Caryophyllene Sesquiterpenes from a Chaetomium globosum Endophyte of the Canadian Medicinal Plant Empetrum nigrum.

Punctaporonins T (1) and U (2), new caryophyllene sesquiterpenes, were isolated with three known punctaporonins, A (3), B (4), and C (5), from the endophytic fungus Chaetomium globosum (TC2-041). The structures and relative configurations of punctaporonins T and U were elucidated based on a combination of HRESIMS, 1D/2D NMR spectroscopic analysis, and X-ray diffraction analysis, while their absolute configuration is presumed to be consistent with the co-isolated 3-5 on biogenetic arguments. Compound 1 showed weak inhibitory activity against both Mycobacterium tuberculosis and Staphylococcus aureus.

Chaetomadramines A-E, a class of siderophores with potent neuroprotective activity from the fungus Chaetomium madrasense cib-1.

Five hydroxamate siderophores, chaetomadramines A-E (1-5), along with seven known compounds were isolated from the fermented rice culture of the fungus Chaetomium madrasense cib-1. Compounds 1-5 were structurally elucidated on the basis of spectroscopic data, which were a group of unusual hydroxamate siderophores, bearing a long fatty acyl on the α-NH2 of the Nδ-hydroxylated ornithine. Compounds 2-5 were new. The structural elucidation and spectroscopic data of 1 were reported for the first time. Compounds 2-4 significantly improved the survival rates of PC12 cells in the neuroprotective activity assay at the concentration of 40 µM.

Cytochalasan Alkaloids as TRAIL Sensitizers from an Endophytic Fungus Chaetomium sp.

Two new cytochalasans with a rare 6/6/5/5/7 pentacyclic ring system, named chaetoconvosins C-D (1: -2: ), together with two known congeners (3: -4: ), were isolated from the fermentation of an endophytic fungus, Chaetomium sp. SG-01, harbored in the fibrous roots of Schisandra glaucescens Diels. Their structures including the absolute configuration were elucidated by extensive spectroscopic (HRESIMS, NMR, and ECD) and X-ray crystallographic analyses. The TRAIL-resistance-overcoming activity of 1: -4: in a TRAIL-resistant HT29 colorectal cancer cell line was evaluated, which revealed that co-treatment of 1: -4: at 50 µM with TRAIL (150 ng/mL) reduced the HT29 cell viability by 19.0%, 24.1%, 17.9%, and 15.5%, respectively, compared to treatment with 1: -4: alone.

Salchaetoglobosins A and B: Cytochalasan alkaloids from Chaetomium globosum D38, a fungus derived from Salvia miltiorrhiza.

Chemical investigation on the solid rice culture of Chaetomium globosum D38, an endophytic fungus derived from Salvia miltiorrhiza, has afforded two new 19,20-seco-chaetoglobosins, salchaetoglobosins A (1) and B (2), along with three known analogues, chaetoglobosins E (3), Fex (4), and Vb (5). Their structures and absolute configurations were elucidated by a set of spectroscopy and single-crystal X-ray crystallography. Compounds 1-5 were evaluated for their cytotoxic activities against HCT-116 (colorectal carcinoma) and PC3 (prostate cancer) cells, as well as the NO production inhibitory effects in LPS-stimulated RAW264.7 cells.

Bioactive potential of endophytic fungus Chaetomium globosum and GC-MS analysis of its responsible components.

The recent exploration of various medicinal plants for bioactive potential has led to the growing interest to explore their endophytes for such bioactive potential which may turn out to be better option than the plants. In the present study, Chaetomium globosum, an endophytic fungus isolated from Moringa oleifera Lam has been explored for its various biological activities. The chloroformic extract of C. globosum showed good antimutagenicity against the reactive carcinogenic mutagen, 2-aminofluorene (2-AF) in Ames test. The antiproliferative activity against various cell lines such as HCT-15, HeLa and U87-MG was found to be dose dependent and the viability reduced to 9.26%, 15.7% and 16.3%, respectively. Further, the chloroformic fungal extract was investigated for free radical scavenging activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethyl-benzthiazolin-6-sulfonic acid) assay which showed the IC50 value of 45.16 µg/ml and 50.55 µg/ml, respectively. The fungal extract also showed good ferric reducing power. Total phenolic and flavonoid content was found to be in linear relationship with the antioxidant potential of the fungal extract. High performance liquid chromatography showed the presence of phenolics which may help to combat the free radicals. The presence of various bioactive compounds was analysed by GC-MS which endorsed Chaetomium globosum to be a promising candidate for drug development.

Anticancer potential of NF-κB targeting apoptotic molecule "flavipin" isolated from endophytic Chaetomium globosum.

BACKGROUND: Anticancer compounds from natural sources have drawn attention due to their structural diversity and relatively lesser side effects. Endophytic fungi are one such natural resource from, which plethoras of anticancerous compounds have been isolated. PURPOSE: The objective of the study was to isolate and characterize the bioactive metabolite from Chaetomium globosum that exhibits astonishing antiproliferative activity against cancerous cell lines. METHODS: Flavipin was isolated by bioassay-guided fractionation and identified using FT-IR, EI-MS and NMR studies. MTT assay was used to determine the cytotoxicity. Fluorescent staining (AO/EB) and DNA fragmentation studies confirmed the occurrence of apoptosis. Real time PCR and Western blotting were used to analyze the expression of apoptosis related genes and its proteins, respectively. RESULTS: Flavipin inhibited proliferation of A549, HT-29 and MCF-7 cancer cells in dose dependent manner with an IC50 concentration of 9.89 µg/ml, 18 µg/ml and 54 µg/ml, respectively, whereas it was comparatively less sensitive (IC50 = 78.89 µg/ml) against normal cell line (CCD-18Co). At IC50 concentration cancerous cells exhibited cell shrinkage and fragmentation of DNA, which indicated that flavipin induced apoptotic cell death. In treated cells there is an up-regulation of p53 gene and its associated protein, whereas reciprocal expression was observed in BCL-2 gene and its protein. Furthermore, western blotting results also showed down-regulation of NFκB. CONCLUSION: This is the first report on the antiproliferative activity of flavipin isolated from endophytic C. globosum and also proposed that interaction of flavipin with NFкB could be a possible mechanism for this activity. Flavipin induced apoptosis at low concentrations in cancer cell lines (A549, HT-29) and exhibited itself as a potential anticancer agent.

Acetylcholinesterase inhibitory active metabolites from the endophytic fungus Colletotrichum sp. YMF432.

An endophytic fungus, Chaetomium sp. YMF432, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation based on its special environment. From the extracts of fermentation solid of strain YMF 432, eight compounds including 1-O-methylemodin (1), 5-methoxy-2-methyl-3-tricosyl-1,4-benzoquinone (2), 4,8-dihydroxy-1-tetralone (3), (3ß,5α,6α, 22E)-3-hydroxy-5,6-epoxy-7-one-8(14),22-dien-ergosta (4), ergosta-4,6,8(14),22-tetraen-3-one (5), ß-sitostenone (6), ß-sitosterol (7) and (22E,24R)-ergosta-5,7,22 -trien-3ß-ol (8) were obtained. Their structures were elucidated on the basis of their spectroscopic data. These compounds were evaluated for acetylcholinesterase inhibitory activities in vitro. Compounds 1, 2, and 4 showed moderate acetylcholinesterase inhibitory activities (IC50 from 37.7 ± 1.5 to 370.0 ± 2.9 µM).

Diagnostic fragmentation filtering for the discovery of new chaetoglobosins and cytochalasins.

RATIONALE: Microbial natural products are often biosynthesized as classes of structurally related compounds that have similar tandem mass spectrometry (MS/MS) fragmentation patterns. Mining MS/MS datasets for precursor ions that share diagnostic or common features enables entire chemical classes to be identified, including novel derivatives that have previously been unreported. Analytical data analysis tools that can facilitate a class-targeted approach to rapidly dereplicate known compounds and identify structural variants within complex matrices would be useful for the discovery of new natural products. METHODS: A diagnostic fragmentation filtering (DFF) module was developed for MZmine to enable the efficient screening of MS/MS datasets for class-specific product ions(s) and/or neutral loss(es). This approach was applied to series of the structurally related chaetoglobosin and cytochalasin classes of compounds. These were identified from the culture filtrates of three fungal genera: Chaetomium globosum, a putative new species of Penicillium (called here P. cf. discolor: closely related to P. discolor), and Xylaria sp. Extracts were subjected to LC/MS/MS analysis under positive electrospray ionization and operating in a data-dependent acquisition mode, performed using a Thermo Q-Exactive mass spectrometer. All MS/MS datasets were processed using the DFF module and screened for diagnostic product ions at m/z 130.0648 and 185.0704 for chaetoglobosins, and m/z 120.0808 and 146.0598 for cytochalasins. RESULTS: Extracts of C. globosum and P. cf. discolor strains revealed different mixtures of chaetoglobosins, whereas the Xylaria sp. produced only cytochalasins; none of the strains studied produced both classes of compounds. The dominant chaetoglobosins produced by both C. globosum and P. cf. discolor were chaetoglobosins A, C, and F. Tetrahydrochaetoglobosin A was identified from P. cf. discolor extracts and is reported here for the first time as a natural product. The major cytochalasins produced by the Xylaria sp. were cytochalasin D and epoxy cytochalasin D. A larger unknown "cytochalasin-like" molecule with the molecular formula C38 H47 NO10 was detected from Xylaria sp. culture filtrate extracts and is a current target for isolation and structural characterization. CONCLUSIONS: DFF is an effective LC/MS data analysis approach for rapidly identifying entire classes of compounds from complex mixtures. DFF has proved useful in the identification of new natural products and allowing for their partial characterization without the need for isolation.

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.

[Chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster and their in vitro antitumor activity].

Isolation and purification of chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster was performed through silica gel column chromatography, gel filtration over Sephadex LH-20, preparative TLC and HPLC. Five compounds were obtained and their structures were determined as chaetoglobosin V(1), chaetoglobosin Vb(2), tyrosol(3), 5-methyluracil(4)and uracil(5), respectively, based on HR-MS and NMR data and comparison with literatures. In vitro cytotoxicity of compounds against human hepatocellular carcinoma cell line SMMC-7721 were measured byMTT method, and results showed that compound 1 could obviously inhibit the proliferation of SMMC-7721 cells with an IC50 value of 60.5 mg•L⁻¹, while the IC50 value of positive control cisplatin was 19.96 mg•L⁻¹. Further studies discovered that compound 1 could lead to G2 phase arrest in SMMC-7721 cells and induce SMMC-7721 cells apoptosis. The ratio of Bcl-2/Bax in SMMC-7721 cells was decreased. The expression of protein Caspases-3,-8,-9 was improved and the expression and phosphorylation level of Akt were reduced. Aforementioned results revealed that in vitro antitumor activity of compound 1 against SMMC-7721 cells were related to G2 phase cell cycle arrest and induced-apoptosis. The induced-apoptosis was involved in both the mitochondrial pathway and the death receptor pathway and connected with activity decline of PI3K/Akt signaling pathway.

Secondary metabolites from endophytic fungus Chaetomium sp. induce colon cancer cell apoptotic death.

A rare depsipeptide, chaetomiamide A (1), together with two known diketopiperazines (2, 3) were isolated from the cultures of endophytic fungus Chaetomium sp., which was isolated from the root of Cymbidium goeringii. Compound 1 represents a rare skeleton with a 13-membered ring system. It structure was established on the basis of spectroscopic data interpretation. The configuration of 1 was determined by NOESY and Marfey's analysis. These isolates were evaluated for anticancer activity and 3 displayed more potent cytotoxicity than the positive control cisplatin associated with G2/M cell cycle arrest. In addition, 3 induced apoptosis via caspase-3 induction and PARP cleavage, concomitantly with the increase of Bax and decrease of Bcl-2.

Four new steroids from the endophytic fungus Chaetomium sp. M453 derived of Chinese herbal medicine Huperzia serrata.

An endophytic fungus, Chaetomium sp. M453, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation. Three unusual C25 steroids, neocyclocitrinols E-G (1-3), and 3ß-hydroxy-5,9-epoxy-(22E,24R)-ergosta-7,22-dien-6-one (4) together with three known steroids were isolated from solid fermentation products of the fungus, which were elucidated by extensive spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS experiments. The absolute configuration of 1 was determined by X-ray crystallographic analysis and CD analyses. The acetylcholinesterase inhibitory activities of compounds 1-4 were tested in vitro. Compound 4 showed weak acetylcholinesterase inhibitory activity.

[Chemical constituents from endophyte Chaetomium globosum in Imperata cylindrical].

Isolation and purification of chemical constituents from solid culture of endophyte Chaetomium globosum in Imperata cylindrical was performed through silica gel column chromatography, gel filtration over Sephadex LH-20 and preparative HPLC. Nine compounds were obtained and their structures were determined as chaetoglobosin F(1), chaetoglobosin Fex(2), chaetoglobosin E(3) cytoglobosin A(4), penochalasin C(S), isochaetoglobosin D (6), N-benzoylphenylalaninyl-N-benzoyphenylalaninate(7), uracil(8) and 5-methyluracil(9), respectively, based on HR-MS and NMR data and comparison with literatures. Compound 7 was isolated from Chaeeomium sp. for the first time. In vitro cytotoxicity of compounds was evaluated using MTT mothed and 1,3,4 and 5 showed inhibition activity to the human cervical carcinoma cell HeLa with IC50 values of 99.43, 23.77, 97.92, 86.25 micromol x L(-1), while positive cotolocisnin Ad apno1ch alse IC50 24.33 micromol x L(-1).

Bioactive metabolites from Chaetomium aureum: structure elucidation and inhibition of the Hsp90 machine chaperoning activity.

Chemical investigation of the EtOAc extract of the fungus Chaetomium aureum, an endophyte of the Moroccan medicinal plant Thymelaea lythroides, afforded one new resorcinol derivative named chaetorcinol, together with five known metabolites. The structures of the isolated compounds were determined on the basis of one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry as well as by comparison with the literature. All compounds were tested for their activity towards the Hsp90 chaperoning machine in vitro using the progesterone receptor (PR) and rabbit reticulocyte lysate (RRL). Among the isolated compounds, only sclerotiorin efficiently inhibited the Hsp90 machine chaperoning activity. However, sclerotiorin showed no cytotoxic effect on breast cancer Hs578T, MDA-MB-231 and prostate cancer LNCaP cell lines. Interestingly, deacetylation of sclerotiorin increased its cytotoxicity toward the tested cell lines over a period of 48 h.

Chaetoglobosin Y, a new cytochalasan from Chaetomium globosum.

Chaetoglobosin Y (1), was isolated from the endolichenic fungal strain Chaetomium globosum (No. 64-5-8-2), along with related six known cytochalasans, chaetoglobosin Fex (2), chaetoglobosin E (3), isochaetoglobosin D (4), chaetoglobosin G (5), cytoglobosin B (6), and cytoglobosin C (7). Their structures were determined by detailed spectroscopic analyses and comparison with those of the closely related compounds previously reported. The cytotoxicity to HCT-116 cell line of 2-7 was evaluated in vitro with doxorubicin as positive control.

Cytochalasin H, an active anti-angiogenic constituent of the ethanol extract of Gleditsia sinensis thorns.

Angiogenesis, the process of new vessel formation from the pre-existing blood vasculature, is critical for continuous tumor growth and is considered to be a validated antitumor target. The results of our previous study demonstrate the anti-angiogenic potential of an extract of Gleditsia sinensis thorns, which has been traditionally used in Korean medicine to remedy diverse diseases, including tumors. In the present study, we attempted to identify the active anti-angiogenic constituents of the ethanol extract of G. sinensis thorns (EEGS). By virtue of in vitro activity-guided fractionation using human umbilical vein endothelial cells (HUVEC) primary endothelial cells, chromatographic separation, and NMR spectral analyses, we isolated and identified the potent active constituent, cytochalasin H, a biologically active secondary metabolite of fungi. This unexpected active constituent may have originated from the endophytic fungi, Chaetomium globosum, which naturally populate G. sinensis, the identity of which was determined by analysis of fungal community. Cytochalasin H isolated from the EEGS showed in vitro anti-angiogenic activities such as suppressed cell growth and mobility in HUVEC, and inhibited the pro-angiogenic protein-induced formation of new blood vessels in vivo. The anti-angiogenic effect of cytochalasin H was in part due to reduced expression of pro-angiogenic factor, such as endothelin-1. This is the first report regarding the isolation and identification of cytochalasin H, as an active anti-angiogenic constituent of G. sinensis thorns.

Chemical constituents from an endophytic fungus Chaetomium globosum Z1.

A new ergosterol, 15beta-hydroxyl-(22E,24R)-ergosta-3, 5, 8, 22-tetraen-one (1), along with three known ergosterols, two known cytochalasins, and two known azapholines were isolated from Chaetomium globosum Z1. The structures of these compounds were elucidated on the basis of spectroscopic methods (HR-ESI-MS, 1D NMR, and 2D NMR). Compound 6 showed significant cytotoxic activity against A-549 and MG-63 cell lines with IC50 values of 6.96 and 1.73 microg/mL, respectively.

Novel dibenzo[b,e]oxepinones from the freshwater-derived fungus Chaetomium sp. YMF 1.02105.

Six new dibenzo[b,e]oxepinone metabolites, chaetones A-F (1-6), as well as three known compounds, 1-hydroxy-6-methyl-8-hydroxymethylxanthone (7), citreorosein (8), and emodin (9), were obtained from a freshwater-derived fungal strain Chaetomium sp. YMF 1.02105. Their structures were established on the basis of extensive spectroscopic data analysis and comparison with spectroscopic data reported. Compounds 1-6 are further additions to the small group of dibenzo[b,e]oxepinones represented by arugosins A-H. Compounds 1-7 were tested for their cytotoxic activities against A549, Raji, HepG2, MCF-7, and HL-60 cell lines. The results showed that compound 3 had significant cytotoxicity with IC50 values of 1.2, 1.8, 1.9, 2.3, and 1.6 µg/mL, respectively, against the five cancer cell lines. All compounds showed modest antimicrobial activity against Staphylococcus aureus (ATCC 6538) in standard disk assays.

New azaphilones and chlorinated phenolic glycosides from Chaetomium elatum with caspase-3 inhibitory activity.

Three new azaphilones, chaetomugilin S (1), 7,5'-bis-epi-chaetoviridin A (2), and 7-epi-chaetoviridin E (3), and two new chlorinated phenolic glycosides, globosumoside A (4) and globosumoside B (5), were isolated from the crude extract of the fungal strain Chaetomium elatum No. 89-1-3-1. Their structures were determined by detailed NMR and MS spectroscopic analyses. The absolute configurations of C-7 in chaetomugilin S (1), 7,5'-bis-epi-chaetoviridin A (2), and 7-epi-chaetoviridin E (3) were assigned by CD experiments, and the absolute configurations of 1 and 2 were established by X-ray crystallography. Compounds 1-3 are the first examples of 7R-configurated azaphilones with a chlorinated isochromen from Chaetomium spp. In addition, compounds 1-3 showed inhibitory activity in the cysteine aspartyl-specific protease-3 (caspase-3) enzymatic assay, with IC50 values of 20.6, 10.9, and 7.9 µM, respectively.

Bioactive metabolites from Chaetomium globosum L18, an endophytic fungus in the medicinal plant Curcuma wenyujin.

An endophytic fungus, strain L18, isolated from the medicinal plant Curcuma wenyujin Y.H. Chen et C. Ling was identified as Chaetomium globosum Kunze based on morphological characteristics and sequence data for the internal transcribed spacer (ITS-5.8S-ITS2) of the nuclear ribosomal DNA. A new metabolite named chaetoglobosin X (1), together with three known compounds erogosterol (2), ergosterol 5α,8-peroside (3) and 2-methyl-3-hydroxy indole (4), were isolated from C. globosum L18. Their structures were elucidated by spectroscopic methods including NMR, UV, IR and MS data and comparison with published data. Chaetoglobosin X (1) is hitherto unknown, whereas 2-methyl-3-hydroxy indole (4) is reported for the first time as a fungal metabolite, and erogosterol (2) and ergosterol 5α,8-peroside (3) are known fungal metabolites previously identified in other genera. Chaetoglobosin X (1) exhibited a broader antifungal spectrum and showed the strongest cytotoxic activity against H22 and MFC cancer cell lines.