Bioactivity Screening Research Articles

A Family of Antibiotics That Evades Resistance by Binding Polyprenyl Phosphates.

Cilagicin is a Gram-positive active antibiotic that has a dual polyprenyl phosphate binding mechanism that impedes resistance development. Here we bioinformatically screened predicted non-ribosomal polypeptide synthetase encoded structures to search for antibiotics that might similarly avoid resistance development. Synthesis and bioactivity screening of the predicted structures that we identified led to three antibiotics that are active against multidrug-resistant Gram-positive pathogens, two of which, paenilagicin and virgilagicin, did not lead to resistance even after prolonged antibiotic exposure.

Xanthium strumarium seed extract boosts osteogenesis in human dental pulp stem cell model

BackgroundIn traditional medicine, Xanthium strumarium is used as an anti-inflammatory and anti-arthritic plant-based medicine. Human Dental Pulp Stem Cells (hDPSCs) are an ideal in vitro model for drug and bioactive compound screening. This study assessed the potential of X. strumarium aqueous extract on hDPSCs differentiation towards the osteogenic lineage. Materials and methodsHDPSCs were isolated and cultured by explant method and characterized by surface marker expression, Colony Forming units fibroblasts (CFU-F), Population Doubling time (PDT), and tri-lineage differentiation. X. strumarium aqueous seed extract (XSE) was prepared and its cytotoxic effect on hDPSCs was examined by MTT assay. The effect of XSE on hDPSC differentiation into osteocytes was investigated by biochemical staining and gene expression. ResultsThe hDPSCs were positive for CD73, CD90, and CD105 and negative for CD34, CD45, and HLA-DR surface markers. The cells had a colony-forming ability with a PDT of 44.91 h. The hDPSCs differentiated into osteocytes, chondrocytes, and adipocytes. The XSE concentration of 15 μg/ml had a significant increase in hDPSC viability. Alizarin Red S staining revealed that XSE treatment enhanced calcium accumulation and matrix mineralization in hDPSCs. XSE treatment also increased osteonectin and IL-6 transcript expression in osteogenesis-induced hDPSCs. ConclusionX. strumarium aqueous extract is a suitable candidate for bone repair because it promotes osteogenic differentiation in hDPSCs. Therefore this could be explored further in the treatment of bone disorders.

The Genomic-Driven Discovery of Glutarimide-Containing Derivatives from Burkholderia gladioli.

Glutarimide-containing polyketides exhibiting potent antitumor and antimicrobial activities were encoded via conserved module blocks in various strains that favor the genomic mining of these family compounds. The bioinformatic analysis of the genome of Burkholderia gladioli ATCC 10248 showed a silent trans-AT PKS biosynthetic gene cluster (BGC) on chromosome 2 (Chr2C8), which was predicted to produce new glutarimide-containing derivatives. Then, the silent polyketide synthase gene cluster was successfully activated via in situ promoter insertion and heterologous expression. As a result, seven glutarimide-containing analogs, including five new ones, gladiofungins D-H (3-7), and two known gladiofungin A/gladiostatin (1) and 2 (named gladiofungin C), were isolated from the fermentation of the activated mutant. Their structures were elucidated through the analysis of HR-ESI-MS and NMR spectroscopy. The structural diversities of gladiofungins may be due to the degradation of the butenolide group in gladiofungin A (1) during the fermentation and extraction process. Bioactivity screening showed that 2 and 4 had moderate anti-inflammatory activities. Thus, genome mining combined with promoter engineering and heterologous expression were proved to be effective strategies for the pathway-specific activation of the silent BGCs for the directional discovery of new natural products.

Isolation of anticancer bioactive secondary metabolites from the sponge-derived endophytic fungi Penicillium sp. and in-silico computational docking approach.

Fungus-derived secondary metabolites are fascinating with biomedical potential and chemical diversity. Mining endophytic fungi for drug candidates is an ongoing process in the field of drug discovery and medicinal chemistry. Endophytic fungal symbionts from terrestrial plants, marine flora, and fauna tend to produce interesting types of secondary metabolites with biomedical importance of anticancer, antiviral, and anti-tuberculosis properties. An organic ethyl acetate extract of Penicillium verruculosum sponge-derived endophytic fungi from Spongia officinalis yielded seven different secondary metabolites which are purified through HPLC. The isolated compounds are of averufin (1), aspergilol-A (2), sulochrin (3), monomethyl sulochrin (4), methyl emodin (5), citreorosein (6), and diorcinol (7). All the seven isolated compounds were characterized by high-resolution NMR spectral studies. All isolated compounds', such as anticancer, antimicrobial, anti-tuberculosis, and antiviral, were subjected to bioactivity screening. Out of seven tested compounds, compound (1) exhibits strong anticancer activity toward myeloid leukemia. HL60 cell lines have an IC50 concentration of 1.00μm, which is nearly significant to that of the standard anticancer drug taxol. A virtual computational molecular docking approach of averufin with HL60 antigens revealed that averufin binds strongly with the protein target alpha, beta-tubulin (1JFF), with a -10.98 binding score. Consecutive OSIRIS and Lipinski ADME pharmacokinetic validation of averufin with HL60 antigens revealed that averufin has good pharmacokinetic properties such as drug score, solubility, and mutagenic nature. Furthermore, aspergilol-A (2) is the first report on the Penicillium verruculosum fungal strain. We concluded that averufin (1) isolated from Penicillium verruculosum can be taken for further preliminary clinical trials like animal model in-vivo studies and pharmacodynamic studies. A future prospect of in-vivo anticancer screening of averufin can be validated through the present experimental findings.

Journey of Natural Products: From Isolation Stage to Drug’s Approval in Clinical Trials

Nature serves as an excellent inspiration for researchers in the fields of chemistry and medicine. Terrestrial or marine organisms produce billions of natural products with unique chemical and physical properties. Some of them have been used in traditional therapy for specific diseases since ancient times. Although their exact chemical structures have yet to be elucidated clearly in that time, investigations in medicinal chemistry have been well documented. Furthermore, utilizing natural products in drug design and development offers advantages such as high biocompatibility, low toxicity, fewer side effects, wide bioactivities, and large structure diversity. Nowadays, rational drug research using computer-aided drug design is well established to cut the long way of drug discovery and overcome the resistance cases and the increment in the number of active patients. This review will highlight some natural products to comprehensively understand their journey from unknown natural products, isolation, purification, characterization, in silico evaluation, bioactivity screening assay, drug modifications, in vitro investigation, in vivo examination, and clinical trial.

Isolation and Screening of Bioactivities from Bacillus sp. Isolated from Banana Rhizosphere

Bacillus sp. has been widely known to produce various bioactive metabolites related to plant growth. Bacillus sp. has also been known as one of the plant growth-promoting bacteria. In this study, a total of 68 isolates of Bacillus sp. were isolated from the rhizosphere of banana plantation using soil suspension technique. Isolated Bacillus sp. was then subjected to screening of their secondary metabolites such as cellulase, mannanase, xylanase, indole-acetic-acid, and gibberellic acid production before potential isolates were chosen and identified using their 16S rRNA and later subjected to seed germination testing. It was observed that Bacillus sp. isolated produces most of cellulase but did not have much affinity to produce gibberellic acid as only 5 Bacillus sp. were observed producing gibberellic acid. Three of the potential Bacillus sp. were selected and identified as Bacillus pumilus strain PNO21, Bacillus amyloliquefaciens strain PNO7 and Bacillus wiedmannii strain PNO28. Seed germination test also revealed that these 3 Bacillus sp. did not inhibit the seeds germination.

Bioactivity Screening and Genomic Analysis Reveals Deep-Sea Fish Microbiome Isolates as Sources of Novel Antimicrobials.

With the increase in antimicrobial resistance and the subsequent demand for novel therapeutics, the deep-sea fish microbiome can be a relatively untapped source of antimicrobials, including bacteriocins. Previously, bacterial isolates were recovered from the gut of deep-sea fish sampled from the Atlantic Ocean.In this study, we used in vitro methods to screen a subset of these isolates for antimicrobial activity, and subsequently mined genomic DNA from isolates of interest for bacteriocin and other antimicrobial metabolite genes. We observed antimicrobial activity against foodborne pathogens, including Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis and Micrococcus luteus. In total, 147 candidate biosynthetic gene clusters were identified in the genomic sequences, including 35 bacteriocin/RiPP-like clusters. Other bioactive metabolite genes detected included non-ribosomal peptide synthases (NRPS), polyketide synthases (PKS; Types 1 and 3), beta-lactones and terpenes. Moreover, four unique bacteriocin gene clusters were annotated and shown to encode novel peptides: a class IIc bacteriocin, two class IId bacteriocins and a class I lanthipeptide (LanM subgroup). Our dual in vitro and in silico approach allowed for a more comprehensive understanding of the bacteriocinogenic potential of these deep-sea isolates and an insight into the antimicrobial molecules that they may produce.

Synergy Assessment of Four Antimicrobial Bioactive Compounds for the Combinational Treatment of Bacterial Pathogens.

Antimicrobial resistance (AMR) has become a topic of great concern in recent years, with much effort being committed to developing alternative treatments for resistant bacterial pathogens. Drug combinational therapies have been a major area of research for several years, with modern iterations using combining well-established antibiotics and other antimicrobials with the aim of discovering complementary mechanisms. Previously, we characterised four GRAS antimicrobials that can withstand thermal polymer extrusion processes for novel medical device-based and therapeutic applications. In the present study, four antimicrobial bioactive-silver nitrate, nisin, chitosan and zinc oxide-were assessed for their potential combined use as an alternative synergistic treatment for AMR bacteria via a broth microdilution assay based on a checkerboard format. The bioactives were tested in arrangements of two-, three- and four-drug combinations, and their interactions were determined and expressed in terms of a synergy score. Results have revealed interesting interactions based on treatments against recognised test bacterial strains that cause human and animal infections, namely E. coli, S. aureus and S. epidermidis. Silver nitrate was seen to greatly enhance the efficacy of its paired treatment. Combinations with nisin, which is a lantibiotic, exhibited the most interesting results, as nisin has no effect against Gram-negative bacteria when used alone; however, it demonstrated antimicrobial effects when combined with silver nitrate or chitosan. This study constitutes the first study to both report on practical three- and four-drug combinational assays and utilise these methods for the assessment of established and emerging antimicrobials. The novel methods and results presented in this study show the potential to explore previously unknown drug combination compatibility measures in an ease-of-use- and high-throughput-based format, which can greatly help future research that aims to identify appropriate alternative treatments for AMR, including the screening of potential new bioactives biorefined from various sources.

Tag and Snag: A New Platform for Bioactive Natural Product Screening from Mixtures.

Natural products provide an unparalleled diversity of small molecules to fuel drug screening efforts, but deconvoluting the pharmacological activity of natural product mixtures to identify key bioactive compounds remains a vexing and labor-intensive process. Therefore, we have developed a new platform to probe the non-specific pharmacological potential of compounds present in common dietary supplements via shotgun derivatization with isotopically labeled propanoic acid, a live cell affinity assay, which was used to selectively recognize the population of compounds which bind tightly to HeLa cells in culture, and a computational LC-MS data analysis of isotopically labeled compounds from cell lysate. The data analysis showed that hundreds of compounds were successfully derivatized in each extract, and dozens of those compounds showed high affinity for HeLa cells. In total, over a thousand isotopically labeled compounds were screened for cell affinity across three separate experiments, resulting in the identification of several known bioactive compounds with specific protein targets and six previously unreported structures. The new natural products include three tulsinol compounds which were isolated from Ocimum tenuiflorum and three valeraninium alkaloids from Valeriana officinalis. The valeraninium alkaloids constitute a distinct new family of alkaloids from valerian, which may have previously undescribed bioactivity. These results collectively demonstrate the tag and snag workflow's viability as a drug discovery method.

New stilbene metabolites isolated from the tuber of Bletilla striata and their biological assessment

A phytochemical investigation of the tuber of Bletilla striata afforded eight stilbene derivatives, including a new bibenzyl (1) and two new phenanthrene (2 and 3). The structures of these compounds were elucidated using a combination of spectroscopic analyses. Further, the anti-inflammatory activity of all the compounds was evaluated to assess their capability to inhibit nitric oxide (NO) production by RAW 264.7 macrophages. The bioactive screening revealed that compounds 4 and 7 exhibited moderate inhibitory effects against NO production with the IC50 values 38.7 and 16.7 μM, respectively.

GC-MS Analysis and Bioactivity Screening of Leaves and Fruits of Zanthoxylum armatum DC.

Zanthoxylum armatum DC. is a plant that has been homologated for medicine and food by the Chinese for three thousand years. In this study, the essential oils of fresh leaves and fruits were extracted by hydrodistillation, the aromas of fresh leaves and fruits were extracted by headspace solid-phase microextraction and their chemical compositions were analyzed by gas chromatography mass spectrometry. The main components of the leaf essential oils were linalool (62.01%), 2-undecanone (9.83%) and 2-tridecanone (5.47%); the fruit essential oils were linalool (72.17%), limonene (8.05%) and sabinene (6.77%); the leaf aromas were limonene (39.15%), β-myrcene (15.8%), sabinene (8.17%) and linalool (5.25%); the fruit aromas were limonene (28.43%), sabinene (13.56%), linalool (11.47%) and β-myrcene (8.64%). By comparison, it was found that the composition of leaf essential oils and fruit essential oils were dominated by oxygenated monoterpenes, while the composition of their aromas were both dominated by monoterpenes; the relative content of non-terpene components in leaf essential oil and leaf aroma is second only to oxygenated monoterpenes, while their content in fruits is low; the chemical composition of leaf aromas and fruit aromas were richer than those of essential oils. In this study, we reported for the first time that the antitumor, tyrosinase inhibition, HMGR inhibition and nitric oxide production inhibition activity of leaf essential oils were stronger than those of fruit essential oils in in vitro tests. The results of the study can provide a reference for the recycling and green low-carbon transformation of the leaves, and also help to deepen the understanding of the value of the volatile chemical constituents of this plant in “forest medicine” or “aromatherapy”, and provide new ideas for the transformation of the value of the plant in the secondary and tertiary industry chain.

Chemical and Bioactive Screening of Green Polyphenol-Rich Extracts from Chestnut By-Products: An Approach to Guide the Sustainable Production of High-Added Value Ingredients.

Opportunities for the valorisation of agro-industrial residues of the chestnut (Castanea sativa Mill.) production chain have been fostered with the production of multifunctional polyphenol-rich extracts with the potential to be introduced as natural additives or active components in several products. Nonetheless, it is crucial to explore the feasibility of different extracts from the various by-products for these applications through the exhaustive study of their composition and bioactivities without losing sight of the sustainable character of the process. This work aimed at the screening of the phenolic compound composition and bioactivities of different green extracts of chestnut burs, shells and leaves, as the first step to establish their potential application as natural ingredients, primarily as food preservatives. To this end, maceration (MAC) as a conventional extraction method besides ultrasound and microwave-assisted extractions (UAE and MAE) was employed to obtain the extracts from chestnut by-products using water (W) and hydroethanolic solution (HE) as solvents. Phenolic compounds were analysed by HPLC-DAD-(ESI-)MS/MS; the antioxidant capacity was assessed by colourimetric assays, and the antimicrobial activity was evaluated against several strains of food-borne bacteria and fungi. The leaf extracts obtained by MAC-HE and UAE-HE presented the highest concentration of phenolic compounds (70.92 ± 2.72 and 53.97 ± 2.41 mg.g-1 extract dw, respectively), whereas, for burs and shells, the highest recovery of total phenolic compounds was achieved by using UAE-HE and UAE-W (36.87 ± 1.09 and 23.03 ± 0.26 mg.g-1 extract dw, respectively). Bis-HHDP-glucose isomers, chestanin and gallic acid were among the most abundant compounds. Bur extracts (MAC-HE and UAE-HE) generally presented the highest antioxidant capacity as measured by TBARS, while the best results in DPPH and reducing power assays were found for shell extracts (MAE-W and MAC-HE). Promising antibacterial activity was noticed for the aqueous extracts of burs, leaves and hydroethanolic extracts of shells, with emphasis on the MAE-W extract of burs that showed bactericidal activity against E. cloacae, P. aeruginosa and S. aureus (MBC 5 mg.mL-1). Overall, it can be concluded that chestnut by-products, including burs, shells and leaves, are sources of polyphenolic compounds with significant antioxidant and antimicrobial activities. The choice of extraction method and solvent greatly influenced the composition and bioactivity of the extracts. These findings highlight the potential of chestnut by-products for the development of natural additives, particularly for food preservation, while also emphasizing the importance of sustainable utilization of agricultural waste materials. Further research is warranted to optimize extraction techniques and explore additional applications for these valuable bioactive compounds.

Bioactive compounds screening of Rafflesia sp. and Sapria sp. (Family: Rafflesiaceae) as anti-SARS-CoV-2 via tetra inhibitors: An in silico research

Bioactive compounds screening of Rafflesia sp. and Sapria sp. (Family: Rafflesiaceae) as anti-SARS-CoV-2 via tetra inhibitors: An in silico research

Aging Skin and Natural Bioactives that Impede Cutaneous Aging: A Narrative Review.

The skin aging which entails modifications in the entire skin and skin support system is caused as a result of complex blend of intrinsic and extrinsic factors. The main objective of this review is to provide critical insights into the effect of the aging determinants (intrinsic and extrinsic) on aging skin and to focus on a few classes of natural bioactives that were reported to counteract symptoms of cutaneous aging, pose potential, and beneficial health effect on aging skin supported with relevant scientific evidence. The narrative review of this cutaneous antiaging study incorporating the literature findings was retrieved from the search of computerized databases PubMed and Scopus, hand searches, and authoritative books. The antiaging skin care approach of using bioactives are basically nutritional hormetins, available from our natural heritage, identified as potent free radical scavengers, antioxidants, moisturizers, cell repairing agents, and ultraviolet protectives which have started to seek considerable attention among researchers and consumers due to the undesirable effect of chemical-based constituents on human health and environment. With the booming antiaging strategies, beauty has become the prime factor in considering one's health and overall "wellness". As promoting healthy aging is essential, the objective of aesthetic dermatology should shift from cosmetic interventions to the betterment of quality of life of aging society. The paper also discusses on certain artificial learning/machine-based algorithms, useful in screening of bioactive ingredients, helpful in developing of more tailored formulations. This narrative overview on skin antiaging natural bioactives and artificial learning-based bioactive screening approaches contributes for the improvement in dermatological drug discovery, in the development of novel targeted lead compounds and accelerates aging research and pharmaceutical research.

Phytochemical Analysis and Nanoparticles-Based Bioactivity Screening of Five Medicinal Plant Extracts

Phytochemical Analysis and Nanoparticles-Based Bioactivity Screening of Five Medicinal Plant Extracts

Multi-target bioactive compound screening from the infructescence of Platycarya strobilacea Sieb. et Zucc. by affinity chromatography using immobilized β2 -adrenoceptor and muscarinic-3 acetylcholine receptor as the stationary phase.

As a main source for the recognition and identification of lead compounds, traditional Chinese medicine plays a pivotal role in preventing diseases for years. However, screening bioactive compounds from traditional Chinese medicine remains challenging because of the complexity of the systems and the occurrence of the synergic effect of the compounds. The infructescence of Platycarya strobilacea Sieb. et Zucc is prescribed for allergic rhinitis treatment with unknown bioactive compounds and unclear mechanisms. Herein, we immobilized the β2 -adrenoceptor and muscarine-3 acetylcholine receptor onto the silica gel surface to prepare the stationary phase in a covalent bond through one step. The feasibility of the columns was investigated by the chromatographic method. Ellagic acid and catechin were identified as the bioactive compounds targeting the receptors. The binding constants of ellagic acid were calculated to be (1.56±0.23)×107 M-1 for muscarine-3 acetylcholine receptor and (2.93±0.15)×107 M-1 for β2 -adrenoceptor by frontal analysis. While catechin can bind with muscarine-3 acetylcholine receptor with an affinity of (3.21±0.05)×105 M-1 . Hydrogen bonds and van der Waals' force were the main driving forces for the two compounds with the receptors. The established method provides an alternative for multi-target bioactive compound screening in complex matrices.

Bioactivity Screening and Chemical Characterization of Biocompound from Endophytic Neofusicoccum parvum and Buergenerula spartinae Isolated from Mangrove Ecosystem.

The discovery of biomolecules has been the subject of extensive research for several years due to their potential to combat harmful pathogens that can lead to environmental contamination and infections in both humans and animals. This study aimed to identify the chemical profile of endophytic fungi, namely Neofusicoccum parvum and Buergenerula spartinae, which were isolated from Avecinnia schaueriana and Laguncularia racemosa. We identified several HPLC-MS compounds, including Ethylidene-3,39-biplumbagin, Pestauvicolactone A, Phenylalanine, 2-Isopropylmalic acid, Fusaproliferin, Sespendole, Ansellone, Calanone derivative, Terpestacin, and others. Solid-state fermentation was conducted for 14-21 days, and methanol and dichloromethane extraction were performed to obtain a crude extract. The results of our cytotoxicity assay revealed a CC50 value > 500 μg/mL, while the virucide, Trypanosoma, leishmania, and yeast assay demonstrated no inhibition. Nevertheless, the bacteriostatic assay showed a 98% reduction in Listeria monocytogenes and Escherichia coli. Our findings suggest that these endophytic fungi species with distinct chemical profiles represent a promising niche for further exploring new biomolecules.

Highly multiplexed bioactivity screening reveals human and microbiota metabolome-GPCRome interactions

The human body contains thousands of metabolites derived from mammalian cells, the microbiota, food, and medical drugs. Many bioactive metabolites act through the engagement of G-protein-coupled receptors (GPCRs); however, technological limitations constrain current explorations of metabolite-GPCR interactions. Here, we developed a highly multiplexed screening technology called PRESTO-Salsa that enables simultaneous assessment of nearly all conventional GPCRs (>300 receptors) in a single well of a 96-well plate. Using PRESTO-Salsa, we screened 1,041 human-associated metabolites against the GPCRome and uncovered previously unreported endogenous, exogenous, and microbial GPCR agonists. Next, we leveraged PRESTO-Salsa to generate an atlas of microbiome-GPCR interactions across 435 human microbiome strains from multiple body sites, revealing conserved patterns of cross-tissue GPCR engagement and activation of CD97/ADGRE5 by the Porphyromonas gingivalis protease gingipain K. These studies thus establish a highly multiplexed bioactivity screening technology and expose a diverse landscape of human, diet, drug, and microbiota metabolome-GPCRome interactions.

Bioactivity Profiles of Actinobacterium Strain BTA 1-131 (InaCC A1205) Isolated from Indonesian Sponge Melophlus sarassinorum

The phylum Actinobacteria recognized as the most promising producers of many bioactive compounds. Among actinobacteria, the genus Streptomyces are widely known as prolific producers of many antibiotics, for example Streptomycin. The present study investigates potential bioactivity of actinobacteria BTA 1-131 isolated from an Indonesian marine sponge Melophlus sarassinorum. Molecular identification using the 16S rRNA gene sequencing showed that the isolate is similar to Streptomyces kunmingensis (98.4%). The isolate was cultivated on to three different fermentation media (ISP2, YS, and SYP) to select the best media for bioactive compounds production. The compounds were extracted from both solid and liquid cultures using methanol as a solvent. The crude methanol extracts were tested for antibacterial and anticancer activity. The bioactivity screening indicates active potential of the extracts against bacterial pathogen Staphylococcus aureus ATCC 13420, invasive breast cancer MDA-MB-231 and human colorectal adenocarcinoma cells CaCo-2. The extracts profiling using LC-MS/MS method indicates probable influence among different fermentation media to selectively induce production of target bioactive compounds. Although further compounds dereplication and fractionation are important for specific identification, the present study demonstrates the potential of Streptomyces BTA 1-131 as producer of tetracycline and/or staurosporine. In addition to that, further genome-mining approach and analysis using a whole genome sequencing data also important to comprehensively explore the bioactive potential of the actinobacteria BTA 1-131.

Diversity and Antimicrobial Activity of Intestinal Fungi from Three Species of Coral Reef Fish.

Although intestinal microbiota play crucial roles in fish digestion and health, little is known about intestinal fungi in fish. This study investigated the intestinal fungal diversity of three coral reef fish (Lates calcarifer, Trachinotus blochii, and Lutjanus argentimaculatus) from the South China Sea using a culturable method. A total of 387 isolates were recovered and identified by sequencing their internal transcribed spacer sequences, belonging to 29 known fungal species. The similarity of fungal communities in the intestines of the three fish verified that the fungal colonization might be influenced by their surrounding environments. Furthermore, the fungal communities in different intestines of some fish were significantly different, and the number of yeasts in the hindgut was less than that in fore- and mid-intestines, suggesting that the distribution of fungi in fishes' intestines may be related to the physiological functions of various intestinal segments. In addition, 51.4% of tested fungal isolates exhibited antimicrobial activity against at least one marine pathogenic microorganism. Notably, isolate Aureobasidium pullulans SCAU243 exhibited strong antifungal activity against Aspergillus versicolor, and isolate Schizophyllum commune SCAU255 displayed extensive antimicrobial activity against four marine pathogenic microorganisms. This study contributed to our understanding of intestinal fungi in coral reef fish and further increased the library of fungi available for natural bioactive product screening.