α-Pyrone Polyketides from Streptomyces ambofaciens BI0048, an Endophytic Actinobacterial Strain Isolated from the Red Alga Laurencia glandulifera.

Four new (-) and six previously reported (-) α-pyrone polyketides, along with benzoic acid, hydrocinnamic acid, and ()-cinnamic acid, were isolated from the organic extract resulting from the cultivation of the algicolous strain BI0048, which in turn was isolated from the inner tissues of the red alga . The structure elucidation of the isolated natural products was based on extensive analysis of their spectroscopic data (NMR, MS, UV, IR). Compounds - were evaluated for their antibacterial and cytotoxic activities against two multidrug-resistant strains of and one strain of , as well as two human cancer cell lines.