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Oak bark, which is commonly used in the wood industry, has by-products often repurposed as fuel. Its extracts are rich in compounds with anticancer, antibacterial, antifungal, and anti-inflammatory properties. This study synthesized platinum nanoparticles (PtNPs) using aqueous extracts from Quercus dalechampii (QD), Q. frainetto (QF), and Q. petraea (QP). Key factors during nanoparticle formation included reaction time, metal ion concentration, pH, extract-to-metal ion ratio, and temperature. The PtNPs were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, and transmission electron microscopy. The average diameters were 58.5 ± 7.6 nm for QD-PtNPs, 41.6 ± 5.4 nm for QF-PtNPs, and 41 ± 5.3 nm for QP-PtNPs. Antioxidant and antimicrobial activities were also analyzed. The QP-PtNPs had the highest DPPH (2,2-Diphenyl- 1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), and CUPRAC (Cupric Reducing Antioxidant Capacity) free radical scavenging activities, while QD-PtNPs excelled in ABTS (2,2'-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid)) scavenging. All PtNPs showed strong antimicrobial properties, particularly against Enterococcus faecalis, Escherichia coli, Candida krusei, and Candida auris. These findings suggest that Quercus-mediated PtNPs have significant potential for developing treatments against bacterial and fungal infections, with promising applications in medicine. [ABSTRACT FROM AUTHOR]

Ensuring food safety and protecting consumers are major aspects for commercialized products. Honey, the most prominent in the class of bee products, requires special regulations due to its origin as a natural product. Mislabeling, imitation, and adulteration represent a source of risks for human health. Specific determinations and analyses are essential for controlling the sector and preventing unfair competition. To compare and establish the correct labeling of several different honeys, melissopalynological, physicochemical, mineral content, and microbiological analyses were carried out on 18 samples commercially available in different countries, namely Türkiye, Romania, Bulgaria, and Northern Cyprus. The honey labels were in accordance with the determined pollen content. The physiochemical parameters showed high variability: 4.07–5.25 (pH), 79.95–83.45 (°Brix), 0.262–1.452 µS/cm (electrical conductivity), and 14.6–18.4% (moisture). The samples were quantitatively high in K, P, Na, and Ca, with the highest cumulative mineral content being found for honeys containing Fagaceae pollen. Additionally, the antimicrobial potential of the various honey samples was evaluated against selected bacteria, employing the disk diffusion and serial dilution methods. Results revealed that the honey samples exhibited increased antibacterial activity against Gram-negative bacteria, with notable activity against S. typhimurium, and moderate activity against Gram-positive S. aureus. [ABSTRACT FROM AUTHOR]

Quercus species are utilized for their durable wood, providing sustenance for wildlife, conserving biodiversity, and contributing ecological, medicinal, and esthetic benefits to ecosystems and landscapes. In this study, we aimed to use the bark of three Quercus species (Q. dalechampi, Q. fraineto, and Q. petraea) for the synthesis of silver and gold nanoparticles (AgNPs and AuNPs). The aqueous extracts from the bark of Quercus sp. acted both as reducing and stabilizing agent, facilitating the rapid synthesis of AuNPs (AuQD, AuQF, and AuQP) and AgNPs (AgQD, AgQF, and AgQP). The obtained nanoparticles were characterized using UV-vis spectroscopy, TEM, DLS, and FTIR. Characterizations revealed that the nanoparticles exhibited a variety of shapes, such as polygonal, triangular, and spherical forms, with sizes ranging between 14 and 24 nm for AuNPs and 45–70 nm for AgNPs. The total phenolic content was assessed through spectroscopic methods, while several individual phenolic compounds were identified and quantified using UPLC-PDA. Furthermore, we assessed the antioxidant, antibacterial, and antifungal capacities of AuNPs, AgNPs, and raw extracts. The highest antioxidant activity was observed for raw extracts, followed by AgNPs and AuNPs, while the most potent antibacterial and antifungal activity was observed in AgQP. Moreover, cytotoxicity was examined in a human keratinocyte cell line (HaCaT). The results indicated no cytotoxic effects for AuNPs, while AgNPs and the raw extracts exhibited cytotoxic effects after 48 h of incubation. This research underscores the multifaceted utility of Quercus bark extracts in the green synthesis of metallic nanoparticles and their subsequent bioactivity assessment, suggesting promising perspectives for their application in various fields while urging cautious consideration of their cytotoxic implications. [ABSTRACT FROM AUTHOR]

Polyphenols were extracted from Thuja occidentalis L. bark and characterized in terms of phytochemical composition and biological activity. The optimization process investigated the impacts of extraction duration, ultrasound amplitude, and ethanol concentration on the total phenolic content in the extract. The antioxidant capacity was examined using DPPH and ABTS assays, and anti-enzyme activity against alphaglucosidase, alpha-amylase, lipase, acetylcholinesterase, and tyrosinase was determined. The experimental model revealed optimal extraction parameters: a hydroethanolic solvent with 44% v:v ethanol, a 15-minute extraction time, and a 40% ultrasound amplitude. These parameters were validated and confirmed by reaching the target Total Phenolic Content (TPC) predicted by MODDE software. The resulting lyophilized extract exhibited a high polyphenolic content (161.84 ± 23.48 mg GAE/g dry extract) and demonstrated strong antioxidant properties. Notably, it showed significant inhibition of alpha-glucosidase and alpha-amylase, suggesting potential antidiabetic effects, though its inhibition of tyrosinase activity was relatively weak. These findings provide a foundation for further investigations to confirm the qualitative and quantitative presence of specific polyphenolic metabolites in the extract and elucidate the mechanisms underlying its bioactive properties. [ABSTRACT FROM AUTHOR]

Recent studies highlight the great potential of the plants from the Quercus genus to comprise high contents of bioactive compounds with beneficial effects on human health. The aim of our work is to screen the potential biological effects of the bark of two oak species, namely Quercus petraea and Q. pubescens.The vegetal material was extracted using two different solvents (water and ethanol solution) and extraction methods, namely ultrasonic assisted extraction (UAE) and microwave assisted extraction (MAE). The total polyphenolic and tannin contents were quantified using the Folin-Ciocâlteu method. The antioxidant capacity of the extracts was tested using two complementary methods based on the 1,1-diphenyl-2-picrylhydrazyl -- DPPH and 2,2'-azino-bis(3- ethylbenzothiazoline)-6-sulfonic acid -- ABTS reagents. The antimicrobial activity was evaluated on five different bacterial strains (Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) and three fungi from the Candida genus (C. albicans, C. parapsilosis, C. krusei). Moreover, three enzymes were tested to evaluate the potential inhibitory effects of the extracts (α-glucosidase, tyrosinase and acetylcholinesterase). Higher total polyphenols and tannin yields were observed in the extracts obtained by MAE, compared to the UAE bark extracts. Also, the ethanolic solution was the better solvent for the extraction of bioactive compounds. Antioxidant activities were highlighted for all the tested extracts. A better antibacterial activity was observed against the Gram positive bacterial strains and Klebsiella pneumoniae, extracts from the bark of Quercus petraea being more efficient. The antifungal activity was highlighted against C. krusei. The tested extracts inhibited the activity of α-glucosidase, tyrosinase and acetylcholinesterase. These results highlight biological effects of the bioactive compounds found in the oak bark, that may be used in future pharmaceutical formulations, due to their beneficial effects on human health. [ABSTRACT FROM AUTHOR]

Rose cultivars represent a source with potential for therapeutical applications due to the high content in bioactive phytochemicals, including phenolic derivatives and lipophilic compounds, such as carotenoids. Anthocyanins, a phenolic subclass, represent the major compounds responsible for the colors of roses. In this study, we have aimed to extract, separate, and identify the anthocyanin compounds found in the petals of 25 different rose cultivars. High performance liquid chromatography followed by electrospray ionization mass spectrometry (HPLC-ESI-MS) was used to separate, identify and quantify the individual anthocyanins. The results showed the presence of 9 anthocyanin compounds, whereas the total anthocyanin content of rose cultivars ranged from 20.267-1206.841 mg/100 g FW, from which cyanidin-caffeoyl-glucoside was the most quantitatively represented anthocianin, followed by cyanidin-glucoside and pelargonidin-glucoside. In addition to this, the antioxidant activity was applied using the established DPPH in vitro method (1403 ± 301- 304 ± 37 μmol TE/g FW), as well as the total phenolic content (2600±452-208±23 mg GAE/100 g FW) and the total flavonoid content (160±23-705±49 mg QE/100 g FW). Among the evaluated cultivars, the highest content in anthocyanin was determined for the ‘Amalia’ cultivar. Between the 25 rose cultivars analyzed, the varieties ‘Amalia’, ‘Foc de tabără’, ‘Fruhrot’, and ‘First Red’ followed as being the richest in anthocyanins content and the lowest values were recorded for the varieties ‘Jimini Cricket’, ‘Cri-Cri’, ‘Fortuna’, and ‘Zburlici’. The same trend was observed for the total phenolic and total flavonoid content but also the antioxidant activity. The importance of analyzing anthocyanin content in different rose varieties came from the use of anthocyanins as natural dyes, having potential pharmaceutical ingredients that give various beneficial health effects. [ABSTRACT FROM AUTHOR]

The present study aimed, on the one hand, to improve the yield of microwave assisted extraction (MAE) of polyphenols from beech bark by using a design of experiments (DoE) approach. On the other hand, beech bark extracts (BBE) were characterized in terms of their phytochemical profile and evaluated for biological potential (antioxidant, antibacterial, antifungal, antimutagen, anti-α-glucosidase, and anti-tyrosinase). The extraction time varies with the amount of extracted total phenolic content (TPC). The microwave power favors TPC extraction but in different proportions. The optimum conditions which gave the highest TPC (76.57 mg GAE/g dry plant material) were reached when the microwave power was 300 W, extraction time was 4 min, and the solvent was an ethanol–water (50:50) mixture. The practical value of TPC after a controlled experiment was 76.49 mg GAE/g plant material. The identified compounds were vanillic acid, gallic acid, epicatechin, catechin, protocatechuic acid, chlorogenic acid, ferulic acid, and isoquercitrin. The antioxidant potential of BBEs was demonstrated by in vitro experiments. The BBEs were active against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli, and Candida species. All extracts were antimutagenic and expressed an inhibition on α-glucosidase and tyrosinase activity. Regarding antimutagen activity, the assayed extracts may be considered to have low or no antimutagen effects. [ABSTRACT FROM AUTHOR]