Search Results (1,518)

The growing demand for food and the environmental impact of conventional agriculture have prompted the search for sustainable alternatives. Phycocyanin (PC) and total phenolic compounds (TPC) extracted from Spirulina platensis have shown potential for the biological control of phytopathogens. The extraction method directly influences the yield and stability of these compounds. This study aimed to establish an efficient extraction protocol for PC and TPC and to evaluate their antimicrobial efficacy in vitro against Colletotrichum orchidearum, Fusarium nirenbergiae, and Alternaria sp. isolated from hydroponically grown lettuce. The phytopathogens were identified based on phylogenetic analyses using sequences from the ITS, EF1-α, GAPDH, and RPB2 gene regions. This is the first report of C. orchidearum in hydroponic lettuce culture in Brazil, expanding its known host range. Extracts were obtained using hydroalcoholic solvents and phosphate buffer (PB), combined with ultrasound-assisted extraction (bath and probe). The extracts were tested for in vitro antifungal activity. Data were analyzed by ANOVA (p < 0.05), followed by Tukey’s test. The combination of the PB and ultrasound probe resulted in the highest PC (95.6 mg·g⁻¹ biomass) and TPC (21.9 mg GAE·g⁻¹) yields, using 10% (w/v) biomass. After UV sterilization, the extract retained its PC and TPC content. The extract inhibited C. orchidearum by up to 53.52% after three days and F. nirenbergiae by 54.17% on the first day. However, it promoted the growth of Alternaria sp. These findings indicate that S. platensis extracts are a promising alternative for the biological control of C. orchidearum and F. nirenbergiae in hydroponic systems. Full article

Background/Objectives: Actinobacteria are one of the largest bacterial phyla. These microbes produce bioactive compounds, such as antifungals, antibiotics, immunological modulators, and anti-tumor agents. Studies on actinobacteria isolated from the Brazilian Savannah biome (Cerrado) are scarce and mostly address metagenomics or the search for hydrolytic enzyme-producing microbes. Solanum lycocarpum (lobeira) is a tree widely employed in regional gastronomy and pharmacopeia in Central Brazil. Methods: In this work, 60 actinobacteria isolates were purified from the rhizosphere of S. lycocarpum. Eight Streptomyces spp. isolates were selected for in vitro antifungal activity against Cryptococcus neoformans H99, the C. neoformans 89-610 fluconazole-tolerant strain, C. gattii NIH198, Candida albicans, C. glabrata, and C. parapsilosis. The ability of the aqueous extracts of the isolates to induce the in vitro secretion of tumor necrosis factor (TNF-α), nitric oxide (NO), interleukin-6 (IL-6), and IL-10 by murine macrophages was also evaluated. Results: All extracts showed antifungal activity against at least two yeast species. Streptomyces spp. LAP11, LDB2, and LDB17 inhibited C. neoformans growth by 40–93%. Most extracts (except LAP2) also inhibited C. gattii. None inhibited C. albicans, but all inhibited C. glabrata (40–90%). Streptomyces sp. LAP8 extract increased nitric oxide production by approximately 347-fold in murine macrophages, while LDB11 extract suppressed LPS-induced TNF-α production by 70% and simultaneously increased IL-10 secretion, suggesting immunosuppressive potential. Conclusions: The results revealed that Cerrado actinobacteria-derived aqueous extracts are potential sources of antifungal and immunomodulatory biocompounds. Full article

The most prevalent growth of Candida cells is based on biofilm development, which causes the intensification of antifungal resistance against a large range of chemicals. Nanoparticles can be synthesized using green methods via various biological extracts and reducing agents to control Candida biofilms. This study aims to compare copper oxide nanoparticles (CuONPs) synthesized through chemical methods and those synthesized using Cinnamomum verum-based green methods against Candida infections and their biofilms isolated from Iraqi patients, with the potential to improve treatment outcomes. The physical and chemical properties of these nanoparticles were characterized using Fourier-transform infrared spectroscopy (FT-IR,) scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Four strains of Candida were isolated and characterized from Iraqi patients in Tikrit Hospital and selected based on their ability to form biofilm on polystyrene microplates. The activity of green-synthesized CuONPs using cinnamon extract was compared with both undoped and doped (Fe, Sn) chemically synthesized CuONPs. Four pathogenic Candida strains (Candida glabrata, Candida lusitaniae, Candida albicans, and Candida tropicalis) were isolated from Iraqi patients, demonstrating high biofilm formation capabilities. Chemically and green-synthesized CuONPs from Cinnamomum verum showed comparable significant antiplanktonic and antibiofilm activities against all strains. Doped CuONPs with iron or tin demonstrated lower minimum inhibitory concentration (MIC) values, indicating stronger antibacterial activity, but exhibited weaker anti-adhesive properties compared to other nanoparticles. The antiadhesive activity revealed that C. albicans strain seems to produce the most resistant biofilms while C. glabrata strain seems to be more resistant towards the doped CuONPs. Moreover, C. tropicalis was the most sensitive to all the CuONPs. Remarkably, at a concentration of 100 µg/mL, all CuONPs were effective in eradicating preformed biofilms by 47–66%. The findings suggest that CuONPs could be effective in controlling biofilm formation by Candida species resistant to treatment in healthcare settings. Full article

In the context of the valorization of agri-food by-products, tomato (Solanum lycopersicum L.) seeds represent a protein-rich matrix containing potential bioactives. The aim of the present work is to develop a biochemical pipeline for (i) achieving high protein recovery from tomato seed, (ii) optimizing the hydrolysis with different proteases, and (iii) characterizing the resulting peptides. This approach was instrumental for obtaining and selecting the most promising peptide mixture to test for antifungal activity. To this purpose, proteins from an alkaline extraction were treated with bromelain, papain, and pancreatin, and the resulting hydrolysates were assessed for their protein/peptide profiles via SDS-PAGE, SEC-HPLC, and RP-HPLC. Bromelain hydrolysate was selected for antifungal tests due to its greater quantity of peptides, in a broader spectrum of molecular weights and polarity/hydrophobicity profiles, and higher DPPH radical scavenging activity, although all hydrolysates exhibited antioxidant properties. In vitro assays demonstrated that the bromelain-digested proteins inhibited the growth of Fusarium graminearum and F. oxysporum f.sp. lycopersici in a dose-dependent manner, with a greater effect at a concentration of 0.1 mg/mL. The findings highlight that the enzymatic hydrolysis of tomato seed protein represents a promising strategy for converting food by-products into bioactive agents with agronomic applications, supporting sustainable biotechnology and circular economy strategies. Full article

This research analyzes the innovative development of carnauba wax coatings enriched with essential oils (EOs: lemon, orange, grapefruit, clove, oregano, and cinnamon) or fruit by-products (FBPs: avocado, tomato, carrot, orange, lemon, and grapefruit) to improve postharvest preservation of organic oranges and lemons. Six EOs and six FBPs were evaluated for total phenolic content (TPC) and in vitro antifungal activity against Penicillium digitatum. Based on results, grapefruit, oregano, and clove EOs were selected for lemons, while avocado, orange, and grapefruit FBPs were selected for oranges. An in vivo test at 20 °C for 15 days with carnauba wax coatings assessed antifungal performance. Clove EO and avocado FBP showed strong in vitro inhibition and consistent hyphal suppression (~100 and ~82%, respectively). In vivo, coatings with grapefruit EO and avocado FBP significantly reduced fungal decay and sporulation (~75%) in lemons and oranges, respectively. Coated fruits also retained weight losses by ~25% compared to uncoated ones. These findings suggest that phenolic-rich natural extracts, especially from agro-industrial residues like avocado peels, offer a promising and sustainable strategy for postharvest citrus disease control. Further studies should test coating effectiveness in large-scale trials under refrigeration combined with other preservation strategies. Full article

Tuberaria lignosa (Sweet) Samp. (Cistaceae) is a herbaceous species native to southwestern Europe, traditionally used to treat wounds, ulcers, and inflammatory or infectious skin conditions. This study aimed to characterize the phytochemical profile of its aqueous leaf extract and evaluate its skin-related in vitro biological activities. The phenolic composition was determined using UHPLC-HRMS/MS, HPLC-DAD, and quantitative colorimetric assays. Antioxidant activity was assessed against synthetic free radicals, reactive oxygen and nitrogen species, transition metals, and pro-oxidant enzymes. Enzymatic inhibition of tyrosinase, hyaluronidase, collagenase, and elastase were evaluated using in vitro assays. Cytocompatibility was tested on human keratinocytes and NIH/3T3 fibroblasts using MTT and resazurin assays, respectively, while wound healing was evaluated on NIH/3T3 fibroblasts using the scratch assay. Antifungal activity was investigated against several Candida and dermatophyte species, while antibiofilm activity was tested against Epidermophyton floccosum. The extract was found to be rich in phenolic compounds, accounting for nearly 45% of its dry weight. These included flavonoids, phenolic acids, and proanthocyanidins, with ellagitannins (punicalagin) being the predominant group. The extract demonstrated potent antioxidant, anti-tyrosinase, anti-collagenase, anti-elastase, and antidermatophytic activities, including fungistatic, fungicidal, and antibiofilm effects. These findings highlight the potential of T. lignosa as a valuable and underexplored source of bioactive phenolic compounds with strong potential for the development of innovative approaches for skin care and therapy. Full article

Biogenic silver nanoparticles (AgNPs) were synthesized via a green chemistry strategy using wheat extract and subsequently functionalized with a carboxymethyl chitosan–cinnamaldehyde (CMC=CIN) conjugate through covalent imine bonding. The resulting nanohybrid (AgNP–CMC=CIN) was extensively characterized to confirm successful biofunctionalization: UV–Vis spectroscopy revealed characteristic cinnamaldehyde absorption peaks; ATR-FTIR spectra confirmed polymer–terpene bonding; and TEM analysis evidenced uniform nanoparticle morphology. Dynamic light scattering (DLS) measurements indicated an increase in hydrodynamic size upon coating (from 59.46 ± 12.63 nm to 110.17 ± 4.74 nm), while maintaining low polydispersity (PDI: 0.29 to 0.27) and stable surface charge (zeta potential ~ −30 mV), suggesting colloidal stability and homogeneous polymer encapsulation. Antifungal activity was evaluated against Fusarium oxysporum, Penicillium citrinum, Aspergillus niger, and Aspergillus brasiliensis. The minimum inhibitory concentration (MIC) against F. oxysporum was significantly reduced to 83 μg/mL with AgNP–CMC=CIN, compared to 708 μg/mL for uncoated AgNPs, and was comparable to the reference fungicide tebuconazole (52 μg/mL). Seed priming with AgNP–CMC=CIN led to improved germination (85%) and markedly reduced fungal colonization, while maintaining a favorable phytotoxicity profile. These findings highlight the potential of polysaccharide-terpene-functionalized biogenic AgNPs as a sustainable alternative to conventional fungicides, supporting their application in precision agriculture and integrated crop protection strategies. Full article

Plants of the Annona genus have garnered increasing scientific interest due to their rich phytochemical profile and broad spectrum of biological activities, which include antimicrobial, antiproliferative, and cytotoxic effects. Among the most studied compounds are acetogenins and Annonacins, which exhibit potent bioactivity and have been identified as key agents in the green synthesis and stabilization of nanomaterials. In recent years, the integration of Annona plant extracts—particularly from leaves—into nanotechnology platforms has opened new avenues in the development of eco-friendly and biocompatible nanostructures for biomedical applications. This review provides a comprehensive overview of the current knowledge regarding the antimicrobial properties of nanomaterials synthesized using extracts from Annona species. This review encompasses 74 indexed articles published between 2012 and 2023, focusing on the synthesis of nanomaterials using extracts from this genus that exhibit antimicrobial and biomedical properties. The search was conducted in databases such as Google Scholar, Web of Science, and Scopus. Emphasis is placed on their antibacterial, antifungal, and anthelmintic effects, as well as additional therapeutic potentials, such as antidiabetic, antihypertensive, antiproliferative, and cytotoxic activities. The analysis of the recent literature highlights how Annona-derived phytochemicals contribute significantly to the functionalization and enhanced biological performance of these nanomaterials. This work aims to support future research focused on the rational design of Annona-based nanostructures as promising candidates in antimicrobial and therapeutic strategies. Full article

Malva sylvestris L. is a herbaceous plant, distributed worldwide, rich in biological active compounds, and known for its health benefits. In this study, extracts from different parts (leaves, flowers, and roots) of this plant were prepared using green classic (70% ethanol) and natural deep eutectic solvents (NADESs) based on choline chloride and acetic acid (NADES1) or glycerol (NADES2). Their antioxidant, antibacterial (against B. cereus, S, aureus, E. coli, and P. aeruginosa), and antifungal activity (against P. chrysogenum, F. oxysporum, A. parasiticus, A. flavus, A. niger A. carbonarius, and A. ochraceus) were compared. Ethanolic extracts were characterized with the highest total contents of phenols, flavonoids, and condensed tannins. Ethanolic and NADES flower extracts were the richest in the antioxidants tested. Alkaloids were extracted in low quantities. The experimentally determined antioxidant potential of the extracts proved the highest DPPH scavenging activity of ethanolic extracts and the lowest of NADES1 extracts. The ABTS scavenging capacity of NADES1 and ethanolic extracts displayed comparable results, while NADES2 extracts were characterized as having the highest FRAP activity. NADES1 extracts manifested pronounced antibacterial activity, partially due to the low pH of the pure solvent, as well as inconsistent antifungal activity—from moderate to a complete lack of activity. A strong positive correlation was reported between the DPPH radical scavenging capacity and phenolic compound content. Future detailed investigations on the mechanism of the antimicrobial activity of NADES1 extracts are necessary to clarify the observed phenomenon of the decreased antifungal potential of NADES1 extracts compared to the pure solvent NADES1. Full article

Horticulture and agriculture are facing the challenge of growing healthy and high-quality crops. Plant extracts are currently being widely investigated as an alternative means of plant protection. Interest in these measures has increased in order to reduce the use of chemical pesticides, environmental pollution, and adverse effects on human health. Also, due to the goals of the European Green Deal and the decreasing use of chemical pesticides, it has become essential to look for safer alternatives. The aim of this study was to investigate the inhibitory effect of plant extracts of clove (Syzygium aromaticum L.) and rosemary (Rosmarinus officinalis L.) against Colletotrichum acutatum and Botrytis cinerea plant pathogens and to evaluate fungal pathogens recovery after the exposure to the extract. The plant extracts (PEs) were obtained by subcritical CO₂ extraction. The inhibitory effect of PEs was investigated in vitro at concentrations of 1200, 1600, 2000, 2400, 2800, and 3000 μL/L. Petri dishes were incubated at 25 ± 2 °C, and the mycelial growth of fungal pathogens was evaluated at 2, 4, and 7 days after inoculation (DAI). Reinoculation was then performed. The research showed that both plant extracts had an antifungal effect. However, clove PE was more effective. This allows us to say that plant-based measures can inhibit plant pathogens, but it is essential to determine the optimal concentrations and test them with different pathogens. Full article

Anaerobes, the oldest evolutionary life forms, have been unexplored for their potential to produce secondary metabolites due to the difficulties observed in their cultivation. Antimicrobials derived from anaerobic bacteria are an emerging and valuable source of novel therapeutic agents. The urgent need for new antimicrobial agents due to rising antibiotic resistance has prompted an investigation into anaerobic bacteria. The conventional method of antimicrobial discovery is based on cultivation and extraction methods. Antibacterial and antifungal substances are produced by anaerobic bacteria, but reports are limited due to oxygen-deficient growth requirements. The genome mining approach revealed the presence of biosynthetic gene clusters involved in various antimicrobial compound synthesis. Thus, the current review is focused on antimicrobials derived from anaerobes to unravel the potential of anaerobic bacteria as an emerging valuable source of therapeutic agents. These substances frequently consist of peptides, lipopeptides, and other secondary metabolites. Many of these antimicrobials have distinct modes of action that may be able to go around established resistance pathways. To this effect, we discuss diverse antimicrobial compounds produced by anaerobic bacteria, their biosynthesis, heterologous production, and activity. The findings suggest that anaerobic bacteria harbor significant biosynthetic potential, warranting further exploration through recombinant production for developing new antibiotics. Full article

Two new very-long-chain 5-n-alkylresorcinol (AR) homologues, that is, 5-n-nonacosylbenzene-1,3-diol and 5-n-hentriacontylbenzene-1,3-diol, were isolated from acetone extracts of Ailanthus altissima samaras. These phenolic compounds were detected in nearly equal proportions, although their total content varied considerably between samples from urban-grown trees. No correlation was observed between AR levels and the physiological state of the tree, suggesting that environmental conditions may strongly influence AR biosynthesis in A. altissima. Furthermore, the isolated AR mixture exhibited antifungal activity against soil-borne phytopathogens of the genera Fusarium and Rhizoctonia. Full article

A previously undescribed cis-clerodane diterpenoid, diangelate solidagoic acid J (1), along with two known cis-clerodane diterpenoids, solidagoic acid C (2) and solidagoic acid D (3), as well as two known unsaturated monoacylglycerols, 1-linoleoyl glycerol (4) and 1-α-linolenoyl glycerol (5), were isolated and characterized from the n-hexane leaf extract of Solidago gigantea (giant goldenrod). Compounds 2–5 were identified first in this species, and compounds 4 and 5 are reported here for the first time in the Solidago genus. The bioassay-guided isolation procedure included thin-layer chromatography (TLC) coupled with a Bacillus subtilis antibacterial assay, preparative flash column chromatography, and TLC–mass spectrometry (MS). Their structures were elucidated via extensive spectroscopic and spectrometric techniques such as one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution tandem mass spectrometry (HRMS/MS). The antimicrobial activities of the isolated compounds were evaluated by a microdilution assay. All compounds exhibited weak to moderate antibacterial activity against the Gram-positive plant pathogen Clavibacter michiganensis, with MIC values ranging from 17 to 133 µg/mL, with compound 5 being the most potent. Only compound 1 was active against Curtobacterium flaccumfaciens pv. flaccumfaciens, while compound 3 demonstrated a weak antibacterial effect against B. subtilis and Rhodococcus fascians. Additionally, the growth of B. subtilis and R. fascians was moderately inhibited by compounds 1 and 5, respectively. None of the tested compounds showed antibacterial activity against Gram-negative Pseudomonas syringae pv. tomato and Xanthomonas arboricola pv. pruni. No bactericidal activity was observed against the tested microorganisms. Compounds 2 and 3 displayed weak antifungal activity against the crop pathogens Bipolaris sorokiniana and Fusarium graminearum. Our results demonstrate the efficacy of bioassay-guided strategies in facilitating the discovery of novel bioactive compounds. Full article

The present study aimed to identify the active chemical compounds, mainly phenolic acids, of Champia parvula and Moringa oleifera, evaluate the pharmacokinetic properties of their primary compounds, and assess a novel method for the biocontrol of blue mold by evaluating the antifungal activity of both extracts. Gas chromatography (GC) and high-performance liquid chromatography (HPLC) were utilized to identify the active chemical compounds, mainly phenolic acids. GC illustrated the presence of long-chain aliphatic fatty acids like eicosanoic acid with the formation of oct-1-en-3-ol compounds attached. Catechin was the main bioactive component among the several bioactive compounds identified by HPLC analysis, exhibiting favorable pharmacokinetic behavior, including good absorption, distribution, and metabolic stability. According to the findings, both extracts had antifungal activity, but C. parvula extract (100 mg/mL) exhibited the strongest in vitro and in vivo antifungal activity, with the highest percentages of inhibition (disk diffusion method) against Penicillium expansum, Penicillium crustosum, and Talaromyces atroroseus, ranging between 62.67 and 100%. C. parvula extract (100 mg/mL) could fully inhibit the pathogenicity and aggressiveness of the five tested strains in apple fruits (in vivo). In conclusion, the extract from C. parvula and M. oleifera shows potential antifungal properties and a high phytochemical content. Full article

Plant species harbor diverse rhizospheric bacteria within their resilient root zones, serving as a valuable reservoir of bioactive microorganisms with strong potential for natural antifungal and plant growth-promoting applications. This study aimed to investigate the antagonistic potential of Bacillus zhangzhouensis, isolated from Zygophyllum oxianum in the Aral Sea region, Uzbekistan, against the fungal pathogen Cytospora mali. Due to its strong antifungal activity, B. zhangzhouensis was selected for bioactive compound profiling. Methanolic extracts were fractionated via silica and Sephadex gel chromatography, followed by antifungal screening using the agar diffusion method. A highly active fraction (dichloromethane/methanol, 9:1) underwent further purification, yielding twelve antifungal sub-fractions. Mass spectrometry analysis across positive and negative ion modes identified 2475 metabolites, with polar solvents—particularly methanol—enhancing compound recovery. Refinement using Bacillus-specific references identified six known antibiotics. Four pure compounds were isolated and structurally characterized using NMR: oleanolic acid, ursolic acid, cyclo-(Pro-Ser), and uracil. Their growth regulatory activity was assessed on Amaranthus retroflexus, Nicotiana benthamiana, triticale, and Triticum aestivum at concentrations of 5, 20, 100, and 500 mg L−1. All compounds negatively affected root growth in a concentration-dependent manner, especially in monocots. Interestingly, some treatments enhanced stem growth, particularly in N. benthamiana. These findings indicate that B. zhangzhouensis produces diverse bioactive compounds with dual antifungal and plant growth-modulatory effects, highlighting its potential as a biocontrol agent and a source of natural bioactive compounds. Full article