Bioactive chemical constituents from the marine-derived fungus Cladosporium sp.DLT-5

A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidation determined the planar structure of 1.Subsequent electronic circular dichroism(ECD)experiment assigned the absolute configuration of 1.Compounds 1,2,4–6,and 10 displayed different degrees of neuroprotective activities on human neuroblastoma cells SH-SY5Y.Five compounds(1,3–5,and 13)emerged resistance to protein tyrosine phosphatase 1B(PTP1B),further kinetic analysis and molecular docking study indicated that the most potent compound 13(IC50value of 10.74±0.61μmol/L)was found as a noncompetitive inhibitor for PTP1B.Surface plasmon resonance(SPR)and molecular docking studies also demonstrated the interaction between compound 12 and Niemann-Pick C1 Like 1(NPC1L1),which has been identified as significant therapeutic target for hypercholesteremia.In addition,compounds 3,6,and 14 showed attractive inhibitory activity against the phytopathogenic fungi:Colletotrichum capsici.Therefore,library of Cladosporium metabolites is enriched and new active uses of known compounds are explored.

Chemical constituents of marine mangrove-derived endophytic fungus Alternaria tenuissima EN-192

A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN- 192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids： penijanthine A （1）, paspaline （2）, paspalinine （3）, and penitrem A （4）; three tricycloalternarene derivatives： tricycloalternarene 3a （5）, tricycloalternarene lb （6）, and tricycloalternarene 2b （7）; and two alternariol congeners： djalonensone （8） and alternariol （9）. The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 gg/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived Alternaria tenuissima and also the first report of the isolation ofindole-diterpenoids from fungal genus Alternaria.

Chemical constituents of marine algal-derived endophytic fungus Exophiala oligosperma EN-21

Seven compounds (1–7) were identified from the cultivation of the endophytic fungus Exophiala oligosperma (EN-21) that was isolated from the inner tissue of the marine red alga Laurencia similis. Their structures were identified with spectroscopic and chemical methods as 2-phenoxynaphthalene (1), (2S, 3R, 4E, 8E)-1-O-β-D-glucopyranosyl-3-hydroxy-2-[(R)-2′-hydroxyoctadecanoyl] amino-9-methyl-4, 8-octadeca-diene (2), (22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol (3), (22E, 24R)-3β, 5α, 9α-trihydroxy- ergosta-7, 22-dien-6-one (4), (22E, 24R)-5α, 6α-epoxy-ergosta-8, 22-dien-3β, 7α-diol (5), (22E, 24R)- ergosta-4, 6, 8(14), 22-tetraen-3-one (6), and euphorbol (7). This paper reports for the first time the chemical constituents of fungus Exophiala oligosperma and the discovery of compound 1 as a natural product from the fungus.

Metabolites from mangrove endophytic fungus Dothiorella sp.

Mangroves are special woody plant communities in the intertidal zone of tropical and subtropical coasts. They prove to be a natural microorganisms and new metabolites storage. In the study of mangrove endophytic fungi metabolites, four new compounds, Compounds 1, 2, 3 and 4, as well as a known octaketide, oytosporone B (5), are isolated from an endophytic fungus, Dothiorella sp., HTF3. They all show cytotoxic activities. The elucidation of these structures is mainly based on 1D/ 2D NMR and ESI-MS spectral analyses.

A New Cytotoxic Sterol Produced by an Endophytic Fungus from Castaniopsis fissa at the South China Sea Coast

A new sterol, ergosta-8(9),22-diene-3,5,6,7-tetraol(3β,5α,6β,7α,22E)(A) together with three known sterols: 3β, 5α,6β-trihydroxyergosta-7,22-diene (B), 3β-hydroxy-5α,8α- epidioxyer-gosta-6,22-diene (C) and ergosterol (D) were isolated from the mycelia of an unidentified endophytic fungus separated from Castaniopsis fissa (chestnut tree). Compound A exhibited potent selective cytotoxicity against Bel-7402, NCI4460 and L-02 cell lines with IC50 values 8.445, 5.03, 13.621 μg/mL, respectively.

Two Cyclic Peptides Produced by the Endophytic Fungus # 2221 from Castaniopsis fissa on the South China Sea Coast

New cyclic peptides 1 and 2 were isolated from the endophytic fungus #2221 fromCastaniopsis fissa on the south China sea coast. By 2D NMR methods and chiral HPLC technique,their structures were elucidated as cyclo (L-Val-L-Leu-L-Val-L-Leu) and cyclo(L-Leu-L-Ala-L-Leu-L-Ala), respectively.

Secondary Metabolites from the Endophytic Fungus Xylaria sp.hg1009

A detailed chemical investigation of the secondary metabolites produced by the endophytic fungus Xylaria sp.isolated from the stems of Isodon sculponeatus afforded six new compounds,xylariahgins A-F(1-6),two new natural products(7 and 8),along with two known compounds(9 and 10)(Fig.1).The structures of all compounds were unambiguously established by analyzing their spectroscopic data or referring to pertinent literature.Compounds 1-8 were tested for their cytotoxic activity against five human tumor cell lines.

A new naphthoquinoneimine derivative from the marine algal-derived endophytic fungus Aspergillus niger EN-13

Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative, namely, 5,7-dihydroxy-2-[1-（4- methoxy-6-oxo-6H-pyran-2-yl）-2-phenylethylamino]-[ 1,4]naphthoquinone. The structure of the new compound was established on the basis of various NMR spectroscopic analyses including 2D NMR techniques, El-MS, and HR-ESI-MS. This compound displayed moderate antifungal activity.

Antimicrobial activity of kojic acid from endophytic fungus Colletotrichum gloeosporioides isolated from Sonneratia apetala,a mangrove plant of the Sundarbans

Objective: To isolate and evaluate the antimicrobial activity of the active principle(s) from the ethyl acetate(EtOAc) extract of endophytic fungus Colietotrichum gloeosporioides(C.gloeosporioides) isolated from Sonneratia apetala. Methods: Water agar technique was used to isolate the fungus, and both microscopic and molecular techniques were used for identification of the strain. Potato dextrose broth was used to grow the fungus in large-scale. Reversed-phase preparative HPLC analysis was performed to isolate the major active compound, kojic acid. The EtOAc extract and kojic acid were screened for their antimicrobial activity against two Grampositive and two Gram-negative bacteria as well as a fungal strain using the resazurin 96-well microtitre plate antimicrobial assay. Results: The fungus C. gloeosporioides was isolated from the leaves of Sonneratia apetala. Initial identification of the fugal isolate was carried out using spore characteristics observed under the microscope. Subsequently, the ITS1-5.8 S-ITS2 sequencing was employed for species-level identification of the fungus C. gloeosporioides. Five litres of liquid culture of the fungus produced approximately 610 mg of a mixture of secondary metabolites.Kojic acid(1) was isolated as the main secondary metabolite present in the fungal extract, and the structure was confirmed by 1 D, 2 D NMR and mass spectrometry. The EtOAc extract and compound 1 exhibited considerable antimicrobial activity against all tested microorganisms.Whilst the minimum inhibitory concentration(MIC) values from the EtOAc extract ranged between 2.4×10^(-4)mg/mL and 2.5 mg/mL, those of kojic acid(1) were between 0.125 mg/mL and1 mg/mL. The EtOAc extract and kojic acid(1) were most active against Pseudomonas aeruginosa(MIC = 2.4×10^(-4). mg/mL) and Micrococcus luteus(MIC = 0.125 mg/mL), respectively. Conclusions:The results revealed that the endophytic fungus C. gloeosporioides could be a good source of commercially important kojic acid, which exhibited antimicrobial properties.

Preliminary study on Salvia miltiorrhiza bung endophytic fungus

Objective To select the strains which can produce tanshinone ⅡA like its host plant Salvia miltiorrhiza bung.Methods A total of 50 strains of endophytic fungi were isolated from healthy,living and symptomless tissues of Salvia miltiorrhiza bung,among which 29 strains were obtained from the root,14 from the stem,3 from the leaf,3 from the flower and 1 from the seed.Their antimicrobial activities against nine different bacteria,including both Gram-negative and Gram-positive bacteria,were measured by Oxford plate agar diffusion bioassay.Results Our data showed that all but four strains had significant antibacterial activities on at least one indicator bacterium to some extent,and five strains(DR1,DR4,DR16,DR18 and DF2)manifested quite prominent antibacterial activities against certain pathogenic bacteria.In some degree,it might indicate that this endophytic fungus isolated from the tissues of Salvia miltiorrhiza bung has a potential value as a natural antibacterial medicine as well.Thin layer chromatography(TLC)and high-performance liquid chromatography(HPLC)were carried out to test selected strains,both inside and outside of the cell to see if any strain can produce tanshinone ⅡA.The result showed that extracts from three strains,labeled as DR12(outside cell),DR21(inside cell)and DF3(inside cell),had a component with the same Rf value in TLC assay as that of authentic tanshinone ⅡA.The extract from DR12(outside cell)and DR21(inside cell)had a peak at retention time identical to that of authentic tanshinone ⅡA in HPLC.Conclusion The fungi appear to produce the bioactive compound tanshinone ⅡA,and they could be used to produce tanshinone ⅡA by fermentation.It provides a new way to synthesize this natural medicine.

Three new pyrrole alkaloids from the endophytic fungus Albifimbria viridis

Three new pyrrole alkaloids albifipyrrols A-C(1-3),were isolated from the endophytic fungus Albifimbria viridis col-lected from the Chinese medicinal plant.Their structures were elucidated by extensive NMR and HRESIMS spectro-metric analyses.All compounds were evaluated for immunosuppressive activity.Fortunately,compound 2 exhibits certain inhibition specifically against the LPS-induced proliferation of B lymphocyte cells with IC50 value 16.16μM.

The antifungal properties of terpenoids from the endophytic fungus Bipolaris eleusines

A series of terpenoids(1-17),comprising six new compounds designated bipolariterpenes A-F(1-6)and eleven rec-ognized compounds(7-17),were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines.Their structures and stereochemistry were clarified by HRESIMS,NMR,DP4+probability analyses,and computations for electronic circular dichroism(ECD).All compounds are made up of six meroterpenoids,four sesterterpenes and seven sesquiterpenes.Among them,four sesterterpenes(4,5,10,11)were investigated for their antifungal,antibacterial and cytotoxic properties,and six meroterpenoids(1-3,7-9)were evaluated for their antifungal properties.The compounds 7,9,and 10 had substantial antifungal activity against Epidermophyton floccosum at a concentration of 100μM.No antibacterial and cytotoxic activities were observed.

Identification of the Diterpenoids Produced by Endophytic Fungus of Torreya fargesii and Its Inhibitory Effect on Hela Cells

[Objectives] The purpose of this study is to dissociate endophytic fungus producing diterpenoids from Torreya fargesii tissue and examines its inhibiting effect on tumor cells. [Methods]Plant endophytes were isolated and purified to study their resistance to Gram-positive( G+) and Gram-negative bacteria( G-). High performance liquid chromatography( HPLC) was used for analysis of the retention time,relative peak area and percentage content of its metabolite. By liquid chromatography-mass spectrometry( HPLC-MS),the material characteristic of the ion pair information of the metabolites was measured. The bacterial strain was also classified. [Results] The results showed that the secondary metabolites produced by the strain BP6 T3 possessed double resistance to G+and G-bacteria. The strain was identified as Penicillium sp by preliminary classification. Through HPLC analysis,the retention time of fermentation extracts was 12. 8 min with almost the same as the standard of taxol. According to the chromatograph,the relative peak area was 12 887. 11,the average relative percentage was about 15. 8%,and the content of taxol analogs in fermentation broth reached 16. 59 mg/L. The material characteristic of the formation of ion fragments of taxane analogues in metabolic extracts was identical to that of the taxol standard determined by HPLC-MS. It can be initially determined that strain BP6 T3 can produce taxane compounds. Taxol substance produced by this strain had obvious inhibitory effect on Hela cells with the concentration increasing. Different precursors had a significant effect on the production of paclitaxel metabolites in this strain. L-phenylalanine was used as the precursor and the yield increased most,with an increase rate of 425. 7%. [Conclusions] The strain is expected to be used for mass production in antitumor drug taxol.

Two New Quinazoline Derivatives from the Moss Endophytic Fungus Aspergillus sp. and Their Anti-inflammatory Activity

Two new quinazoline derivatives versicomides E(1)and F(2),and 10 known compounds(3-12)were isolated from the moss endophytic fungus Aspergillus sp.Their structures were determined on the basis of extensive spectroscopic data analysis and ECD calculations.Among them,the compound 7(6-hydroxy-3-methoxyviridicatin)was first reported as a natural product.Inhibition on LPS-induced NO production in RAW 264.7 murine macrophages found that compounds 5,7 and 8 showed significant inhibitory effects on NO production,with IC50 values of 49.85,22.14 and 46.02μM respectively.

Arthrinins E-G, Three Botryane Sesquiterpenoids from the Plant Endophytic Fungus Arthrinium sp. HS66

Arthrinins E-G(1-3),three new sesquiterpenoids possessing non-isoprenoid botryane skeleton,were isolated from the fermentation of an endophytic fungus named Arthrinium sp.HS66 which colonized in the stems of Isodon xerophilus.Their structures were determined by extensive spectroscopic methods.Furthermore,the structure of 1 was unambiguously confirmed by X-ray diffraction,while those of 2 and 3 were verified through quantum chemical calculation of NMR data and ECD spectra.

Isolation and Identification of an Endophytic Fungus Associated with Juglans regia L. and Its Bioactivity

[Objective] This study was to screen out endophytic fungal strains from the bark of Juglans regia L. [Method] The bark of J. regia was washed with running water and placed on medium to let the fungi grown; the fungal colonies were studied via morphological observation and anti-microbial activity. [Result] An endophytic fungus showing broad-scope, highly active anti-microbial activity was screened out. This fungus showed anti-microbial activity seven Gram-positive and four Gram-negative bacterial indicators, six skin pathogenic fungi and seven pathogenic fungi to different extent. Morphological observation on the ITS sequence showed that this fungus is consistent with Paecilomyces lilacinus in genus Paecilomyces bainier（with homology of over 99%）. Accordingly this fungus was designated as Paecilomyces lilacinus JY-1024. [Conclusion] This study for the first time reported the isolation of P. lilacinus from J. regia and its in vitro antimicrobial activity to several pathogens.

Effect of Endophytic Fungus on Pyrola calliantha H. Andr Responsed to Cold Stress

This study measured the antioxidant enzyme activities of Pyrola under cold and endophytic fungal infection conditions[i.e.,peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)],and the contents of malondialdehyde(MDA),soluble sugar and soluble protein.In addition,the changes in the anatomical structure of Pyrola vegetable organ during cold stress upon inoculation with a synergistic endophytic fungus were also analyzed.It was found that the soluble sugar and soluble protein contents and POD,SOD and CAT activies of Pyrola all increased,when the plants were exposed to temperature of-5℃.In particular,the MDA contents and the POD activies significantly increased compared with those of the control.In addition,the soluble sugar and soluble protein contents increased during the treatment,which involved in both inoculation with an endophytic fungus and low temperature;however,with a reduction in the concentration of endophytic fungus,those two indicators decreased.The optimal concentration of endophytic fungus was 5×10^(7) cfu·mL^(-1).From the anatomical structure of Pyrola root,endophytic fungi were found to improve the health of.Pyrola in cold weather.These results showed that endophytic fungi played a vital role in the growth of Pyrola,which was an evergreen plant that could survive exposure to low temperature.

Tridepsides from the endophytic fungus colletotrichum gloeosporioides associated with a toxic medicinal plant tylophora ovata

Introduction:Bioactive secondary metabolites from the microbes living in frigid,toxic or other extreme environments are emerging as a new medicinal resource.Here,we report the discovery of new antidiabetic and anti-inflammatory compounds with novel structures from endophytic fungi hosted toxic medicinal plant.Methods:The endophytic fungus isolated from toxic plants was fermented and extracted.The obtained extracts were purified with preparative HPLC to yield pure compounds.The purified compounds were examined by PTP1b inhibition and NO inhibition assays to evaluate their bioactivities.Results:One new tridepsides(Compound 1),one new benzeneacetic acid derivative(Compound 3)and five known compounds(Compounds 2 and 4-7)were isolated from the ethyl acetate extract of Colletotrichum gloeosporioides,an endophytic fungus obtained from a toxic medicinal plant Tylophora ovata.Their structures were determined by spectroscopic data(1D and 2D NMR,HRESIMS)analyses.Compound 2 showed significant inhibitory activity against PTP1b with an IC50 value of 0.84μM.Compounds 2 and 3 exhibited moderate inhibitory activities against the NO(nitric oxide)release in LPS-induced RAW 264.7 cells at 10μM with percent inhibition of 39%and 33%,respectively.Conclusion:The Compound 2 has potent PTP1b inhibitory effect indicating its antidiabetic potential and thus might be considered a lead compound for antidiabetic drug development.

Antimicrobial and cytotoxic activities of endophytic fungus Colletotrichum gloeosporioides isolated from endemic tree Cinnamomum malabatrum

In a survey of endophytic fungi associated with endemic plant Cinnamomum malabatrum leaves harbored a bioactive endophytic isolate CMS 3 was identified as Colletotrichum gloeosporioides through morphological and phylogenetic analysis based on ITS-rDNA.The ethyl acetate extract of fermentation broth of Colletotrichum gloeosporioides CMS 3 displayed antimicrobial activity against gram positive and gram negative bacteria as well as the fungal pathogen,Candida albicans.The ethyl acetate crude extract showed in vitro cytotoxicity against the HeLa,MCF-7 and MG63 cancer cell lines with the IC50 values of 94.2μg/ml,84.3μg/ml and 162μg/ml respectively.Gas chromatography and Mass Spectrophotometry(GC-MS)analysis of crude extract confirmed that CMS 3 was a prolific producer of secondary metabolites,in which nearly 74%of the metabolites not listed in the NIST database.Major compounds were phenol 3,5-dimethoxy acetate(11.82%),4'-isopropylidene-bis-(2-cyclohexyl)phenol,N-Didehydrohexacarboxyl-2,4,5-trimethylpiperazine and 1,2,4-Triazolium ylide.These metabolites may be responsible for its antimicrobial and cytotoxic activities.

Isolation of the Endophytic Fungi of Paris polyphylla var. yunnanensis and Their Effects on the Embryo Development of P. polyphylla var. yunnanensis Seeds

[Objective] This study aimed to isolate the endophytic fungi of Paris polyphylla var. yunnanensis and investigate their effects on the embryo development of P. polyphylla var. yunnanensis seeds. [Method] The endophytic fungi of P. polyphylla were isolated and identified morphologically, and their effects on the embryo development of P. polyphylla var. yunnanensis seeds were studied by using paraffin sectioning and microphotography. [Result] Nine endophytic fungi, i.e. P. polyphylla var. yunnanensis endophytic fungi PPYEF-1, PPYEF-2, PPYEF-3, PPYEF-4, PPYEF-5, PPYEF-6, PPYEF-7, PPYEF-8 and PPYEF-9 belonging to seven genera in five families, three orders were isolated from the rhizomes. Except PPYEF-4 (Cladosporium sp.), other fungi could promote the embryo development of the P. polyphylla var. yunnanensis seeds, mostly reaching the extremely significant or significant level. PPYEF-9 (Trichoderma sp.) resulted in the highest embryo length and embryo-emerging ratio. [Conclusion] This paper could provide a reference for the application of the endophytic fungi of P. polyphylla var. yunnanensis in the dormancy-breaking of P. polyphylla var. yunnanensis seeds.