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.

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.

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.

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.

The antifeedant and antifungal cryptic metabolites isolated from tobacco endophytes induced by host medium and coculture.

Four new cryptic metabolites including one fumagillol derivative (2), one cyclohexenone derivative (4), one 10-membered lactone (5), and one natural 4-epi-brefeldin C (8), along with seven known compounds were found from isogenesis endophytes Aspergillus fumigatus, Penicillium janthinellum, Nigrospora sp., and Stagonosporopsis sp. induced by host Nicotiana tabacum medium and co-culture. The structures were determined mainly by spectroscopic methods, including extensive 1D, 2D NMR, MS techniques, ECD calculation, and Mosher's method. Compound 2 possessed a novel 1, 3-dioxetane residue and cyclohexane-containing terpenoid skeleton. Compounds 2, 4-7 and 10 showed significant antifungal activities against the plant pathogen Nigrospora sp. with MICs of 1 µg/mL. 2, 4, 5-7, and 10 indicated antifungal activities against Penicillium janthinellum, Aspergillus fumigatus, Phomopsis sp., and Alternaria sp. with MICs ≤8 µg/mL. Compounds 2, 6-8, and 10 (50 µg/cm2) and microbial fermentation extracts (100 µg/cm2) showed antifeedant activities against silkworms with feeding deterrence indices of 21-100%.

The induced cryptic metabolites and antifungal activities from culture of Penicillium chrysogenum by supplementing with host Ziziphus jujuba extract.

The productions of cryptic metabolites including three undescribed drimane sesquiterpenoids, penicichrins A-C, and three known compounds from Penicillium chrysogenum were activated by the host Ziziphus jujuba medium. The structures were established by comprehensive analysis of spectroscopic data. The spiro ß-lactone, and gem-dimethyl dihydroxylation in induced penicichrins A-C were rare in natural products. Cryptic metabolites, monaspurpurone was first found in Penicillium. 4-Methoxy-3-methylgoniothalamin, and 2-hydroxy-l-phenyl-l,4-pentanedione were second example of isolation. Penicichrin A, monaspurpurone, 4-methoxy-3-methylgoniothalamin, physcion, ergosterol, and ergosta-7,22-dien-3ß-ol had antifungal activities against phytopathogens, P. chrysogenum, Alternaria alternata and Aspergillus fumigatus with MICs ≤2 µg/mL, and 2-hydroxy-l-phenyl-l,4-pentanedione had flowering activity. So the chemical constituents from Z. jujuba could induce the productions of cryptic metabolites with plant growth-promoting activity from endophyte P. chrysogenum.

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 selective anti-fungal metabolites from Irpex lacteus and applications in the chemical interaction of Gastrodia elata, Armillaria sp., and endophytes.

The investigation of the metabolites from endophyte Irpex lacteus cultured in host "tian ma" (Gastrodia elata) revealed five new tremulane sesquiterpenes (1-5), and a new tetrahydrofuran derivative (6). Compound 1 was the first tremulane glucoside, and 6 possessed a rare tetrahydropyran-tetrahydrofuran scaffold. Main metabolite (2,3-dihydroxydodacane-4,7-dione, 14) from I. lacteus showed significant selectivity for antifungal activity against phytopathogen and endophytes associated with G. elata rather than against Armillaria sp. providing nutrition for the host G. elata. 14 accounted for 27.4% of isolated compounds from G. elata medium, and 69.3% by co-culturing with Armillaria sp. So the I. lacteus tended to promote the growth of Armillaria sp. in co-culture by producing 2,3-dihydroxydodacane-4,7-dione (14) to selective inhibit the phytopathogen and endophyte existed in host G. elata for the benefit of G. elata-Armillaria symbiosis. And the results were in accord with the real environment of G. elata depending on the nutrition of Armillaria. Some metabolites had anti-fungal activities against phytopathogens of G. elata with MICs ≤8 µg/mL.

Myrothins A-F from Endophytic Fungus Myrothecium sp. BS-31 Harbored in Panax notoginseng.

Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe-microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A-F (1-6) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B (2) and E (5) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F (6) showed weak activity against F. oxysporum.

Antifeedant and antiphytopathogenic metabolites from co-culture of endophyte Irpex lacteus, phytopathogen Nigrospora oryzae, and entomopathogen Beauveria bassiana.

Five new tremulane sesquiterpenoids were isolated from co-culture of endophyte Irpex lacteus, phytopathogen Nigrospora oryzae, and entomopathogen Beauveria bassiana. All compounds showed obvious antifeedant activities against silkworm with inhibition percentages of 73-99%, at concentrations of 50 µg/cm2. Compound 11 indicated notable antifeedant activity with inhibition percentage of 93% at concentration of 6.25 µg/cm2 among them. Compounds 2, 3, 4, 8, 9, 15 and 16 indicated anti-fungal activities against I. lacteus with MIC values ≤8 µg/mL, compounds 11, 12, 16-18 showed significant anti-fungal activity against N. oryzae with MICs ≤ 4 µg/mL, and compounds 2, 5, 12 and 18 indicated significant anti-fungal activity against B. bassiana with MICs ≤ 8 µg/mL. In addition, the I. lacteus should unite B. bassiana to inhibit the production of phytotoxins from N. oryzae in the ternary culture.

Penctrimertone, a bioactive citrinin dimer from the endophytic fungus Penicillium sp. T2-11.

Penctrimertone (1), a novel citrinin dimer bearing a 6/6/6/6 tetracyclic ring scaffold, along with two known compounds xerucitrinic acid A (2) and citrinin (3) were isolated from the endophytic fungus Penicillium sp. T2-11. Their structures were unequivocally established by a comprehensive interpretation of the spectroscopic data, with the stereochemistry for 1 was defined by a combination of TDDFT-ECD calculations and the DP4+ probability analysis based on NMR chemical shift calculations. Bioassays revealed that compound 1 exhibited noticeable antimicrobial activities and moderate cytotoxicity. A plausible biosynthetic pathway of 1 was also proposed.

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 from Daldinia eschscholzii JC-15 by red ginseng medium.

Red ginseng (RG) is one of the most popular herbal medicines and used as a dietary supplement in recent years. The bioactive ingredient in RG can induce the production of novel microbial metabolite from fermented RG. Using the one strain-many compounds strategy, the reinvestigation of the metabolites from Daldinia eschscholzii JC-15 cultured in red ginseng medium led to the isolation of an unprecedented benzopyran-naphthalene hybrid, daldinsin (1) and a new lactone (2). In this research, a new lactone, 8-hydroxylhelicascolide A (2) instead of helicascolide A was produced by the D. eschscholzii JC-15 induced by the red ginseng medium. Compound 1 showed anti-acetylcholinesterase activity with the inhibition ratio of 38.8% at 50 µM. Compound 2 indicated antimicrobial activities against Fusarium Solani, F. oxysporum, and Escherichia coli with MICs at 128 µg/mL. RG is therefore a promising activator in production of novel microbial metabolite.

Peniterester, a carotane-type antibacterial sesquiterpene from an artificial mutant Penicillium sp. T2-M20.

Peniterester (1), a new tricyclic sesquiterpene, together with 6 known compounds (2-7) were isolated from the secondary metabolites of an artificial mutant Penicillium sp. T2-M20 which was obtained from the parental strain Penicillium sp. T2-8 via UV irradiation as well as nitrosoguanidine (NTG) induction. Peniterester was only produced by the mutant T2-M20 on the basis of LC-MS analysis. Meanwhile, the results of in vitro bioactivities screening indicated that peniterester owned obvious antibacterial activities against Bacillus subtilis, Escherichia coli and Staphylococcus aureus with MICs of 8.0, 8.0 and 4.0 µg/mL, respectively.

New azaphilones and tremulane sesquiterpene from endophytic Nigrospora oryzae cocultured with Irpex lacteus.

Five new metabolites belonging to two backbones of pulvilloric acid-type azaphilone and tremulane sesquiterpene were obtained and their structures were determined by spectral analysis. Based on the biogenesis analysis, tremulane sesquiterpenes were obtained from Irpex lacteus by the stimulation of mixed-culture. The antifungal selectivities of metabolites produced by fungus against their co-culture fungus and common pathogens, exhibited competitive interaction of this mix-culture. The tremulane sesquiterpene conocenol B produced by I. lacteus through the induction of Nigrospora oryzae showed selectivity of anti-fungal activity against its co-culture fungus, N. oryzae, with MICs at 16 µg/mL and 128 µg/mL against I. lacteus. The fungus can metabolize these new compounds to inhibit the growth of co-culture fungus while not inhibiting its own growth. Compound 5 was active against acetylcholinesterase (AChE) with a ratio of 35% at the concentration of 50 µM.

New bioactive compounds from aquatic endophyte Chaetomium globosum.

Two new oxidation products-related aureonitol and cytochalasan were isolated from Chaetomium globosum fermented in Chinese yam (Dioscorea opposita) and determined as 10,11-dihydroxyl- aureonitol (1) and yamchaetoglobosin A (2). Compound 2 indicated significant inhibitory effect on nitric oxide production in LPS-activated macrophages, anti-acetylcholinesterase activity with the inhibition ratios of 92.5, 38.2% at 50 µM, and cytotoxicity to HL-60, A-549, SMMC-7721, MCF-7 and SW480 with the range of inhibition ratio at 51-96% for a concentration of 40 µM. Compounds 1, 2 showed weak anticoagulant activity with PT at 16.8 s. Few work was reported on the anti-acetylcholinesterase, and anticoagulant activities of aureonitol, and cytochalasan derivatives. The preliminary structure-activity relationship stated that the oxidation ring-opening in yamchaetoglobosin A can retain the inhibitory effect against NO production and tumor cell.

Phytotoxic, antibacterial, and antioxidant activities of mycotoxins and other metabolites from Trichoderma sp.

A new natural mycotoxin was isolated from the fermentation broth of Trichoderma sp. Jing-8 and the structure was determined as alternariol 1'-hydroxy-9-methyl ether (1), together with twelve known compounds. The structures were elucidated on the basis of their 1D, 2D NMR spectra and mass spectrometric data. Compounds 1, 8 and 9 indicated inhibitions against germination of the seeds of cabbage with MICs < 3 µg/mL. The compound 1 showed the antibacterial activity against Bacillus subtilis and Staphylococcus aureus with MICs at 64 µg/mL. Compound 1 and 3 showed significant DPPH radical-scavenging activities with IC50 at 12 µg/mL, respectively. The OH at C-1' in compound 1 decreased the cytotoxicity of these mycotoxins. A primary structure-activity relationship about the alternariol derivatives was discussed. Compounds 2-7 and 8 were the first time to be isolated from the Trichoderma.

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.

Medelamine C, a new omega-hydroxy alkylamine derivative from endophytic Streptomyces sp. YIM 66142.

A new alkylamine derivative and a common fatty acid were isolated from Streptomyces sp. YIM 66142. On the basis of spectral data, including HRMS, NMR and 2D NMR, their structures were determined as medelamine C (1) and isomyristic acid (2). The omega-hydroxyl group in structure 1 is rare in a natural alkylamine. The possible biosynthetic pathway in the genus Streptomyces from isomyristic acid (2) to medelamines is proposed. Compound 1 showed no obvious cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, SW480 cell lines. The omega-hydroxyl and the acetyl at NH in compound 1 decreased its cytotoxicity in comparison with that of medelamine.

[Studies on the chemical constituents from the aerial parts of Gladiolus gandavensis].

OBJECTIVE: To study the chemical constituents of the aerial parts of Gladiolus gandavensis. METHODS: These compounds were isolated by silica gel, Sephades LH-20 and RP-18 column chromatographies. And their structures were elucidated by spectroscopic methods. RESULTS: Ten compounds were isolated, and their structures were identified as kaempferol (I), apigenin-7-O-alpha-L-rhamnoside(II), tamarixetin-3-robinobioside(III), nicotiflorin(IV), astragalin-2"-O-beta-D-glucopyranoside(V), quercetin-3-O-(6"-O-Ecaffeoyl)-beta-D-glucopyranoside(VI), beta-sitosterol(VII), daucosterol(VII), isopentylgentiobioside(IX), glycerol-alpha-monohexacosanate(X). CONCLUSION: Except for compounds VII and VIII, others compounds are obtained from this plant for the first time.