Daldinia Eschscholtzii Research Articles

Evaluation of Ointments with Daldinia eschscholtzii in Wound Healing in an In Vivo Model.

Fungi are a source of a variety of secondary metabolites of importance in different areas of biotechnology. Several compounds have been characterized with antioxidant, antimicrobial, and anti-inflammatory activity from fungi of the division of the Ascomycota, among which is the species Daldinia eschscholtzii, an endophyte fungus of pantropical distribution. In this study, we evaluated the effect of an ointment made with D. eschscholtzii on the wound healing of BALB/c mice. The species was corroborated using a molecular marker Internal Transcribed Spacer (ITS1 and ITS4). The extracts and dust of the fungus were considered nontoxic as they caused a mortality of <15% in the nematode Panagrellus redivivus, and experimental ointments had no adverse effects on the skin of BALB/c mice. Wounds treated with the D. eschscholtzii ointments had 99.9-100% wound contraction after 17 days, which was similar to commercial healing (positive control). As such, the ointment of D. eschscholtzii is a natural alternative to improve wound healing.

Morphological and molecular identification of fungi isolated from selected brri rice varieties

A total of 19 fungal species were isolated from the seeds of selected rice varieties (BRRI dhan 90 to BRRI dhan 99) following Tissue planting method and Blotter method. The isolated fungi were Aspergillus niger, A. ochraceus, A. oryzae, A. tamarii, A. terreus, Chaetomium globosum, Cladosporium oxysporum, Colletotrichum gloeosporioides, Corynespora cassiicola, Curvularia lunata, Curvularia soli, Daldinia eschscholtzii, Fusarium solani, Penicillium oxalicum,Penicillium sclerotiorum, Pestalotiopsis guepinii, Pyricularia oryzae and Rhizopus stolonifer. Fourteen fungi were selected for molecular identification. Out of the 19 fungal isolates, 14 were confirmed up to species level through ITS sequence based molecular analysis. Among the isolated fungi Pnicillium sclerotiorum and Curvularia soli are the new record for Bangladesh. Association of Daldinia eschscholtzii with rice seeds is also recorded first time from world. Bangladesh J. Plant Taxon. 31(1): 73-82, 2024 (June)

Assessment of decay caused by Trametes flavida and Daldinia eschscholtzii on several hardwood species

AbstractWood‐decay fungi are major contributors to damage wood and logs, resulting in substantial economic losses. This study assessed the decay caused by Trametes flavida and Daldinia eschscholtzii on Gmelina arborea, Samanea saman, Albizia lebbeck, Acacia auriculiformis and Swietenia mahagoni. Both fungi demonstrated their ability to decay wood. However, the extent of damage varied significantly among the tested hardwood species. Findings showed that Trametes flavida caused greater wood mass and density loss than Daldinia eschscholtzii. Among the tested hardwood species, G. arborea was found to be more susceptible to the decay fungi, followed by S. saman, A. lebbeck, A. auriculiformis and S. mahagoni, respectively. The study will encourage the scientific management of timber and logs in sawmill depots to minimize the decay of wood and incurred economic loss.

Isolation of Endophytic Fungi from Rui (Harrisonia perforata (Blanco) Merr.) and Determining Their Antibacterial, Antioxidant, and Cytotoxic Activity

Endophytic fungi produce bioactive metabolites that exhibit antibacterial, antioxidant, and anti-cancer activity. Rui (Harrisonia perforata (Blanco) Merr.) is a traditional medicinal plant proven to be an antibacterial and anticancer. Endophytic fungi live in plant tissues without damaging or producing chemicals that infect the host cell. Endophytes produce the same and similar compound as an original plant. This study aimed to isolate the endophytic fungi from Rui and determine their antibacterial, antioxidant, and cytotoxic activity. 13 fungal isolates were successfully isolated using PDA for seven days at 30°C. Molecular identification using the ITS1 and ITS4 DNA sequences only revealed six species: Diaporthe sp., Phomopsis sp., Aspergillus tubingensis, Aspergillus viridinutans, Pseudofusicoccum sp., and Daldinia eschscholtz. Seven isolates showed antibacterial activity based on plate assay. Aspergillus tubingensis and RA-1 exhibited antibacterial activity against Staphylococcus aureus and Salmonella typhi, with the MIC and MBC starting from 24 to 32 mg/ml. The DPPH assay showed the most increased antioxidant activity in Daldinia eschscholtzii with an IC50 of 98.14±2.39 µg/ml. The Brine Shrimp Lethality Test (BSLT) showed the highest potential cytotoxic activity, as shown by Aspergillus tubingensis and Phomopsis sp. with LC50 of 7.78±7.48 and 30.83±0.39 µg/ml. In conclusion, our study demonstrates that the fungal extract from Rui could be a source of antibacterial, antioxidant, and cytotoxic agents.

Antifeedant, Antifungal Cryptic Polyketides with Six Structural Frameworks from Tea Endophyte Daldinia eschscholtzii Propelled by the Antagonistic Coculture with Phytopathogen Colletotrichum pseudomajus and Different Culture Methods.

The antagonistic coculture with tea phytopathogen Colletotrichum pseudomajus induces antifungal cryptic metabolites from isogenesis endophyte Daldinia eschscholtzii against tea phytopathogens. Sixteen new polyketides with six structural frameworks including ten cryptic ones, named coldaldols A-C (1-3), collediol (5), and daldinrins A-L (10-20 and 23), were found from the coculture of C. pseudomajus and D. eschscholtzii by different culture methods. The unique framework of compounds 11 and 12 featured a benzopyran-C7 polyketone hybrid, and compounds 13-16 were characterized by the novel benzopyran dimer. The structures were determined mainly by spectroscopic methods, including extensive one-dimensional (1D), two-dimensional (2D) NMR, high resolution electrospray ionisation mass spectroscopy (HRESIMS), ECD calculation, and single-crystal X-ray diffraction. The configuration of acyclic compounds 5 and 18 were determined by application of the universal NMR database. Most compounds showed significant antifungal activities against the tea pathogens C. pseudomajus and Alternaria sp. with MICs of 1-8 μg/mL. Compound 12 had stronger antifungal activity than that of positive drug nystatin. The ether bond at C-4 of the benzopyran derivative increased the antifungal activity. Compounds 4-9 and 11-23 showed antifeedant activities against silkworms with feeding deterrence indices of 15-100% at the concentration of 50 μg/cm2.

Secondary Metabolite of Endophytic Fungi Daldinia eschscholtzii from The Leaves of Syzygium polyanthum

Salam (Syzygium polyanthum) is a plant that is often used by Indonesian people as traditional medicine. The leaves are consumed to treat various diseases. This study reports the endophytic fungi found from S. polyanthum leaves and its secondary metabolites. Endophytic fungi species were determined through morphological and molecular identification. Potato Dextrose Broth medium was used for the cultivation process and ethyl acetate was used as a solvent for the extraction process. Antioxidant tests was carried out by using the DPPH method. Chromatographic techniques were used for the isolation of secondary metabolite and spectroscopic analysis was carried out to identify their chemical structures. The results of morphological and molecular analysis showed that the sample was Daldinia eschscholtzii. The secondary metabolite obtained from this endophytic fungus was idetified as fonsecinone A with good antioxidant activity. The secondary metabolite have the potential to become a source antioxidants through further research.

Phylloremediation of pyrene and anthracene by endophytic fungi inhabiting tea leaves (Camellia sinensis (L.) Kuntze) in Sri Lanka

ABSTRACT Polyaromatic hydrocarbons (PAHs) released from vehicular emissions and oil refineries deposit on the phyllosphere, compromising the quality of leaf-based food products by posing many health issues. Nevertheless, the tea phyllosphere harbours a variety of endophytes that are highly effective at degrading polyaromatic hydrocarbons, anthracene, and pyrene. The present study attempts to analyse the pyrene and anthracene degrading capability of phyllosphere endophytic fungi that inhabit Camellia sinensis (L.) Kuntze leaves. The frequency of occurrence of endophytic fungi in different leaf tissue layers was examined using light and scanning electron microscopy (SEM). The best pyrene and anthracene degrading strains were selected based on the High-Performance Liquid Chromatography (HPLC) results, and further kinetic assays. Light microscopy and SEM observations highlighted a heterogeneous endophytic fungal distribution among leaf tissue layers; the upper epidermis had the highest fungal distribution compared to other leaf layers. HPLC results revealed that Phyllosticta capitalensis, Colletotrichum gloeosporioides, Colletotrichum siamense, Pseudopestalotiopsis chinensis, and Daldinia eschscholtzii, have higher pyrene and anthracene degradation respectively and their PAH degradation kinetics follow the first-order kinetic model. The best anthracene and pyrene degrader, P. capitalensis showed the lowest half-life. The present investigation highlights the potential of P. capitalensis, the best pyrene and anthracene degrader that can remediate PAHs deposited on the phyllosphere of tea leaves.

Differential Volatile Organic Compound Expression in the Interaction of Daldinia eschscholtzii and Mycena citricolor.

Fungi exhibit a wide range of ecological guilds, but those that live within the inner tissues of plants (also known as endophytes) are particularly relevant due to the benefits they sometimes provide to their hosts, such as herbivory deterrence, disease protection, and growth promotion. Recently, endophytes have gained interest as potential biocontrol agents against crop pathogens, for example, coffee plants (Coffea arabica). Published results from research performed in our laboratory showed that endophytic fungi isolated from wild Rubiaceae plants were effective in reducing the effects of the American leaf spot of coffee (Mycena citricolor). One of these isolates (GU11N) from the plant Randia grandifolia was identified as Daldinia eschscholtzii (Xylariales). Its antagonism mechanisms, effects, and chemistry against M. citricolor were investigated by analyzing its volatile profile alone and in the presence of the pathogen in contactless and dual culture assays. The experimental design involved direct sampling of agar plugs in vials for headspace (HS) and headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) analysis. Additionally, we used ultrahigh-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS) to identify nonvolatile compounds from organic extracts of the mycelia involved in the interaction. Results showed that more volatile compounds were identified using HS-SPME (39 components) than those by the HS technique (13 components), sharing only 12 compounds. Statistical tests suggest that D. eschscholtzii inhibited the growth of M. citricolor through the release of VOCs containing a combination of 1,8-dimethoxynapththalene and terpene compounds affecting M. citricolor pseudopilei. The damaging effects of 1,8-dimethoxynaphthalene were corroborated in an in vitro test against M. citricolor pseudopilei; scanning electron microscopy (SEM) photographs confirmed structural damage. After analyzing the UHPLC-HRMS/MS data, a predominance of fatty acid derivatives was found among the putatively identified compounds. However, a considerable proportion of features (37.3%) remained unannotated. In conclusion, our study suggests that D. eschscholtzii has potential as a biocontrol agent against M. citricolor and that 1,8-dimethoxynaphthalene contributes to the observed damage to the pathogen's reproductive structures.

Antioxidant and L-asparaginase activities of culturable endophytic fungi from ornamental Dendrobium orchids.

This study reports the antioxidant potential and L-asparaginase production of culturable fungal endophytes from Dendrobium orchids in Malaysia. Twenty-nine isolates were screened using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay to determine their free radical scavenging activities and antioxidant capacity (IC50 and AEAC). L-asparaginase production of fungal endophytes was detected by the qualitative plate assay, and the enzyme activities estimated via the Nesslerization method. All 29 endophytic isolates exhibited various degrees of radical scavenging activities (35.37%-77.23%), with Fusarium fujikuroi (D1) identified as having the highest antioxidant capacity (IC50 6.097 mg/mL) and the highest AEAC value (11.55 mg/g). For L-asparaginase production, the majority of the isolates (89.66%) showed positive results, especially among the culturable species of Fusarium, Trichoderma, and Daldinia. Most Fusarium spp. were able to produce L-asparaginase (80.77%), but the highest L-asparaginase activity was detected in Daldinia eschscholtzii (D14) with 2.128 units/mL. Results from this study highlighted the potential of endophytic fungi from medicinal orchids (Dendrobium sp.) as natural sources of bioactive compounds to be developed into novel antioxidants and anticancer drugs.

Plant growth-promoting traits and activation of defense enzymes in traditional rice variety by fungal endophytes isolated from seeds of indigenous rice cultivars of Northeast India

The present investigation was carried out to expound on the role of seed borne endophytic fungi isolated from native rice cultivars of North East India. Altogether 226 fungal isolates were obtained from the surface-sterilized seeds of the 10 selected rice cultivars. The major isolates were species of Curvularia, Aspergillus, Fusarium, Gliocladium, Mucor, Penicillium, Bipolaris, Basidiobolus, Periconia, and non-sporulating mycelia sterilia. Principal Component Analysis (PCA) revealed dominance of Fusarium and Curvularia with high degree of colonization in Ampack and Chakhao rice cultivars. Altogether 84.61% of the isolates, showed siderophores activity on CAS agar medium and 76.92% of the isolates showed phosphorus solubilization activity. The result indicated that 84.61% of the isolates showed positive for ammonia production and interestingly grew in nitrogen-deficient Jensen's agar medium. The fungal isolates BD9, KON7, AM34, AM10, and Mycelia sterilia exhibited the highest antagonistic activity against rice pathogen Magnaporthe grisea. Enhanced production of peroxidase, polyphenol oxidase, chitinase, and superoxide dismutase enzyme was observed when a traditional rice plant was inoculated with a consortium made of fungal isolates AM34 and AM10 (Treatment 3). This combination exhibited a moderate increase in catalase production. Consortia made of other fungal isolates were not efficient in producing any defense enzymes. The isolates AM10, AM28, AM16, AM34, and AN 20 were identified as Fusarium annulatum, Daldinia eschscholtzii, Montagnula scabiosae, Fusarium redolens and Aspergillus flavus respectively based on microscopic and molecular characterization

Screening and evaluation of antidiabetic activities of endophytic fungi associated with Etlingera elatior

Abstract. Nurjannah L, Azhari A, Wulandari AP, Amin S, Supratman U. 2023. Screening and evaluation of antidiabetic activities of endophytic fungi associated with Etlingera elatior. Biodiversitas 24: 3481-3487. Etlingera elatior (Jack) R.M.Sm. has been well-documented to have antioxidant and antidiabetic properties. Among all medical conditions worldwide, diabetes mellitus is one of the leading causes of death. Therefore, research on the discovery of antidiabetic medicines inhibitory to ?-glucosidase (an enzyme for degrading complex dietary carbohydrates into sugar in the digestive process) is urgently needed. This study aims to isolate and evaluate the potential of the fermentation culture of endophytic fungi associated with E. elatior to inhibit the activity of ?-glucosidase. The endophytic fungi were isolated from various parts of E. elatior. A total of 29 isolates were successfully isolated from the plant's roots, stems, leaves, and flowers. The endophytic fungi were tested for their ability to inhibit ?-glucosidase activity in bioassays. Among those isolates, 8 were inhibitory to such an enzyme, and 2 showed the highest inhibitory activities. Morphotype and molecular identification of those isolates, using their Internal Transcribed Spacer (ITS) regions of ribosomal DNA (rDNA), identified them as Daldinia eschscholtzii isolate CFL 7 and Hypoxylon trugodes voucher YMJ 57, with IC50 values of 738 µg/mL and 825 µg/mL, respectively. That indicates that they are potentially used in preventing or treating diabetic mellitus.

Potential use of bacterial strain in the genus Serratia to biocontrol fungal pathogens associated with defoliation on Pinus patula

ABSTRACT Pathogenic fungi that cause defoliation in different pine species, including Pinus patula, have been reported. The most common practice for controlling these pathogens is the use of fungicides, which have adverse environmental consequences. The objective of this study was to evaluate an alternative for pathogen control without affecting the ecosystem. Bacteria with antifungal activity obtained from forest soil were isolated and biochemically and molecularly identified for evaluation in biocontrol assays of fungi associated with defoliation under laboratory and field conditions. Two species of the genus Serratia, Serratia grimesii and S. proteamaculans, were identified as bacteria with antifungal activity. In vitro biocontrol was achieved by reducing the mycelium growth of fungi associated with diseased needles of P. patula: Alternaria alternata, Annulohypoxylon stygium, Botryosphaeria dothidea, Curvularia lunata, C. pseudobrachyspora, C. spicifera, C. trifolii, Daldinia sp., Daldinia eschscholtzii, Diplodia sapinea, Lophodermium indianum, and Myrmaecium rubricosum. The fungi in P. patula (Annulohypoxylon stygium and Daldinia eschscholtzii) decreased their damage by 82% and 77%, respectively, in the presence of Serratia under humid chamber conditions. In addition, the incidence of lesions (IL) and Disease Severity Index were significantly reduced under natural conditions. The results showed that biocontrol with bacteria of the genus Serratia is an alternative for the management of health in Pinus patula trees.

Isolation and molecular identification of agarwood-inducing fungi and their virulence test using Aquilaria sp. seedlings

Abstract. Lukman, Dinarti D, Siregar UJ, Turjaman M, Sudarsono. 2023. Isolation and molecular identification of agarwood-inducing fungi and their virulence test using Aquilaria sp. seedlings. Biodiversitas 24: 140-148. Agarwood is a lump of fragrant resin with a dark color and distinctive aroma from secondary metabolite products that accumulate in wood fibers produced from the genus Aquilaria and Gyrinops, a plant defense mechanism against damage caused by wounds and infection of specific fungal pathogens. The three main factors in producing agarwood sapwood are the presence of plants that have the potential to produce agarwood (family Thymelaceae) as a host, a supportive environment, and the presence of specific fungal pathogens. The isolation, identification, and virulence testing of local isolates must be made to get the correct agarwood-inducing pathogens without posing potential environmental problems. A total of five explants of Aquilaria sp. branches producing agarwood from the study site were used. This study aims to isolate local strains of fungi associated with agarwood formation from North Aceh regency, Aceh province, Indonesia, figure out their virulence against and ability to induce agarwood from seedlings of target trees, and determine their species identity. The experiments comprised isolation, macroscopic and microscopic identification, virulence tests, and species identification based on ITS sequences. The study resulted in five local Aceh isolates (LAI-1- LAI-5). Four isolates (LAI-1 - LAI-4) can induce agarwood formation, and oneisolate (LAI-5) is a white rot fungus. The ITS sequence analysis showed that LAI-1 - LAI-4 were Fusarium solani, while two colonies taken from LAI-5 isolate were identified as Ceriporia lacerataor Irpex laceratus (LAI-5 colony#1), and Daldinia eschscholtzii (LAI-5 colony #3). Based on these findings, the LA-5 isolate was probably a mixture of the two white rot fungus isolates.

Phaeohyphomycosis: A study from tertiary health care center in North India

Phaeohyphomycosis refers to infections caused by phaeoid/dematiaceous or darkly pigmented fungi. This study was undertaken to further increase our knowledge about the incidence of phaeohyphomycosis and its causative agents. The present study was conducted over a period of one and a half years (January 2018-June 2019) on specimens received from patients with varied clinical manifestations ranging from superficial infections, subcutaneous cysts, pneumonia, brain abscess to a disseminated infection. These specimens were processed in the Department of Microbiology for potassium hydroxide (KOH) examination and culture and in Pathology for cytology/histopathological examination (HPE). All specimens positive on direct examination for dark grey, brown or black fungi were included in the study. A total of 20 specimens were confirmed as phaeohyphomycosis. Most of the patients belonged to the age group of 41 to 50 years. Male: Female ratio was 2.3:1. Trauma was the most common risk factor. Spectra of the isolated fungal pathogens comprised of Bipolaris species, Exophiala species, Curvularia geniculata, Phialemonium species, Daldinia eschscholtzii, Hypoxylon anthochroum, Phaeoacremonium species, Leptosphaerulina australis, Medicopsis romeroi, Lasiodiplodia theobromae, Eutypella species, Chaetomium globosum, Alternaria species, Cladophialophora bantiana and 2 unidentified dematiaceous fungi. Recovery from phaeohyphomycosis was seen in 12 patients, 7 were lost to follow up and one patient succumbed to the illness. Infections caused by phaeoid fungi can no longer be viewed as rare. In fact, phaeohyphomycosis can have myriad of presentations spanning from mild cutaneous infections to fatal brain disease. Therefore, a high index of clinical suspicion is needed to diagnose such infections. The primary treatment modality remains surgical removal of the lesion in cutaneous or subcutaneous infections however disseminated disease with a guarded prognosis requires aggressive management.

Biodeterioration of low-density polyethylene by mangrove-associated endolichenic fungi and their enzymatic regimes.

Fungal involvement in the biodeterioration of low-density polyethylene (LDPE) has received great attention in recent years. Among diverse groups of fungi, endolichenic fungi (ELF) are adapted to thrive in resource-limited conditions. The present study was designed to investigate the potential of mangrove-associated ELF, in the biodeterioration of LDPE and to quantify key-depolymerizing enzymes. A total of 31 ELF species, isolated from 22 lichens of mangrove ecosystems in Negombo lagoon, Sri Lanka were identified using DNA barcoding techniques. ELF were inoculated into a mineral salt medium, containing LDPE strips and incubated at 28 ± 2°C, for 21 days, under laboratory conditions. After incubation, biodeterioration was monitored based on percent reductions in weights and tensile properties, increments in the degree of water absorption, changes in peaks of infrared spectra and surface erosions using scanning electron microscopy. Out of 31 species, Chaetomium globosum, Daldinia eschscholtzii, Neofusicoccum occulatum, Phanerochaete chrysosporium, Schizophyllum commune and Xylaria feejeensis showed significant changes. Production of depolymerizing enzymes by these species was assayed qualitatively using plate-based methods and quantitatively by mass-level enzyme production. Among them, Phanerochaete chrysosporium showed the highest enzyme activities as (9·69 ± 0·04) × 10-3 , (1·96 ± 0·01) × 10-3 , (5·73 ± 0·03) × 10-3 , (0·88 ± 0·01), (0·64 ± 0·06), (1·43 ± 0·01) U ml-1 for laccase, lignin peroxidase, manganese peroxidase, amylase, lipase and esterase, respectively.

Diversified Polyketides With Anti-inflammatory Activities From Mangrove Endophytic Fungus Daldinia eschscholtzii KBJYZ-1.

In total, five new polyketide derivatives: eschscholin B (2), dalditone A and B (3 and 4), (1R, 4R)-5-methoxy-1,2,3,4-tetrahydronaphthalene-1,4-dio (5), and daldilene A (6), together with 10 known as analogs (1, 7–15) were isolated from the mangrove endophytic fungus Daldinia eschscholtzii KBJYZ-1. Their structures and absolute configurations were established by extensive analysis of NMR and HRESIMS spectra data combined with ECD calculations and the reported literature. Compounds 2 and 6 showed significant cell-based anti-inflammatory activities with IC50 values of 19.3 and 12.9 μM, respectively. In addition, western blot results suggested that compound 2 effectively inhibits the expression of iNOS and COX-2 in LPS-induced RAW264.7 cells. Further molecular biology work revealed the potential mechanism of 2 exerts anti-inflammatory function by inactivating the MAPK and NF–κB signaling pathways.

Molecular Characterization of Fungi Associated with Smoked Micromesistius poutassou (Blue whiting) from Different Markets in Lagos, Nigeria.

Micromesistius poutassou (Blue whiting) popularly called ‘’Panla’’ in Nigeria. It is one of the affordable fishes imported to Nigeria. With the rising cost of meat, milk and protein foods, consumers have become increasingly interested in fish as a source of protein for its availability and affordability rate. Smoked samples of Micromesistius poutassou were randomly purchased from ten different markets in ten local governments in Lagos state. This collection (purchase) were carried out between June and November 2019 (6 months). The associated fungi were isolated using the pour-plate method and extracted its DNA with the aid of Zymo DNA extraction kit. The extracted fungal DNA were amplified by PCR (Polymerase chain reaction) using specific internal transcribed spacer primer (ITS1/ITS4) and sequenced. Of the total 480 smoked Micromesistius poutassou sampled, ten fungi species were identified and characterised. These fungi include: Kodamaea ohmeri, Daldinia eschscholtzii, Aspergillus longivesica, Aspergillus flavus, Phoma sp, Aspergillus sp, Mucor circinelloides, Aspergillus tamarii, Aspergillus niger, and Geotrichum candidum. Results from this study revealed that smoked Micromesistius poutassou, which are being consumed by Lagosians on the daily basis were heavily contaminated with pathogenic fungi.

Molecular Characterization of Potential Crop Pathogens Associated with Weeds as Endophytes in Uniilorin Plantations, Nigeria

Crop diseases are usually caused by inoculum of pathogens which might exist on alternate hosts or weeds as endophytes. These endophytes, cum pathogens, usually confer some beneficial attributes to these weeds or alternate hosts from protection against herbivores, disease resistance, stress tolerance to secondary metabolites production. This study was therefore carried out to isolate potential crop pathogens which exist as endophytes on weed species in the University of Ilorin plantations. Green asymptomatic leaves were collected from 10 weed species across the plantations, and processed for their endophytic fungi isolation. Isolates were purified into pure cultures and used for molecular identification using the internal transcribed spacer (ITS) region of the ribosomal DNA. Phylogenetic analysis of the fungal sequences using MEGA software revealed 9 fungal genera belonging to 13 species, with species in the genera Curvularia, Epicoccum and Daldinia occurring in more than one weed species, while other genera such as Alternaria, Fusarium, Chaetomium, Macrophomina, Arthrinium and Phomopsis occurred in just one weed species each. Daldinia eschscholtzii was isolated in this study as an endophyte from Loudetia arundinacea for the first time. This plant is very abundant in Nigeria and Africa where it is used majorly for thatching and feeding livestocks. This also represents the first endophytic fungi from the genus Loudetia. Potential relationship between the occurrences of these fungi as endophytes and as pathogens are discussed. These discoveries represent the first large-scale molecular identification and several first reports of endophytes from these weed species. These results also represent the first records of some of these fungi in Nigeria.

Daldiniaeschsone A, a Rare Tricyclic Polyketide Having a Chromone Unit Fused to a δ-Lactone and Its Symmetrical Biphenyl Dimer, Daldiniaeschsone B, from an Endophytic Fungus Daldinia eschscholtzii SDBR-CMUNKC745.

Daldiniaeschsone A (1), a rare tricyclic polyketide having a chromone unit fused to a δ-lactone and its symmetrical 6,6′-biphenyl dimer, daldiniaeschsone B (2), together with three known compounds (3−5), were isolated from a plant-derived endophytic fungus, Daldinia eschscholtzii SDBR-CMUNKC745. Their structures were elucidated by extensive 1D and 2D NMR spectroscopic data and HRESIMS. All compounds showed α-glucosidase inhibitory activity with IC50 values ranging from 0.16−0.85 mM and compound 1 was the best α-glucosidase inhibitory activity (IC50 = 0.16 mM).

Mitochondrial damage produced by phytotoxic chromenone and chromanone derivatives from endophytic fungus Daldinia eschscholtzii strain GsE13.

Bioassay-guided fractionation of the organic extracts of the endophyte Daldinia eschscholtzii strain GsE13 led to the isolation of several phytotoxic compounds, including two chromenone and two chromanone derivatives: 5-hydroxy-8-methoxy-2-methyl-4H-chromen-4-one, 1; 5-hydroxy-2-methyl-4H-chromen-4-one, 2; 5-methoxy-2-methyl-chroman-4-one, 3; and 5-methoxy-2-methyl-chroman-4-ol, 4; as well as other aromatic compounds: 4,8-dihydroxy-1-tetralone, 5; 1,8-dimethoxynaphthalene, 6; and 4,9-dihydroxy-1,2,11,12-tetrahydroperyl-ene-3,10-quinone, 7. Compounds 1, 4, and 7 were isolated for the first time from D. eschscholtzii. The phytotoxicity of all the compounds was determined on germination, root growth, and oxygen uptake in seedlings of a monocotyledonous (Panicum miliaceum) and three dicotyledonous plants (Medicago sativa, Trifolium pratense, and Amaranthus hypochondriacus). In general, root growth was the most affected process in all four weeds, and chromenones 1 and 2 were the most phytotoxic compounds. Phytotoxins 1-4 inhibited basal oxygen consumption rate in isolated mitochondria from M. sativa seedlings and also caused serious damage to their membrane potential (ΔΨm) in percentages greater than 50% at concentrations lower than 2 mM. Based on these results, compounds 1-4 of endophytic origin could be promising for the development of new herbicides potentially useful in agriculture or for the synthesis of promising new molecules. KEY POINTS: • Endophytic fungus Daldinia eschscholtzii produces phytotoxic compounds. • Phytotoxins inhibit basal oxygen consumption rate in isolated M. sativa mitochondria. • Phytotoxins altered the mitochondrial membrane potential.