Secondary metabolites from endophytic fungi: Production, methods of analysis, and diverse pharmaceutical potential

Role of Endophytic Fungi in the Biosynthesis of Metal Nanoparticles and Their Potential as Nanomedicines

Metal nanoparticles (MNPs) produced through biosynthesis approaches have shown favourable physical, chemical, and antimicrobial characteristics. The significance of biological agents in the synthesis of MNPs has been acknowledged as a promising alternative to conventional approaches such as physical and chemical methods, which are confronted with certain challenges. To meet these challenges, the use of endophytic fungi as nano-factories for the synthesis of MNPs has become increasingly popular worldwide in recent times. This review provides an overview of the synthesis of MNPs using endophytic fungi, the mechanisms involved, and their important biomedical applications. A special focus on different biomedical applications of MNPs mediated endophytic fungi involved their antibacterial, antifungal, antiviral, and anticancer applications and their potential as drug delivery agents. Furthermore, this review highlights the significance of the use of endophytic fungi for the green synthesis of MNPs and discusses the benefits, challenges, and prospects in this field.

Antimicrobial, Quorum Sensing Inhibition, and Anti-Cancer Activities of Silver Nanoparticles Synthesized from Kenyan Bacterial Endophytes of Teclea nobilis

Untapped bioactive compounds from microbial endophytes offer a promising solution to counter antimicrobial and chemotherapeutic drug resistance when complexed as silver nanoparticles (AgNPs). AgNPs were biosynthesized using cell-free supernatants from endophytic Streptomyces sp. KE4D and Bacillus safensis KE4K isolated from the Kenyan medicinal plant Teclea nobilis, following fermentation in three different media. Bacterial extracts were analyzed using gas chromatography-mass spectrometry. AgNPs were characterized using Fourier-transform infrared spectroscopy and high-resolution transmission electron microscopy. Antimicrobial activity was assessed using agar well diffusion assays, and quorum sensing inhibition (QSI) was investigated using Chromobacterium violaceum. Anti-cancer potential was evaluated against breast (MCF-7) and prostate cancer (DU-145) cell lines using MTT assays. AgNPs were 5-55 nm in size, with KE4D AgNPs being spherical and KE4K AgNPs exhibiting various shapes. Cyclopropane acetic acids and fatty acids were identified as possible capping agents. Medium-dependent antimicrobial activity was observed, with medium Mannitol and medium 5294 AgNPs displaying stronger activity, particularly against Gram-negative indicators. KE4D medium 5294 AgNPs demonstrated 85.12% violacein inhibition at 140 µg/mL and better QSI activity, whilst KE4K AgNPs were better antimicrobials. The AgNPs IC50 values were <3.5 µg/mL for MCF-7 and <2.5 µg/mL for DU-145 cells. The bioactivity of biosynthesized AgNPs is influenced by the bacterial isolate and fermentation medium, suggesting that AgNP synthesis can be tailored for specific bioactivity.

5,6-Dihydro-5,6-Epoxymultiplolide A, Cytosporone C, and Uridine Production by Diaporthe hongkongensis, an Endophytic Fungus from Minquartia guianensis

Endophytic fungi are valuable sources of bioactive secondary metabolites, with potential applications in pharmaceutical and agricultural fields. This study investigates the metabolic potential of Diaporthe hongkongensis, an endophytic fungus isolated from Minquartia guianensis. To date, no secondary metabolites have been identified from this species, highlighting the novelty of this research and its contribution to understanding the chemical diversity of endophytic fungi. The fungus was cultivated on parboiled rice under static and dark conditions for 28 days, leading to the isolation of the following three compounds: 5,6-dihydro-5,6-epoxymultiplolide A (1), cytosporone C (2), and uridine (3). Structural identification was carried out using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. The results revealed the metabolic versatility of D. hongkongensis, as demonstrated by its ability to produce structurally diverse substances with biological relevance. Hence, it describes the first isolation of secondary metabolites from the endophytic fungus D. hongkongensis, marking a significant step in understanding its chemical profile. The identification of a known antifungal compound and a lactone derivative underscores the biosynthetic potential of this endophytic fungus, while the isolation of a nucleoside expands the chemical repertoire of fungal metabolites, suggesting possible roles in cellular metabolism and stress adaptation. These findings highlight the role of endophytic fungi as prolific sources of structurally diverse and potentially bioactive natural products, supporting further exploration of their biotechnological applications.

Essential oils inhibiting Alternaria alternata and Colletotrichum gloeosporioides: a review

Essential oils (EOs) have been investigated for their effectiveness against fungal fruit pathogens. The present review article summarises the EOs that inhibit Alternaria alternata and Colletotrichum gloeosporioides in the pre- and post-harvest stages of fruits. Thirty-nine scientific papers focusing on the extraction conditions and the antifungal activity of EOs were selected. The retrieved studies came mainly from China and Brazil. Hydrodistillation has been identified as the most used extractive method. The yields and chemical profiles were variable among the species. The in vitro studies were larger than the in vivo studies. The application of EOs reduced the incidence of fungal diseases in tomatoes (Lycopersicon esculentum), papaya (Carica papaya) and mango (Mangifera indica). EOs resulted as a potential ecological alternative for treating fungal diseases in fruits requiring further investigation.

Metabolite profiling and bioactivity of fungal endofauna from Xiphinema nuragicum in the rhizosphere of Withania somnifera

Gut-associated fungal endofauna confronted with stressful conditions have the potential to secrete diverse bioactive metabolites. In this context, the present study aims to uncover the hidden metabolite profiling of less explored fungal gut parasites associated with rhizosphere nematodes of Withania somnifera. The nematode Xiphinema nuragicum, predominantly found in W. somnifera rhizosphere, was explored for its gut endofauna. This study represents the first report on the isolation of X. nuragicum from the rhizosphere of W. somnifera and the exploration of endofauna inhabiting the gut of X. nuragicum. Among different fungal isolates inhabiting the gut of X. nuragicum, Fusarium fujikuroi (R3) was found to be the most potent isolate and was therefore selected for the isolation and identification of its active metabolites. Three compounds were characterized from F. fujikuroi, namely di (2-ethylhexyl) phthalate (DEHP), 2,5-bis(1,1-dimethylethyl) phenol, and 1,4-di-tert-butyl-2-chlorobenzene. The compounds exhibited strong cytotoxic and anti-inflammatory activities with potential therapeutic applications. The present study also revealed the bioremediation potential of X. nuragicum, hosting F. fujikuroi already known for its ability to eliminate environmental pollutants such as DEHP and polycyclic aromatic hydrocarbons (PAHs). Despite these promising findings, in-depth mechanistic studies would be the future perspective of the current study.

Two undescribed benzofuran derivatives from chaetomium elatum

Two undescribed benzofuran derivatives (1-2) were isolated from Chaetomium elatum using silica gel, Sephadex LH-20 column chromatography, and preparative high-performance liquid chromatography (HPLC). The structures of compound 1-2 were characterised by HRESIMS, NMR, HMBC, NOESY spectral analyses, and ECD calculations. Compounds 1-2 demonstrated the ability to mitigate the inflammatory response triggered by lipopolysaccharide (LPS) in RAW264.7 macrophages, as evidenced by RT-PCR assay results showing suppression of key inflammatory factors at the concentration of 30 μM. These findings suggest that 1-2 possess promising anti-inflammatory properties.

Culture-dependent and -independent analyses reveal unique community structure and function in the external mycelial cortices of Ophiocordyceps sinensis

Ophiocordyceps sinensis, also known as DongChong XiaCao (DCXC) in China, is a complex of the parasitic fungus Hirsutella sinensis and its caterpillars host living in extreme alpine environments on the Qinghai-Tibetan Plateau. Wild resources of O. sinensis are threatened by over-harvesting due to its perceived high medicinal value. In recent years, numerous studies have pointed out that endofungal bacteria play an important role in fungal spore germination and zygote formation. In this sense, studying the endofungal bacteria of O. sinensis is of great interest regarding the conservation of this species. In this study, we investigated the community structure (abundance and rare sub-communities) and function of the soil-mycelial-sclerotia-stromata continuum endofungal bacteria in O. sinensis from the Qilian Mountain region of the Tibetan Plateau by using amplicon and macro-genome sequencing technologies. Based on the results, rare taxa exhibited more differences among the components, and enrichment and co-occurrence network analyses revealed that abundant taxa played a more important role. We further found that endofungal bacteria in external mycelial cortices have unique community structures and functions. In particular, they play an important role in material cycling, potentially providing essential nutrients during the lifecycle of O. sinensis. We successfully isolated 52 endofungal bacterial strains using high-throughput isolation techniques, some of them were undetected by high-throughput sequencing. We systematically investigated the structure and function of endofungal bacteria of the O. sinensis, providing a solid foundation for the cultivation and conservation of wild resources of this species at an industrial scale.

Endophytic fungi isolated from Vietnamese nut grass (Cyperus rotundus L. Cyperaceae) - A promising solution to mitigate the prime phenomenon of antibiotic resistance

Multidrug resistance in bacteria poses a significant threat to global health, creating an urgent need for new sources of antibiotics. Nut grass or Cyperus rotundus L., a common Asian medicinal herbal remedy, is gaining increasing attention in the scientific community as a potential source of antimicrobial agents. In this study, endophytic fungi living in this plant were isolated, macro- and micrologically identified, and assessed for their antibacterial properties on both Gram-positive and Gram-negative bacteria. As a result, seven types of endophytic fungi with potential antibacterial activities were obtained from Vietnamese Cyperus rotundus L. These endophytic strains could inhibit Gram-positive bacteria, including Bacillus subtilis, Methicilin-susceptible Staphylococcus aureus (MSSA), and Methicilin-resistant Staphylococcus aureus (MRSA). In particular, the most potent fungus could effectively inhibit not only MRSA but also Escherichia coli, and Pseudomonas aeruginosa. Furthermore, a significant impact of the culture medium on the biomass' antibacterial activity was observed and the Potato Dextrose Agar (PDA) and Czapek-Dox (Cz) media were shown to be the most appropriate culture medium. Altogether, endophytic fungi isolated from Cyperus rotundus L. were shown to be a promising source for antibiotics to tackle the problem of antibiotic resistance.

An Update of Fungal Endophyte Diversity and Strategies for Augmenting Therapeutic Potential of their Potent Metabolites: Recent Advancement

Endophytic fungi represent a significant renewable resource for the discovery of pharmaceutically important compounds, offering substantial potential for new drug development. Their ability to address the growing issue of drug resistance has drawn attention from researchers seeking novel, nature-derived lead molecules that can be produced on a large scale to meet global demand. Recent advancements in genomics, metabolomics, bioinformatics, and improved cultivation techniques have significantly aided the identification and characterization of fungal endophytes and their metabolites. Current estimates suggest there are approximately 1.20 million fungal endophytes globally, yet only around 16% (190,000) have been identified and studied in detail. This underscores the vast untapped potential of fungal endophytes in pharmaceutical research. Research has increasingly focused on the transformation of bioactive compounds by fungal endophytes through chemical and enzymatic processes. A notable example is the anthraquinone derivative 6-O-methylalaternin, whose cytotoxic potential is enhanced by the addition of a hydroxyl group, sharing structural similarities with its parent compound macrosporin. These structure-bioactivity studies open up new avenues for developing safer and more effective therapeutic agents by synthesizing targeted derivatives. Despite the immense promise, challenges remain, particularly in the large-scale cultivation of fungal endophytes and in understanding the complexities of their biosynthetic pathways. Additionally, the genetic manipulation of endophytes for optimized metabolite production is still in its infancy. Future research should aim to overcome these limitations by focusing on more efficient cultivation methods and deeper exploration of fungal endophytes' genetic and metabolic capabilities to fully harness their therapeutic potential.

Potent antibacterial and cytotoxic bioactive compounds from endophytic fungi Diaporthe sp. associated with Salacia intermedia

Antibacterial screening of endophytic fungi from Salacia intermedia identified Diaporthe longicolla as a potent strain exhibiting good activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa, with an MIC of 39.1 µg/mL. Scale-up fermentation and chromatographic purification of this strain yielded three known compounds, which were cytochalasin J (1), cytochalasin H (2), and dicerandrol C (3), as identified by liquid chromatography - high mass resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance (NMR) spectroscopy. Among those compounds, dicerandrol C exhibited broad-spectrum antibacterial activity against ATCC and multidrug-resistant strains of Bacillus subtilis, S. aureus, and P. aeruginosa, and multidrug-resistant strains of Klebsiella pneumoniae and Escherichia coli, with MIC values ranging from 1.04 to 33.30 µM. Furthermore, dicerandrol C outperformed tetracycline in antibacterial efficacy against S. aureus ATCC 6538 and methicillin-resistant S. aureus (MRSA) strains (MIC of 1.04 µM). Further antibacterial evaluation showed that cytochalasin J (221.43 µM), cytochalasin H (202.59 µM), and dicerandrol C (tested at its MIC values of 1.04 µM for S. aureus ATCC 6538 and 16.65 µM for P. aeruginosa ATCC 15442) significantly inhibited bacterial biofilm formation. The biofilm inhibition percentages ranged from 61.09 to 78.17% for S. aureus and 41.22-56.83% for P. aeruginosa. In cytotoxicity assays against MCF-7 cells, all three compounds reduced cell viability (48.68-74.50%), with dicerandrol C demonstrating the highest potency. These findings highlight the potential of dicerandrol C as a powerful antibacterial and cytotoxic agent, facilitating further investigations into its therapeutic applications.

Endophytic Fungi of Calea pinnatifida (Asteraceae): Dereplication of Crude Extracts, Antimicrobial Properties, and Identification of New Tetronic Acid Derivative Produced by Hypomontagnella barbarensis

Endophytic fungi are increasingly being recognized for their diverse metabolites that may exhibit antimicrobial properties. In our study, we isolated seven endophytic fungal strains from Calea pinnatifida, which were identified as Hypomontagnella barbarensis, Neopestalotiopsis clavispora, Nigrospora sacchari-officinarum, Annulohypoxylon moriforme, Colletotrichum siamense, and Colletotrichum karstii (with two isolates from the same species). Furthermore, the antimicrobial activity of the extracts was assessed, revealing that the extract from Hypomontagnella barbarensis demonstrated activity against Staphylococcus aureus. Further investigation of secondary metabolites, employing UHPLC-HR-ESI-MS/MS in combination with molecular networking, facilitated annotation of the nine compounds. Of these, five were identified based on matches with the GNPS spectral library, and four were predicted based on the molecular network. Notably, from the extract of Hypomontagnella barbarensis, two pairs of diastereoisomeric acyl-tetronic acid derivatives were isolated and characterized using MS and NMR spectroscopy. This study highlights the potential of endophytic fungi as a valuable source of novel antimicrobial agents.

Phytochemistry, Antibacterial and Antioxidant Activities of Grewia lasiocarpa E. Mey. Ex Harv. Fungal Endophytes: A Computational and Experimental Validation Study

The genus Grewia are well-known for their medicinal properties and are widely used in traditional remedies due to their rich phytochemical composition and potential health benefits. This study isolated and characterized five endophytic fungi from Grewia lasiocarpa E. Mey. Ex Harv. and evaluated their in vitro antibacterial and antioxidant activities. Five [Aspergillus fumigatus (MK243397.1), A. fumigatus (MK243451.1), Penicillium raistrickii (MK243492.1), P. spinulosum (MK243479.1), Meyerozyma guilliermondii (MK243634.1)] of the 22 isolated endophytic fungi had inhibitory activity (62.5-1000 µg/mL) against methicillin-resistant Staphylococcus aureus (MRSA). The antioxidant activities were 66.5% and 98.4% for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP), respectively. In silico evaluation of the phytochemicals of the extract (containing majorly n-hexadecanoic acid) was performed against penicillin-binding protein 2a (PBP2a) implicated in the broad clinical resistance of MRSA to conventional beta-lactams. Molecular docking and molecular dynamic simulation analyses revealed that the phytosterol constituents of the extract, especially dehydroergosterol (-46.28 kcal/mol), had good stability (4.35 Å) and compactness (35.08 Å) with PBP2a relative to the unbound PBP2a and amoxicillin-PBP2a complex during the 100 ns simulation period, reinforcing them as putative leads that may be developed as viable alternatives to beta-lactams against infections caused by MRSA. However, the prediction that dehydroergosterol lacks oral bioavailability with poor water solubility suggests that it could benefit from structural optimization for improved druggability. Hence, isolating and derivatizing dehydroergosterol for subsequent evaluation against PBP2a in vitro and in vivo is highly recommended.

Endophytic fungi: nature's solution for antimicrobial resistance and sustainable agriculture

The growing threat of antimicrobial resistance (AMR) has underlined the need for a sustained supply of novel antimicrobial agents. Endophyte microorganism that reside within plant tissues as symbionts have been the source of potential antimicrobial substances. However, many novel and potent antimicrobials are yet to be discovered from these endophytes. The present study investigates the potential of endophytic fungi as a source of novel bioactive chemicals with antibacterial capabilities. These fungi synthesize secondary metabolites such as polyketides and peptides via polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) pathways. Notable substances, like prenylated indole alkaloids and fumaric acid, have shown promising antibacterial and antifungal properties against multidrug-resistant infectious agents. This review also emphasizes the symbiotic link between endophytes and their host plants, which is critical for secondary metabolite production. The study focuses on the significance of isolation methods for endophytes and proposes their use in for sustainable agriculture, bioremediation, and medicine. Future research combining endophytic biodiversity analysis with next-generation sequencing (NGS) and nanotechnology could provide novel techniques for combating AMR and contributing to sustainability across multiple industries.

Effect of Mn(II) and Co(II) on Anti-Candida Metabolite Production by Aspergillus sp. an Endophyte Isolated from Dizygostemon riparius (Plantaginaceae)

Background/Objectives: This study evaluates the effect of Mn(II) and Co(II) ions on the production of anti-Candida metabolites by the endophytic fungus Aspergillus sp., isolated from Dizygostemon riparius. The objective was to identify metal-induced secondary metabolites with antifungal potential against drug-resistant Candida species. Methods: Aspergillus sp. was cultivated in Czapek agar supplemented with MnCl₂ (400 µM) or CoCl₂ (200 µM). Metabolite profiles were analyzed using UHPLC-DAD and LC-ESI-HRMS, followed by structural elucidation via NMR. Antifungal and biofilm inhibition activities were tested against Candida albicans and Candida parapsilosis. Toxicity was assessed using Tenebrio molitor larvae. Results: Key metabolites, including pyrophen, penicillquei B, and fonsecinone B, demonstrated antifungal activity with MIC values of 4.37-280.61 µg/mL. Fonsecinone B exhibited superior biofilm inhibition, surpassing fluconazole in reducing biofilm biomass and viability. In vivo assays showed low toxicity, with survival rates above 80% at 2× MIC/kg. Conclusions: Mn(II) and Co(II) significantly modulated the production of antifungal metabolites in Aspergillus sp. Fonsecinone B emerged as a promising candidate for antifungal therapy due to its potent activity and low toxicity. These findings support further investigation into the therapeutic potential of metal-induced fungal metabolites for combating drug-resistant Candida infections.

A Comprehensive Review of the Diversity of Fungal Secondary Metabolites and Their Emerging Applications in Healthcare and Environment

Fungi and their natural products, like secondary metabolites, have gained a huge demand in the last decade due to their increasing applications in healthcare, environmental cleanup, and biotechnology-based industries. The fungi produce these secondary metabolites (SMs) during the different phases of their growth, which are categorized into terpenoids, alkaloids, polyketides, and non-ribosomal peptides. These SMs exhibit significant biological activity, which contributes to the formulation of novel pharmaceuticals, biopesticides, and environmental bioremediation agents. Nowadays, these fungal-derived SMs are widely used in food and beverages, for fermentation, preservatives, protein sources, and in dairy industries. In healthcare, it is being used as an antimicrobial, anticancer, anti-inflammatory, and immunosuppressive drug. The usage of modern tools of biotechnology can achieve an increase in demand for these SMs and large-scale production. The present review comprehensively analyses the diversity of fungal SMs along with their emerging applications in healthcare, agriculture, environmental sustainability, and nutraceuticals. Here, the authors have reviewed the recent advancements in genetic engineering, metabolic pathway manipulation, and synthetic biology to improve the production and yield of these SMs. Advancement in fermentation techniques, bioprocessing, and co-cultivation approaches for large-scale production of SMs. Investigators further highlighted the importance of omics technologies in understanding the regulation and biosynthesis of SMs, which offers an understanding of novel applications in drug discovery and sustainable agriculture. Finally, the authors have addressed the potential for genetic manipulation and biotechnological innovations for further exploitation of fungal SMs for commercial and environmental benefits.

Rediscovering the chemistry of the Cunninghamella species: potential fungi for metabolites and enzymes of biological, industrial, and environmental values

Endophytic fungi have a strong affinity for producing the same or comparable compounds to those produced by their hosts. Herein, genetic diversity and environmental adaptation of the Cunninghamella species were briefly investigated. The genetic flexibility in Cunninghamella represents an evolutionary mechanism that allows them to respond effectively to environmental changes. The current review paid much attention toward the phytochemical screening of Cunninghamella sp., revealing the presence of alkaloids, unsaturated sterols, fatty acids, polyphenols, and quinones. The intensive investigations clarified that Cunninghamella sp. are distinguished in producing several numbers of fatty acids, in particular polyunsaturated fatty acids (PUFA), in large quantities compared to other metabolites. The study demonstrated the effective role of Cunninghamella sp. in forming several bioactive metabolites owing to cytochrome P450 (CYP) that confirm significant value of such species for potential media biotransformation. The comparative investigations revealed that the isolation of flavonoids is yet to be reported, while the number of elucidated alkaloids and steroids is still limited. In contrast, successful results in the biotransformation of these metabolites were verified and showed a high affinity to convert simple substances to more valuable agents by Cunninghamella. The biomedical applications of naturally occurring compounds isolated from Cunninghamella were well documented; these included their antimicrobial, anti-cancer, anti-inflammatory, anti-Alzheimer, and antiaging properties. The antimicrobial activity was mostly attributed to the fatty acid contents in Cunninghamella sp. Moreover, tremendous attention was paid towards the agricultural and industrial usage of chitosan as it is one of the most crucial metabolites involved in wide applications. Chitosan is involved in food preservation for extending life storage period and utilized as biofertilizer, which enhances bacterial disease resistance. In addition, Cunninghamella is considered an important enzyme reservoir. Various Cunninghamella sp. produce several important enzymes, such as lignin peroxidase, catalase, cellulase, xylanase, laccase, and CYPs, that can be used for remediation, fertilization, preservation and medicinal purposes. Hence, further in-depth investigations are highly recommended to explore new insights into this potential reservoir of a wide spectrum of chemicals for industrial, medicinal, agricultural, and environmental applications.

Lamiaceae family-derived endophytic fungi: induced tolerance to drought stress in Thymus vulgaris plants

BACKGROUND

Thymus vulgaris is a valuable medicinal plant widely cultivated for its aromatic and medicinal properties. However, like many plants, T. vulgaris faces challenges such as drought stress, which significantly affects its growth, morphological, physiological, and biochemical processes. Understanding how endophytic fungi isolated from Lamiaceae family influence T. vulgaris under varying watering regimes can enhance its resilience against drought stress. This study aims to assess the impact of individual and co-inoculation of three native endophytic species, i.e., Fusarium sp. (F1), Cladosporium puyae (F2), and Curvularia australiensis (F3), on T. vulgaris growth parameters under different irrigation regimes in greenhouse conditions.

RESULTS

It has been discovered that using fungal endophytes as a biological tool can benefits T. vulgaris under drought stress. The results indicated that drought stress significantly reduced the growth, chlorophyll, and carotenoid content of plants lacking endophytes. Combinatory applications with fungal endophytes significantly improved the above-mentioned parameters under drought stress. Lipid peroxidation levels were significantly reduced in plants inoculated with bacterial endophytes. Drought stress significantly increased the activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), glutathione reductase (GR), peroxidase (POD), and catalase (CAT) in drought conditions.

CONCLUSIONS

The findings suggested that the addition of fungal endophytes to the inoculum enhances drought tolerance in T. vulgaris by mitigating the harmful impact of drought stress on plant growth and physiological functions. The higher activity of antioxidant enzymes and improved redox state of glutathione are responsible for plants' greater resistance to drought.

Endophytic Fungi: Cellular factories of novel medicinal chemistries

Inflammation and associated disorders have been a major contributing factor to mortality worldwide. The augmented mortality rate and emerging resistance against the approved therapeutics necessitate the discovery of novel chemistries destined for multiple clinical settings. Cellular factories including endophytic fungi have been tapped for chemical diversity with therapeutic potential. The emerging evidence has suggested the potential of bioactive compounds isolated from the endophytic fungi as putative agents to combat inflammation-associated disorders. The review summarizesand assists the readers in comprehending the structural and functional aspects of the medicinal chemistries identified from endophytic fungi as anticancer, antiobesity, antigout, and immunomodulatory agents.

Exploring Endophytic Fungi as Natural Antagonists against Fungal Pathogens of Food Crops

The yield and quality of cultivated food crops are frequently compromised by the prevalent threat from fungal pathogens that can cause widespread damage in both the pre-harvest and post-harvest stages. This paper investigates the challenges posed by fungal pathogens to the sustainability and yield of essential food crops, leading to significant economic and food security repercussions. The paper critiques the long-standing reliance on synthetic fungicides, emphasizing the environmental and health concerns arising from their widespread and occasionally inappropriate use. In response, the paper explores the potential of biological control agents, specifically endophytic fungi in advancing sustainable agricultural practices. Through their diverse symbiotic relationships with host plants, these fungi exhibit strong antagonistic capabilities against phytopathogenic fungi by producing various bioactive compounds and promoting plant growth. The review elaborates on the direct and indirect mechanisms of endophytic antagonism, such as antibiosis, mycoparasitism, induction of host resistance, and competition for resources, which collectively contribute to inhibiting pathogenic fungal growth. This paper consolidates the crucial role of endophytic fungi, i.e., Acremonium, Alternaria, Arthrinium, Aspergillus, Botryosphaeria, Chaetomium, Cladosporium, Cevidencealdinia, Epicoccum, Fusarium, Gliocladium, Muscodor, Nigrospora, Paecilomyces, Penicillium, Phomopsis, Pichia, Pochonia, Pythium, Ramichloridium, Rosellinia, Talaromyces, Trichoderma, Verticillium, Wickerhamomyces, and Xylaria, in biological control, supported by the evidence drawn from more than 200 research publications. The paper pays particular attention to Muscodor, Penicillium, and Trichoderma as prominent antagonists. It also emphasizes the need for future genetic-level research to enhance the application of endophytes in biocontrol strategies aiming to highlight the importance of endophytic fungi in facilitating the transition towards more sustainable and environmentally friendly agricultural systems.

Fungi-Derived Bioactive Compounds as Potential Therapeutic Agents for Pancreatic Cancer: A Systematic Review

Pancreatic cancer (PC) is one of the tumors with the lowest 5-year survival rate worldwide due to late diagnosis and lack of effective therapy. Because of this, it is necessary to discover new ways of treatment to increase the quality of life of patients. In this context, the secondary metabolites of several fungi have been shown as a possible therapeutic strategy in several types of cancer, such as colorectal cancer, being able to trigger their action through the induction of apoptosis. The objective was to perform a systematic review process to analyze the studies carried out during the last ten years using secondary metabolites derived from fungi as antitumor treatment against PC. After the search process in three databases (PubMed, SCOPUS, and Web of Science) a total of 199 articles were found, with 27 articles finally being included after screening. The results extracted from this systematic review process made it possible to determine the existence of bioactive compounds extracted from fungi that have been effective in in vitro and in vivo conditions and that may be applicable as a possible therapy to avoid drug resistance in PC, one of the major problems of this disease.

Microbial allies: exploring fungal endophytes for biosynthesis of terpenoid indole alkaloids

Terpenoid indole alkaloids (TIAs) are natural compounds found in medicinal plants that exhibit various therapeutic activities, such as antimicrobial, anti-inflammatory, antioxidant, anti-diabetic, anti-helminthic, and anti-tumor properties. However, the production of these alkaloids in plants is limited, and there is a high demand for them due to the increasing incidence of cancer cases. To address this research gap, researchers have focused on optimizing culture media, eliciting metabolic pathways, overexpressing genes, and searching for potential sources of TIAs in organisms other than plants. The insufficient number of essential genes and enzymes in the biosynthesis pathway is the reason behind the limited production of TIAs. As the field of natural product discovery from biological species continues to grow, endophytes are being investigated more and more as potential sources of bioactive metabolites with a variety of chemical structures. Endophytes are microorganisms (fungi, bacteria, archaea, and actinomycetes), that exert a significant influence on the metabolic pathways of both the host plants and the endophytic cells. Bio-prospection of fungal endophytes has shown the discovery of novel, high-value bioactive compounds of commercial significance. The discovery of therapeutically significant secondary metabolites has been made easier by endophytic entities' abundant but understudied diversity. It has been observed that fungal endophytes have better intermediate processing ability due to cellular compartmentation. This paper focuses on fungal endophytes and their metabolic ability to produce complex TIAs, recent advancements in this area, and addressing the limitations and future perspectives related to TIA production.

The inhibitory effects of endophytic metabolites on glycated proteins under non-communicable disease conditions: A review

Protein glycation in human body is closely linked to the onset/progression of diabetes associated complications. These glycated proteins are commonly known as advanced glycation end products (AGEs). Recent literature has also highlighted the involvement of AGEs in other non-communicable diseases (NCDs) such as cardiovascular, cancer, and Alzheimer's diseases and explored the impact of plant metabolites on AGEs formation. However, the significance of endophytic metabolites against AGEs has recently garnered attention but has not been thoroughly summarized thus far. Therefore, the objective of this review is to provide a comprehensive overview of the importance of endophytic metabolites in combating AGEs under NCDs conditions. Additionally, this review aims to elucidate the processes of AGEs formation, absorption, metabolism, and their harmful effects. Collectively, endophytic metabolites play a crucial role in modulating signaling pathways and enhancing the digestibility properties of gut microbiota (GM) by targeting on AGEs/RAGE (receptor for AGEs) axis. Furthermore, these metabolites exhibit anti-AGEs activities similar to those derived from host plants, but at a lower cost and higher production rate. The use of endophytes as a source of such metabolites offers a risk-free and sustainable approach that holds substantial potential for the treatment and management of NCDs.

An Investigation of Quorum Sensing Inhibitors against Bacillus cereus in The Endophytic Fungus Pithomyces sacchari of the Laurencia sp

Bacillus cereus, a common food-borne pathogen, forms biofilms and generates virulence factors through a quorum sensing (QS) mechanism. In this study, six compounds (dankasterone A, demethylincisterol A3, zinnimidine, cyclo-(L-Val-L-Pro), cyclo-(L-Ile-L-Pro), and cyclo-(L-Leu-L-Pro)) were isolated from the endophytic fungus Pithomyces sacchari of the Laurencia sp. in the South China Sea. Among them, demethylincisterol A3, a sterol derivative, exhibited strong QS inhibitory activity against B. cereus. The QS inhibitory activity of demethylincisterol A3 was evaluated through experiments. The minimum inhibitory concentration (MIC) of demethylincisterol A3 against B. cereus was 6.25 μg/mL. At sub-MIC concentrations, it significantly decreased biofilm formation, hindered mobility, and diminished the production of protease and hemolysin activity. Moreover, RT-qPCR results demonstrated that demethylincisterol A3 markedly inhibited the expression of QS-related genes (plcR and papR) in B. cereus. The exposure to demethylincisterol A3 resulted in the downregulation of genes (comER, tasA, rpoN, sinR, codY, nheA, hblD, and cytK) associated with biofilm formation, mobility, and virulence factors. Hence, demethylincisterol A3 is a potentially effective compound in the pipeline of innovative antimicrobial therapies.

Antimicrobial Action Mechanisms of Natural Compounds Isolated from Endophytic Microorganisms

Infectious diseases are a significant challenge to global healthcare, especially in the face of increasing antibiotic resistance. This urgent issue requires the continuous exploration and development of new antimicrobial drugs. In this regard, the secondary metabolites derived from endophytic microorganisms stand out as promising sources for finding antimicrobials. Endophytic microorganisms, residing within the internal tissues of plants, have demonstrated the capacity to produce diverse bioactive compounds with substantial pharmacological potential. Therefore, numerous new antimicrobial compounds have been isolated from endophytes, particularly from endophytic fungi and actinomycetes. However, only a limited number of these compounds have been subjected to comprehensive studies regarding their mechanisms of action against bacterial cells. Furthermore, the investigation of their effects on antibiotic-resistant bacteria and the identification of biosynthetic gene clusters responsible for synthesizing these secondary metabolites have been conducted for only a subset of these promising compounds. Through a comprehensive analysis of current research findings, this review describes the mechanisms of action of antimicrobial drugs and secondary metabolites isolated from endophytes, antibacterial activities of the natural compounds derived from endophytes against antibiotic-resistant bacteria, and biosynthetic gene clusters of endophytic fungi responsible for the synthesis of bioactive secondary metabolites.

Harnessing fungal endophytes for natural management: a biocontrol perspective

In the ever-evolving realm of agriculture, the convoluted interaction between plants and microorganisms have assumed paramount significance. Fungal endophytes, once perceived as mere bystanders within plant tissues, have now emerged as dynamic defenders of plant health. This comprehensive review delves into the captivating world of fungal endophytes and their multifaceted biocontrol mechanisms. Exploring their unique ability to coexist with their plant hosts, fungal endophytes have unlocked a treasure trove of biological weaponry to fend off pathogens and enhance plant resilience. From the synthesis of bioactive secondary metabolites to intricate signaling pathways these silent allies are masters of biological warfare. The world of fungal endophytes is quite fascinating as they engage in a delicate dance with the plant immune system, orchestrating a symphony of defense that challenges traditional notions of plant-pathogen interactions. The journey through the various mechanisms employed by these enigmatic endophytes to combat diseases, will lead to revelational understanding of sustainable agriculture. The review delves into cutting-edge research and promising prospects, shedding light on how fungal endophytes hold the key to biocontrol and the reduction of chemical inputs in agriculture. Their ecological significance, potential for bioprospecting and avenues for future research are also explored. This exploration of the biocontrol mechanisms of fungal endophytes promise not only to enrich our comprehension of plant-microbe relationships but also, to shape the future of sustainable and ecofriendly agricultural practices. In this intricate web of life, fungal endophytes are indeed the unsung heroes, silently guarding our crops and illuminating a path towards a greener, healthier tomorrow.