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.

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.

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.

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.

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.

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.

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.

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.

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.

Griseofulvin enantiomers and bromine-containing griseofulvin derivatives with antifungal activity produced by the mangrove endophytic fungus Nigrospora sp.QQYB1

Marine microorganisms have long been recognized as potential sources for drug discovery.Griseofulvin was one of the first antifungal natural products and has been used as an antifungal agent for decades.In this study,12 new griseofulvin derivatives[(±)-1-2,(+)-3,(±)-4,10-12,and 14-15]and two new griseofulvin natural products(9 and 16)together with six known analogues[(-)-3,5-8,and 13]were isolated from the mangrove-derived fungus Nigrospora sp.QQYB1 treated with 0.3%NaCl or 2%NaBr in rice solid medium.Their 2D structures and absolute configurations were established by extensive spectroscopic analysis(1D and 2D NMR,HRESIMS),ECD spectra,computational calculation,DP4+analysis,and X-ray single-crystal diffraction.Compounds 1-4 represent the first griseofulvin enantiomers with four absolute configurations(2S,6'S;2R,6'R;2S,6'R;2R,6'S),and compounds 9-12 represent the first successful production of brominated griseofulvin derivatives from fungi via the addition of NaBr to the culture medium.In the antifungal assays,compounds 6 and 9 demonstrated significant inhibitory activities against the fungi Colletotrichum truncatum,Microsporum gypseum,and Trichophyton mentagrophyte with inhibition zones varying between 28 and 41 mm(10μg/disc).The structure-activity relationship(SAR)was analyzed,which showed that substituents at C-6,C-7,C-6'and the positions of the carbonyl and double bond of griseofulvin derivatives significantly affected the antifungal activity.

Metabolites from the endophytic fungus HP-1 of Chinese eaglewood

AIM: To study the chemical constituents from the fermentation of the endophytic fungus HP-1 of Chinese eaglewood. METHODS: The chemical constituents were isolated by column chromatography on silica gel and Sephadex LH-20, and their structures were elucidated on the basis of spectroscopic analysis. RESULTS: Four compounds were isolated and identified as 3α, 3β, 10β-trimethyl-decahydroazuleno[6, 7]furan-8, 9, 14-triol(1), 4-hydroxyphenylacetic acid(2), 4-hydroxyphenethyl alcohol(3), and 5-hydroxymethyl-2-furancarboxaldehyde(4). CONCLUSION: Compound 1 was a new compound. Compound 2 showed antibacterial activity against Staphylococcus aureus.

Uncommon N-Methoxyindolediketopiperazines from Acrostalagmus luteoalbus,a Marine Algal Isolate of Endophytic Fungus

Main observation and conclusion Four new N-methoxyindolediketopiperazines(acrozines D—G,1—4)and six known congeners(5—10)were purified from the organic extract of Acrostalagmus luteoalbus TK-43,which was a marine algal-derived fungus obtained from Codium fragile.Their structures were determined by interpretation of NMR and mass spectroscopic data.The structures of compounds 1,2,and 4 including their absolute configurations were confirmed by single-crystal X-ray diffraction,while the absolute configuration of compound 3 was elucidated by comparative analysis of ECD and TDDFT-ECD calculations.Compounds 1—4,with a unique methoxy substitution at N-2,were rarely discovered among indolediketopiperazine alkaloids.All these compounds were evaluated for antimicrobial activities against human-and aquatic-pathogenic bacteria and plant-related pathogenic fungi,with compounds 5 and 7 exhibiting potent activity against Edwardsiella icataluri(MIC=3 and 5μmol/L,respectively),while compound 9 displayed a broad spectrum of antibacterial activities.The four new compounds were further tested for anti-acetylcholinesterase(AChE)properties,and compound 3 exhibited inhibitory activity with IC_(50)value of 8.4μmol/L.

Two new diterpenoids from the endophytic fungus Trichoderma sp.Xy24 isolated from mangrove plant Xylocarpus granatum

Two new harziane diterpenoids, named（9R,10R）-dihydro-harzianone（1） and harzianelactone（2）, were isolated from the endophytic fungus Trichoderma sp. Xy24 by using various column chromatography techniques. Their structures were determined on the basis of extensive spectroscopic（HR-ESI-MS, 1D NMR, 2D NMR and CD） analyses. Among them, 1 was the reductive product of harzianone and 2 was the Baeyer–Villiger monooxygenase catalyzed oxidation product of harzianone. Compound 1 exhibited cytotoxic activity against He La and MCF-7 cell lines with IC（50） values of 30.1 μmol/L and 30.7 μmol/L,respectively.

A new isocoumarin from metabolites of the endophytic fungus Alternaria tenuissima(Nees & T.Nees:Fr.) Wiltshire

A new isocoumarin,tenuissimasatin（1）,was isolated from metabolites of the endophytic fungus Alternaria tenuissima（Nees ＆ T.Nees：Fr.） Wiltshire,which was isolated from the bark of Erythrophleum fordii Oliver,together with 11 known compounds（2- 12）.The structure and absolute configuration of 1 was determined by means of NMR and CD analysis.Compound 3 shows selective cytotoxic activity on human colon cancer cell HCT-8（IC_（50） = 1.78μmol/L） by MTT test in vitro.Other compounds show no such activities（IC_（50）〉10μmol/L）.

Rubratoxin C,a new nonadride derivative from an endophytic fungus Penicillium sp.F-14

One new nonadride derivative rubratoxin C （1） together with a known compound rubratoxin B （2） were isolated from an endophytic fungus Penicillium sp. F-14. Their structures were elucidated by various spectroscopic methods. Bioassays showed that 2 had moderate cytotoxic effect against HCT-8, BEL-7402, Ketr3, A2780, MCF-7 and BGC-823 human cancer cell lines, and 1 exhibited weak activity.

Pestaloamides A and B,two spiro-heterocyclic alkaloid epimers from the plant endophytic fungus Pestalotiopsis sp.HS30

Pestaloamides A and B(1 and 2),two novel alkaloids featuring an unprecedented spiro[imidazothiazoledione-alkylidenecyclopentenone]scaffold,were obtained from the cultures of an endophytic fungus Pestalotiopsis sp.HS30 which inhabited the stems of Isodon xerophilus.Their planar structures and absolute configurations were fully determined by extensive spectroscopic analysis and X-ray crystallography.In addition,both compounds 1 and 2 showed the latent tumor immunotherapy activity through markedly promoting the cell surface engagement of NKG2 D ligands involving MICA/B and ULBP1 in HCT116 cells.