RESUMEN
Three new cyclohexadepsipeptides of the isaridin class including isaridin G (1), desmethylisaridin G (2), and desmethylisaridin C1 (3), along with three related known metabolites (4-6), were isolated and identified from the marine bryozoan-derived fungus Beauveria felina EN-135. The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis, and the structures and absolute configurations of compounds 1-3 were confirmed by single-crystal X-ray diffraction analysis. The crystal structures showed the presence of ß-turns for the Tyr(3)/N-Me-Val(4) and Phe(3)/N-Me-Val(4) amide bonds in compounds 2 and 3, respectively, in the cis conformations, which were opposite other reported isaridins. The conformations of the HMPA(1)-Pro(2) amide bond in compound 2 are different in the solution and in the crystal structures, which showed trans and cis geometries, respectively, while compounds 1 and 3 do not exhibit this phenomenon. Each of the isolated compounds was evaluated for antimicrobial activity and brine shrimp lethality. Compound 3 exhibited antibacterial activity against E. coli with an MIC value of 8 µg/mL.
Asunto(s)
Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Beauveria/química , Depsipéptidos/aislamiento & purificación , Depsipéptidos/farmacología , Animales , Antibacterianos/química , Artemia/efectos de los fármacos , Cristalografía por Rayos X , Depsipéptidos/química , Edwardsiella tarda/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Biología Marina , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Estereoisomerismo , Vibrio/efectos de los fármacosRESUMEN
In addition to 13 known compounds, four new bisabolane sesquiterpenes, okamurenes A-D (1-4), a new chamigrane derivative, okamurene E (5), and a new C12-acetogenin, okamuragenin (6), were isolated from the marine red alga Laurencia okamurai. The structures of these compounds were determined through detailed spectroscopic analyses. Of these, okamurenes A and B (1 and 2) are the first examples of bromobisabolane sesquiterpenes possessing a phenyl moiety among Laurencia-derived sesquiterpenes, while okamuragenin (6) was the first acetogenin aldehyde possessing a C12-carbon skeleton. Each of the isolated compounds was evaluated for the brine shrimp (Artemia salina) lethal assay and 7-hydroxylaurene displayed potent lethality with LD50 1.8 µM.
Asunto(s)
Acetogeninas/aislamiento & purificación , Laurencia/química , Sesquiterpenos/aislamiento & purificación , Acetogeninas/química , Acetogeninas/toxicidad , Animales , Artemia/efectos de los fármacos , Dosificación Letal Mediana , Sesquiterpenos/química , Sesquiterpenos/toxicidad , Análisis EspectralRESUMEN
The marine sediment-derived fungus Penicillium commune QSD-17 was re-investigated and cultured on rice solid medium. Two new compounds, isophomenone (1) and 3-deacetylcitreohybridonol (2), together with seven known derivatives (3-9), were identified. Their structures were determined by spectroscopic analysis.
Asunto(s)
Fermentación , Sedimentos Geológicos/microbiología , Penicillium/metabolismo , Biología Marina , Metabolismo , Estructura Molecular , Naftoles , OryzaRESUMEN
Bioassay-guided fractionation of the culture extract of Aspergillus wentii EN-48, an endophytic fungus isolated from an unidentified marine brown algal species of the genus Sargassum, led to the isolation of three new tetranorlabdane diterpenoids, asperolides A-C (1-3), and five related derivatives (4-8). The structures of these compounds were established on the basis of spectroscopic interpretation, and compound 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of 1 was determined by application of the modified Mosher's method. An X-ray structure for wentilactone B (6) is also reported. Compounds 1-8 were evaluated for cytotoxic and antibacterial activities.
Asunto(s)
Aspergillus/química , Diterpenos/aislamiento & purificación , Phaeophyceae/química , Ampicilina/farmacología , Cristalografía por Rayos X , Diterpenos/química , Diterpenos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Células HeLa , Humanos , Biología Marina , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Estructura Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
A novel triazole carboxylic acid, penipanoid A (1), two new quinazolinone alkaloids, penipanoids B (2) and C (3), and a very recently reported quinazolinone derivative (4) were isolated from the marine sediment-derived fungus Penicillium paneum SD-44. Their structures were elucidated by spectroscopic analysis, and the structure for 1 was confirmed by X-ray crystallographic analysis. Compound 1 represents the first example of a triazole derivative from marine sediment-derived fungi, and compound 2 is a rare quinazolinone derivative having a dihydroimidazole ring system. The cytotoxicity of compounds 1 and 4 and the antimicrobial activity of 1-4 were evaluated.
Asunto(s)
Alcaloides/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Imidazoles/aislamiento & purificación , Penicillium/química , Quinazolinonas/aislamiento & purificación , Triazoles/aislamiento & purificación , Alcaloides/química , Alcaloides/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Ácidos Carboxílicos , Ensayos de Selección de Medicamentos Antitumorales , Sedimentos Geológicos/química , Humanos , Imidazoles/química , Imidazoles/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Quinazolinonas/química , Quinazolinonas/farmacología , Triazoles/química , Triazoles/farmacologíaRESUMEN
Chemical investigation of Penicillium commune QSD-17, a fungus isolated from a marine sediment sample collected in the southern China Sea, yielded six new azaphilone derivatives, namely, comazaphilones A-F (1-6). The structures of these compounds were established on the basis of spectroscopic analysis. Attempts to define the absolute configuration of these azaphilones through investigation of Mosher's esters failed, possibly due to steric crowding at C-6 and C-7 and due to the degradation of these azaphilone derivatives under the reaction conditions. The inhibitory activities of the six azaphilones against four bacteria, one pathogenic fungus, and seven tumor cell lines were evaluated. Compounds 3-5 displayed potent inhibitory activity against several of these bacteria, while compounds 4-6 showed cytotoxic activity against human pancreatic tumor cell line SW1990. The preliminary SAR results indicated that the double bond at C-10 and the location of the orsellinic acid unit at C-6 in these azaphilones are important for the antibacterial activity and cytotoxicity, respectively. This is the first report of the isolation of azaphilone derivatives from a marine sediment-derived fungus.
Asunto(s)
Antibacterianos/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Benzopiranos/aislamiento & purificación , Penicillium/química , Pigmentos Biológicos/aislamiento & purificación , Antibacterianos/química , Antibacterianos/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Benzopiranos/química , Benzopiranos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Sedimentos Geológicos/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Pigmentos Biológicos/química , Pigmentos Biológicos/farmacología , Relación Estructura-ActividadRESUMEN
7-Nor-ergosterolide (1), a rare 7-norsteroid with an unusual pentalactone B-ring system, and two new steroid derivatives, 3ß,11α-dihydroxyergosta-8,24(28)-dien-7-one (2) and 3ß-hydroxyergosta-8,24(28)-dien-7-one (3), were characterized from the culture extract of Aspergillus ochraceus EN-31, an endophytic fungus isolated from the marine brown alga Sargassum kjellmanianum. In addition, nine known related steroids were isolated and identified. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configuration of the new steroids (1-3) was determined by application of the modified Mosher's method. Compound 1, which represents the first example of a 7-nor-ergosteroid possessing a pentalactone B-ring system in a naturally occurring steroid, displayed cytotoxicity against NCI-H460, SMMC-7721, and SW1990 cell lines with IC(50) values of 5.0, 7.0, and 28.0 µg/mL, respectively. Compound 2 also displayed cytotoxicity against the SMMC-7721 cell line with an IC(50) value of 28.0 µg/mL.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Aspergillus ochraceus/química , Noresteroides/química , Noresteroides/aislamiento & purificación , Antineoplásicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Concentración 50 Inhibidora , Biología Marina , Estructura Molecular , Noresteroides/farmacología , Resonancia Magnética Nuclear Biomolecular , Phaeophyceae/microbiología , EstereoisomerismoRESUMEN
Cytoglobosins A-G (1-7), seven new cytochalasan derivatives, along with two structurally related known compounds, isochaetoglobosin D (8) and chaetoglobosin F(ex) (9), were isolated and identified from the cultures of Chaetomium globosum QEN-14, an endophytic fungus derived from the marine green alga Ulva pertusa. The structures of the new natural products as well as their relative configurations were elucidated on the basis of 1D and 2D NMR spectra (COSY, HSQC, HMBC, and NOESY) and HRESIMS data. Cytoglobosins C and D (3 and 4) displayed cytotoxic activity against the A-549 tumor cell line.
Asunto(s)
Alcaloides Indólicos/aislamiento & purificación , Animales , Chaetomium/química , Chlorophyta/microbiología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacología , Células KB , Leucemia P388 , Biología Marina , Ratones , Estructura Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
A sample of the marine brown alga D. divaricata collected off the coast of Yantai (P.R. China) was dried, powdered, and extracted with the mixture of CHCl(3) and MeOH (1:1, v/v). By a combination of silica gel and Sephadex LH-20 column chromatography and preparative TLC, a new cadinane sesquiterpene 1,4-epoxymuurolan-5beta-ol (1) was isolated from this species. Its structure was established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data.
Asunto(s)
Phaeophyceae/química , Sesquiterpenos/química , Cromatografía en Capa Delgada , Espectroscopía de Resonancia Magnética , Estructura Molecular , Sesquiterpenos Policíclicos , Sesquiterpenos/aislamiento & purificaciónRESUMEN
Asperamides A (1) and B (2), a sphingolipid and their corresponding glycosphingolipid possessing a hitherto unreported 9-methyl-C20-sphingosine moiety, were characterized from the culture extract of Aspergillus niger EN-13, an endophytic fungus isolated from marine brown alga Colpomenia sinuosa. The structures were elucidated by spectroscopic and chemical methods as (2S,2'R,3R,3'E,4E,8E)-N-(2'-hydroxy-3'-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (1) and 1-O-beta-D-glucopyranosyl-(2S,2'R,3R,3'E,4E,8E)-N-(2'-hydroxy-3'-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (2). In the antifungal assay, asperamide A (1) displayed moderate activity against Candida albicans.