Guignardia Mangiferae Research Articles

Evaluation and chemical characterization of bioactive secondary metabolites from endophytic fungi associated with the ethnomedicinal plant Bergenia ciliata

Abstract The objective of this work was to assess the bioactive potential of endophytic fungi, Colletotrichum brevisporum (JPSK3), Pestalotiopsis microspora (JPSK19), and Guignardia mangiferae (JPSK25), from Bergenia ciliata. The antibacterial effects were determined by the well diffusion technique against human pathogens (Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Salmonella typhi) and they showed good activities. In the antioxidant assay, the fungal extract P. microspora shows higher free radical scavenging effects in 2,2-diphenyl-1-picrylhydrazyl (82.48%), hydrogen peroxide (84.91%), superoxide (78.85%), and reducing power absorbance of 0.125 at a dosage of 125 g/mL than other two fungi. The fungal extract was also subjected to phenol and flavonoid quantifications. The fungus P. microspora shows the highest phenol (89.56 0.03 mg of GAE/g of extract) and flavonoid (51.52 0.69 mg of quercetin equivalents/g of extract), respectively. The chemical composition of abundant biologically active compounds was determined by gas chromatography-mass spectrophotometry (GC-MS). Furthermore, it was confirmed through spectral and analytical analysis (thin layer chromatography, ultraviolet, Fourier transform infrared spectroscopy, high-performance liquid chromatography, GC-MS, and nuclear magnetic spectroscopy). In P. microspora, the compound phenol, p-tert-butyl (C10H14O), was confirmed for the first time. This fungal compound could be a potential alternative medicine in the future. This is the first work on endophytic fungal studies of ethnomedicinal plant Bergenia ciliata.

Bioprospecting the Antibacterial Activity of Endophytic Fungi from Noni (Morinda citrifolia) against Bacterial Spot of the Passion Fruit Tree

Bacterial spot, which is the main disease occurring in passion fruit trees, is caused by the bacterium Xanthomonas axonopodis pv. passiflorae, leading to large annual losses in passion fruit crops. This study aims to find extracts and/or bioactive compounds of endophytic fungi of noni (Morinda citrifolia) to treat bacterial spot in passion fruit trees. Nine fungi isolated from a specimen of M. citrifolia from the Brazilian Amazon are studied. The fungus Guignardia mangiferae NF17 shows the best inhibition results and is selected for the isolation of its secondary metabolites by chromatography techniques. The isolated compounds Sydowinol (S1) and Sydowinin A (S2) are identified by nuclear magnetic resonance (NMR). Compounds S1 and S2, as well as the acetonitrile extract from the biomass of G. mangiferae NF17, are tested against four strains of X. axonopodis pv. passiflorae obtained from plants infected by bacterial spot, and which inhibited bacterial growth up to the lowest concentration tested (3.125 µg/mL). This study reports, for the first time, the antibacterial activity against X. axonopodis pv. passiflorae by the compounds Sydowinol and Sydowinin A. Compounds S1 and S2 are reported for the first time for the genus Gignardia.

First report of secondary leaf fall in rubber trees caused by Phyllosticta capitalensis in the Eastern Plains of Colombia

Rubber trees (Hevea brasiliensis) are planted on 65,545 hectares in Colombia (Minagricultura, 2021). Since September 2020, unusual leaf spots were observed on mature leaves of rubber trees (clones RRIM 600 and FX 3864), in three plantations in the Eastern Plains region. The regular spots (usually 1–3 per leaf) were up to 8 mm in diameter, with a clearly defined brownish to blackish margin and a necrotic centre (Figure 1). The disease led to secondary leaf fall, causing up to 30% defoliation. Diseased leaves were collected and transferred to the laboratory for diagnosis. After surface disinfection with ethanol (70%) and sodium hypochlorite (2%), 0.5 cm2 sections of diseased tissue were transferred to potato dextrose agar (PDA) medium and incubated at 28°C for two weeks. The developing colonies had irregular borders and gradually turned dark greyish-green in colour, then black (Figure 2a). Sporulation was induced on a parboiled rice medium (Figure 2b) under controlled conditions (12 hr photoperiod, relative humidity 50%, 26 ±2°C). Pycnidia with conidia were observed after 44 days. Conidia (Figure 3a) were small, single-celled, hyaline, ovoid to elongate, measuring 8–11×5-6 μm. Pycnidia were dark, ostiolate and lenticular to globose (Figure 3b). These morphological characters were consistent with the descriptions of Phyllosticta species (Wikee et al., 2013). Two isolates (14_SAT and 15_SAT) were deposited in the Agrosavia fungi collection and used for DNA-based identification. The ITS, TEF1 and ACT genes were amplified and sequenced using primers ITS5/ITS4 (White et al., 1990), EF1-728F/EF1-986R and ACT-512F/ACT-783R (Carbone & Kohn, 1999), respectively. BLASTn analysis showed that the ITS (GenBank Accession Nos. OL898551 and OL957043) had 100% identity with P. capitalensis strain CBS128856 (OL957169), ACT (OM782674 and OM782675) had 100% identity with P. capitalensis isolate CPC25327 (KY855640), and TEF1 (OM782672 and OM782673) had 100% identity with Guignardia mangiferae (syn. P. capitalensis) strain CBS 100175 (FJ538378). A multilocus phylogenetic analysis revealed isolates clustered together in a clade with reference strains of P. capitalensis (Figure 4). For inoculation studies, H. brasilisensis seedlings of variety RRIM 600 were transferred to a growth chamber (24 hr dark initially, thereafter 12 hr light/dark; 26°C; relative humidity >90%). The abaxial surface of three healthy stage B leaves were sprayed with a conidial suspension of isolate 14_SAT (1×106 spores ml 1), while three control leaves were sprayed with sterile water. The experiment was repeated after one month with the 15_SAT isolate. Chlorotic lesions were observed 48 hours after inoculation and necrotic spots appeared after five days. The pathogen was successfully re-isolated on PDA medium and morphologically confirmed as P. capitalensis. No symptoms were observed on the control leaves. Phyllosticta capitalensis has been identified previously as a rubber foliar pathogen in Sri Lanka (Herath et al., 2019). Narayanan & Reju (2020) isolated the fungus from rubber leaves in India showing the same symptoms as reported here. This is the first report of P. capitalensis causing secondary leaf fall in rubber plantations in Colombia. Further monitoring of this new disease is required to determine its impact. The authors thank Mavalle and Rubberland for allowing leaf sampling in their plantations. This work was carried out with financial support from Agrosavia (Project 1001205) and CIRAD.

Terpene−Shikimate conjugated meroterpenoids from the endophytic fungus Guignardia mangiferae

Nine undescribed shikimate-conjugated meroterpenes, as well as nine known compounds, were isolated from solid cultures of the fungus Guignardia mangiferae, an endophyte obtained from the leaves of Dendrobium nobile. The structures of these undescribed compounds were characterized by analyses of their 1D and 2D NMR and HRESIMS data, and their absolute configurations were assigned by single-crystal X-ray crystallography, electronic circular dichroism (ECD) calculations, modified Mosher's method, and Mo2(OCOCH3)4-induced ECD experiments. Of these compounds, mangnardone A represents the first example of terpene–shikimate-conjugated meroterpenoid with a hydroxy group at C-5. In addition, the X-ray diffraction analysis of mangnardone I is the first example to confirm the structure of bicycloalternarene (BCA) meroterpenoid by single-crystal data. Nine undescribed meroterpenes inhibited nitric oxide (NO) production in LPS-induced RAW 264.7 cells with IC50 values in the range of 4.7–40.0 μM.

Diversity of endophytic fungi from the leaves of Vaccinium dunalianum.

This study was focus on investigating the community composition of endophytic fungi in the leaves of Vaccinium dunalianum Wight. Based on a combination of morphological features and molecular evidence, 239 endophytic fungal isolates belonging to 33 genera including 62 species were obtained and identified. By comparing the relative abundance (RA) values, the most frequent species belonged to Phyllosticta and Guignardia with RA of 26·78 and 14·22% respectively. Of which, the strains P. capitalensis and G. mangiferae with potential antimicrobial activity were the dominant endophytes to the sampling of leaves. A high diversity of endophytic fungi from V. dunalianum leaves was observed with high species richness S (62), Margalef index D' (11·1386), Shannon-Wiener index H' (3·2588), Simpson's diversity index Ds (0·9179), probability of interspecific encounter index (0·9218), and evenness Pielou index J (0·7896) but a low dominant index λ (0·0821). SIGNIFICANCE AND IMPACT OF THE STUDY: The isolated 239 endophytic fungal strains belong to 33 genera, 62 species, in which a high diversity of endophytic fungi was observed in Vaccinium dunalianum leaves. In this study, two taxa Phyllosticta capitalensis and Guignardia mangiferae with potential antimicrobial activity were the dominant endophytes. This is a promising source of natural bioactive compounds for future agro-industry application.

Antibacterial Activities of Endophytic Fungi from Capsicum annuum L. (Siling labuyo) leaves and fruits

Endophytic fungi were isolated from Capsicum annuum (siling labuyo) from three ecological zones in the province of Albay, Philippines and were identified through morpho-cultural characteristics and by molecular analysis of the internal transcribed spacer (ITS) region of the 18S ribosomal DNA. Eight fungal endophytes were isolated from the leaves and fruits. Seven were identified as Colletotrichum gloeosporioides, Lasiodiplodia pseudotheobromae, Nigrospora sphaerica, Guignardia mangiferae, Coprinopsis cinerea, Colletotrichum siamense and Colletotrichum truncatum while one remained unidentified. The extracted metabolites from the isolates were then screened for their antibacterial activities at 1,000 µg/mL. Among the fungal isolates, C. cinerea was found to be the most active against Staphylococcus aureus and Escherichia coli with zones of inhibition (ZOI) of 16.00 ± 1.00 and 17.00 ± 1.53 mm, respectively. Phytochemical screening showed that C. cinerea produced a variety of secondary metabolites such as flavonoids, alkaloids, terpenoids and quinones. The other fungal endophytes were also found to synthesize various secondary compounds that may be responsible for their antibacterial activities.

Biocontrol Potential of Fungal Endophytes against Fusarium oxysporum f. sp. cucumerinum Causing Wilt in Cucumber.

Endophytic fungi have received much attention as plant growth promoters as well as biological control agents against many plant pathogens. In this study, 30 endophytic fungal species, isolated from various plants in China, were evaluated using in vitro dual culture assay against Fusarium oxysporum f. sp. cucumerinum, causing wilt in cucumber. The results of the present study clearly showed that all the 30 endophytic fungal isolates were highly capable of inhibiting the mycelial colony growth of Fusarium oxysporum f. sp. cucumerinum with inhibition % over 66% as compared to control treatments. Among all of them, 5 isolates were highly effective such as, Penicillium sp., Guignardia mangiferae, Hypocrea sp., Neurospora sp., Eupenicillium javanicum, and Lasiodiplodia theobromae, respectively. The Penicillium sp. and Hypocrea sp. were highly effective as compared to other isolates. From in vitro results 10 best isolates were selected for greenhouse studies. The results of the greenhouse studies showed that among all of them 3 endophytic fungal isolates successfully suppressed wilt severity when co-inoculation with pathogen Fusarium. oxysporum f. sp. cucumerinum. The endophytic fungi also enhanced plant growth parameters of the host plants, the antagonistic fungal isolates increased over all plant height, aerial fresh, and dry weight as compared to control.

Fungal Community of Culturable Fungal Endophytes Associated with Cinchona calisaya Collected from Gambung, West Java, Indonesia

Previous studies regarding endophytic fungi associated with Cinchona were focused on the analysis of quinine and related fungal metabolites. In the current study, the community structure of culturable endophytic fungi associated with C. calisaya (i.e., leaf, petiole, twig, root, flower, and fruit) were analyzed and elucidated. Representative isolates from various morphotypes were identified based on a sequence generated from the Internal Transcribed Spacer (ITS) rDNA region. A total of 638 fungal strains were isolated from 700 plant segments. All isolates belong to the phylum Ascomycota and are dominated by a member of Sordariomycetes. The fungal endophyte community within C. cali-saya consists of 23 known species, 10 species complexes, and 6 unidentified species. Based on the Shannon-Wiener diversity index, the leaves and fruits host the most diverse endophytic fungi, followed by twigs, petioles, and bark. Members of the genus Diaporthe are commonly found in all C. calisaya organs. Neofussicoccum sp. was only one found within twigs; the Colletotrichum gloeosporioides complex and Guignardia mangiferae were only found within leaves; the C. brasiliense complex was detected in flowers; and Fusarium oxysporum is specific to roots.

Characteristics of endophytic fungi from Polygonum hydropiper suggest potential application for P-phytoextraction

Endophytes may play important roles in phytoremediation; however, little information is available on the endophytes of phosphorus (P)-accumulating plants and their potential application in P-phytoextraction. Here, 30 endophytic fungi were isolated from Polygonum hydropiper and classified into 24 taxonomic groups, with 76.7% being Ascomycota and 23.3% being Basidiomycota. Metarhizium anisopliae, Guignardia mangiferae and Phaeophlebiopsis peniophoroides were the dominant species. The Simpson and Shannon diversity indices were higher in shoots than in roots. The isolates had varied plant-growth-promoting traits with all being indole-3-acetic acid positive and only 18 exhibiting siderophore activities. P solubilization capability varied with fungal species and P sources; it correlated negatively with pH but positively with organic acids in a tricalcium phosphate medium. However, in a phytin medium, it did not correlate with pH, but positively with phosphatase activities. Five endophytes were found to have the greatest potential as inoculants to assist P. hydropiper in future P-phytoextraction studies.

Mangiterpenes A–C and 2′,3′-seco-manginoid C, four sesquiterpene/monoterpene–shikimate–conjugated spirocyclic meroterpenoids from Guignardia mangiferae

Mangiterpenes A–C and 2′,3′-seco-manginoid C, four undescribed sesquiterpene/monoterpene–shikimate–conjugated meroterpenoids with spiro ring systems, were isolated from Guignardia mangiferae. The structures and absolute configurations of these compounds were established by comprehensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Mangiterpenes A–C represent the first examples of sesquiterpene–shikimate-conjugated spirocyclic meroterpenoids, and 2′,3′-seco-manginoid C features an unexpected 2′,3′-seco-manginoids skeleton. Mangiterpene C strongly inhibited the production of NO inducted by LPS, with an IC50 value of 5.97 μM. It showed an anti-inflammatory effect by means of blocking in the NF-κB signaling pathway and decreasing the expression of inflammatory mediators.

Manginoids A-G: Seven Monoterpene-Shikimate-Conjugated Meroterpenoids with a Spiro Ring System from Guignardia mangiferae.

Manginoids A-G (1-7), seven monoterpene-shikimate-conjugated meroterpenoids with a spiro ring system, were isolated from Guignardia mangiferae. Compounds 1-4 are four isomers with epimeric and double-bond isomeric features possessing a 6-oxaspiro[bicyclo[3.2.1]octane-3,5'-indene] ring, which represent the first examples of spiro meroterpenoids bearing a bridged spirocyclohexanedione moiety. Compounds 5 and 6 possess an unexpected 2,4-dioxatricyclo[3.3.1.03,7]nonane motif, which fuses with a 6-oxabicyclo[3.2.1]octane moiety. Compound 1 exhibits inhibitory activities against 11β-hydroxysteroid dehydrogenase type 1 with an IC50 value of 0.84 μM.

Determining the Pathogenic Potential of Non-sporulating Molds Isolated from Cutaneous Specimens.

Although non-sporulating molds (NSM) are frequently isolated from patients and have been recognized as agents of pulmonary disease, their clinical significance in cutaneous specimens is relatively unknown. Therefore, this study aimed to identify NSM and to determine the keratinolytic activity of isolates from cutaneous sites. NSM isolates from clinical specimens such as skin, nail, and body fluids were identified based on their ribosomal DNA sequences. Of 17 NSM isolates (7 Ascomycota, 10 Basidiomycota), eleven were identified to species level while five were identified to the genus level. These include Schizophyllum commune, a known human pathogen, Phoma multirostrata, a plant pathogen, and Perenniporia tephropora, a saprophyte. To determine fungal pathogenicity, keratinolytic activity, a major virulence factor, was evaluated ex vivo using human nail samples by measuring dye release from keratin azure, for NSM along with pathogens (Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Fusarium spp.) and nonpathogenic (endophyte) fungi for comparison. This study showed that pathogenic fungi had the highest keratinolytic activity (7.13±0.552 keratinase units) while the nonpathogenic endophytes had the lowest activity (2.37±0.262 keratinase units). Keratinolytic activity of two Ascomycota NSM (Guignardia mangiferae and Hypoxylon sp.) and one Basidiomycota NSM (Fomitopsis cf. meliae) was equivalent to that of pathogenic fungi, while Xylaria feejeensis showed significantly higher activity (p<0.05) than nonpathogenic endophytes. These results indicate that the pathogenic ability of NSM is species dependent; clinical isolates, especially more frequently isolated species, may be involved in disease etiology.

Guignardones P-S, New Meroterpenoids from the Endophytic Fungus Guignardia mangiferae A348 Derived from the Medicinal Plant Smilax glabra.

Four new meroterpenoids, guignardones P–S (1–4), and three known analogues (5–7) were isolated from the endophytic fungal strain Guignardia mangiferae A348. Their structures were elucidated on the basis of spectroscopic analysis and single crystal X-ray diffraction. All the isolated compounds were evaluated for their inhibitory effects on SF-268, MCF-7, and NCI-H460 human cancer cell lines. Compounds 2 and 4 exhibited weak inhibitions of cell proliferation against MCF-7 cell line.

Impact of Domestication on the Endophytic Fungal Diversity Associated With Wild Zingiberaceae at Mount Halimun Salak National Park

Mount Halimun Salak National Park is one of the tropical forest remnants in Java island. The national park has been recognized with high diversity of wild Zingiberaceae. Of that Zingiberaceae, two species namely Alpinia malaccensis (AM) and Horstendia conica (HC), were domesticated as garden plants in the surrounding area of the forest for medicinal use. The impact of domestication on the fungal endophytes associated with these two species of Zingiberaceae is reported here. Fungal endophyte diversity in the wild and domesticated AM and HC was analyzed based on the culturable fungi. Identification of species level used morphological and molecular approaches of ITS rDNA sequence. This study determined 19 species of fungal endophytes, namely Arthrinium malaysianum, Aspergillus flavipes, As. sydowii, Chaetomium globosum, Cladosporium oxysporum, Cladosporium sp., Colletotrichum boninense-complex, Co. cliviae-complex, Co. gloeosporioides-complex, Diaporthe sp., D. anacardii, D. gardenia, Exophiala sp., E. lecanii-corni, Guignardia mangiferae, Ochroconis gallopava, Penicillium citrinum, Pyricularia costina, and unsporulated Sydowiellaceae. Among them, A. malaysianum, C. globosum, Co. cliviae-complex, D. gardenia, and unsporulated Sydowiellaceae were only found in domesticated plants, while some others were absent. Colletotrichum boninense-complex was commonly found in both wild and domesticated plants. Domestication activity affected the diversity of endophytic fungi of AM and HC.

Eremophilane Sesquiterpenes and Polyketones Produced by an Endophytic Guignardia Fungus from the Toxic Plant Gelsemium elegans.

A cultured endophytic fungus, Guignardia mangiferae, isolated from the toxic plant Gelsemium elegans yielded five new sesquiterpenes (1-5), two new polyketones (6 and 7), and two known terpene polyketones (8 and 9). Their structures were elucidated using spectroscopic methods. On the basis of circular dichroism, the absolute configurations of the new compounds were determined. Compounds 1, 3, 4, and 9 inhibited lipopolysaccharide-induced NO production in BV2 cells with IC50 values of 15.2, 6.4, 4.2, and 4.5 μM, respectively (positive control curcumin, IC50 = 3.9 μM).

Diversity of endophytic fungi in Glycine max

Endophytic fungi are microorganisms that live within plant tissues without causing disease during part of their life cycle. With the isolation and identification of these fungi, new species are being discovered, and ecological relationships with their hosts have also been studied. In Glycine max, limited studies have investigated the isolation and distribution of endophytic fungi throughout leaves and roots. The distribution of these fungi in various plant organs differs in diversity and abundance, even when analyzed using molecular techniques that can evaluate fungal communities in different parts of the plants, such as denaturing gradient gel electrophoresis (DGGE). Our results show there is greater species richness of culturable endophytic filamentous fungi in the leaves G. max as compared to roots. Additionally, the leaves had high values for diversity indices, i.e. Simpsons, Shannon and Equitability. Conversely, dominance index was higher in roots as compared to leaves. The fungi Ampelomyces sp., Cladosporium cladosporioides, Colletotrichum gloeosporioides, Diaporthe helianthi, Guignardia mangiferae and Phoma sp. were more frequently isolated from the leaves, whereas the fungi Fusarium oxysporum, Fusarium solani and Fusarium sp. were prevalent in the roots. However, by evaluating the two communities by DGGE, we concluded that the species richness was higher in the roots than in the leaves. UPGMA analysis showed consistent clustering of isolates; however, the fungus Leptospora rubella, which belongs to the order Dothideales, was grouped among species of the order Pleosporales. The presence of endophytic Fusarium species in G. max roots is unsurprising, since Fusarium spp. isolates have been previously described as endophyte in other reports. However, it remains to be determined whether the G. max Fusarium endophytes are latent pathogens or non-pathogenic forms that benefit the plant. This study provides a broader knowledge of the distribution of the fungal community in G. max leaves and roots, and identifies the genetic relationships among the isolated species.

Exploitation of endophytic fungus, Guignardia mangiferae for extracellular synthesis of silver nanoparticles and their in vitro biological activities

The aim of this study was to synthesize highly biocompatible and functionalized silver nanoparticles using endophytic fungi isolated from the leaves of medicinal plants. Among 13 fungi tested, the isolate, Guignardia mangiferae (Bios PTK 4) extracellularly synthesized well-dispersed and extremely stable silver nanoparticles under optimized reaction conditions within 12h. These nanoparticles were characterized by HR-TEM, SAED, XRD and EDX analyses. G. mangiferae synthesized 5–30nm sized, spherical shaped silver nanoparticles. Effect of pH on the antibacterial activity of silver nanoparticles was studied using well diffusion assay; on the basis of particle stability and antibacterial activity, pH 7 was found to be optimum. The leakage of intracellular components has clearly demonstrated that silver nanoparticles damage the bacterial cells by formation of pores, which affect the membrane permeability and finally leads to cell death. In addition, silver nanoparticles exhibited excellent antifungal activity against plant pathogenic fungi. Cytotoxic effects of silver nanoparticles showed IC50 values of 63.37, 27.54 and 23.84μg/mL against normal African monkey kidney (Vero), HeLa (cervical) and MCF-7 (breast) cells, respectively, at 24h incubation period. Thus, the obtained results convincingly suggest that silver nanoparticles synthesized from G. mangiferae are highly biocompatible and have wider applicability and they could be explored as promising candidates for a variety of biomedical/pharmaceutical and agricultural applications.

Molecular phylogeny, diversity, symbiosis and discover of bioactive compounds of endophytic fungi associated with the medicinal Amazonian plant Carapa guianensis Aublet (Meliaceae)

We investigated the endophytic fungal community associated with the Amazonian medicinal plant Carapa guianensis and its potential for providing bioactive compounds. A total of 162 endophytic fungal isolates were obtained and identified by molecular methods. These isolates were classified into 35 different taxa in the genera Aspergilllus, Beltrania, Botryosphaeria, Colletotrichum, Diaporthe, Endomelanconiopsis, Fusarium, Guignardia, Pestalotiopsis, Phomopsis, Pilidiella, Trichoderma, and Xylaria. The most frequent colonisers recovered of C. guianensis were Colletotrichum sp. 1, Diaporthe cf. mayteni, and Pestalotiopsis sp. 1. The fungal community had a moderate richness but high diversity and evenness indices. Colletotrichum sp. and Pilidiella wangiensis displayed selective antibacterial activity; Diaporthe cf. mayteni and Endomelanconiopsis endophytica showed high activity against amastigote forms of Trypanosoma cruzi; and Colletrotrichum sp. Guignardia mangiferae, Pestalotiopsis sp., and Diaporthe melonis were able to inhibit yellow fever virus proliferation. Our results suggest that the plants living in the tropical forest, such as the Amazonian hotspot region, can live in symbiosis with hidden and underestimated rich communities of endophytic fungi, which deserve protocols and/or specific laws to keep its future conservation. The capability of these endophytic fungi to produce bioactive compounds may be part of their chemical defense and adaptive response to survive and colonizing the plant host in wild environment. Consequently, these fungal communities may provide a source of bioactive molecules, including those able to inhibit or control neglected tropical diseases.

Meroterpenes with toll-like receptor 3 regulating activity from the endophytic fungus Guignardia mangiferae.

The endophytic fungus Guignardia mangiferae isolated from Ilex cornuta leaves was shown to produce a family of meroterpenes with toll-like receptor 3 regulating activity (1-9), of which 1-3 possessed new structures. The absolute stereochemistry of 1-3 was assigned through a combination of nuclear magnetic resonance experiments, chemical derivation, CD spectra, and single-crystal X-ray diffraction analyses (CuK α ). The precursor labeled cultivation suggests that these meroterpenes are most likely assembled through terpenoid-shikimate pathways. Moreover, meroterpenes 1-3, 5-7, and 9 selectively upregulate, but 4 and 8 downregulate the toll-like receptor 3 expression in mouse dendritic cells at 10.0 µM.

Diversity of endophytic fungi and screening of fungal paclitaxel producer from Anglojap yew, Taxus x media

BackgroundEndophytic fungi represent underexplored resource of novel lead compounds and have a capacity to produce diverse class of plant secondary metabolites. Here we investigated endophytic fungi diversity and screening of paclitaxel-producing fungi from Taxus x media.ResultsEighty-one endophytic fungi isolated from T. media were grouped into 8 genera based on the morphological and molecular identification. Guignardia and Colletotrichum were the dominant genera, whereas the remaining genera were infrequent groups. The genera Glomerella and Gibberella were first reported in Taxus. Three representative species of the distinct genera gave positive hits by molecular marker screening and were capable of producing taxol which were validated by HPLC-MS. Among these 3 taxol-producing fungi, the highest yield of taxol was 720 ng/l by Guignardia mangiferae HAA11 compared with those of Fusarium proliferatum HBA29 (240 ng/l) and Colletotrichum gloeosporioides TA67 (120 ng/l). This is the first report of taxol producer from Guignardia. Moreover, the lower similarities of ts and bapt between microbial and plant origin suggested that fungal taxol biosynthetic cluster might be repeatedly invented during evolution, nor horizontal gene transfer from Taxus species.ConclusionsTaxol-producing endophytic fungi could be a fascinating reservoir to generate taxol-related drug lead and to elucidate the remained 5 unknown genes or the potential regulation mechanism in the taxol biosynthesis pathway.