Antimicrobial Metabolites from a Marine-Derived Actinomycete in Vietnam's East Sea

Abstract

Two new compounds, a quinoline alkaloid (1) and a 1,4-dioxane derivative (2), were isolated from culture broth of the marine-derived actinomycete Micromonospora sp. (strain G019) by bioassay-guided fractionation. This actinomycete strain was isolated from sediment, collected at Cát Bà Peninsula, Vietnam. The taxonomic identification was achieved by analysis of 16S rRNA gene sequences. On the basis of morphological and phylogenetic evidence, strain G019 was assigned to the genus Micromonospora. The structures of 1 and 2 were established by spectroscopic data analysis, including one-and two-dimensional NMR, and MS. Compound 1 was found to have antibacterial activity against Escherichia coli (MIC: 48 µg/mL), Salmonella enterica (MIC: 96 µg/mL) and Enterococcus faecalis (MIC: 128 µg/mL), while compound 2 showed inhibitory activity against Enterococcus faecalis (MIC: 32 µg/mL) and Candida albicans (MIC: 64 µg/mL).

A statistical approach to enhance the productivity of Streptomyces baarensis MH-133 for bioactive compounds

“…In contrast, the other solvent extracts did not exhibit any antibacterial activity. Previous studies have demonstrated that ethyl acetate extraction is the primary method for obtaining the majority of antibiotic metabolites sourced from actinomycetes [ 45 ]. Furthermore, literature have noted that the strains from which the molecule is derived, the solvent used for extraction, and the specific pathogens against which the compound is tested all contribute to the variation in the antibacterial activity of the compounds [ 46 ].…”

Antibiotics Development and the Potentials of Marine-Derived Compounds to Stem the Tide of Multidrug-Resistant Pathogenic Bacteria, Fungi, and Protozoa

“…Anti-candida activities against C. albicans ATCC 10231 have been reported for metabolites produced by Pseudonocardia endophytica VUK-10 [24], S. cheonanensis VUK-A [25] (India), and Micromonospora sp. strain G019 [26] (Vietnam). These bacterial isolates respectively produced proline containing cyclic dipeptides (MIC, 8 and 64 µg/mL) (Table S1); 2-Methyl butyl propyl phthalate (1) (MIC, 8 ± 0.01 µg/mL) and diethyl phthalate (2) (MIC, 32 ± 0.02 µg/mL); and 1,4-dioxane derivative (2) and quinoline alkaloid (1) (MIC, 64 µg/mL).…”

Secondary Metabolites from Marine Micromonospora: Chemistry and Bioactivities

“…Compound 115 exhibited inhibitory activities against E. coli , Salmonella enterica , and Enterococcus faecalis with MIC values of 48, 96, and 128 μg/mL. Compound 116 displayed antibacterial activities against Enterococcus faecalis and C. albicans with MIC values of 32 and 64 μg/mL …”