated its antioxidant, antidiabetic, tyrosinase inhibition, anti-inflammatory, antibacterial, and photocatalytic degradation potentials. The phytochemical analysis gave positive results for tannins, saponins, steroids, cardiac steroidal glycoside, protein, and carbohydrates. The manufactured VPPE-AuNPs were studied by UV–Vis scan (with surface plasmon resonance of 552 nm), X-ray diffraction analysis (XRD) (with average crystallite size of 44.41 nm as per the Scherrer equation), scanning electron microscopy–energy-dispersive X-ray (SEM-EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), particle size, zeta potential, etc. The mean dimension of the manufactured VPPE-AuNPs is 112.2 d.nm (PDI—0.149) with a −26.1 mV zeta potential. The VPPE-AuNPs displayed a significant antioxidant effect (93.24% DPPH scavenging and 74.23% SOD inhibition at 100 µg/mL); moderate tyrosinase effect (with 30.76%); and substantial α-glucosidase (95.63%) and α-amylase effect (50.66%) at 100 µg/mL. Additionally, it was found to be very proficient in the removal of harmful methyl orange and methylene blue dyes with degradation of 34.70% at 3 h and 24.39% at 5 h, respectively. Taken altogether, the VPPE-AuNPs have been proven to possess multiple biopotential activities, which can be explored by the food, cosmetics, and biomedical industries.

Study of the phenolic compounds of the leaves and flowers of Anacyclus pyrethrum using HPLC-UV/SM and evaluation of their antioxidant, antibacterial, and antifungal activities

Study of the phenolic compounds of the leaves and flowers of Anacyclus pyrethrum using HPLC-UV/SM and evaluation of their antioxidant, antibacterial, and antifungal activities