Antimicrobial and Antibiofilm Activities of the Fungal Metabolites Isolated from the Marine Endophytes Epicoccum nigrum M13 and Alternaria alternata 13A

Exploring Fungal Diversity in Seagrass Ecosystems for Pharmaceutical and Ecological Insights

Marine ecosystems are important in discovering novel fungi with interesting metabolites that have shown great potential in pharmaceutical and biotechnological industries. Seagrasses, the sole submerged marine angiosperm, host diverse fungal taxa with mostly unknown metabolic capabilities. They are considered to be one of the least studied marine fungal habitats in the world. This review gathers and analyzes data from studies related to seagrasses-associated fungi, including taxonomy and biogeography, and highlights existing research gaps. The significance of the seagrass-fungal associations remains largely unknown, and current understanding of fungal diversity is limited to specific geographical regions such as the Tropical Atlantic, Mediterranean, and Indo-Pacific. Our survey yielded 29 culture-dependent studies on seagrass-associated endophytic and epiphytic fungi, and 13 miscellaneous studies, as well as 11 meta-studies, with no pathogenic true fungi described. There is a significant opportunity to expand existing studies and conduct multidisciplinary research into novel species and their potential applications, especially from understudied geographical locations. Future research should prioritize high-throughput sequencing and mycobiome studies, utilizing both culture-dependent and -independent approaches to effectively identify novel seagrass-associated fungal taxa.

New 1,3-diphenyl-1H-pyrazol-5-ols as anti-methicillin resistant Staphylococcus aureus agents: Synthesis, antimicrobial evaluation and in silico studies

In the present work, two hybrid series of pyrazole-clubbed pyrimidine and pyrazole-clubbed thiazole compounds 3-21 from 4-acetyl-1,3-diphenyl-1H-pyrazole-5(4H)-ole 1 were synthesized as novel antimicrobial agents. Their chemical structures were thoroughly elucidated in terms of spectral analyses such as IR, 1H NMR, 13C NMR and mass spectra. The compounds were in vitro evaluated for their antimicrobial efficiency against various standard pathogen strains, gram -ive bacteria (Pseudomonas aeruginosa, Klebsiella pneumonia), gram + ive bacteria (MRSA, Bacillus subtilis), and Unicellular fungi (Candida albicans) microorganisms. The ZOI results exhibited that most of the tested molecules exhibited inhibition potency from moderate to high. Where compounds 7, 8, 12, 13 and 19 represented the highest inhibition potency against most of the tested pathogenic microbes comparing with the standard drugs. In addition, the MIC results showed that the most potent molecules 7, 8, 12, 13 and 19 showed inhibition effect against most of the tested microbes at low concentration. Moreover, the docking approach of the newly synthesized compounds against DNA gyrase enzyme was performed to go deeper into their molecular mechanism of antimicrobial efficacy. Further, computational investigations to calculate the pharmacokinetics parameters of the compounds were performed. Among them 7, 8, 12, 13 and 19 are the most potent compounds revealed the highest inhibition efficacy against most of the tested pathogenic microbes comparing with the standard drugs.

Halophilomyces hongkongensis, a Novel Species and Genus in the Lulworthiaceae with Antibacterial Potential, Colonizing the Roots and Rhizomes of the Seagrass Halophila ovalis

Seagrass serves as a quintessential reservoir for obligate marine Lulworthiaceae fungi. Our current knowledge of the mycological diversity associated with seagrass in Hong Kong remains poor. We analyzed the diversity of fungi associated with the most widely distributed seagrass species in Hong Kong Halophila ovalis (Hydrocharitaceae), using a combination of culture-based methods and high-throughput amplicon sequencing. Halophilomyces hongkongensis, a novel fungal species in a newly proposed genus within the Lulworthiaceae family, was isolated from H. ovalis roots and rhizomes. The novel fungus showed distinct morphological characteristics, while both combined 18S-28S and internal transcribed spacer (ITS) phylogenetic trees based on maximum likelihood and Bayesian methods supported its discrimination from other existing Lulworthiaceae members. The ITS2 region in the Illumina sequencing results of multiple H. ovalis compartments, water, and adjacent non-seagrass sediments revealed continuous recruitment of H. hongkongensis by H. ovalis throughout the year despite dramatically fluctuating environmental conditions, with remarkably high proportions of this taxon found in root and rhizome internal tissues, possibly indicating a strong and specialized relationship established between the Lulworthiaceae fungal partner and its seagrass host. The inhibitory abilities exhibited by H. hongkongensis against Staphylococcus aureus SA29213 and ATCC 43300 (methicillin-resistant) may imply its capacity in producing (novel) antibacterial compounds. The discovery of H. hongkongensis as the first novel Lulworthiaceae taxon in Hong Kong, along with its distributional pattern in the seagrass meadow, provides valuable insights into the systematics and ecology of this strictly marine fungal family.

Design, synthesis, structure elucidation, antimicrobial, molecular docking, and SAR studies of novel urea derivatives bearing tricyclic aromatic hydrocarbon rings

The targeted compounds were prepared using both (9H-fluoren-9-ylidene)hydrazine (1) and 10H-phenothiazine (2) as starting materials. The treatment of 1 or 2 with different isocyanates afforded the title compounds 7a-d, 8a, and 8b in excellent yield. All compounds were characterized and ascertained by infrared, nuclear magnetic resonance, and elemental analyses as well as single-crystal X-ray diffraction. The antimicrobial efficiency of all was tested in vitro, and a noticeable inhibition activity against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans was obtained by compounds 7a, 7b, 8a, and 8b. Moreover, the biofilm mechanism activity was strongly inhibited by compounds 7b and 8b for all bacterial pathogens, with a percentage ratio of more than 55%. The findings from the molecular docking simulation revealed that compounds 7a, 7b, 8a, and 8b exhibited favorable binding energies and interacted effectively with the active sites of sterol 14-demethylase, dihydropteroate synthase, gyrase B, LasR (major transcriptional activator of P. aeruginosa), and carbapenemase for C. albicans, S. aureus, B. subtills, K. pneumoniae, and P. aeruginosa, respectively. These results suggest that the compounds have the potential to inhibit the activity of these enzymes and demonstrate promising antimicrobial properties. Moreover, the in silico evaluation of drug likeness and absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles for compounds 7a, 7b, 8a, and 8b demonstrated their compatibility with Lipinski's, Ghose's, Veber's, Muegge's, and Egan's rules. These findings suggest that these compounds possess favorable physicochemical properties, making them promising candidates for continued drug development efforts.

New quinazolin-2,4-dione derivatives incorporating acylthiourea, pyrazole and/or oxazole moieties as antibacterial agents via DNA gyrase inhibition

This article contributes to the search for new therapeutic agents for treatment of diseases caused by bacterial pathogens. In this study, a new series of compounds incorporating numerous bioactive moieties such as quinazolin-2,4-dione, acylthiourea linkage, and/or five membered nitrogen heterocycles (pyrazole and oxazole) 2-5a-c was described to identify new antibacterial drug candidates via inhibition of DNA gyrase enzyme. The precursor N-[N'-(2-cyano-acetyl)-hydrazinocarbothioyl]-4-(2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-benzamide 2 was prepared by treatment of compound 1 with ammonium thiocyanate and cyanoacetic acid hydrazide through multicomponent reaction (MCR). In addition, compounds 3a-d and 4a-b were synthesized by treatment of 2 with aromatic aldehydes and/or ketones through Knoevenagel reaction, affording high purity products in satisfactory yields. Moreover, new heterocyclic moieties such as pyrazole and/or oxazole attached to quinazolin-2,4-dione core 5a-c were synthesized by treatment of 3c with different nucleophilic reagents like hydrazine, phenyl hydrazine and hydroxyl amine, respectively. Subsequently, the obtained products were structurally characterized by IR, 1H-, 13C-NMR, and MS analyses. The minimum inhibitory concentration (MIC) and antibacterial potency of all compounds were estimated against two G-ve (E. coli and P. aeruginosa), and two G+ve bacteria (B. subtilis and S. aureus). Encouragingly, compound 3c demonstrated the best antibacterial activity against all the strains of the tested pathogenic bacteria at low concentrations compared with the standard drug, Ciprofloxacin. Electron withdrawing groups such as -NO2 and -Cl enhance the antibacterial activity. Next, a molecular docking study between the synthesized derivatives and the target enzyme, DNA gyrase enzyme (PDB: 2xct) was undertaken to investigate intermolecular interactions between the compounds and target enzyme.

Cytotoxic naphtho- and benzofurans from an endophytic fungus Epicoccum nigrum Ann-B-2 associated with Annona squamosa fruits

Chemical exploration of the total extract derived from Epicoccum nigrum Ann-B-2, an endophyte associated with Annona squamosa fruits, afforded two new metabolites, epicoccofuran A (1) and flavimycin C (2), along with four known compounds namely, epicocconigrone A (3), epicoccolide B (4), epicoccone (5) and 4,5,6-trihydroxy-7-methyl-1,3-dihydroisobenzofuran (6). Structures of the isolated compounds were elucidated using extensive 1D and 2D NMR along with HR-ESI-MS. Flavimycin C (2) was isolated as an epimeric mixture of its two diastereomers 2a and 2b. The new compounds 1 and 2 displayed moderate activity against B. subtilis, whereas compounds (2, 3, 5, and 6) showed significant antiproliferative effects against a panel of seven different cancer cell lines with IC50 values ranging from 1.3 to 12 µM.

Anti-Cancer and Anti-Oxidant Bioactive Metabolites from Aspergillus fumigatus WA7S6 Isolated from Marine Sources: In Vitro and In Silico Studies

Cancer is a huge global disease burden. Every year, tens of millions of people worldwide are diagnosed with cancer, and more than half of them die as a result of it. The great biodiversity of the marine environment has increasingly piqued the interest of experts, especially in the field of drug discovery. The marine fungus Aspergillus fumigatus WA7S6 has been selected among a group of fungi isolated from marine sponges as it exhibits a pronounced antimicrobial activity toward a group of pathogenic microbes. The fungus has been identified genetically by amplification and analysis of its 18srRNA gene. The fungus crude extract has been obtained by cultivation of the fungus on rice media. The crude extract was tested for antibacterial activity against a variety of pathogenic microorganisms. The results demonstrated a pronounced antimicrobial action against P. aeruginosa, S. aureus, A. niger, and Candida albicans. Furthermore, we tested the antioxidant potential of the Aspergillus fumigatus WA7S6 crude extract using three different methods: ATBS, DPPH, and lipid peroxidation assays. Results showed that the crude extract WA7S6 had an IC50 value of 21.35 µg/mL. The anticancer potential of the crude extract was also evaluated against cancer cell lines such as Hela, MCF, and WI-38. The chemical profiling of the fungus extract was identified via GC-mass and in silico molecular docking of the identified compounds on heme oxygenase, as a stress protein included in cellular protection, antioxidant, and anti-inflammatory activities, suggesting that some compounds, such as 9-Tetradecynoic acid, 11-Hexadecynoic acid, methyl ester, and dehydromevalonic lactone, could be relevant for antioxidant purposes.

Antibiofilm activity of marine microbial natural products: potential peptide- and polyketide-derived molecules from marine microbes toward targeting biofilm-forming pathogens

Controlling and treating biofilm-related infections is challenging because of the widespread presence of multidrug-resistant microbes. Biofilm, a naturally occurring matrix of microbial aggregates, has developed intricate and diverse resistance mechanisms against many currently used antibiotics. This poses a significant problem, especially for human health, including clinically chronic infectious diseases. Thus, there is an urgent need to search for and develop new and more effective antibiotics. As the marine environment is recognized as a promising reservoir of new biologically active molecules with potential pharmacological properties, marine natural products, particularly those of microbial origin, have emerged as a promising source of antibiofilm agents. Marine microbes represent an untapped source of secondary metabolites with antimicrobial activity. Furthermore, marine natural products, owing to their self-defense mechanisms and adaptation to harsh conditions, encompass a wide range of chemical compounds, including peptides and polyketides, which are primarily found in microbes. These molecules can be exploited to provide novel and unique structures for developing alternative antibiotics as effective antibiofilm agents. This review focuses on the possible antibiofilm mechanism of these marine microbial molecules against biofilm-forming pathogens. It provides an overview of biofilm development, its recalcitrant mode of action, strategies for the development of antibiofilm agents, and their assessments. The review also revisits some selected peptides and polyketides from marine microbes reported between 2016 and 2023, highlighting their moderate and considerable antibiofilm activities. Moreover, their antibiofilm mechanisms, such as adhesion modulation/inhibition targeting biofilm-forming pathogens, quorum sensing intervention and inhibition, and extracellular polymeric substance disruption, are highlighted herein.

In-vitro investigation on the biological activities of squalene derived from the soil fungus Talaromyces pinophilus

The consistent increase in multidrug resistance among pathogens and increased cancer incidence are serious public health concerns and threaten humans by killing countless lives. In the present study, Talaromyces pinophilus CJ15 was characterized and evaluated for its antibacterial, candidicidal and cytotoxic activities. The selected isolate Talaromyces pinophilus CJ15 with 18S rRNA gene sequence of 1021 base pairs exhibited antifungal activity on plant pathogens via dual culture. The GC-MS profiling of crude extract illustrated the existence of many bioactive macromolecules which include squalene belonging to the terpenoids family. The biological macromolecules in the bioactive fraction of CJ15 exhibited increasing antibacterial activity with an increase in concentration such that the highest activity was recorded against Shigella flexneri with 15, 18, 20, and 24 mm inhibition zones at 25, 50, 75 and 100 μl concentrations, respectively. The squalene, having a molecular weight of 410.718 g/mol, displayed candidicidal activity with a right-side shifted log phase in the growth curve of all the treated Candida species, indicating delayed exponential growth. In cytotoxic activity, the extracted squalene exhibited an IC50 concentration of 26.22 μg/ml against JURKAT cells and induced apoptosis-induced cell death. This study's outcomes encourage the researchers to explore further the development of new and improved bioactive macromolecules that could help to prevent infections and human blood cancer.

Antibacterial Activity of Quinoline-Based Derivatives against Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa: Design, Synthesis, DFT and Molecular Dynamic Simulations

Bacterial virulence becomes a significant challenge for clinical treatments, particularly those characterized as Multi-Drug-Resistant (MDR) strains. Therefore, the preparation of new compounds with active moieties could be a successful approach for eradication of MDR strains. For this purpose, newly synthesized quinoline compounds were prepared and tested for their antimicrobial activity against Methicillin-Resistant Staphylococcus Aureus (MRSA) and Pseudomonas Aeruginosa (PA). Among the synthesized derivatives, compounds 1-(quinolin-2-ylamino)pyrrolidine-2,5-dione (8) and 2-(2-((5-methylfuran-2-yl)methylene)hydrazinyl)quinoline (12) were shown to possess the highest antimicrobial activity with the minimum inhibitory concentration with the values of 5±2.2 and10±1.5 μg/mL towards Pseudomonas aeruginosa without any activity towards MRSA. Interestingly, compounds 2-(2-((1H-indol-3-yl)methylene)hydrazinyl)quinoline (13) and 2-(4-bromophenyl)-3-(quinolin-2-ylamino)thiazolidin-4-one (16c) showed significant inhibition activity against Staphylococcus aureus MRSA and Pseudomonas aeruginosa. Compound 13 (with indole moiety) particularly displayed excellent bactericidal activity with low MIC values 20±3.3 and 10±1.5 μg/mL against Staphylococcus aureus MRSA and Pseudomonas aeruginosa, respectively. Effects molecular modelling was used to determine the mode of action for the antimicrobial effect. The stability of complexes formed by docking and target-ligand pairing was evaluated using molecular dynamics simulations. The compounds were also tested for binding affinity to the target protein using MM-PBSA. Density-functional theory (DFT) calculations were also used to investigate the electrochemical properties of various compounds.

Insight into novel anti-mucormycosis therapies: investigation of new anti-mucormycosis laser-induced photodynamic therapy based on a sulphone bis-compound loaded silica nanoemulsion

For drug delivery applications, silica nanoemulsion encapsulated with organic compounds are becoming increasingly more desirable. Therefore, the emphasis of this research was on the synthesis of a new potent antifungal drug-like candidate (1,1'-((sulfonylbis(4,1-phenylene)bis(5-methyl-1H-1,2,3-triazole-1,4-diyl))bis(3-(dimethylamino)prop-2-en-1-one), SBDMP), the chemical structure of which was confirmed on the basis of its spectral and microanalytical data. Then, silica nanoemulsion loaded with SBDMP was prepared using Pluronic F-68 as a potent surfactant. The particle shape, hydrodynamic size, and zeta potential of the produced silica nanoemulsion (with and without drug loading) were assessed. The antitumoral activity of the synthesized molecules showed the superiority of SBDMP and silica nanoemulsion with and without SBDMP loading against Rhizopus microsporous and Syncephalastrum racemosum. Subsequently, the laser-induced photodynamic inactivation (LIPDI) of Mucorales strains was determined using the tested samples. The optical properties of the samples were investigated using UV-vis optical absorption and the photoluminescence. The photosensitivity of the selected samples appeared to enhance the eradication of the tested pathogenic strains when exposed to a red (640 nm) laser light. The optical property results verified that the SBDMP-loaded silica nanoemulsion has a high depth of penetration into biological tissues due to a two-absorption photon (TAP) mechanism. Interestingly, the photosensitizing of the nanoemulsion loaded with a newly synthesized drug-like candidate, SBDMP, opens up a new route to apply new organic compounds as photosensitizers under laser-induced photodynamic therapy (LIPDT).

Aspergillus niger CJ6 extract with antimicrobial potential promotes in-vitro cytotoxicity and induced apoptosis against MIA PaCa-2 cell line

Nowadays, the increased number of multidrug-resistant strains among pathogens is a severe public health concern and cancer is posing a great threat for humans. These problems should be tackled with the development of novel and broad-spectrum antimicrobials from microbial origin. During the present study, the bioactive secondary metabolites from Aspergillus niger CJ6 were extracted, characterized; their biological properties were evaluated by subjecting them for antimicrobial, antifungal and anticancer activities. The potent isolate Aspergillus niger CJ6 with nucleotide sequence of 959 base pairs showed antagonistic activity against fungal pathogens in dual culture. The chemical profiling of crude ethyl acetate extract indicated the presence of various bioactive molecules belonging to phenolic, hydrocarbons, and phthalate derivative classes. In antimicrobial activity, the crude extract displayed increasing activity with increased concentration; the highest activity observed against Shigella flexneri with 15 ± 1.0, 19 ± 0.5, 20 ± 1.0 and 24 ± 1.0 mm zones of inhibition at 25, 50, 75 and 100 μl concentrations. The MTT assay illustrated deformed cells of MIA PaCa-2 cell line in in-vitro cytotoxic activity; outflow of cell matrix and membrane rupture; the IC₅₀ of 90.78 μg/ml suggested moderate potential of extract to prevent cancer cell growth. The apoptosis/necrosis study by flow cytometer exhibited 8.98 ± 0.85% early and 73 ± 0.7% of late apoptotic population with 3.8 ± 1.1% necrotic cells; only 14.22 ± 0.6% of healthy cells suggested the increased apoptosis inducing capacity of Aspergillus niger CJ6 crude extract. The outcomes of this study persuade further exploration on the identification, purification and development of novel bioactive agents that could help battle fatal diseases in humans.

Marine natural products

Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1425 in 416 papers for 2021), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.

Morphinan Alkaloids from the Leaves of Alphonsea cylindrica and Their Antibacterial Properties

A phytochemical study has been carried out on CH₂Cl₂ extract of Alphonsea cylindrica leaves, resulting in the isolation of three new morphinan alkaloids. They are kinomenine (1: ), N-methylkinomenine (2: ), and hydroxymethylkinomenine (3: ). The structures of these compounds were elucidated by extensive spectroscopic analysis (1D and 2D NMR, IR, UV, HRESIMS) and comparison with the data reported in literature for similar alkaloids. Kinomenine (1: ) and N-methylkinomenine (2: ) showed weak inhibition against S. aureus (MIC values of 1: and 2:  = 500 µg/mL; pIC₅₀ values in 95% C. I. of: 1:  = 2.9 to 3.0; 2:  = 2.9 to 3.1), while kinomenine (1: ) also showed weak inhibition against E. coli (MIC values of 1:  = 500 µg/mL; pIC₅₀ value in 95% C. I. of: 1:  = 2.9) by broth microdilution method. The results obtained can be used as future referencefor the discovery of morphinans and the potential of A. cylindrica as an antibacterial source.

Secondary metabolites produced by endophytic fungi, Alternaria alternata, as potential inhibitors of the human immunodeficiency virus

Antiretroviral treatment has significantly reduced human immunodeficiency virus infection and mortality. However, the current treatment regimen is limited by adverse side effects, the emergence of drug resistance, and the inability to eliminate viral reservoirs. Here, fifteen endophytic fungi were isolated from Sclerocarya birrea and Hypoxis plants. Crude extracts of Alternaria alternata (strain ID PO4PR1, PO4PR2, and PO2PL1) of the fifteen isolate's crude extracts showed anti-HIV-1 activity in TZM-bl cell line at inhibitory concentration (IC₅₀) values ranging from 0.017 to 1.170 μg/ml. The three crude extracts also maintained the virus replication inhibition profile on PBMCs and CD4⁺ T cells at concentrations ranging from 0.3 to 50.2 ng/ml. Partial purification using the solid phase extraction and analysis with Gas Chromatography-Mass spectrophotometry showed a diverse profile. The bioactive compounds were identified based on peak area, retention time, similarity index. The major compounds from GC-MS analysis of A. Alternata revealed the existence of cyclotrisiloxane octamethyl (22.92%); Propaninitrile (16,67%); Pyrrolol[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl) (10.42%); Silane, diethylethoxy(2-ethoxyethyloxy) (4.17%); Coumarin, 3,4-dihydro-4,5,7-trimethyl- 4,5,7-Trimethyl-2-chromanone (13.7%) and 1,2-Cyclobutanedicarbonitrile (2.08%) with previously reported biological activities such as antimicrobial, anti-inflammatory and antioxidant properties. Therefore, these bioactive compounds from A. alternata fungal endophytes could be repurposed as potential anti-HIV agents. This study showed the potential of endophytic fungi, Alternaria alternata from S. birrea, and Hypoxis species as producers of anti-HIV compounds.

Screening of Bioactive Compounds from Endophytic Marine-Derived Fungi in Saudi Arabia: Antimicrobial and Anticancer Potential

Nowadays, endophytic fungi represent a rich source of biological active compounds. In the current study, twelve endophytic fungal species were isolated from Avicennia marina leaves. From the isolates, Aspergillus niger, Penicillium rubens and Alternaria alternata recorded the highest isolation frequency (80%), relative density (12.5%) and antimicrobial activity. The antimicrobial and anticancer activities of P. rubens were more effective than those of A. niger and A. alternata; therefore, its identification was confirmed via the ITS rRNA gene. Filtrate extracts of P. rubens, A. alternata and A. niger were analyzed using GC-MS and showed different detected constituents, such as acetic acid ethyl ester, N-(4,6-Dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide, 1,2-benzenedicarboxylic acid, hexadecanoic acid and octadecanoic acid. Filtrate extract of P. rubens exhibited the presence of more compounds than A. alternata and A. niger. Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus were more inhibited by P. rubens extract than A. alternata or A. niger, with inhibition zones of 27.2 mm, 22.21 mm, 26.26 mm, 27.33 mm, 28.25 mm and 8.5 mm, respectively. We observed negligible cytotoxicity of P. rubens extract against normal cells of human lung fibroblasts (WI-38 cell line), unlike A. alternata and A. niger extracts. Proliferation of prostate cancer (PC-3) was inhibited using P. rubens extract, exhibiting mortality levels of 75.91% and 76.2% at 200 µg/mL and 400 µg/mL of the extract. Molecular docking studies against the crystal structures of C. albicans (6TZ6) and the cryo-EM structure of B. subtilis (7CKQ) showed significant interactions with benzenedicarboxylic acid and N-(4,6-dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide as a constituent of P. rubens extract. N-(4,6-dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide had the highest scores of −6.04905 kcal/mol and −6.590 kcal/mol towards (6tz6) and (7CKQ), respectively.

Bioactive secondary metabolites from marine Actinomyces sp. AW6 with an evaluation of ADME-related physicochemical properties

This study was designed to evaluate the antimicrobial, antioxidant, and cytotoxic potentials of the marine actinomycetes spp. isolated from the Red Sea water, Hurghada, Egypt. Out of 80 actinomycetes isolates, one isolate AW6 was selected based on its antioxidant activity (IC₅₀ about 5.24 µg/mL which scavenged 91% of formed DPPH free radicals) and antimicrobial potential against E. coli, S. aureus, B. subtilis, and P. aeruginosa, A. niger, and C. albicans. The strain was identified based on phenotypic and genotypic analysis, and deposited in the GenBank with accession number OK090864.1. Cultivation of the selected strain on rice, chromatographic purification, and structural elucidation led to the isolation of two compounds C1: umbelliferone, and C2: 1-methoxy-3-methyl-8-hydroxy-anthraquinone. The antimicrobial activity of the obtained compounds showed that C1 and C2 have low antibacterial activity toward S. aureus and E. coli with no pronounced activity toward P. aeruginosa, C. albicans, and A. niger. Additionally, the antioxidant activity of C1 and C2 revealed that C2 has a good antioxidant activity, with DPPH scavenging activity reaching (55.25%), followed by C1 (30.20%). Moreover, both compounds displayed anti-Gyr-B enzyme activity with IC₅₀ value of (3.79 ± 0.21 µM) for C1, and (IC₅₀ = 13 ± 0.71 µM) for C2. The ADME-related physicochemical properties of the obtained compound were predicted using SwissADME web tools and the ProToxii webserver was used to estimate in silico toxicity.

Diverse polyketides from the marine endophytic Alternaria sp. LV52: Structure determination and cytotoxic activities

We report the isolation and characterization of five polyketides [alternariol (1), alternariol-9-methyl ether (2), altertoxin I (3), altertoxin II (4) and tenuazonic acid (5)] from the marine endophytic Alternaria sp. LV52 derived from Cystoseira tamariscifolia, collected from the Red Sea at Nabq-Bay, Egypt. The chemical structures of compounds 1-5 were identified by extensive 1D, 2D NMR, and HR mass measurements. Isolation and phenotypic and genotypic characterization of the producing fungus is reported. The antimicrobial activity of the produced extract and derived compounds was examined against a panel of test organisms. In addition, an in vitro cytotoxic activity of 1-5 was performed against diverse cancer cell lines: HEPG2, HELA, A549 and PC3, revealing that compounds 2 and 4 are potentially cytotoxic against A549 and PC3 with EC50 of 0.73 µg/ml (2.69 µM) and 0.17 µg/ml (0.64 µM) for 2, and 0.40 µg/ml (1.15 µM) and 0.12 µg/ml (0.33 µM) for 4, respectively.

Metabolites With Cytotoxic Activities From the Mangrove Endophytic Fungus Fusarium sp. 2ST2

Two new 3-decalinoyltetramic acid derivatives with peroxide bridge fusarisetins E (1) and F (2), one new chromone fusarimone A (5), two new benzofurans fusarifurans A (9) and B (10), three new isocoumarins fusarimarins A–C (11–13), as well as five known analogues 3, 4, 6–8 and 14 were isolated from mangrove endophytic fungus Fusarium sp. 2ST2. Their structures and absolute configurations were established by spectroscopic analysis, density functional theory-gauge invariant atomic orbital NMR calculation with DP4+ statistical analysis, and electronic circular dichroism calculation. Compounds 1 and 2 showed significant cytotoxicity against human A549 cell lines with IC₅₀ values of 8.7 and 4.3 μM, respectively.

Chevalones H-M: Six New α-Pyrone Meroterpenoids from the Gorgonian Coral-Derived Fungus Aspergillus hiratsukae SCSIO 7S2001

Six new α-pyrone meroterpenoid chevalones H–M (1–6), together with six known compounds (7–12), were isolated from the gorgonian coral-derived fungus Aspergillus hiratsukae SCSIO 7S2001 collected from Mischief Reef in the South China Sea. Their structures, including absolute configurations, were elucidated on the basis of spectroscopic analysis and X-ray diffraction data. Compounds 1–5 and 7 showed different degrees of antibacterial activity with MIC values of 6.25–100 μg/mL. Compound 8 exhibited potent cytotoxicity against SF-268, MCF-7, and A549 cell lines with IC₅₀ values of 12.75, 9.29, and 20.11 μM, respectively.

Solvent-Free Synthesis, In Vitro and In Silico Studies of Novel Potential 1,3,4-Thiadiazole-Based Molecules against Microbial Pathogens

A new series of 1,3,4-thiadiazoles was synthesized by the reaction of methyl 2-(4-hydroxy-3-methoxybenzylidene) hydrazine-1-carbodithioate (2) with selected derivatives of hydrazonoyl halide by grinding method at room temperature. The chemical structures of the newly synthesized derivatives were resolved from correct spectral and microanalytical data. Moreover, all synthesized compounds were screened for their antimicrobial activities using Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Staphylococcus aureus, and Candida albicans. However, compounds 3 and 5 showed significant antimicrobial activity against all tested microorganisms. The other prepared compounds exhibited either only antimicrobial activity against Gram-positive bacteria like compounds 4 and 6, or only antifungal activity like compound 7. A molecular docking study of the compounds was performed against two important microbial enzymes: tyrosyl-tRNA synthetase (TyrRS) and N-myristoyl transferase (Nmt). The tested compounds showed variety in binding poses and interactions. However, compound 3 showed the best interactions in terms of number of hydrogen bonds, and the lowest affinity binding energy (−8.4 and −9.1 kcal/mol, respectively). From the in vitro and in silico studies, compound 3 is a good candidate for the next steps of the drug development process as an antimicrobial drug.

Metabolites Produced by Fungi against Fungal Phytopathogens: Review, Implementation and Perspectives

Many fungi, especially endophytes, have been found to produce multiple benefits in their plant hosts, with many of these benefits associated with the protection of plants against fungal diseases. This fact could be used in the development of new bio-products that could gradually reduce the need for chemical fungicides, which have been associated with multiple health and environmental problems. However, the utilization of the living organism may present several issues, such as an inconsistency in the results obtained and more complicated management and application, as fungal species are highly influenced by environmental conditions, the type of relationship with the plant host and interaction with other microorganisms. These issues could be addressed by using the bioactive compounds produced by the fungus, in cases where they were responsible for positive effects, instead of the living organism. Multiple bioactive compounds produced by fungal species, especially endophytes, with antifungal properties have been previously reported in the literature. However, despite the large amount of these metabolites and their potential, extensive in-field application on a large scale has not yet been implemented. In the present review, the main aspects explaining this limited implementation are analyzed, and the present and future perspectives for its development are discussed.

Antifungal Metabolites as Food Bio-Preservative: Innovation, Outlook, and Challenges

Perishable food spoilage caused by fungi is a major cause of discomfort for food producers. Food sensory abnormalities range from aesthetic degeneration to significant aroma, color, or consistency alterations due to this spoilage. Bio-preservation is the use of natural or controlled bacteria or antimicrobials to enhance the quality and safety of food. It has the ability to harmonize and rationalize the required safety requirements with conventional preservation methods and food production safety and quality demands. Even though synthetic preservatives could fix such issues, there is indeed a significant social need for "clean label" foods. As a result, consumers are now seeking foods that are healthier, less processed, and safer. The implementation of antifungal compounds has gotten a lot of attention in recent decades. As a result, the identification and characterization of such antifungal agents has made promising advances. The present state of information on antifungal molecules, their modes of activity, connections with specific target fungi varieties, and uses in food production systems are summarized in this review.

Potentials of Endophytic Fungi in the Biosynthesis of Versatile Secondary Metabolites and Enzymes

World population growth and modernization have engendered multiple environmental problems: the propagation of humans and crop diseases and the development of multi-drug-resistant fungi, bacteria and viruses. Thus, a considerable shift towards eco-friendly products has been seen in medicine, pharmacy, agriculture and several other vital sectors. Nowadays, studies on endophytic fungi and their biotechnological potentials are in high demand due to their substantial, cost-effective and eco-friendly contributions in the discovery of an array of secondary metabolites. For this review, we provide a brief overview of plant–endophytic fungi interactions and we also state the history of the discovery of the untapped potentialities of fungal secondary metabolites. Then, we highlight the huge importance of the discovered metabolites and their versatile applications in several vital fields including medicine, pharmacy, agriculture, industry and bioremediation. We then focus on the challenges and on the possible methods and techniques that can be used to help in the discovery of novel secondary metabolites. The latter range from endophytic selection and culture media optimization to more in-depth strategies such as omics, ribosome engineering and epigenetic remodeling.

Potentially Bioactive Fungus Mediated Silver Nanoparticles

Fungal metabolites, proteins, and enzymes have been rich sources of therapeutics so far. Therefore, in this study, the hypha extract of a newly identified noble fungus (Alternaria sp. with NCBI Accession number: MT982648) was used to synthesize silver nanoparticles (F-AgNPs) to utilize against bacteria, fungi, and lung cancer. F-AgNPs were characterized by using physical techniques, including UV–visible spectroscopy, zeta potential, DLS, XRD, TEM, and HR-TEM. The particles were found to be polydispersed and quasi-spherical in shape under TEM. They had an average size of ~15 nm. The well dispersed particles were found to have consistent crystallinity with cubic phase geometry under XRD and HR-TEM. The presence of different functional groups on the surfaces of biosynthesized F-AgNPs was confirmed by FTIR. The particle distribution index was found to be 0.447 with a hydrodynamic diameter of ~47 d.nm, and the high value of zeta potential (−20.3 mV) revealed the stability of the nanoemulsion. These particles were found to be active against Staphylococcus aureus (multidrug resistance-MDR), Klebsiella pneumonia, Salmonella abony, and Escherichia coli (MDR) with MIC₅₀ 10.3, 12.5, 22.69, and 16.25 µg/mL, respectively. Particles also showed inhibition against fungal strains, including A. flavus, A. niger, T. viridens, and F. oxysporium. Their inhibition of biofilm formation by the same panel of bacteria was also found to be very promising and ranged from 16.66 to 64.81%. F-AgNPs also showed anticancer potential (IC₅₀—21.6 µg/mL) with respect to methotrexate (IC₅₀—17.7 µg/mL) against lung cancer cell line A549, and they did not result in any significant inhibition of the normal cell line BEAS-2. The particles were found to alter the mitochondrial membrane potential, thereby disturbing ATP synthesis and leading to high ROS formation, which are responsible for cell membrane damage and release of LDH, intracellular proteins, lipids, and DNA. A high level of ROS also elicits pro-inflammatory signaling cascades that lead to programmed cell death by either apoptosis or necrosis.

Mycopharmaceuticals and Nutraceuticals: Promising Agents to Improve Human Well-Being and Life Quality

Fungi, especially edible mushrooms, are considered as high-quality food with nutritive and functional values. They are of considerable interest and have been used in the synthesis of nutraceutical supplements due to their medicinal properties and economic significance. Specific fungal groups, including predominantly filamentous endophytic fungi from Ascomycete phylum and several Basidiomycetes, produce secondary metabolites (SMs) with bioactive properties that are involved in the antimicrobial and antioxidant activities. These beneficial fungi, while high in protein and important fat contents, are also a great source of several minerals and vitamins, in particular B vitamins that play important roles in carbohydrate and fat metabolism and the maintenance of the nervous system. This review article will summarize and discuss the abilities of fungi to produce antioxidant, anticancer, antiobesity, and antidiabetic molecules while also reviewing the evidence from the last decade on the importance of research in fungi related products with direct and indirect impact on human health.

Development of Antimicrobial Laser-Induced Photodynamic Therapy Based on Ethylcellulose/Chitosan Nanocomposite with 5,10,15,20-Tetrakis(m-Hydroxyphenyl)porphyrin

The development of new antimicrobial strategies that act more efficiently than traditional antibiotics is becoming a necessity to combat multidrug-resistant pathogens. Here we report the efficacy of laser-light-irradiated 5,10,15,20-tetrakis(m-hydroxyphenyl)porphyrin (mTHPP) loaded onto an ethylcellulose (EC)/chitosan (Chs) nanocomposite in eradicating multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Surface loading of the ethylcelllose/chitosan composite with mTHPP was carried out and the resulting nanocomposite was fully characterized. The results indicate that the prepared nanocomposite incorporates mTHPP inside, and that the composite acquired an overall positive charge. The incorporation of mTHPP into the nanocomposite enhanced the photo- and thermal stability. Different laser wavelengths (458; 476; 488; 515; 635 nm), powers (5-70 mW), and exposure times (15-45 min) were investigated in the antimicrobial photodynamic therapy (aPDT) experiments, with the best inhibition observed using 635 nm with the mTHPP EC/Chs nanocomposite for C. albicans (59 ± 0.21%), P. aeruginosa (71.7 ± 1.72%), and S. aureus (74.2 ± 1.26%) with illumination of only 15 min. Utilization of higher doses (70 mW) for longer periods achieved more eradication of microbial growth.