New Antifungal and Antifeedant Metabolites from Daldinia eschscholtzii Cocultured with Colletotrichum pseudomajus.

The synchronous co-culture of Daldinia eschscholtzii and Colletotrichum pseudomajus produced one new linear polyketide, eschscholin C (1), along with three known compounds (2-4). One new acorane sesquiterpene, coldaldrin A (5), and one new amide derivative, coldaldamide A (6) as the probe for polyketide intermediate capture, and three known compounds (7-9) were isolated from the sequential co-culture of D. eschscholtzii with C. pseudomajus. The structures and absolute configurations of 1, 5 and 6 were established by spectroscopic analysis including 1D, 2D NMR, the calculations of the NMR, and ECD data. Most compounds showed significant antifungal activities against the tea pathogens C. pseudomajus, and Fusarium asiaticum with MICs of 2-8 µg/mL. Compound 4 also showed antifeedant activity against silkworms with feeding deterrence indices of 79% at the concentration of 50 µg/cm2.

Novel Antifungal and Antifeedant Metabolites from Penicillium chrysogenum Co-Cultured with Nemania primolutea and Aspergillus fumigatus.

The endophyte Nemania primolutea, inhibited the growth of Penicillium chrysogenum in the coculture system. Four new compounds, nemmolutines A-B (1-2), and penigenumin (3) from N. primolutea, penemin (4) from P. chrysogenum were isolated from the coculture. On the other hand, P. chrysogenum inhibited the Aspergillus fumigatus in the coculture. Induced metabolites (13-16) with monasone naphthoquinone scaffolds including a new one from P. chrysogenum were produced by the coculture of P. chrysogenum, and A. fumigatus. Interesting, cryptic metabolites penicichrins A-B isolated from wild P. chrysogenum induced by host Ziziphus jujuba medium were also found in induced P. chrysogenum cultured in PDB ordinary medium. So the induction of penicichrin production by supplementing with host extract occurred in the fungus P. chrysogenum not the host medium. The productions of penicichrins were the spontaneous metabolism, and the metabolites (13-16) were the culture driven. Compounds 4, 6, 8, 10, 11, 14, and 15 showed significant antifungal activities against the phytopathogen Alternaria alternata with MICS of 1-8 µg/mL, and compounds 7, 9, and 12 indicated significant antifeedant activities against silkworms with feeding deterrence indexes (FDIs) of 92 %, 66 %, and 64 %. The carboxy group in 4-(2-hydroxybutynoxy)benzoic acid derivatives, and xylabisboeins; the hydroxy group in mellein derivatives; and the quinoid in monasone naphthoquinone increased the antifungal activities.

New Metabolites, Antifeedant, Insecticidal Activities, and Reciprocal Relationship Between Insect and Fungus from Endophyte Schizophyllum commune.

Five new bisabolane sesquiterpenes, a new polyketide, along with seven known compounds, were isolated from endophyte Schizophyllum commune associated with a famous medicinal and edible plant, Gastrodia elata. Most compounds 1-12, and extract indicated antifeedant activities against silkworm with feeding deterrence index (FDI) of 21-85 %, at concentrations of 20 µg/cm2 , 40 µg/cm2 , respectively. Compound 6 indicated obvious insecticidal activity with fatality rate of 60 %, at the concentration of 20 µg/cm2 . Five bisabolane sesquiterpenes, two ergosterols, and a glyceride showed insecticidal synergism by combining with abamectin. Interesting, ergosterol peroxide (13) distributed widely in mushrooms and fungi, was found to have feeding attractant activities on insects and antifungal activity against entomopathogen Beauveria bassiana. The reciprocal relationship should be occurred between S. commune and pests for the fungus produced ergosterol peroxide to attract the pests propagating spore, and its anti-entomopathogen activity was also benefit for the health of insects.

Antifeedant and Antifungal Activities of Metabolites Isolated from the Coculture of Endophytic Fungus Aspergillus tubingensis S1120 with Red Ginseng.

A new globoscinic acid derivative, aspertubin A (1) along with four known compounds, were obtained from the co-culture of Aspergillus tubingensis S1120 with red ginseng. The chemical structures of compounds were characterized by using spectroscopic methods, the calculated and experimental electronic circular dichroism. Panaxytriol (2) from red ginseng, and asperic acid (4) showed significant antifeedant effect with the antifeedant rates of 75 % and 80 % at the concentrations of 50 µg/cm2 . Monomeric carviolin (3) and asperazine (5) displayed weak attractant activity on silkworm. All compounds were assayed for antifungal activities against phytopathogens A. tubingensis, Nigrospora oryzae and Phoma herbarum and the results indicated that autotoxic aspertubin A (1) and panaxytriol (2) possessed selective inhibition against A. tubingensis with MIC values at 8 µg/mL. The co-culture extract showed higher antifeedant and antifungal activities against P. herbarum than those of monoculture of A. tubingensis in ordinary medium. So the medicinal plant and endophyte showed synergistic effect on the plant disease resistance by active compounds from the coculture of A. tubingensis S1120 and red ginseng.

The chemical diversity, the attractant, anti-acetylcholinesterase, and antifungal activities of metabolites from biocontrol Trichoderma harzianum uncovered by OSMAC strategy.

Eight new compounds (1-8) were discovered from Trichoderma harzianum associated with edible mushroom by the one strain many compounds (OSMAC) strategy. Triharzianin A (1) is the first naturally scaffold characterized by a C13-prostaglandin skeleton. The configurations of 1-3, and 5 were determined by the Mosher's method, experimental and calculated ECD spectra, and plausible biosynthesis of stereospecific epoxidation. Most compounds indicated obvious feeding attractant activities to silkworm with attraction rates at 30-90%. Compound 7 showed anti-acetylcholinesterase (anti-AChE) activity with a ratio of 29% at a concentration of 50 µM for insecticidal potential. So 2,​3-​dialkylchromone (7) had potential of chemical entrapment and killing of insects. Compounds 2, 3 and 7-11 showed antifungal activities against Aspergillus fumigates, and Trichoderma sp. from mushroom with MICs ≤ 300 µM. The four fermentation extracts also indicated obvious feeding attractant activities to silkworm for the activities brought by active metabolites from T. harzianum. The material base of biocontrol induced by the interaction of host-fungal symbiont can be investigated by the antifungal metabolites against pathogen fungi.

The Cocultured Nigrospora oryzae and Collectotrichum gloeosporioides, Irpex lacteus, and the Plant Host Dendrobium officinale Bidirectionally Regulate the Production of Phytotoxins by Anti-phytopathogenic Metabolites.

The distinctive nature of the endophyte Irpex lacteus, host plant, and the phytopathogen Collectotrichum gloeosporioides resulted in both negative and positive regulation of the production of phytotoxins from Nigrospora oryzae. The coculture of nonhomologous I. lacteus and N. oryzae resulted in a greater number of anti-phytopathogenic metabolites from the dominant endophyte than the coculture of homologous I. lacteus and N. oryzae. The coculture of the phytopathogen N. oryzae and either the nonhomologous (isolation of I. lacteus and N. oryzae from the different plants) or homologous (isolation of I. lacteus and N. oryzae from the same plant) endophyte I. lacteus from different sources indicated that the nonhomologous I. lacteus grew faster than the homologous I. lacteus, and the production of phytotoxic azaphilone from the phytopathogenic N. oryzae decreased due to the inhibition resulting from being cocultured with nonhomologous I. lacteus. On the other hand, the production of phytotoxic azaphilone was promoted by the coculture of two phytopathogens, N. oryzae and C. gloeosporioides. The extract of the host plant, Dendrobium officinale, also increased anti-phytopathogenic metabolite production. Six new phytotoxic azaphilones from N. oryzae, four new tremulane sesquiterpenes from I. lacteus, and a new polyketone were isolated. The endophyte-phytopathogen, phytopathogen-phytopathogen, and endophyte-phytopathogen-host interactions can induce the chemical diversity of novel anti-phytopathogenic metabolites.

Inducing Intermediates in Biotransformation of Natural Polyacetylene and A Novel Spiro-γ-Lactone from Red Ginseng by Solid Co-Culture of Two Gut Chaetomium globosum and The Potential Bioactivity Modification by Oxidative Metabolism.

The ω-hydroxyl-panaxytriol (1) and ω-hydroxyl-dihydropanaxytriol (2)-are rare examples of polyacetylene metabolism by microbial transformation, and these new metabolites (1, 2) from fermented red ginseng (FRG) by solid co-culture induction of two Chaetomium globosum should be the intermediates of biotransformation of panaxylactone (metabolite A). The metabolic pathway of panaxylactone was also exhibited. The ingredients of red ginseng (RG) also induced the production of rare 6/5/5 tricyclic ring spiro-γ-lactone skeleton (3). The ω-hydroxylation of new intermediates (1, 2) decreases cytotoxicity and antifungal activity against C. globosum compared with that of its bioprecursor panaxytriol. Additionally, compounds 1 and 2 indicated obvious inhibition against nitric oxide (NO) production, with ratios of 44.80 ± 1.37 and 23.10 ± 1.00% at 50 µM. 1 has an equivalent inhibition of NO production compared with the positive drug. So, the microbial biotransformation that occurred in FRG fermented by gut C. globosum can change the original bioactivity of polyacetylene, which gave a basis about the metabolic modification of red ginseng by intestinal fungus fermentation.

Inducing Secondary Metabolite Production by Co-culture of the Endophytic Fungus Phoma sp. and the Symbiotic Fungus Armillaria sp.

Co-culturing the endophytic fungus Phoma sp. YUD17001 from Gastrodia elata with Armillaria sp. in liquid nutrient medium resulted in the production of five new secondary metabolites, including two phenolic compounds, phexandiols A and B (1 and 2), three aliphatic ester derivatives, phomesters A-C (3-5), and a known fatty acid (6). The structures and absolute configurations of these compounds were elucidated by the interpretation of data from detailed spectroscopic analysis, Mosher's method, and electronic circular dichroism spectra, together with consideration of the biogenetic origins. None of the five new compounds were detected in single-strain cultures under identical fermentation conditions. The results of this work indicated that the production of 1-5 involved a complicated interaction process. None of the new compounds possessed significant cytotoxicity or antimicrobial activities.

New Bisabosquals from Stachybotrys sp. PH30583 Elicited on Solid Media.

Stachybotrys sp. PH30583 cultured in liquid medium only led to one structure type of novel isochroman dimers. Using the one strain-many compounds strategy, the reinvestigation of the metabolites from Stachybotrys sp. PH30583 cultured in rice solid medium led to the isolation of four triprenyl phenols, including two new bisabosquals and two known phenylspirodrimanes. Nitrobisabosquals A and B (1 and 2) are the first case of pyrrolidone-bisabosquals reported in literature. Totally different compounds were isolated using rice solid medium, compared with those isolated using liquid medium, so that rice solid medium presents a key factor in the production of triprenyl phenols. Compound 1 exhibited cytotoxicity against tumor cells, A-549, HL-60, MCF-7 SMMC-7721, and SW480, as well as weak anticoagulant activity with activated partial thromboplastin time (APTT) of 32.1 ± 0.17 s (p < 0.05 vs. Con.) at a concentration of 5 mM. Triprenyl phenol metabolites could be used as chemotaxonomic markers for Stachybotrys.

New Azaphilones from Nigrospora oryzae Co-Cultured with Beauveria bassiana.

In this study, the co-culture of Nigrospora oryzae and Beauveria bassiana, the endophytes in the seeds of Dendrobium officinale, were examined for metabolite diversity. Five new azaphilones were isolated, and their structures were determined by spectral analysis. In terms of azaphilones, compound 2 had an unprecedented skeleton, with a bicyclic oxygen bridge. The antifungal selectivities of the metabolite produced by N. oryzae against its co-culture fungus, B. bassiana, and common pathogens exhibited competitive interaction in this mix-culture. Compounds 1 and 2 showed obvious nitric oxide (NO) inhibitory activity with ratios of 37%, and 39%, respectively, at a concentration of 50 µM.

Novel Isochroman Dimers from Stachybotrys sp. PH30583: Fermentation, Isolation, Structural Elucidation and Biological Activities.

The rare anishidiol and five new isochromans, including three novel dimers with unprecedented skeletons, were isolated from Stachybotrys sp. PH30583. Their structures were determined by spectral analyses. The bioactivities of these compounds were also investigated. The dimers (6-10) inhibited acetylcholinesterase at 50 µM, but the monomers did not. To investigate the biogenesis of the novel dimers, a time-course investigation of metabolite production was undertaken.

The antifungal metabolites from coculture of Aspergillus fumigatus and Alternaria alternata associated with Coffea arabica.

One new cyclohexenone derivative, asperfumtone A (1) along with six known compounds were obtained from the coculture of Aspergillus fumigatus and Alternaria alternata associated with Coffea arabica. The configuration of 2 was first reported in the research. The structures were determined by extensive spectroscopic analyses, and ECD calculation. Compounds 3, 4 and 7 showed significant antifungal activities against coffee phytopathogens A. alternata and Fusarium incarnatum with MICs of 1 µg/mL. Compounds 1 and 2 showed weak antifungal activities against A. alternata and F. incarnatum with MICs of 32-64 µg/mL.

The Antiphytopathogenic Metabolites and the Synergy of Endophytes Paraphaeosphaeria sp., Nigrospora oryzae from the Same Ginkgo biloba Host.

Two endophytes from the same Ginkgo biloba host were isolated and cultured separately. Three new eremophilane sesquiterpenoids (1-3), three new furan derivates (6, 8-9), one new polyketide (10), and four known compounds (4, 5, 7, 11) from Paraphaeosphaeria sp. and two new 10-membered macrolides (12-13), a new liner polyketide (14), a new benzofuran (15), and six known compounds (16-21) from Nigrospora oryzae were isolated. The structures of the isolated compounds were determined by spectroscopic methods, NMR calculations, and ECD calculations. The compounds 3-7, 9-10, 12, and 14-17 showed significant antiphytopathogenic effects against mycotoxigenic Alternaria sp. comparable to the activity of nystatin (positive control). Compounds 2, 6, 8, 9, and 18 indicated inhibitions against phytopathogen Fusarium asiaticum with MICs < 10 µg/mL. In addition, the compounds with weak antifungal activities from two endophytes were mixed to test their antifungal activity. The results showed that the metabolites from two endophytes had synergistic antifungal effects, and the beneficial interactions between natural products can induce more antifungal effects against plant pathogens than that of single compounds.

The new analogues of ß-trans-bergamotene from endophytic fungus Nigrospora sp. E121 with yam culture medium.

Two new bicyclic sesquiterpenes,Δ9-2, 5, 11-trihydroxyl-ß-cis-bergamotene (3) and Nigrohydroin A (4), together with ten known compounds (1, 2 and 5-12) were obtained from endophytic fungus Nigrospora sp. E121. The structures were elucidated on the basis of their 1D and 2D NMR spectra and mass spectrometric data. The possible biosynthetic pathway of compounds 1, 2, 3 and 4 in Nigrospora sp. E121were reported according to literature. The phytotoxic assay results indicated that the acetyl fragment in α-acetylorcinol may contribute to the phytotoxic activity of this compound.

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.

Three new fumagillol analogues and antifungal activity from Aspergillus fumigatus cocultured with Paraphaeosphaeria sp.

Two fungi Aspergillus fumigatus YXG-12-2, and Paraphaeosphaeria sp. YXG-18 were isolated from medicinal plant Ginkgo biloba. The interaction of endophytes and host could induce the productions of antifungal metabolites against pathogens for the plant resistance. Three new fumagillol analogues, fumiparaphines A-C were isolated from A. fumigatus cocultured with Paraphaeosphaeria sp. in host medium. New compounds 2, and 3 had the similar fumagillol structures with tetrahydrofuran or tetrahydropyrane residue. The structures were established by 1D, 2D NMR, mass spectrometry, and calculated ECD spectra. Fumiparaphine A (1) indicated significant antifungal activity against the phytopathogen Alternaria alternata with MIC of 2 µg/mL.

Antifungal and antifeedant terpenoids from Paraphaeosphaeria sp. cultured by extract of host Ginkgo biloba.

Five undescribed terpenoids including a polyketide-terpenoid hybrid paraphaone, and four eremophilane sesquiterpenoids, paraphaterpenes A-D, as well as two known compounds were isolated from the endophytic fungus Paraphaeosphaeria sp. cultured by extract of host Ginkgo biloba L. The structures were established by spectroscopic analyses, and the single-crystal X-ray diffraction. The antifungal activity of Paraphaeosphaeria sp. cultured by extract of G. biloba against the plant pathogen Alternaria alternata was significant and higher than that of PDB medium. Tested compounds indicated antifeedant activities against silkworms with feeding deterrence index at 10-70%. Paraphaone, paraphaterpenes A, C, D and alternariol methyl ether showed significant antifungal activities against the phytopathogens A. alternata, Aspergillus fumigatus, and entomopathogen Beauveria bassiana with MICs ≤4 µg/mL. And the preliminary structure-activity relationship of eremophilane sesquiterpenoids was exhibited. The culture of Paraphaeosphaeria sp. by host G. biloba medium afforded agricultural antibiotics.

Antibiotic Guanacastane Diterpenoids with Two New Skeletons from Psathyrella candolleana Uncovered by Semisolid and Liquid Media.

The culture of Psathyrella candolleana in host Dioscorea opposite medium produced seven new guanacastane diterpenoids, psayamin (1) as an unprecedented 5/7/6/6/6/6/7/5-fused octacyclic spiro scaffold both under liquid and semisolid conditions, psathins A-C (4-6) with a 5/7/6 tricyclic backbone by liquid medium, psathins D-E (7-8) as the same unprecedented skeletons of 5/6/7/6-fused tetracyclic or 6/7/6 tricyclic structures, and psathin F (9) with a 5/7/5/6 tetracyclic backbone by semisolid medium. The structures were elucidated by detailed spectroscopic analyses and those of 1 and 7 were determined by single-crystal X-ray crystallography. The semisolid culture led to four structure types of the guanacastane diterpenoid. Compound 5 showed antifungal activity against phytopathogen Fusarium incarnatum with a minimum inhibitory concentration (MIC) of 8 µg/mL, while compound 4 showed significant antifungal activity against Alternaria sp. with an MIC of 2 µg/mL. Compounds 1 and 8 also showed antifeedant activities against the silkworms with the feeding deterrence indices of 50%, at the concentrations of 50 µg/cm2. Compound 1 showed significant cytotoxicity with IC50 at 10.87 ± 0.24-15.96 ± 0.30 µM and anti-acetylcholinesterase activity with IC50 at 37.3 µM. Also, compound 1 remarkably induced apoptosis of HL-60 at 10, 20 µM in a concentration-dependent manner. The spiral ring of 1 was vital in cytotoxicity and anti-acetylcholinesterase activity. The different media fermented by P. candolleana resulted in the chemical diversity of bioactive guanacastane diterpenoids and potential applications in the agricultural and food functions.

The antifungal metabolites isolated from maize endophytic fungus Fusarium sp. induced by OSMAC strategy.

Six new sesquiterpenes, fusarchlamols A-F (1, 2, 4-7); one new natural product of sesquiterpenoid, methyltricinonoate (3); and ten known compounds were found from Fusarium sp. cultured in two different media by the one strain many compounds strategy. The compounds (1, 2, and 4-11) were isolated from Fusarium sp. in PDB medium, and compounds (3-5, 8, and 10-17) were discovered from Fusarium sp. in coffee medium. Additionally, the configuration of 8 was first reported in the research by Mosher's method. The structures were established by 1D, 2D NMR, mass spectrometry, calculated ECD spectra, and Mosher's method. Compounds 1, 2, 6/7, 12, and 16 indicated significant antifungal activities against the phytopathogen Alternaria alternata isolated from Coffea arabica with MICs of 1 µg/mL. The investigation on the anti-phytopathogen activity of metabolites can provide lead compounds for agrochemicals.

A new butenolide with antifungal activity from solid co-cultivation of Irpex lacteus and Nigrospora oryzae.

A new antifungal butenolide irperide (1) along with five known compounds were isolated from the co-culture of endophyte Irpex lacteus and pathogenic Nigrospora oryzae. The structure of 1, including the absolute configuration, was elucidated by analysis of NMR, HR-ESI-MS data and ECD spectra. Compounds 1, 4 and 6 exhibited significant antifungal activity against Aspergillus fumigatus, with MIC values of 1, 2 and 1 µg/mL, respectively.