Marine Fungi: A Source of Potential Anticancer Compounds

The cytochalasans: potent fungal natural products with application from bench to bedside

Covering: 2000-2023Cytochalasans are a fascinating class of natural products that possess an intricate chemical structure with a diverse range of biological activities. They are known for their complex chemical architectures and are often isolated from various fungi. These compounds have attracted attention due to their potential pharmacological properties, including antimicrobial, antiviral, and anticancer effects. For decades, researchers have studied these molecules to better understand their mechanisms of action and to explore their potential applications in medicine and other fields. This review article aims to shed light over the period 2000-2023 on the structural diversities of 424 fungal derived cytochalasans, insights into their biosynthetic origins, pharmacokinetics and their promising therapeutic potential in drug discovery and development.

Isolation of Ten New Sesquiterpenes and New Abietane-Type Diterpenoid with Immunosuppressive Activity from Marine Fungus Eutypella sp

Background: Ten new sesquiterpenes, including eight eremophilane-type sesquiterpenes (1-8) and two compounds (9-10) with a cyclopentane ring, representing an undescribed subtype of sesquiterpene, along with a new abietane-type diterpenoid (11), were isolated and identified from a deep-sea-derived fungus: Eutypella sp. Methods: Their structures were elucidated on the basis of various spectroscopic analyses, mainly including nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESIMS) data, 13C NMR calculations with DP4+ probability analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction experiments. Results: Furthermore, compound 11 exhibited potent immunosuppressive activity with IC50 values of 8.99 ± 1.08 μM in a lipopolysaccharide (LPS) model and 5.39 ± 0.20 μM in a concanavalin A (ConA) model.

The Cytotoxic Activity of Secondary Metabolites from Marine-Derived Penicillium spp.: A Review (2018-2024)

Marine-derived Penicillium spp., including Penicillium citrinum, Penicillium chrysogenum, and Penicillium sclerotiorum, have emerged as prolific producers of structurally diverse secondary metabolites with cytotoxic activity. This review systematically categorizes 177 bioactive compounds isolated from marine Penicillium spp. between 2018 and 2024, derived from diverse marine environments such as sediments, animals, plants, and mangroves. These compounds, classified into polyketides, alkaloids, terpenoids, and steroids, exhibit a wide range of cytotoxic activities. Their potency is categorized as potent (<1 μM or <0.5 μg/mL), notable (1-10 μM or 0.5-5 μg/mL), moderate (10-30 μM or 5-15 μg/mL), mild (30-50 μM or 15-25 μg/mL), and negligible (>50 μM or >25 μg/mL). The current review highlights the promising role of marine Penicillium spp. as a rich repository for the discovery of anticancer agents and the advancement of marine-inspired drug development.

Searching potential GSK-3β inhibitors from marine sources using atomistic simulations

Glycogen synthase kinase-3 beta, GSK-3β, is one of the most common targets for cancer treatment. Inhibiting the biological activity of the enzyme can lead to the prevention of cancer development. Especially, estimating a new inhibitor for preventing GSK-3β by using natural compounds is of great interest. In this context, the marine compounds were investigated for their ligand-binding affinity to GSK-3β via atomistic simulations. The compounds, including xanalteric acid I, chaunolidone A, macrolactin V, and aspergiolide A, were suggested that can inhibit GSK-3β via molecular docking and steered-MD simulations. Moreover, the potency of these compounds was also confirmed via the perturbation simulations. Furthermore, the toxicity prediction also indicates that these compounds would adopt less toxicity. Therefore, it may be argued that four compounds can play as potential inhibitors preventing GSK-3β. In addition, the residues including Ile62, Val135, Pro136, Arg141, Lys183, Gln185, Asn186, and Asp200 play a crucial role in the GSK-3β binding process.

New steroid and meroterpenoids from a sewage fungus Eurotium sp

A new steroid, eurotether (1), and three new meroterpenoids, tricycloalternarene I (2), tricycloalternarene J (3) and (2R,3S,4aR)-altenuene-2-acetoxy ester B (4), along with six known compounds (5-10) were isolated from a sewage fungus Eurotium sp. XL-0006. Their structures were elucidated based on NMR analysis, electronic circular dichroism (ECD) calculations and single crystal X-ray diffraction experiments. Compound 1 was the first example of steroid combined with a dibenzo-α-pyrone through double oxygen bridges, and compounds 1-10 were first discovered from Eurotium genus. Compounds 1-6 were evaluated for antibacterial activities against eight clinical drug-resistant bacteria using the microbroth dilution method.

Diterpenoids of Marine Organisms: Isolation, Structures, and Bioactivities

Diterpenoids from marine-derived organisms represent a prolific source of secondary metabolites, characterized by their exceptionally promising chemical structures and pronounced pharmacological properties. In recent years, marine diterpenoids have garnered considerable attention and are regarded as a prominent area of scientific research. As a vital class of metabolites, diterpenoids show diverse biological activities, encompassing antibacterial, antifungal, antiviral, anti-inflammatory, inhibitory, and cytotoxic activities, among others. With the rapid advancement of equipment and identified technology, there has been a tremendous surge in the discovery rate of novel diterpenoid skeletons and bioactivities derived from marine fungi over the past decade. The present review compiles the reported diterpenoids from marine fungal sources mainly generated from January 2000 to December 2024. In this paper, 515 diterpenoids from marine organisms are summarized. Among them, a total of 281 structures from various fungal species are included, comprising 55 from sediment, 39 from marine animals (predominantly invertebrates, including 17 from coral and 22 from sponges), and 53 from marine plants (including 34 from algae and 19 from mangrove). Diverse biological activities are exhibited in 244 compounds, and among these, 112 compounds showed great anti-tumor activity (45.90%) and 110 metabolites showed remarkable cytotoxicity (45.08%). Furthermore, these compounds displayed a range of diverse bioactivities, including potent anti-oxidant activity (2.87%), promising anti-inflammatory activity (1.64%), great anti-bacterial activity (1.64%), notable anti-thrombotic activity (1.23%), etc. Moreover, the diterpenoids' structural characterization and biological activities are additionally elaborated upon. The present critical summary provides a comprehensive overview of the reported knowledge regarding diterpenoids derived from marine fungi, invertebrates, and aquatic plants. The systematic review presented herein offers medical researchers an extensive range of promising lead compounds for the development of marine drugs, thereby furnishing novel and valuable pharmaceutical agents.

Direct 3D Mass Spectrometry Imaging Analysis of Environmental Microorganisms

Assessing the spatial distribution of microorganisms' metabolites in growth medium remains a challenge. Here, we present the first use of the newly developed LARAPPI/CI-MSI 3D (laser ablation remote atmospheric pressure photoionization/chemical ionization mass spectrometry imaging) method for direct three-dimensional (3D) mass spectrometry imaging of bacterial and fungal metabolites in solid culture media. Two-dimensional (2D) MSI was also performed, and it indicated the presence of metabolites belonging to, and including, amino acids and their derivatives, dipeptides, organic acids, fatty acids, sugars and sugar derivatives, benzene derivatives, and indoles. Distribution at a selected depth within the culture medium with the estimation of concentration across all dimensions of 16 metabolites was visualized using LARAPPI/CI-MSI 3D. The imaging results were correlated with the results of ultra-high-performance liquid chromatography-ultra-high-resolution mass spectrometry (UHPLC-UHRMS). A total of 351-393 chemical compounds, depending on the tested microorganism, were identified, while 242-262 were recognized in the HMDB database in MetaboAnalyst (v 6.0). The LARAPPI/CI-MSI 3D method enables the rapid screening of the biotechnological potential of environmental strains, facilitating the discovery of industrially valuable biomolecules.

Multi-omics analysis of the correlation between surface microbiome and metabolome in Saccharina latissima (Laminariales, Phaeophyceae)

The microbiome of Saccharina latissima, an important brown macroalgal species in Europe, significantly influences its health, fitness, and pathogen resistance. Yet, comprehensive studies on the diversity and function of microbial communities (bacteria, eukaryotes, and fungi) associated with this species are lacking. Using metabarcoding, we investigated the epimicrobiota of S. latissima and correlated microbial diversity with metabolomic patterns (liquid chromatography coupled to tandem mass spectrometry). Specific epibacterial and eukaryotic communities inhabit the S. latissima surface, alongside a core microbiota, while fungal communities show lower and more heterogeneous diversity. Metabolomic analysis revealed a large diversity of mass features, including putatively annotated fatty acids, amino derivatives, amino acids, and naphthofurans. Multiple-factor analysis linked microbial diversity with surface metabolome variations, driven mainly by fungi and bacteria. Two taxa groups were identified: one associated with bacterial consortia and the other with fungal consortia, each correlated with specific metabolites. This study demonstrated a core bacterial and eukaryotic microbiota associated with a core metabolome and highlighted interindividual variations. Annotating the surface metabolome using Natural Products databases suggested numerous metabolites potentially involved in interspecies chemical interactions. Our findings establish a link between microbial community structure and function, identifying two microbial consortia potentially involved in the chemical defense of S. latissima.

Identification of novel cyclin-dependent kinase 4/6 inhibitors from marine natural products

Cyclin-dependent kinases 4 and 6 (CDK4/6) are crucial regulators of cell cycle progression and represent important therapeutic targets in breast cancer. This study employs a comprehensive computational approach to identify novel CDK4/6 inhibitors from marine natural products. We utilized structure-based virtual screening of the CMNPD database and MNP library, followed by rigorous filtering based on drug-likeness criteria, PAINS filter, ADME properties, and toxicity profiles. From an initial hit of 9,497 compounds, 2,344 passed drug-likeness and PAINS filters. Further ADME filtering yielded 50 compounds, of which 25 exhibited non-toxic profiles. These 25 candidates underwent consensus molecular docking using seven distinct algorithms: AutoDockTools 4.2, idock, LeDock, Qvina 2, Smina, AutoDock Vina 1.2.0, PLANTS, and rDock. Based on these results, six top-scoring compounds were selected for comprehensive 500 nanosecond all-atom molecular dynamics simulations to evaluate their structural stability and interactions with CDK4/6. Our analysis revealed that compounds CMNPD11585 and CMNPD2744 demonstrated superior stability in their interactions with CDK4/6, exhibiting lower RMSD and RMSF values, more favorable binding free energies, and persistent hydrogen bonding patterns. These compounds also showed lower Solvent Accessible Surface Area values, indicating better compatibility with the CDK4/6 active site. Subsequent in-vitro studies using MTT assays on MCF-7 breast cancer cells confirmed the cytotoxic effects of these compounds, with CMNPD11585 showing the highest potency, followed by CMNPD2744.

Combating COVID-19 and its co-infection by Aspergillus tamarii SP73-EGY using in vitro and in silico Studies

The COVID-19 pandemic has caused significant mortality and morbidity for millions of people. Severe Acute Respiratory Syndrome-2 (SARS-CoV-2) virus is capable of causing severe and fatal diseases. We evaluated the antiviral properties of Aspergillus tamarii SP73-EGY isolate extract against low pathogenic coronavirus (229E), Adeno-7- and Herpes-2 viruses. The extract showed a high selectivity index (SI = 43.4) and a significant inhibition of 229E (IC50 = 8.205 μg/ml). It was stronger than the drug control, remdesivir (IC50 = 38.2 μg/ml, SI = 7.29). However, the extract showed minimal efficacy against Adeno-7- and Herpes-2-Viruses (IC50 = 22.52, 47.79 μg/ml, and SI = 6.75, 5.08, respectively). It exhibited profound efficacy against the highly pathogenic SARS-CoV-2 (IC50 = 8.306 μg/ml, SI = 42.2). Kojic acid, the primary component of the extract, showed substantial antiviral activity against SARS-CoV-2 (IC50 = 23.4 μg/ml, SI = 5.6), Remdesivir (IC50 = 4.55 μg/ml, SI = 61.45). Therefore, the extract demonstrated the most notable antiviral characteristics against coronavirus infection. Co-infecting microorganisms may contribute to immune system deterioration and airway injury caused by SARS-CoV-2. The extract showed significant efficacy against E. coli and P. aeruginosa, with an inhibition range of 3.5-10 mm at a concentration of 200 mg/ml. A molecular docking study showed that hexadecanoic, Kojic, octanoic acids, and 4(4-Methylbenzylidene)cyclohexane-1,3-dione have stronger binding affinity to the SARS-CoV-2 Mpro than Remdesivir. Molecular dynamics simulations were employed to examine the structural stability and flexibility of these complexes. This confirmed the high binding affinities of Kojic acid and 4(4-Methylbenzylidene)cyclohexane-1,3-dione, thereby proving their potential as novel anti-SARS-CoV-2.

Novel compound, pleuropyronine, and other polyketides isolated from the edible mushroom Pleurotus ostreatus suppress bacterial biofilm formation

An increase in the number of drug-resistant microbes is a major threat to human health. Bacterial drug resistance is mostly mediated by biofilm formation. In this study, the culture filtrate from the edible mushroom, Pleurotus ostreatus, was fractionated to isolate compounds that inhibit the biofilm formation of six pathogenic bacteria. Notably, we isolated compounds 1-6 using bioassay-guided chromatographic separations. Spectroscopic and X-ray diffraction analyses identified 1 as a novel fused bicyclic pyrone-furan, named pleuropyronine, whereas 2-6 were known polyketides. Pleuropyronine inhibited biofilm formation in four Gram-negative bacteria, with IC50 values ranging from 5.4 to 8.7 µg/mL, whereas 2-6 exhibited IC50 values between 1.0 and 5.3 µg/mL against five bacteria. Additionally, pleuropyronine bioactivity was confirmed by the inhibition of exopolysaccharide and biofilm formation induced by C6-homoserine lactone. Thus, this may serve as a pioneering study on the pharmacological potential of isolated compounds, offering valuable insights for future research.

Anticancer Effect of Mycotoxins From Penicillium aurantiogriseum: Exploration of Natural Product Potential

Research into biologically natural substances with antitumor properties, known for their potential to induce fewer side effects and exhibit specificity toward cancerous cells, remains imperative. The pressing demand for novel agents in cancer therapy underscores the intensive investigation of natural products from microorganisms. Penicillium aurantiogriseum, frequently isolated from food and feed, emerges as a promising candidate against pathogenic bacteria and fungi. This species harbors numerous mycotoxins that warrant extensive clinical study due to their potential in cancer treatment. Identifying mycotoxins with anticancer properties produced by P. aurantiogriseum could unveil novel therapeutic targets and enrich the pharmacological landscape. This review provides a comprehensive overview of the utilization of P. aurantiogriseum mycotoxins in cancer research and elucidates therapeutic agents' advantages and limitations. P. aurantiogriseum produces at least 15 mycotoxins with potent anticancer effects mediated through diverse mechanisms, including enzyme inhibition (e.g., pseurotin), induction of apoptosis (e.g., auranthine, aurantiamides A, aurantiomides A-C, penicillic acid, penitrem, verrucisidinol, acetate verrucosidinol, and chaetoglobosin A), and cell-cycle arrest (e.g., anicequol, aurantiamine, and Taxol). Although certain mycotoxins, such as Taxol, Anacin, and Compactin, are used in commerce, many others remain relatively unexplored. The mycotoxins derived from P. aurantiogriseum hold considerable potential for cancer treatment, offering novel therapeutic avenues and enhancing current treatments through synergistic combinations and advanced delivery systems.

Polyketides and alkaloids from the fungus Aspergillus Fumigatus YB4-17 and ent-Fumiquinazoline J induce apoptosis, paraptosis in human hepatoma HepG2 cells

Hepatocellular carcinoma (HCC) is one of the most common malignancies. The currently available clinical drugs for HCC frequently cause serious side effects and the treatment outcomes are unsatisfactory. It is urgent to develop effective drugs with high selectivity and low adverse effects for HCC. Metabolites produced by microorganisms have shown great potential in the development of therapeutic agents for HCC. In our study, the EtOAc extract of the strain Aspergillus fumigatus YB4-17 exhibited significant cytotoxicity towards the HCC HepG2 cells at 10 μg/mL. Various column chromatographic separations of the extract afforded seven polyketides (1-7), including a new diphenyl ether derivative (1), along with fourteen known alkaloids (8-21). The structure elucidation was conducted via NMR spectroscopic data and MS data analysis. The absolute configuration of compound 11 was confirmed by comparing experimental and calculated electronic circular dichroism spectrum for the first time. The biological evaluation of these metabolites revealed that compound 11 selectively inhibited the proliferation of HCC HepG2 cells with negligible toxicity to normal cells. Mechanism study indicated that compound 11 induced apoptosis and paraptosis in HepG2 cells, providing a novel therapeutic perspective for the treatment of hepatocellular carcinoma.

Design, synthesis and biological evaluation of marine naphthoquinone-naphthol derivatives as potential anticancer agents

1'-Hydroxy-4',8,8'-trimethoxy-[2,2'-binaphthalene]-1,4-dione (compound 5), a secondary metabolite recently discovered in marine fungi, demonstrates promising cytotoxic and anticancer potential. However, knowledge regarding the anticancer activities and biological mechanisms of its derivatives remains limited. Herein, a series of novel naphthoquinone-naphthol derivatives were designed, synthesised, and evaluated for their anticancer activity against cancer cells of different origins. Among these, Compound 13, featuring an oxopropyl group at the ortho-position of quinone group, exhibited the most potent inhibitory effects on HCT116, PC9, and A549 cells, with IC50 values decreasing from 5.27 to 1.18 μM (4.5-fold increase), 6.98 to 0.57 μM (12-fold increase), and 5.88 to 2.25 μM (2.6-fold increase), respectively, compared to compound 5. Further mechanistic studies revealed that compound 13 significantly induced cell apoptosis by increasing the expression levels of cleaved caspase-3 and reducing Bcl-2 proteins through downregulating the EGFR/PI3K/Akt signalling pathway, leading to the inhibition of proliferation in HCT116 and PC9 cells. The present findings suggest this novel naphthoquinone-naphthol derivative may hold potential as an anticancer therapeutic lead.

Marine Fungi Bioactives with Anti-Inflammatory, Antithrombotic and Antioxidant Health-Promoting Properties Against Inflammation-Related Chronic Diseases

Fungi play a fundamental role in the marine environment, being promising producers of bioactive molecules in the pharmacological and industrial fields, which have demonstrated potential health benefits against cardiovascular and other chronic diseases. This review pertains to the analysis of the lipid compositions across various species of marine fungi and their constantly discovered substances, as well as their anti-inflammatory, antioxidant, and antithrombotic effects. The health-promoting aspects of these microorganisms will be explored, through the investigation of several mechanisms of action and interference of their bioactives in biochemical pathways. Despite exceptional results in this field, the potential of marine microorganisms remains largely unexplored due to the limited number of specialists in marine microbiology and mycology, a relatively recent science with significant contributions and potential in biodiversity and biotechnology.

Anti-cancer activity of secreted aspartyl proteinase protein from Candida tropicalis on human cervical cancer HeLa cells

Cervical cancer is the fourth leading cause of cancer-related death in women worldwide. Microbial products are valuable sources of anti-cancer drugs. The aim of this study was to isolate secreted aspartyl proteinase protein from Candida tropicalis, investigate its inhibitory effect on human cervical cancer HeLa cells, and analyze the expression profiling of selected nuclear stem cell-associated transcription factors. The presence of secreted aspartyl proteinase protein was confirmed by the expression of SAP2 and SAP4 genes in C. tropicalis during the yeast-hyphae transition phase. The enzyme was purified and characterized using the aqueous two-phase system purification method, as well as proteolytic activity and the Bradford and micro-Kjeldahl methods, respectively. The in vitro anti-cancer properties of secreted aspartyl proteinase protein were evaluated by MTT assay, microscopic image analysis, nitric oxide (NO) scavenging activity assay, intracellular reactive oxygen species (ROS) production assay, and RT-qPCR. The isolated C. tropicalis secreted aspartyl proteinase protein exhibited proteinase activity with values ranging from 93.72 to 130.70 μg/mL and 89.88-127.72 μg/mL according to the Bradford and micro-Kjeldahl methods, respectively. Secreted aspartyl proteinase showed effective cytotoxicity in HeLa cell line leading to significant morphological changes. Additionally, it exhibited increased free radical scavenging activity compared to the untreated control group, as evidenced by nitrite inhibition. ROS production increased in HeLa cells exposed to secreted aspartyl proteinase. The expression levels of the nuclear stem cell-associated transcription factors octamer-binding transcription factor 4 (OCT4), sex determining region Y-box 2 (SOX2), and Nanog homeobox (NANOG) were significantly downregulated in the HeLa cells treated with secreted aspartyl proteinase. Secreted aspartyl proteinase protein may be a promising anti-cancer agent, as it effectively affects gene expression and may ultimately reduce the development and progression of cervical cancer. Targeting the genes related to nuclear stem cell-associated transcription factors may provide a novel amenable to cancer treatment.

Gliotoxin triggers cell death through multifaceted targeting of cancer-inducing genes in breast cancer therapy

Fungal secondary metabolites have a long history of contributing to pharmaceuticals, notably in the development of antibiotics and immunosuppressants. Harnessing their potent bioactivities, these compounds are now being explored for cancer therapy, by targeting and disrupting the genes that induce cancer progression. The current study explores the anticancer potential of gliotoxin, a fungal secondary metabolite, which encompasses a multi-faceted approach integrating computational predictions, molecular dynamics simulations, and comprehensive experimental validations. In-silico studies have identified potential gliotoxin targets, including MAPK1, NFKB1, HIF1A, TDP1, TRIM24, and CTSD which are involved in critical pathways in cancer such as the NF-κB signaling pathway, MAPK/ERK signaling pathway, hypoxia signaling pathway, Wnt/β-catenin pathway, and other essential cellular processes. The gene expression analysis results indicated all the identified targets are overexpressed in various breast cancer subtypes. Subsequent molecular docking and dynamics simulations have revealed stable binding of gliotoxin with TDP1 and HIF1A. Cell viability assays exhibited a dose-dependent decreasing pattern with its remarkable IC50 values of 0.32, 0.14, and 0.53 μM for MDA-MB-231, MDA-MB-468, and MCF-7 cells, respectively. Likewise, in 3D tumor spheroids, gliotoxin exhibited a notable decrease in viability indicating its effectiveness against solid tumors. Furthermore, gene expression studies using Real-time PCR revealed a reduction of expression of cancer-inducing genes, MAPK1, HIF1A, TDP1, and TRIM24 upon gliotoxin treatment. These findings collectively underscore the promising anticancer potential of gliotoxin through multi-targeting cancer-promoting genes, positioning it as a promising therapeutic option for breast cancer.

Recent advancement of novel marine fungi derived secondary metabolite fibrinolytic compound FGFC in biomedical applications: a review

For several decades, products derived from marine natural sources (PMN) have been widely identified for several therapeutic applications due to their rich sources of bioactive sub-stances, unique chemical diversity, biocompatibility and excellent biological activity. For the past 15 years, our research team explored several PMNs, especially fungi fibrinolytic compounds (FGFCs). FGFC is an isoindolone alkaloid derived from marine fungi, also known as staplabin analogs or Stachybotrys microspora triprenyl phenol (SMTP). For instance, our previous studies explored different types of FGFCs such as FGFC 1, 2, 3 and 4 from the marine fungi Stachybotrys longispora FG216 derived metabolites. The derivatives of FGFC are potentially employed in several disease treatments, mainly for stroke, cancer, ischemia, acute kidney injury, inflammation, cerebral infarction, thrombolysis and hemorrhagic activities, etc. Due to the increasing use of FGFCs in pharmaceutical and biomedical applications, it is important to understand the fundamental signaling concept of FGFCs. Hence, for the first time, this review collectively summarizes the background, types, mode of action and biological applications of FGFCs and their current endeavors for future therapies.

Exploring the Chemical Constituents and Nutritive Potential of Bee Drone (Apilarnil): Emphasis on Antioxidant Properties

A lesser-known bee product called drone brood homogenate (DBH, apilarnil) has recently attracted scientific interest for its chemical and biological properties. It contains pharmacologically active compounds that may have neuroprotective, antioxidant, fertility-enhancing, and antiviral effects. Unlike other bee products, the chemical composition of bee drone larva is poorly studied. This study analyzed the chemical compostion of apilarnil using several methods. These included liquid chromatography-mass spectrometry (LC-MS/MS) and a combination of gas chromatography/mass spectrometry with solid phase micro-extraction (SPME/GC-MS). Additionally, antioxidant activity of the apilarnil was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. A chemical assessment of apilarnil showed that it has 6.3±0.00, 74.67±0.10 %, 3.65±0.32 %, 8.80±1.01 %, 13.16±0.94 %, and 8.79±0.49 % of pH, moisture, total lipids, proteins, flavonoids, and carbohydrates, respectively. LC-MS/MS analysis and molecular networking (GNPS) of apilarnil exhibited 44 compounds, including fatty acids, flavonoids, glycerophospholipids, alcohols, sugars, amino acids, and steroids. GC-MS detected 30 volatile compounds in apilarnil, mainly esters (24 %), ketones (23.84 %), ethers (15.05 %), alcohols (11.41 %), fatty acids (10.06), aldehydes (6.73 %), amines (5.46), and alkene (5.53 %). The antioxidant activity of apilarnil was measured using DPPH with an IC50 of 179.93±2.46 μg/ml.

Study of marine microorganism metabolites: new resources for bioactive natural products

The marine environment has remained a source of novel biological molecules with diversified applications. The ecological and biological diversity, along with a unique physical environment, have provided the evolutionary advantage to the plant, animals and microbial species thriving in the marine ecosystem. In light of the fact that marine microorganisms frequently interact symbiotically or mutualistically with higher species including corals, fish, sponges, and algae, this paper intends to examine the potential of marine microorganisms as a niche for marine bacteria. This review aims to analyze and summarize modern literature data on the biotechnological potential of marine fungi and bacteria as producers of a wide range of practically valuable products (surfactants, glyco-and lipopeptides, exopolysaccharides, enzymes, and metabolites with different biological activities: antimicrobial, antitumor, and cytotoxic). Hence, the study on bioactive secondary metabolites from marine microorganisms is the need of the hour. The scientific novelty of the study lies in the fact that for the first time, the data on new resources for obtaining biologically active natural products - metabolites of marine bacteria and fungi - were generalized. The review investigates the various kinds of natural products derived from marine microorganisms, specifically focusing on marine bacteria and fungi as a valuable source for new natural products. It provides a summary of the data regarding the antibacterial, antimalarial, anticarcinogenic, antibiofilm, and anti-inflammatory effects demonstrated by marine microorganisms. There is currently a great need for scientific and applied research on bioactive secondary metabolites of marine microorganisms from the standpoint of human and animal health.

Shikimate-Derived Meroterpenoids from the Ascidian-Derived Fungus Amphichorda felina SYSU-MS7908 and Their Anti-Glioma Activity

Glioma is a clinically heterogeneous type of brain tumor with a poor prognosis. Current treatment approaches have limited effectiveness in treating glioma, highlighting the need for novel drugs. One approach is to explore marine natural products for their therapeutic potential. In this study, we isolated nine shikimate-derived diisoprenyl-cyclohexene/ane-type meroterpenoids (1-9), including four new ones, amphicordins A-D (1-4) from the ascidian-derived fungus Amphichorda felina SYSU-MS7908, and further semisynthesized four derivatives (10-13). Their structures were extensively characterized using 1D and 2D NMR, modified Mosher's method, HR-ESIMS, NMR and ECD calculations, and X-ray crystallography. Notably, amphicordin C (3) possesses a unique benzo[g]chromene (6/6/6) skeleton in this meroterpenoid family. In an anti-glioma assay, oxirapentyn A (7) effectively inhibited the proliferation, migration, and invasion of glioma cells and induced their apoptosis. Furthermore, an in silico analysis suggested that oxirapentyn A has the potential to penetrate the blood-brain barrier. These findings highlight the potential of oxirapentyn A as a candidate for the development of novel anti-glioma drugs.

Macrosphelides from Antarctic fungus Pseudogymnoascus sp. (strain SF-7351) and their neuroprotective effects on BV2 and HT22 cells

Strategies for reducing inflammation in neurodegenerative diseases have attracted increasing attention. Herein, we discovered and evaluated the neuroprotective potential of fungal metabolites isolated from the Antarctic fungus Pseudogymnoascus sp. (strain SF-7351). The chemical investigation of the EtOAc extract of the fungal strain isolate revealed a novel naturally occurring epi-macrosphelide J (1), a novel secondary metabolite macrosphelide N (2), and three known compounds, namely macrosphelide A (3), macrosphelide B (4), and macrosphelide J (5). Their structures were established unambiguously using spectroscopic methods, such as one-dimensional and two-dimensional nuclear magnetic resonance (1D and 2D-NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and gauge-including atomic orbital (GIAO) NMR chemical shift calculations, with the support of the advanced statistical method DP4+. Among the isolated metabolites, the absolute configuration of epi-macrosphelide J (1) was further confirmed using single-crystal X-ray diffraction analysis. The neuroprotective effects of the isolated metabolites were evaluated in lipopolysaccharide (LPS)-induced BV2 and glutamate-stimulated HT22 cells. Only macrosphelide B (4) displayed substantial protective effects in both BV2 and HT22 cells. Molecular mechanisms underlying this activity were investigated using western blotting and molecular docking studies. Macrosphelide B (4) inhibited the inflammatory response by reducing the nuclear translocation of NF-κB (p65) in LPS-induced BV2 cells and induced the Nrf2/HO-1 signaling pathway in both BV2 and HT22 cells. The neuroprotective effect of macrosphelide B (4) is related to the interaction between Keap1 and p65. These results suggest that macrosphelide B (4), present in the fungus Pseudogymnoascus sp. (strain SF-7351), may serve as a candidate for the treatment of neurodegenerative diseases.

Antifungal activity of cyclopaldic acid from Antarctic Penicillium against phytopathogenic fungi

Plant pathogens cause great economic losses in agriculture. To reduce damage, chemical pesticides have been frequently used, but these compounds in addition to causing risks to the environment and health, its continuous use has given rise to resistant phytopathogens, threatening the efficiency of control methods. One alternative for such a problem is the use of natural products with high antifungal activity and low toxicity. Here, we present the production, isolation, and identification of cyclopaldic acid, a bioactive compound produced by Penicillium sp. CRM 1540, a fungal strain isolated from Antarctic marine sediment. The crude extract was fractionated by reversed-phase chromatography and yielded 40 fractions, from which fraction F17 was selected. We used 1D and 2D Nuclear Magnetic Resonance analysis in DMSO-d6 and CDCl3, together with mass spectrometry, to identify the compound as cyclopaldic acid C11H10O6 (238 Da). The pure compound was evaluated for antimicrobial activity against phytopathogenic fungi of global agricultural importance, namely: Macrophomina phaseolina, Rhizoctonia solani, and Sclerotinia sclerotiorum. The antifungal assay revealed the potential of cyclopaldic acid, produced by Penicillium sp. CRM 1540, as a leading molecule against M. phaseolina and R. solani, with more than 90% of growth inhibition after 96h of contact with the fungal cells using 100 µg mL-1, and more than 70% using 50 µg mL-1.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03792-9.

Retracted: Isolation and purifications of an ambuic acid derivative compound from marine algal endophytic fungi Talaromyces flavus that induces apoptosis in MDA-MB-231 cancer cells

In recent years, there has been a lot of buzz about the possibilities of marine microflora as a source of new therapeutic drugs. The strong anti-tumor potency of compounds found in marine resources reflects the ocean's enormous potential as a source of anticancer therapeutics. In this present investigation, an ambuic acid derivative anticancer compound was isolated from Talaromyces flavus, and its cytotoxicity and apoptosis induction potential were analyzed. T. flavus was identified through morphological and molecular analysis. The various organic solvent extracts of T. flavus grown on different growth mediums were evaluated for cytotoxicity on different cancer cell lines. The potent cytotoxicity was shown in the ethyl acetate extract of a fungal culture grown in the M1-D medium for 21 days. Furthermore, the anticancer compound was identified using preparative thin layer chromatography, followed by its purification in significant proportions using column chromatography. The spectroscopic and chromatographic analysis revealed that the structure of the purified molecules was an ambuic acid derivative. The ambuic acid derivative compound showed potent cytotoxicity on MDA-MB-231 (breast cancer cells) with an IC50 value of 26 μM and induced apoptosis in the MDA-MB-231 cells in a time-dependent and reactive oxygen species-independent manner.

Calculation of binding affinity of JAK1 inhibitors via accurately computational estimation

Janus kinase 1 (JAK1) is a tyrosine kinase that is involved in the initiation of responses to a number of different cytokine receptor families. The JAK1-dependent pathway is a therapeutic target, and several JAK inhibitors have been developed thanks to intensive research. However, since the ATP binding sites of JAK family members are quite alike, JAK1 inhibitors can thus be less selective, resulting in unanticipated adverse effects. Despite this, minor variations in the ATP-binding site have been extensively used to find a variety of small compounds with different inhibitory properties. Stronger binding affinity of JAK1 inhibitors is believed to be able to reduce the negative effects, leading to better treatment results. Therefore, a thorough computational search that can effectively identify ligands with extremely high binding affinity for JAK1 to serve as promising inhibitors is required. Here, a method combining steered-molecular dynamic (SMD) simulations with a modified linear interaction energy (LIE) model has been developed to evaluate the binding affinities of known JAK1 inhibitors. The correlation coefficient between the estimated and experimental values was 0.72 and a root-mean-square error was 0.97 kcal•mol-1, revealing that the SMD/LIE method can precisely and quickly predict the binding free energies of JAK1 inhibitors. Furthermore, three marine fungus-derived compounds, namely hansforesters E, hansforesters G and tetroazolemycins B, were identified to be particularly promising JAK1 inhibitors, accordingly. These findings show that the SMD/LIE method has a lot of promise for in silico screening of possible JAK1 inhibitors from a vast number of compounds that are now accessible.Communicated by Ramaswamy H. Sarma.

Phoma spp. an untapped treasure of cytotoxic compounds: current status and perspectives

The genus Phoma has been explored for a wide range of secondary metabolites signifying a huge range of bioactivities. Phoma sensu lato is a major group that secretes several secondary metabolites. The genus Phoma mainly includes Phoma macrostoma, P. multirostrata, P. exigua, P. herbarum, P. betae, P. bellidis, P. medicaginis, P. tropica, and many more species from the genus that are continuously being identified for their potential secondary metabolites. The metabolite spectrum includes bioactive compounds like phomenon, phomin, phomodione, cytochalasins, cercosporamide, phomazines, and phomapyrone reported from various Phoma spp. These secondary metabolites show a broad range of activities including antimicrobial, antiviral, antinematode, and anticancer. The present review is aimed to emphasize the importance of Phoma sensu lato fungi, as a natural source of biologically active secondary metabolites, and their cytotoxic activities. So far, cytotoxic activities of Phoma spp. have not been reviewed; hence, this review will be novel and useful for the readers to develop Phoma-derived anticancer agents. KEY POINTS: • Different Phoma spp. contain a wide variety of bioactive metabolites. • These Phoma spp. also secrete cytotoxic and antitumor compounds. • The secondary metabolites can be used for the development of anticancer agents.

Unraveling anticancer potential of a novel serine protease inhibitor from marine yeast Candida parapsilosis ABS1 against colorectal and breast cancer cells

The study was planned to isolate a serine protease inhibitor compound with anticancer potential against colorectal and breast cancer cells from marine yeast. Protease enzymes play a crucial role in the mechanism of life-threatening diseases like cancer, malaria and AIDS. Hence, blocking these enzymes with potential inhibitors can be an efficient approach in drug therapy for these diseases. A total of 12 marine yeast isolates, recovered from mangrove swamps of Sundarbans, India, showed inhibition activity against trypsin. The yeast isolate ABS1 showed highest inhibition activity (89%). The optimum conditions for protease inhibitor production were found to be glucose, ammonium phosphate, pH 7.0, 30 °C and 2 M NaCl. The PI protein from yeast isolate ABS1 was purified using ethyl acetate extraction and anion exchange chromatography. The purified protein was characterized using denaturing SDS-PAGE, Liquid Chromatography Electrospray Ionization Mass Spectrometry (LC-ESI-MS), Reverse Phase High Pressure Liquid Chromatography (RP-HPLC) and Fourier Transform Infra-red Spectroscopy (FTIR) analysis. The intact molecular weight of the PI protein was determined to be 25.584 kDa. The PI protein was further studied for in vitro anticancer activities. The IC₅₀ value for MTT cell proliferation assay was found to be 43 µg/ml against colorectal cancer HCT15 cells and 48 µg/ml against breast cancer MCF7 cells. Hoechst staining, DAPI staining and DNA fragmentation assay were performed to check the apoptotic cells. The marine yeast was identified as Candida parapsilosis ABS1 (Accession No. MH782231) using 18s rRNA sequencing.

Absolute Stereochemistry and Cytotoxic Effects of Vismione E from Marine Sponge-Derived Fungus Aspergillus sp. 1901NT-1.2.2

The metabolic profile of the Aspergillus sp. 1901NT-1.2.2 sponge-associated fungal strain was investigated using the HPLC MS technique, and more than 23 peaks in the HPLC MS chromatogram were detected. Only two minor peaks were identified as endocrocin and terpene derivative MS data from the GNPS database. The main compound was isolated and identified as known anthraquinone derivative vismione E. The absolute stereochemistry of vismione E was established for the first time using ECD and quantum chemical methods. Vismione E showed high cytotoxic activity against human breast cancer MCF-7 cells, with an IC₅₀ of 9.0 µM, in comparison with low toxicity for normal human breast MCF-10A cells, with an IC₅₀ of 65.3 µM. It was found that vismione E inhibits MCF-7 cell proliferation and arrests the cell cycle in the G1 phase. Moreover, the negative influence of vismione E on MCF-7 cell migration was detected. Molecular docking of vismione E suggested the IMPDH2 enzyme as one of the molecular targets for this anthraquinone derivative.

Aspergillus Carneus metabolite Averufanin induced cell cycle arrest and apoptotic cell death on cancer cell lines via inducing DNA damage

Cancer is one of the leading causes of death worldwide, accounting for nearly 10 million deaths in 2020. Current treatment methods include hormone therapy, γ-radiation, immunotherapy, and chemotherapy. Although chemotherapy is the most effective treatment, there are major obstacles posed by resistance mechanisms of cancer cells and side-effects of the drugs, thus the search for novel anti-cancer compounds, especially from natural sources, is crucial for cancer pharmaceutics research. One natural source worthy of investigation is fungal species. In this study, the cytotoxicity of 5 metabolic compounds isolated from filamentous fungus Aspergillus Carneus. Arugosin C, Averufin, Averufanin, Nidurifin and Versicolorin C were analyzed using NCI-SRB assay on 10 different cell lines of breast cancer, ovarian cancer, glioblastoma and non-tumorigenic cell lines. Averufanin showed highest cytotoxicity with lowest IC₅₀ concentrations especially on breast cancer cells. Therefore, Averufanin was further investigated to enlighten cell death and molecular mechanisms of action involved. Cell cycle analysis showed increase in SubG1 phase suggesting apoptosis induction which was further confirmed by Annexin V and Caspase 3/7 Assays. H2A.X staining revealed accumulation of DNA damage in cells treated with Averufanin and finally western blot analysis validated DNA damage response and downstream effects of Averufanin treatment in various signaling pathways. Consequently, this study shows that Averufanin compound induces cell cycle arrest and cell death via apoptosis through causing DNA damage and can be contemplated and further explored as a new therapeutic strategy in breast cancer.

Evaluation of Lipid Extracts from the Marine Fungi Emericellopsis cladophorae and Zalerion maritima as a Source of Anti-Inflammatory, Antioxidant and Antibacterial Compounds

Marine environments occupy more than 70% of the earth's surface, integrating very diverse habitats with specific characteristics. This heterogeneity of environments is reflected in the biochemical composition of the organisms that inhabit them. Marine organisms are a source of bioactive compounds, being increasingly studied due to their health-beneficial properties, such as antioxidant, anti-inflammatory, antibacterial, antiviral, or anticancer. In the last decades, marine fungi have stood out for their potential to produce compounds with therapeutic properties. The objective of this study was to determine the fatty acid profile of isolates from the fungi Emericellopsis cladophorae and Zalerion maritima and assess the anti-inflammatory, antioxidant, and antibacterial potential of their lipid extracts. The analysis of the fatty acid profile, using GC-MS, showed that E. cladophorae and Z. maritima possess high contents of polyunsaturated fatty acids, 50% and 34%, respectively, including the omega-3 fatty acid 18:3 n-3. Emericellopsis cladophorae and Z. maritima lipid extracts showed anti-inflammatory activity expressed by the capacity of their COX-2 inhibition which was 92% and 88% of inhibition at 200 µg lipid mL-1, respectively. Emericellopsis cladophorae lipid extracts showed a high percentage of inhibition of COX -2 activity even at low concentrations of lipids (54% of inhibition using 20 µg lipid mL-1), while a dose-dependent behaviour was observed in Z. maritima. The antioxidant activity assays of total lipid extracts demonstrated that the lipid extract from E. cladophorae did not show antioxidant activity, while Z. maritima gave an IC20 value of 116.6 ± 6.2 µg mL-1 equivalent to 92.1 ± 4.8 µmol Trolox g-1 of lipid extract in the DPPH• assay, and 101.3 ± 14.4 µg mL-1 equivalent to 106.6 ± 14.8 µmol Trolox g-1 of lipid extract in the ABTS•+ assay. The lipid extract of both fungal species did not show antibacterial properties at the concentrations tested. This study is the first step in the biochemical characterization of these marine organisms and demonstrates the bioactive potential of lipid extracts from marine fungi for biotechnological applications.

Recent advances in the discovery, biosynthesis, and therapeutic potential of isocoumarins derived from fungi: a comprehensive update

Microorganisms still remain the main hotspots in the global drug discovery avenue. In particular, fungi are highly prolific producers of vast structurally diverse specialized secondary metabolites, which have displayed a myriad of biomedical potentials. Intriguingly, isocoumarins is one distinctive class of fungal natural products polyketides, which demonstrated numerous remarkable biological and pharmacological activities. This review article provides a comprehensive state-of-the-art over the period 2000-2022 about the discovery, isolation, classifications, and therapeutic potentials of isocoumarins exclusively reported from fungi. Indeed, a comprehensive list of 351 structurally diverse isocoumarins were documented and classified according to their fungal sources [16 order/28 family/55 genera] where they have been originally discovered along with their reported pharmacological activities wherever applicable. Also, recent insights around their proposed and experimentally proven biosynthetic pathways are also briefly discussed.

Effects and Mechanisms of Action of Preussin, a Marine Fungal Metabolite, against the Triple-Negative Breast Cancer Cell Line, MDA-MB-231, in 2D and 3D Cultures

Triple-negative breast cancer (TNBC) represents an aggressive subtype of breast cancer (BC) with a typically poorer prognosis than other subtypes of BC and limited therapeutic options. Therefore, new drugs would be particularly welcome to help treat TNBC. Preussin, isolated from the marine sponge-associated fungus, Aspergillus candidus, has shown the potential to reduce cell viability and proliferation as well as to induce cell death and cell cycle arrest in 2D cell culture models. However, studies that better mimic the tumors in vivo, such as 3D cell cultures, are needed. Here, we studied the effects of preussin in the MDA-MB-231 cell line, comparing 2D and 3D cell cultures, using ultrastructural analysis and the MTT, BrdU, annexin V-PI, comet (alkaline and FPG modified versions), and wound healing assays. Preussin was found to decrease cell viability, both in 2D and 3D cell cultures, in a dose-dependent manner, impair cell proliferation, and induce cell death, therefore excluding the hypothesis of genotoxic properties. The cellular impacts were reflected by ultrastructural alterations in both cell culture models. Preussin also significantly inhibited the migration of MDA-MB-231 cells. The new data expanded the knowledge on preussin actions while supporting other studies, highlighting its potential as a molecule or scaffold for the development of new anticancer drugs against TNBC.

In silico bioprospecting of antiviral compounds from marine fungi and mushroom for rapid development of nutraceuticals against SARS-CoV-2

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) affects human respiratory function that causes COVID-19 disease. COVID-19 has spread rapidly all over the world and became a pandemic within no time. Therefore, it is the need of hour to screen potential lead candidates from natural resources like edible mushrooms and marine fungi. These natural resources are very less explored till now and known to be the source for many medicinal compounds with several health benefits. These medicinal compounds can be easily exploited for the faster development of nutraceuticals for controlling SARS-CoV-2 infections. Our Insilico research suggests, bioactive compounds originating from mushroom and marine fungi shows strong potential to interact with ACE2 receptor or main protease of SARS-CoV-2, showing the inhibition activity towards the enzymatic protease. We performed a series of Insilico studies for the validation of our results, which includes Molecular docking, drug likeness property investigation by Swiss ADME tools, MD simulation, and thermodynamically stable free binding energy calculation. Overall, these results suggest that Ganodermadiol and Heliantriol F bioactive compounds originating from edible mushroom has strong potential to be developed as low-cost nutraceutical against SARS-CoV-2 viral infection. The drug candidate isolated from marine fungi and edible mushroom are highly unexplored for the development of potential alternative drug against SARS-CoV-2 virus with minimum side effects. Though our in silico studies of these compounds are showing a promising results against SARS-CoV-2 main protease and ACE2 receptor binding domain, the effectiveness of these bioactive compounds should be further validated by proper clinical trials.Communicated by Ramaswamy H. Sarma.

Diversity and Biosynthetic Potential of Fungi Isolated from St. John's Island, Singapore

Adaptation to a wide variety of habitats allows fungi to develop unique abilities to produce diverse secondary metabolites with diverse bioactivities. In this study, 30 Ascomycetes fungi isolated from St. John's Island, Singapore were investigated for their general biosynthetic potential and their ability to produce antimicrobial secondary metabolites (SMs). All the 30 fungal isolates belong to the Phylum Ascomycota and are distributed into 6 orders and 18 genera with Order Hypocreales having the highest number of representative (37%). Screening for polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes using degenerate PCR led to the identification of 23 polyketide synthases (PKSs) and 5 nonribosomal peptide synthetases (NRPSs) grouped into nine distinct clades based on their reduction capabilities. Some of the identified PKSs genes share high similarities between species and known reference genes, suggesting the possibility of conserved biosynthesis of closely related compounds from different fungi. Fungal extracts were tested for their antimicrobial activity against S. aureus, Methicillin-resistant S. aureus (MRSA), and Candida albicans. Bioassay-guided fractionation of the active constituents from two promising isolates resulted in the isolation of seven compounds: Penilumamides A, D, and E from strain F4335 and xanthomegnin, viomellein, pretrichodermamide C and vioxanthin from strain F7180. Vioxanthin exhibited the best antibacterial activity with IC50 values of 3.0 μM and 1.6 μM against S. aureus and MRSA respectively. Viomellein revealed weak antiproliferative activity against A549 cells with an IC50 of 42 μM. The results from this study give valuable insights into the diversity and biosynthetic potential of fungi from this unique habitat and forms a background for an in-depth analysis of the biosynthetic capability of selected strains of interest with the aim of discovering novel fungal natural products.

Naturally Occurring Organohalogen Compounds-A Comprehensive Review

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

Metabolomic Strategy to Characterize the Profile of Secondary Metabolites in Aspergillus aculeatus DL1011 Regulated by Chemical Epigenetic Agents

Chemical epigenetic regulation (CER) is an effective method to activate the silent pathway of fungal secondary metabolite synthesis. However, conventional methods for CER study are laborious and time-consuming. In the meantime, the overall profile of the secondary metabolites in the fungi treated by the CER reagent is not well characterized. In this study, suberohydroxamic acid (SBHA), a histone deacetylase inhibitor, was added to a culture of Aspergillus aculeatus DL1011 and a new strategy based on LC-MS/MS analysis integrated with various metabolomic tools (MetaboAnalyst, MS-DIAL, SIRIUS and GNPS) was developed to characterize the profile of induced metabolites. As a result, 13.6%, 29.5% and 27.2% of metabolites were identified as newly biosynthesized, increasing and decreasing in abundance by CER, respectively. The structures of the 18 newly induced secondary metabolites were further identified by the new strategy to demonstrate that 72.2% of them (1 novel compound and 12 known compounds) were first discovered in A. aculeatus upon SBHA treatment. The accuracy of the new approach was confirmed by purification and NMR data analysis of major newly biosynthesized secondary metabolites. The bioassay showed that the newly biosynthesized compounds, roseopurpurin analogues, showed selective activities against DPPH scavenging, cytotoxicity and SHP1 inhibition. Our research demonstrated that CER was beneficial for changing the secondary metabolic profile of fungi and was an effective means of increasing the diversity of active metabolites. Our work also supplied a metabolomic strategy to characterize the profile changes and determine the newly induced compounds in the secondary metabolites of fungi treated with the chemical epigenetic regulator.

Antimycobacterial activity and molecular docking of methanolic extracts and compounds of marine fungi from Saldanha and False Bays, South Africa

The number and diversity of drugs in the tuberculosis (TB) drug development process has increased over the years, yet the attrition rate remains very high, signaling the need for continued research in drug discovery. In this study, crude secondary metabolites from marine fungi associated with ascidians collected from Saldanha and False Bays (South Africa) were investigated for antimycobacterial activity. Isolation of fungi was performed by sectioning thin inner-tissues of ascidians and spreading them over potato dextrose agar (PDA). Solid state fermentation of fungal isolates on PDA was then performed for 28 days to allow production of secondary metabolites. Afterwards, PDA cultures were dried and solid-liquid extraction using methanol was performed to extract fungal metabolites. Profiling of metabolites was performed using untargeted liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS). The broth microdilution method was used to determine antimycobacterial activity against Mycobacterium smegmatis mc²155 and Mycobacterium tuberculosis H37Rv, while in silico flexible docking was performed on selected target proteins from M. tuberculosis. A total of 16 ascidians were sampled and 46 fungi were isolated. Only 32 fungal isolates were sequenced, and their sequences submitted to GenBank to obtain accession numbers. Metabolite profiling of 6 selected fungal extracts resulted in the identification of 65 metabolites. The most interesting extract was that of Clonostachys rogersoniana MGK33 which inhibited Mycobacterium smegmatis mc²155 and Mycobacterium tuberculosis H37Rv growth with minimum inhibitory concentrations (MICs) of 0.125 and 0.2 mg/mL, respectively. These results were in accordance with those from in silico molecular docking studies which showed that bionectin F produced by C. rogersoniana MGK33 is a potential inhibitor of M. tuberculosis β-ketoacyl-acyl carrier protein reductase (MabA, PDB ID = 1UZN), with the docking score observed as -11.17 kcal/mol. These findings provided evidence to conclude that metabolites from marine-derived fungi are potential sources of bioactive metabolites with antimycobacterial activity. Even though in silico studies showed that bionectin F is a potent inhibitor of an essential enzyme, MabA, the results should be validated by performing purification of bionectin F from C. rogersoniana MGK33 and in vitro assays against MabA and whole cells (M. tuberculosis).

Cytotoxic secondary metabolites isolated from Penicillium sp. YT2019-3321, an endophytic fungus derived from Lonicera Japonica

Introduction

Endophytic fungi associated with medicinal plants have proven to possess a high potential to produce structurally diverse metabolites, some of which are valuable for medicinal applications. In this study, Penicillium sp. YT2019-3321, an endophytic fungus derived from traditional Chinese medicine Lonicera japonica, was chemically studied.

Methods

The chemical structures of the isolated compounds were established by a correlative interpretation of HRESIMS and NMR spectroscopic data. The optical resolution of (±)-1 by chiral HPLC yielded individual enantiomers (+)-1 and (-)-1, and their stereochemistry were solved by X-ray diffraction crystallography, respectively.

Results and discussion

Eight structurally diversified secondary metabolites, including two previously unreported polyketides, named (±)-chrysoalide B (1) and penicidone E (2), were isolated and identified from Penicillium sp. YT2019-3321. Compound 2 possessed the γ-pyridone nucleus, which is rarely found in natural products. Cytotoxic assay revealed that the new compound 2 demonstrated a dose-dependent cytotoxicity against the human pancreatic tumor cells PATU8988T with the IC₅₀ value of 11.4 μM. Further studies indicated that 2 significantly induced apoptosis of PATU8988T cell lines, characterized by the morphologies abnormity, the reduction of cell number, the upregulation of proportion of apoptotic cells, and the ratio of Bcl-2 to Bax. Our study demonstrates that fungal secondary metabolites may have important significance in the discovery of drug leads.

Marine fungi showing multifunctional activity against human pathogenic microbes and cancer

Multifunctional drugs have shown great promise in biomedicine. Organisms with antimicrobial and anticancer activity in combination with antioxidant activity need further research. The Red Sea and the Arabian Gulf coasts were randomly sampled to find fungi with multifunctional activity. One hundred strains (98 fungi and 2 lichenized forms) were isolated from 15 locations. One-third of the isolates inhibited clinical bacterial (Staphylococcus aureus, Bacillus subtilis, Vibrio cholerae, Salmonella typhi, S. paratyphi) and fungal pathogens (Talaromycets marneffei, Malassezia globose, Cryptococcus neoformans, Candida albicans, Aspergillus fumigatus) and four cancer cell lines (Hep G2 liver, A-549 lung, A-431skin, MCF 7 breast cancer). Bacterial and cancer inhibition was often accompanied by a high antioxidant activity, as indicated by the principal component analysis (PCA). PCA also indicated that fungal and bacterial pathogens appeared to be inhibited mostly by different marine fungal isolates. Strains with multifunctional activity were found more from the Rea Sea than from the Arabian Gulf coasts. The highest potential for multifunctional drugs were observed for Acremonium sp., Acrocalymma sp., Acrocalymma africana, Acrocalymma medicaginis (activity reported for the first time), Aspergillus sp. Cladosporium oxysporum, Emericellopsis alkaline, Microdochium sp., and Phomopsis glabrae. Lung, skin, and breast cancers were inhibited 85%-97% by Acremonium sp, while most of the isolates showed low inhibition (ca 20%). The highest antifungal activity was observed for Acremonium sp., Diaporthe hubeiensis, Lasiodiplodia theobromae, and Nannizia gypsea. One Acremonium sp. is of particular interest to offer a multifunctional drug; it displayed both antifungal and antibacterial activity combined with high antioxidant activity (DPPH scavenging 97%). A. medicaginis displayed combined antibacterial, anticancer, and antioxidant activity being of high interest. Several genera and some species included strains with both high and low biological activities pointing out the need to study several isolates to find the most efficient strains for biomedical applications.

Marine Cellulases and their Biotechnological Significance from Industrial Perspectives

Marine microorganisms represent virtually unlimited sources of novel biological compounds and can survive extreme conditions. Cellulases, a group of enzymes that are able to degrade cellulosic materials, are in high demand in various industrial and biotechnological applications, such as in the medical and pharmaceutical industries, food, fuel, agriculture, and single-cell protein, and as probiotics in aquaculture. The cellulosic biopolymer is a renewable resource and is a linearly arranged polysaccharide of glucose, with repeating units of disaccharide connected via β-1,4-glycosidic bonds, which are broken down by cellulase. A great deal of biodiversity resides in the ocean, and marine systems produce a wide range of distinct, new bioactive compounds that remain available but dormant for many years. The marine environment is filled with biomass from known and unknown vertebrates and invertebrate microorganisms, with much potential for use in medicine and biotechnology. Hence, complex polysaccharides derived from marine sources are a rich resource of microorganisms equipped with enzymes for polysaccharides degradation. Marine cellulases' extracts from the isolates are tested for their functional role in degrading seaweed and modifying wastes to low molecular fragments. They purify and renew environments by eliminating possible feedstocks of pollution. This review aims to examine the various types of marine cellulase producers and assess the ability of these microorganisms to produce these enzymes and their subsequent biotechnological applications.

How far have we explored fungi to fight cancer?

The use of fungal cultures have been well documented in human history. Although its used in healthcare, like penicillin and statins, have saved countless of lives, but there is still no fungal products that are specifically indicated for cancers. Research into fungal-derived materials to curb cancers in the recent decades have made a considerable progress in terms of drug delivery vehicles, anticancer active ingredients and cancer immunotherapy. Various parts of the organisms have successfully been exploited to achieve specific tasks. Apart from the identification of novel anticancer compound from fungi, its native capsular structure can also be used as drug cargo to achieve higher oral bioavailability. This review summarises the anticancer potential of fungal-derived materials, highlighting the role of capsular polysaccharides, proteins, and other structures in variety of innovative utilities to fit the current pharmaceutical technology. Many bioactive compounds isolated from fungi have also been formulated into nanoparticles to achieve greater anticancer activity. The progress of fungal compounds and their analogues in clinical trials is also highlighted. In addition, the potential of various fungal species to be developed for anticancer immunotherapy are also discussed.

Anticancer peptides mechanisms, simple and complex

Peptide therapy has started since 1920s with the advent of insulin application, and now it has emerged as a new approach in treatment of diseases including cancer. Using anti-cancer peptides (ACPs) is a promising way of cancer therapy as ACPs are continuing to be approved and arrived at major pharmaceutical markets. Traditional cancer treatments face different problems like intensive adverse effects to patient's body, cell resistance to conventional chemical drugs and in some worse cases the occurrence of cell multidrug resistance (MDR) of cancerous tissues against chemotherapy. On the other hand, there are some benefits conceived for peptides usage in treatment of diseases specifically cancer, as these compounds present favorable characteristics such as smaller size, high activity, low immunogenicity, good biocompatibility in vivo, convenient and rapid way of synthesis, amenable to sequence modification and revision and there is no limitation for the type of cargo they carry. It is possible to achieve an optimum molecular and functional structure of peptides based on previous experience and bank of peptide motif data which may result in novel peptide design. Bioactive peptides are able to form pores in cell membrane and induce necrosis or apoptosis of abnormal cells. Moreover, recent researches have focused on the tumor recognizing peptide motifs with the ability to permeate to cancerous cells with the aim of cancer treatment at earlier stages. In this strategy the most important factors for addressing cancer are choosing peptides with easy accessibility to tumor cell without cytotoxicity effect towards normal cells. The peptides must also meet acceptable pharmacokinetic requirements. In this review, the characteristics of peptides and cancer cells are discussed. The various mechanisms of peptides' action proposed against cancer cells make the next part of discussion. It will be followed by giving information on peptides application, various methods of peptide designing along with introducing various databases. Future aspects of peptides for employing in area of cancer treatment come as conclusion at the end.

Chemical diversity, medicinal potentialities, biosynthesis, and pharmacokinetics of anthraquinones and their congeners derived from marine fungi: a comprehensive update

Marine fungi receive excessive attention as prolific producers of structurally unique secondary metabolites, offering promising potential as substitutes or conjugates for current therapeutics, whereas existing research has only scratched the surface in terms of secondary metabolite diversity and potential industrial applications as only a small share of bioactive natural products have been identified from marine-derived fungi thus far. Anthraquinones derived from filamentous fungi are a distinct large group of polyketides containing compounds which feature a common 9,10-dioxoanthracene core, while their derivatives are generated through enzymatic reactions such as methylation, oxidation, or dimerization to produce a large variety of anthraquinone derivatives. A considerable number of reported anthraquinones and their derivatives have shown significant biological activities as well as highly economical, commercial, and biomedical potentialities such as anticancer, antimicrobial, antioxidant, and anti-inflammatory activities. Accordingly, and in this context, this review comprehensively covers the state-of-art over 20 years of about 208 structurally diverse anthraquinones and their derivatives isolated from different species of marine-derived fungal genera along with their reported bioactivity wherever applicable. Also, in this manuscript, we will present in brief recent insights centred on their experimentally proved biosynthetic routes. Moreover, all reported compounds were extensively investigated for their in-silico drug-likeness and pharmacokinetics properties which intriguingly highlighted a list of 20 anthraquinone-containing compounds that could be considered as potential drug lead scaffolds.

Marine biome-derived secondary metabolites, a class of promising antineoplastic agents: A systematic review on their classification, mechanism of action and future perspectives

Cancer is one of the most deadly diseases on the planet. Over the past decades, numerous antineoplastic compounds have been discovered from natural resources such as medicinal plants and marine species as part of multiple drug discovery initiatives. Notably, several marine flora (e.g. Ascophyllum nodosum, Sargassum thunbergii) have been identified as a rich source for novel cytotoxic compounds of different chemical forms. Despite the availability of enormous chemically enhanced new resources, the anticancer potential of marine flora and fauna has received little attention. Interestingly, numerous marine-derived secondary metabolites (e.g., Cytarabine, Trabectedin) have exhibited anticancer effects in preclinical cancer models. Most of the anticancer drugs obtained from marine sources stimulated apoptotic signal transduction pathways in cancer cells, such as the intrinsic and extrinsic pathways. This review highlights the sources of different cytotoxic secondary metabolites obtained from marine bacteria, algae, fungi, invertebrates, and vertebrates. Furthermore, this review provides a comprehensive overview of the utilisation of numerous marine-derived cytotoxic compounds as anticancer drugs, as well as their modes of action (e.g., molecular target). Finally, it also discusses the future prospects of marine-derived drug developments and their constraints.

Fungal Mushrooms: A Natural Compound With Therapeutic Applications

Fungi are extremely diverse in terms of morphology, ecology, metabolism, and phylogeny. Approximately, 130 medicinal activities like antitumor, immunomodulation, antioxidant, radical scavenging, cardioprotective and antiviral actions are assumed to be produced by the various varieties of medicinal mushrooms. The polysaccharides, present in mushrooms like β-glucans, micronutrients, antioxidants like glycoproteins, triterpenoids, flavonoids, and ergosterols can help establish natural resistance against infections and toxins.. Clinical trials have been performed on mushrooms like Agaricus blazei Murrill Kyowa for their anticancer effect, A. blazei Murrill for its antihypertensive and cardioprotective effects, and some other mushrooms had also been evaluated for their neurological effects. The human evaluation dose studies had been also performed and the toxicity dose was evaluated from the literature for number of mushrooms. All the mushrooms were found to be safe at a dose of 2000 mg/kg but some with mild side effects. The safety and therapeutic effectiveness of the fungal mushrooms had shifted the interest of biotechnologists toward fungal nanobiotechnology as the drug delivery system due to the vast advantages of nanotechnology systems. In complement to the vital nutritional significance of medicinal mushrooms, numerous species have been identified as sources of bioactive chemicals. Moreover, there are unanswered queries regarding its safety, efficacy, critical issues that affect the future mushroom medicine development, that could jeopardize its usage in the twenty-first century.

Development of the CRISPR-Cas9 System for the Marine-Derived Fungi Spiromastix sp. SCSIO F190 and Aspergillus sp. SCSIO SX7S7

Marine-derived fungi are emerging as attractive producers of structurally novel secondary metabolites with diverse bioactivities. However, the lack of efficient genetic tools limits the discovery of novel compounds and the elucidation of biosynthesis mechanisms. Here, we firstly established an effective PEG-mediated chemical transformation system for protoplasts in two marine-derived fungi, Spiromastix sp. SCSIO F190 and Aspergillus sp. SCSIO SX7S7. Next, we developed a simple and versatile CRISPR-Cas9-based gene disruption strategy by transforming a target fungus with a single plasmid. We found that the transformation with a circular plasmid encoding cas9, a single-guide RNA (sgRNA), and a selectable marker resulted in a high frequency of targeted and insertional gene mutations in both marine-derived fungal strains. In addition, the histone deacetylase gene rpd3 was mutated using the established CRISPR-Cas9 system, thereby activating novel secondary metabolites that were not produced in the wild-type strain. Taken together, a versatile CRISPR-Cas9-based gene disruption method was established, which will promote the discovery of novel natural products and further biological studies.

Diverse host-associated fungal systems as a dynamic source of novel bioactive anthraquinones in drug discovery: Current status and future perspectives

BACKGROUND

Despite, a large number of bioactive anthraquinones (AQs) isolated from host-living fungi, only plant-derived AQs were introduced in the global consumer markets. Host-living fungi represents renewable and extendible resources of diversified metabolites to be exploited for bioactives production. Unique classes of AQs from fungi include halogenated and steroidal AQs, and absent from planta are of potential to explore for biological activity against urging diseases such as cancer and multidrug-resistant pathogens. The structural diversity of fungal AQs, monomers, dimers, trimers, halogenated, etc… results in a vast range of pharmacological activities.

AIM OF REVIEW

The current study capitalizes on uncovering the diversity and distribution of host-living fungal systems producing AQs in different terrestrial ecosystems ranging from plant endophytes, lichens, animals and insects. Furthermore, the potential bioactivities of fungal derived AQs i.e., antibacterial, antifungal, antiviral (anti-HIV), anticancer, antioxidant, diuretic and laxative activities are assembled in relation to their structure activity relationship (SAR). Analyzing for structure-activity relationship among fungal AQs may facilitate bioengineering of more potential analogues. Withal, elucidation of AQs biosynthetic pathways in fungi is discussed from different fungal hosts to open up new possibilities for potential biotechnological applications. Such comprehensive review unravels terrestrial host-living fungal systems as a treasure trove in drug discovery, in addition to future perspectives and trends for their exploitation in pharmaceutical industries.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Such comprehensive review unravels terrestrialhost-living fungal systems as a treasure trove in drug discovery, in addition to future perspectives and trends for their exploitation in pharmaceutical industries.

Production, Bioprocessing and Anti-Proliferative Activity of Camptothecin from Penicillium chrysogenum, "An Endozoic of Marine Sponge, Cliona sp.", as a Metabolically Stable Camptothecin Producing Isolate

Exploring the metabolic potency of fungi as camptothecin producers raises the hope of their usage as an industrial source of camptothecin, due to their short-life span and the feasibility of metabolic engineering. However, the tiny yield and loss of camptothecin productivity of fungi during storage and sub-culturing are challenges that counteract this approach. Marine fungi could be a novel source for camptothecin production, with higher yield and reliable metabolic sustainability. The marine fungal isolate Penicillium chrysogenum EFBL # OL597937.1 derived from the sponge "Cliona sp." has been morphologically identified and molecularly confirmed, based on the Internal Transcribed Spacer sequence, exhibiting the highest yield of camptothecin (110 μg/L). The molecular structure and chemical identity of P. chrysogenum derived camptothecin has been resolved by HPLC, FTIR and LC-MS/MS analyses, giving the same spectroscopic profiles and mass fragmentation patterns as authentic camptothecin. The extracted camptothecin displayed a strong anti-proliferative activity towards HEP-2 and HCT-116 (IC₅₀ values 0.33-0.35 µM). The yield of camptothecin was maximized by nutritional optimization of P. chrysogenum with a Plackett-Burman design, and the productivity of camptothecin increased by 1.8 fold (200 µg/L), compared to control fungal cultures. Upon storage at 4 °C as slope culture for 8 months, the productivity of camptothecin for P. chrysogenum was reduced by 40% compared to the initial culture. Visual fading of the mycelial pigmentation of P. chrysogenum was observed during fungal storage, matched with loss of camptothecin productivity. Methylene chloride extracts of Cliona sp. had the potency to completely restore the camptothecin productivity of P. chrysogenum, ensuring the partial dependence of the expression of the camptothecin biosynthetic machinery of P. chrysogenum on the chemical signals derived from the sponge, or the associated microbial flora. This is the first report describing the feasibility of P. chrysogenum, endozoic of Cliona sp., for camptothecin production, along with reliable metabolic biosynthetic stability, which could be a new platform for scaling-up camptothecin production.