New bioactive metabolites from the elicited marine sponge-derived bacterium Actinokineospora spheciospongiae sp. nov.

Several approaches have been dedicated to activate the cryptic gene clusters in the genomes of actinomycetes for the targeted discovery of new fascinating biomedical lead structures. In the current study, N-acetylglucosamine was used to maximize the chemical diversity of sponge-derived actinomycete Actinokineospora spheciospongiae sp. nov. HR–ESI–MS was employed for dereplication study and orthogonal partial least square-discriminant analysis was applied to evaluate the HR–ESI–MS data of the different fractions. As a result, two new fridamycins H (1) and I (2), along with three known compounds actinosporin C (3), D (4), and G (5) were isolated from the solid culture of sponge-associated actinomycete Actinokineospora spheciospongiae sp. nov., elicited with N-acetylglucosamine. Characterization of the isolated compounds was pursued using mass spectrometry and NMR spectral data. Fridamycin H (1) exhibited significant growth inhibitory activity towards Trypanosoma brucei strain TC221. These results highlight the potential of elicitation in sponge-associated actinomycetes as an effective strategy for the discovery of new anti-infective natural products.