RESUMEN
One new bicyclic lactam, cladosporilactam A (1), and six known 12-membered macrolides (2-7) were isolated from a gorgonian-derived Cladosporium sp. fungus collected from the South China Sea. Their complete structural assignments were elucidated by comprehensive spectroscopic investigation. Quantum chemistry calculations were used in support of the structural determination of 1. The absolute configuration of 1 was determined by calculation of its optical rotation. Cladosporilactam A (1) was the first example of 7-oxabicyclic[6.3.0]lactam obtained from a natural source. Compound 1 exhibited promising cytotoxic activity against cervical cancer HeLa cell line with an IC50 value of 0.76 µM.
Asunto(s)
Antineoplásicos/aislamiento & purificación , Organismos Acuáticos/química , Ascomicetos/química , Compuestos Bicíclicos Heterocíclicos con Puentes/aislamiento & purificación , Lactamas Macrocíclicas/aislamiento & purificación , Lactamas/aislamiento & purificación , Macrólidos/aislamiento & purificación , Animales , Antozoos/microbiología , Antineoplásicos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Células HeLa/efectos de los fármacos , Humanos , Lactamas/farmacología , Lactamas Macrocíclicas/farmacología , Macrólidos/farmacología , Espectroscopía de Resonancia MagnéticaRESUMEN
Three new lumazine peptides, penilumamides B-D (2-4), and one known analogue, penilumamide (1), together with a new cyclic pentapeptide, asperpeptide A (5), were isolated from the gorgonian-derived fungus Aspergillus sp. XS-20090B15. Among them, 2 was obtained from the feeding culture with l-methionine of this strain. All structures were elucidated by spectroscopic methods and chemical derivatization. Compounds 1-4 are rare lumazine peptides, of which 1 and 3 are formed from 2 by oxidation of the l-methionine residue.
Asunto(s)
Antozoos/microbiología , Aspergillus/química , Péptidos Cíclicos/aislamiento & purificación , Alcaloides/farmacología , Animales , Bacillus cereus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Metionina/análogos & derivados , Metionina/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Nocardia/efectos de los fármacos , Resonancia Magnética Nuclear Biomolecular , Oligopéptidos/química , Péptidos Cíclicos/química , Pseudomonas/efectos de los fármacos , Pteridinas/química , Salmonella enterica/efectos de los fármacos , Sesquiterpenos/farmacología , Staphylococcus/efectos de los fármacos , Vibrio/efectos de los fármacosRESUMEN
Four nucleoside derivatives (1-4) were isolated from the fungus Aspergillus versicolor derived from the gorgonian Dichotella gemmacea collected in the South China Sea. Their structures were elucidated by comprehensive spectroscopic method of NMR and MS analysis. All isolated metabolites were evaluated for their cytotoxicity, antibacterial activity and lethality towards brine shrimp Artemia salina. Compounds 1/2 exhibited selective antibacterial activity against Staphylococcus epidermidis with an MIC value of 12.5 µM. It should be noted that 1 and 2, whose structures were listed in SciFinder Scholar, had no associated reference. This is the first report about their isolation, structure elucidation and biological activities.