RESUMO
Four new secondary metabolites, giovaninones A-D (1-4), were isolated from an ethyl acetate extract of a culture of a marine-derived Streptomyces strain designated SS99BA-2. Chemical analysis was completely conducted in a coupled automated LC-SPE system with the use of a cryogenic NMR probehead and HRMS. The application of this system to identify, purify and elucidate all the structures is described.
Assuntos
Pirazinas/química , Água do Mar/microbiologia , Streptomyces/metabolismo , Brasil , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Pirazinas/isolamento & purificação , Pirazinas/metabolismo , Metabolismo Secundário , Streptomyces/química , Streptomyces/genética , Streptomyces/isolamento & purificaçãoRESUMO
Separation and characterization of limonoids from Switenia macrophylla (Meliaceae) by HPLC-NMR technique has been described. Analyses were carried out using reversed-phase gradient HPLC elution coupled to NMR (600 MHz) spectrometer in stopped-flow mode. Separated peaks were collected into an interface unit prior to NMR measurements, which were performed with suppression of solvent signals by shaped pulses sequences. Structure elucidation of the limonoids was attained by data obtained from 1H NMR, TOCSY, gHSQC and gHMBC spectra without conventional isolation that is usually applied in natural products studies.
