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1.
Phytochemistry ; 222: 114103, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636686

RESUMO

Eight new cytochalasans rosellichalasins A-H (1-8), as well as two new shunt metabolites rosellinins A (9) and B (10) before intramolecular Diels-Alder cycloaddition reaction in cytochalasan biosynthesis, along with nine known cytochalsans (11-19) were isolated from the endophytic fungus Rosellinia sp. Glinf021, which was derived from the medicinal plant Glycyrrhiza inflata. Their structures were characterized by extensive analysis of 1D and 2D NMR as well as HRESIMS spectra and quantum chemical ECD calculations. The cytotoxic activities of these compounds were evaluated against four human cancer cell lines including HCT116, MDA-MB-231, BGC823, and PANC-1 with IC50 values ranging from 0.5 to 58.2 µM.


Assuntos
Antineoplásicos , Citocalasinas , Ensaios de Seleção de Medicamentos Antitumorais , Xylariales , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citocalasinas/química , Citocalasinas/farmacologia , Citocalasinas/isolamento & purificação , Relação Dose-Resposta a Droga , Endófitos/química , Estrutura Molecular , Relação Estrutura-Atividade , Xylariales/química , Xylariales/classificação
2.
Planta Med ; 88(14): 1299-1310, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35100652

RESUMO

Seven undescribed cytochalasins, multirostratins K - Q (2: -8: ), together with one known analogue, cytochalasin Z3 (1: ), were isolated from the culture of Phoma multirostrata XJ-2-1, an endophytic fungus obtained from the root of Parasenecio albus. Their structures with absolute configurations were determined by 1D and 2D NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), electronic circular dichroism (ECD), single-crystal X-ray crystallography, and chemical methods. The structure of ascochalasin was revised from Δ 13 to Δ 21 by detailed analysis of the NMR data and by comparison with the data for 7: . In a TRAIL (tumor necrosis factor related apoptosis inducing ligand)-resistance-overcoming experiment, co-treatment of 2: or 6: with TRAIL reduced the cell viability of A549 cells by 30.3% and 27.5% at 10 µM, respectively.


Assuntos
Ascomicetos , Citocalasinas , Humanos , Citocalasinas/farmacologia , Citocalasinas/química , Estrutura Molecular , Células A549
3.
Fitoterapia ; 157: 105124, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35007685

RESUMO

Four new cytochalasans, arbuschalasins A-D (1-4), along with thirteen known analogues (5-17), were isolated from the solid rice medium of endophytic fungus Xylaria arbuscula. Arbuschalasins A-B feature a rare 5/6/6/6 fused ring system while arbuschalasin D was characterized as the first example of natural cytochalasans that possesses a 5/5/11 fused scaffold. The structures of 1-4 were assigned by spectroscopic data, with their absolute structures being determined by electronic circular dichroism (ECD) calculations. All of the isolates were evaluated against the human colorectal adenocarcinoma cell lines (HCT15). Compounds 6 and 7 showed significant inhibitory effects (IC50 values were 13.5 and 13.4 µM, respectively), being more active than those of the positive control, fluorouracil (103.1 µM).


Assuntos
Ascomicetos/química , Citocalasinas/isolamento & purificação , Rhizophoraceae/microbiologia , Linhagem Celular Tumoral , Sobrevivência Celular , Citocalasinas/química , Fermentação , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular
4.
Planta Med ; 88(14): 1293-1298, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34963184

RESUMO

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.


Assuntos
Alcaloides , Chaetomium , Chaetomium/química , Chaetomium/metabolismo , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Citocalasinas/farmacologia , Citocalasinas/química , Estrutura Molecular
5.
Mar Drugs ; 19(8)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34436277

RESUMO

Four new cytochalasans, phychaetoglobins A-D (1-4), together with twelve known cytochalasans (5-16), were isolated from a mangrove-associated fungus Chaetomium globosum kz-19. The new structures were elucidated on the basis of extensive 1D and 2D NMR, HR ESIMS spectroscopic analyses, and electronic circular dichroism (ECD) calculations. The absolute configuration of 2 was established by application of Mosher's method. Compounds 4-8 exhibited moderate cytotoxicities against A549 and HeLa cell lines with the IC50 values less than 20 µM.


Assuntos
Antineoplásicos/química , Chaetomium , Citocalasinas/química , Células A549/efeitos dos fármacos , Antineoplásicos/farmacologia , Organismos Aquáticos , Citocalasinas/farmacologia , Células HeLa/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Fitoterapia
6.
J Nat Prod ; 82(11): 2994-3001, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31674782

RESUMO

Flavipesines A and B (1 and 2) and asperchalasines E-H (3-6), two cytochalasans with an unusual ring system and four merocytochalasans possessing a 5/6/11/5/5/6 ring system, were isolated from Aspergillus flavipes, along with three related compounds (7-9). Their structures, including absolute configurations, were determined on the basis of data from HRESIMS, NMR, ECD, molecular modeling, and single-crystal X-ray diffraction. Flavipesines A and B (1 and 2) represent the first examples of cytochalasans possessing a 5/6/7/6 ring system with a C-18-O-C-21 bridge. Compounds 3, 7, and 9 show moderate inhibitory activities against isocitrate dehydrogenase 1 (IDH1). This is the first report on the IDH1 inhibitory activities of cytochalasans.


Assuntos
Aspergillus/química , Citocalasinas/química , Simulação por Computador , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Isocitrato Desidrogenase/antagonistas & inibidores , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular , Difração de Raios X
7.
Rapid Commun Mass Spectrom ; 33(1): 133-139, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30325552

RESUMO

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.


Assuntos
Citocalasinas/química , Descoberta de Drogas/métodos , Alcaloides Indólicos/química , Software , Espectrometria de Massas em Tandem/métodos , Chaetomium/química , Chaetomium/metabolismo , Cromatografia Líquida , Citocalasinas/análise , Avaliação Pré-Clínica de Medicamentos/métodos , Fermentação , Alcaloides Indólicos/análise , Metabolômica/métodos , Penicillium/química , Penicillium/metabolismo , Xylariales/química , Xylariales/metabolismo
8.
Fitoterapia ; 132: 53-59, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30496809

RESUMO

Six new seco-cytochalasins A-F (1-6), two new asperlactones G-H (7-8) along with three known cytochalasins (9-11) were isolated from the solid cultures of an endophytic fungus Aspergillus sp. Their structures were elucidated by comprehensive spectral analysis, and their absolute configurations were determined through Mo2(OCOCH3)4-induced electronic circular dichroism (ECD) spectra and Rh2(OCOCF3)4-induced ECD experiment. Compounds 5 and 6 were rare seco-cytochalasins possessing an α, ß-unsaturated furanone structure in their side-chains. These isolates exhibited cytotoxicity against human lung cancer A-549 cell line with IC50 values ranging from 7.8 to 70.2 µM. At the concentration of 16 µM, compound 4 also exerted a 3-fold enhancement of doxorubicin susceptibility on doxorubicin-resistant human breast cancer (MCF-7/DOX) cell line.


Assuntos
Aspergillus/química , Citocalasinas/química , Pinellia/microbiologia , Tubérculos/microbiologia , Células A549 , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , China , Citocalasinas/isolamento & purificação , Endófitos/química , Humanos , Células MCF-7 , Estrutura Molecular
9.
Can J Microbiol ; 64(11): 835-843, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29874477

RESUMO

In the present study, we evaluated the antifungal potential of cytochalasins produced by Diaporthe taxa against phytopathogenic fungi. Using molecular methods, seven endophytic fungal strains from the medicinal plants Copaifera pubiflora and Melocactus ernestii were identified as Diaporthe miriciae, while two isolates were identified to the genus level (Diaporthe sp.). All crude extracts of Diaporthe species produced via solid-state fermentation were evaluated by 1H NMR analyses. Crude extracts of the isolates D. miriciae UFMGCB 6350, 7719, 7646, 7653, 7701, 7772, and 7770 and Diaporthe sp. UFMGCB 7696 and 7720 were demonstrated to produce highly functionalized compounds. The extracts of D. miriciae UFMGCB 7719 and 6350 were selected as representative Diaporthe samples and subjected to bioassay-directed fractionation to isolate cytochalasins H and J. Cytochalasins H and J were evaluated for activities against the fungal plant pathogens Colletotrichum fragariae, Colletotrichum gloeosporioides, Colletotrichum acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and Phomopsis viticola using microdilution broth assays. Cytochalasins H and J exhibited the most potent activities against the Phomopsis species tested. Our results showed that Diaporthe species were potential producers of different cytochalasins, which exhibit potential for controlling fungal diseases in planta and (or) maintaining antagonism.


Assuntos
Antifúngicos/farmacologia , Colletotrichum/efeitos dos fármacos , Citocalasinas/farmacologia , Endófitos/isolamento & purificação , Proteínas Fúngicas/farmacologia , Plantas Medicinais/microbiologia , Antifúngicos/química , Ascomicetos/química , Citocalasinas/química , Endófitos/química , Proteínas Fúngicas/química , Espectroscopia de Ressonância Magnética
10.
J Appl Microbiol ; 125(1): 111-120, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29573314

RESUMO

AIM: To explore the potential of Rosellinia sanctae-cruciana an endophytic fungus associated with Albizia lebbeck for pharmaceutically important cytotoxic compounds. METHODS AND RESULTS: One novel cytochalasin, named jammosporin A (1) and four known analogues (2-5) were isolated from the culture of the endophytic fungus R. sanctae-cruciana, harboured from the leaves of the medicinal plant A. lebbeck. Their structures were elucidated by extensive spectroscopic analyses including one-dimensional and two-dimensional nuclear magnetic resonance data along with MS data and by comparison with literature reports. In preliminary screening the ethyl acetate extract of the fungal culture was tested for cytotoxic activity against a panel of four cancer cell lines (MOLT-4, A549, MIA PaCa-2 and MDA-MB-231), and found to be active against MOLT-4 with an IC50 value of 10 µg ml-1 . Owing to the remarkable cytotoxic activity of the extract the isolated compounds (1-5) were evaluated for their cytototoxicity against the MOLT-4 cell line by MTT assay. Interestingly, compounds 1-2, 4 and 5 showed considerable cytotoxic potential against the human leukaemia cancer cell line (MOLT-4) with IC50 values of 20·0, 10·0, 8·0 and 6·0 µmol l-1 , respectively, while compound 3 showed an IC50 value of 25 µmol l-1 . This is the first report of the existence of this class of secondary metabolites in R. sanctae-cruciana fungus. CONCLUSION: This study discovered a novel compound, named jammosporin A, isolated for the first time from R. sanctae-cruciana, an endophytic fungus of A. lebbeck with anticancer activity against the MOLT-4 cell line. SIGNIFICANCE AND IMPACT OF THE STUDY: Rosellinia sanctae-cruciana represents an interesting source of a new compound with bioactive potential as a therapeutic agent against a human leukaemia cancer cell line (MOLT-4).


Assuntos
Albizzia/microbiologia , Ascomicetos/química , Sobrevivência Celular/efeitos dos fármacos , Citocalasinas/isolamento & purificação , Citocalasinas/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Citocalasinas/química , Citocalasinas/toxicidade , Humanos , Concentração Inibidora 50 , Folhas de Planta/microbiologia , Plantas Medicinais/microbiologia
11.
BMC Complement Altern Med ; 16(1): 462, 2016 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-27842536

RESUMO

BACKGROUND: The continuous emergence of multidrug-resistant (MDR) bacteria drastically reduced the efficacy of our antibiotic armory and consequently, increased the frequency of therapeutic failure. The search for bioactive constituents from endophytic fungi against MDR bacteria became a necessity for alternative and promising strategies, and for the development of novel therapeutic solutions. We report here the isolation and structure elucidation of antibacterial and cytotoxic compounds from Phomopsis sp., an endophytic fungus associated with Garcinia kola nuts. METHODS: The fungus Phomopsis sp. was isolated from the nut of Garcinia kola. The crude extract was prepared from mycelium of Phomopsis sp. by maceration in ethyl acetate and sequentially fractionated by column chromatography. The structures of isolated compounds were elucidated on the basis of spectral studies and comparison with published data. The isolated compounds were evaluated for their antibacterial and anticancer properties by broth microdilution and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide methods respectively. The samples were also tested spectrophotometrically for their hemolytic properties against human red blood cells. RESULTS: The fractionation of the crude extract afforded three known cytochalasins including 18-metoxycytochalasin J (1), cytochalasins H (2) and J (3) together with alternariol (4). The cytochalasin compounds showed different degrees of antibacterial activities against the tested bacterial pathogens. Shigella flexneri was the most sensitive microorganism while Vibrio cholerae SG24 and Vibrio cholerae PC2 were the most resistant. Ampicillin did not show any antibacterial activity against Vibrio cholerae NB2, Vibrio cholerae PC2 and Shigella flexneri at concentrations up to 512 µg/mL, but interestingly, these multi-drug resistant bacterial strains were sensitive to the cytochalasin metabolites. These compounds also showed significant cytotoxic properties against human cancer cells (LC50 = 3.66-35.69 µg/mL) with low toxicity to normal non-cancer cells. CONCLUSION: The three cytochalasin compounds isolated from the Phomopsis sp. crude extract could be a clinically useful alternative for the treatment of cervical cancer and severe infections caused by MDR Shigella and Vibrio cholerae.


Assuntos
Antibacterianos/farmacologia , Ascomicetos/química , Citocalasinas/farmacologia , Garcinia kola/microbiologia , Nozes/microbiologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Citocalasinas/química , Citocalasinas/isolamento & purificação , Bactérias Gram-Positivas/efeitos dos fármacos , Células HeLa , Humanos
12.
Nat Prod Commun ; 10(10): 1655-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26669096

RESUMO

Two new metabolites, 6-oxo-12-norcytochalasin D (1) and 4,5-di-isobutyl-2(1H)-pyrimidinone (2), together with seven known metabolites, cytochalasins D (3), Q (4), and N (5), 12-hydroxyzygosporin G (6), heptelidic acid chlorohydrin (7), (+)-heptelidic acid (8), and trichoderonic acid A (9), were isolated from Xylariaceae sp. FL0390, a fungal endophyte inhabiting Spanish moss, Tillandsia usneoides. Metabolite 1 is the first example of a 12-norcytochalasin. All metabolites, except 2 and 9, showed cytotoxic activity in a panel of five human tumor cell lines with IC50S of 0.2-5.0 µM.


Assuntos
Antineoplásicos/farmacologia , Ascomicetos/química , Citocalasinas/farmacologia , Endófitos/química , Tillandsia/microbiologia , Antineoplásicos/química , Citocalasinas/química , Estrutura Molecular
13.
BMC Cancer ; 15: 632, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26357852

RESUMO

BACKGROUND: Although the actin cytoskeleton is vital for carcinogenesis and subsequent pathology, no microfilament-directed agent has been approved for cancer chemotherapy. One of the most studied classes of microfilament-directed agents has been the cytochalasins, mycotoxins known to disrupt the formation of actin polymers. In the present study, we sought to determine the effects of cytochalasin congeners toward human drug sensitive and multidrug resistant cell lines. METHODS: SKOV3 human ovarian carcinoma and several multidrug resistant derivatives were tested for sensitivity against a panel of nine cytochalasin congeners, as well as three clinically approved chemotherapeutic agents (doxorubicin, paclitaxel, and vinblastine). In addition, verapamil, a calcium ion channel blocker known to reverse P-glycoprotein (P-gp) mediated drug resistance, was used in combination with multiple cytochalasin congeners to determine whether drug sensitivity could be increased. RESULTS: While multidrug resistant SKVLB1 had increased drug tolerance (was more resistant) to most cytochalasin congeners in comparison to drug sensitive SKOV3, the level of resistance was 10 to 1000-fold less for the cytochalasins than for any of the clinically approved agents. While cytochalasins did not appear to alter the expression of ATP binding cassette (ABC) transporters, several cytochalasins appeared to inhibit the activity of ABC transporter-mediated efflux of rhodamine 123 (Rh123), suggesting that these congeners do have affinity for drug efflux pumps. Cytochalasins also appeared to significantly decrease the F/G-actin ratio in both drug sensitive and drug resistant cells, indicative of marked microfilament inhibition. The cytotoxicity of most cytochalasin congeners could be increased with the addition of verapamil, and the drug sensitivity of resistant SKVLB1 to the clinically approved antineoplastic agents could be increased with the addition of cytochalasins. As assessed by isobolographic analysis and Chou-Talalay statistics, cytochalasin B and 21,22-dihydrocytochalasin B (DiHCB) demonstrated notable synergy with doxorubicin and paclitaxel, warranting further investigation in a tumor-bearing mammalian model. CONCLUSION: Cytochalasins appear to inhibit the activity of P-gp and potentially other ABC transporters, and may have novel activity against multidrug resistant neoplastic cells that overexpress drug efflux proteins.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma/tratamento farmacológico , Citocalasina B/farmacologia , Citocalasinas/farmacologia , Doxorrubicina/farmacologia , Microtúbulos/efeitos dos fármacos , Neoplasias Ovarianas/tratamento farmacológico , Linhagem Celular Tumoral , Citocalasina B/química , Citocalasinas/química , Avaliação Pré-Clínica de Medicamentos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Feminino , Humanos
14.
Nat Prod Commun ; 10(4): 585-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25973482

RESUMO

The new natural product 4]-hydroxy-deacetyl-18-deoxycytochalasin H (1), together with the known deacetyl-18-deoxycytochalasin H (2) and 18-deoxycytochalasin H (3) were obtained from the endophytic fungus Trichoderma harzianum isolated from leaves of Cola nitida. The structure of the new compound was unambiguously determined by 1D and 2D NMR spectroscopy, and by HRESIMS measurements, as well as by comparison with the literature. Compounds 1-3 showed potent cytotoxic activity against the murine lymphoma (L5178Y) cell line and against human ovarian cancer (A2780 sens and A2780 CisR) cell lines (IC50 0.19-6.97 µM). The A2780 cell lines included cisplatin-sensitive (sens) and -resistant (R) cells.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Citocalasinas/química , Citocalasinas/farmacologia , Trichoderma/química , Animais , Linhagem Celular Tumoral , Linfoma/tratamento farmacológico , Camundongos , Estrutura Molecular
15.
Bioorg Med Chem Lett ; 25(10): 2096-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25881821

RESUMO

Four new cytochalasin derivatives (1-4), together with proxiphomin (5), were isolated from a jellyfish-derived fungus Phoma sp. The planar structures and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed moderate cytotoxicity against a small panel of human solid tumor cell lines (A549, KB, and HCT116).


Assuntos
Citocalasinas/isolamento & purificação , Fungos/química , Cifozoários/microbiologia , Animais , Citocalasinas/química , Estrutura Molecular , Estereoisomerismo
16.
Planta Med ; 81(2): 160-6, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25626143

RESUMO

Four new cytochalasins, arthriniumnins A-D (1-4), a new natural product, ketocytochalasin (5), as well as five known cytochalasin analogues (6-10) were isolated and identified from the fungus Arthrinium arundinis ZSDS1-F3 from the sponge Phakellia fusca. Their structures were elucidated by NMR spectroscopic and mass spectrometric analyses, as well as single crystal X-ray diffraction. Compounds 6 and 9 showed cytotoxicity against K562, A549, Huh-7, H1975, MCF-7, U937, BGC823, HL60, Hela, and MOLT-4 cell lines, with IC50 values ranging from 1.13 to 47.4 µM.


Assuntos
Antineoplásicos/farmacologia , Ascomicetos/química , Citocalasinas/farmacologia , Poríferos/microbiologia , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citocalasinas/química , Citocalasinas/isolamento & purificação , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Difração de Raios X
17.
Nat Prod Commun ; 10(12): 2027-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26882656

RESUMO

Three new compounds, an open-chain cytochalasan scoparasin C (1), a pyrichalasan scoparasin D (2), and a ß-eudesmol type sesquiterpene scopararane C (5), along with three known compounds (3, 4 and 6), were isolated from the marine fungus Eutypella scoparia 1-15. Their structures were determined on the basis of comprehensive NMR and MS analysis. Compound 2 exhibited potent cytotoxicities with very low IC50 values against several cancer cell lines, including A375, A549, HepG2 and MCF-7.


Assuntos
Ascomicetos/química , Citocalasinas/química , Sesquiterpenos/química , Modelos Moleculares , Estrutura Molecular
18.
In Vivo ; 28(6): 1021-31, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25398795

RESUMO

BACKGROUND/AIM: Chemotherapeutic approaches involving microtubule-directed agents such as the vinca alkaloids and taxanes are used extensively and effectively in clinical cancer therapy. There is abundant evidence of critical cytoskeletal differences involving microfilaments between normal and neoplastic cells, and a variety of natural products and semi-synthetic derivatives are available to exploit these differences in vitro. In spite of the availability of such potential anti-neoplastic agents, there has yet to be an effective microfilament-directed agent approved for clinical use. Cytochalasins are mycogenic toxins derived from a variety of fungal sources that have shown promising in vitro efficacy in disrupting microfilaments and producing remarkable cell enlargement and multi-nucleation in cancer cells without producing enlargement and multi-nucleation in normal blood cells. Jasplakinolide is a sponge toxin that stabilizes and rigidifies microfilaments. Insufficient in vivo data has been acquired to determine whether any of the microfilament-directed agents have valuable preferential anticancer activity in pre-clinical tumor model systems. This is partly because the limited availability of these agents precludes their initial use in large-scale mammalian pre-clinical studies. Therefore, the present study sought to determine the tolerated in vivo doses of cytochalasins and jasplakinolide in zebrafish (Danio rerio), a well-studied fish cancer model that is 1.5% the size of mice. We also determined the tolerated levels of a variety of clinically active anti-neoplastic agents in zebrafish for comparison with tolerated murine doses as a means to allow comparison of toxicities in zebrafish expressed as µM concentrations with toxicities in mice expressed in mg/kg. MATERIALS AND METHODS: Tolerated doses in zebrafish with various cytochalasins or jasplakinolide were determined by adding the solubilized test agent to water in which the fish were maintained for 24 h, then restored to their normal tanks and monitored for a total of 96 h. RESULTS: Cytochalasin D at 0.2 µM gave an approximate LD50 in zebrafish, while cytochalasin B was fully-tolerated at 5 µM, and gave an LD50 of 10 µM. 21,22-dihydrocytochalasin B was fully-tolerated at 10 µM. Cytochalasin C was tolerated fully at 1 µM, ten-fold higher than the level for cytochalasin D that was tolerated. Jasplakinolide at 0.5 µM did not exhibit any apparent acute toxicity or affect fish behavior for four days, but delayed toxicity was evident at days 4 and 6 when the fish died. Further, the addition of 5 µM glutathione (GSH) at the time of treatment substantially decreased the toxicity of 10 µM cytochalasin B, a level of cytochalasin B that not otherwise tolerated in vivo. Such observations were likely due to GSH-mediated alkylation of C-20 in cytochalasin B, thereby reducing the rate of oxidation to the highly toxic congener, cytochalasin A, and reacting with any cytochalazin A formed. The protective effects of GSH are further supported by its ability to react with α, ß-unsaturated ketone moieties, as is found in cytochalasin A. GSH at 0.8 uM was able to reduce the toxicity of 0.8 µM cytochalasin D, but it took 20 µM GSH to fully protect against the toxicity of 0.8 µM cytochalasin D. CONCLUSION: Pre-clinical evaluation of rare natural products such as microfilamented-directed agents for efficacy in vivo in tumor-bearing zebrafish is a feasible prospect. Dose-limiting toxicities in zebrafish expressed as µM concentrations in water can be used to estimate in vivo toxicities in mice expressed as mg/kg.


Assuntos
Citoesqueleto de Actina , Antineoplásicos/administração & dosagem , Citocalasinas/administração & dosagem , Depsipeptídeos/administração & dosagem , Neoplasias/patologia , Animais , Antineoplásicos/química , Antineoplásicos/toxicidade , Citocalasinas/química , Citocalasinas/toxicidade , Depsipeptídeos/química , Depsipeptídeos/toxicidade , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Camundongos , Estrutura Molecular , Neoplasias/tratamento farmacológico , Testes de Toxicidade Aguda , Peixe-Zebra
19.
Chin J Nat Med ; 12(7): 512-6, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25053550

RESUMO

AIM: To study the chemical constituents of the solid culture of the endophyte Phomopsis sp. IFB-E060 in Vatica mangachapoi. METHOD: Isolation and purification were performed through silica gel column chromatography, gel filtration over Sephadex LH-20, ODS column chromatography, and HPLC. Structures of the isolated compounds were elucidated by a combination of spectroscopic analyses (UV, CD, IR, MS, 1D, and 2D NMR). The cytotoxicity of the isolates was evaluated in vitro by the MTT method against the human hepatocarcinoma cell line SMMC-7721. RESULTS: Five compounds were isolated from the solid culture of the endophyte Phomopsis sp. IFB-E060 and their structures were identified as 18-methoxy cytochalasin J (1), cytochalasin H (2), (22E, 24S)-cerevisterol (3), ergosterol (4), and nicotinic acid (5). Compound 1 had an inhibition rate of 24.4% at 10 µg·mL(-1) and 2 had an IC50 value of 15.0 µg·mL(-1), while a positive control 5-fluorouracil had an inhibition rate of 28.7% at 10 µg·mL(-1). CONCLUSION: 18-Methoxy cytochalasin J (1), produced by endophytic Phomopsis sp. IFB-E060, is a new cytochalasin with weak cytotoxicity to the human hepatocarcinoma cell line SMMC-7721.


Assuntos
Ascomicetos/química , Citocalasinas/química , Endófitos/química , Magnoliopsida/microbiologia , Ascomicetos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citocalasinas/isolamento & purificação , Citocalasinas/toxicidade , Endófitos/isolamento & purificação , Humanos , Estrutura Molecular , Casca de Planta/microbiologia
20.
Molecules ; 19(5): 6597-608, 2014 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-24858094

RESUMO

Chemical investigation of an acetonitrile fraction from the endophytic fungus Phomopsis sp. led to the isolation of the new natural product 2-hydroxy-alternariol (7) together with the known compounds cytochalasins J (1) and H (2), 5'-epialtenuene (3) and the mycotoxins alternariol monomethyl ether (AME, 4), alternariol (AOH, 5) and cytosporone C (6). The structure of the new compound was elucidated by using 1-D and 2-D NMR (nuclear magnetic resonance) and high resolution mass spectrometry. The cytochalasins J (1) and H (2) and AOH (5) exhibited potent inhibition of the total ROS (reactive oxygen species) produced by stimulated human neutrophils and acted as potent potential anti-inflammatory agents. Moreover, cytochalasin H (2) demonstrated antifungal and acetylcholinesterase enzyme (AChE) inhibition in vitro.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antifúngicos/farmacologia , Ascomicetos/metabolismo , Anti-Inflamatórios não Esteroides/química , Antifúngicos/química , Antioxidantes/química , Antioxidantes/farmacologia , Ascomicetos/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Citocalasinas/química , Citocalasinas/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Endófitos/metabolismo , Humanos , Lactonas , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Micotoxinas/química , Micotoxinas/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Metabolismo Secundário , Senna/microbiologia , Sesquiterpenos/química , Sesquiterpenos/farmacologia
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