Structure Determination, Functional Characterization, and Biosynthetic Implications of Nybomycin Metabolites from a Mining Reclamation Site-Associated .

We report the isolation and characterization of three new nybomycins (nybomycins B-D, -) and six known compounds (nybomycin, ; deoxynyboquinone, ; α-rubromycin, ; β-rubromycin, ; γ-rubromycin, ; and [2α(1,3),4β]-2-(1,3-pentadienyl)-4-piperidinol, ) from the Rock Creek (McCreary County, KY) underground coal mine acid reclamation site isolate sp. AD-3-6. Nybomycin D () and deoxynyboquinone () displayed moderate () to potent () cancer cell line cytotoxicity and displayed weak to moderate anti-Gram-(+) bacterial activity, whereas rubromycins - displayed little to no cancer cell line cytotoxicity but moderate to potent anti-Gram-(+) bacterial and antifungal activity.

Mccrearamycins A-D, Geldanamycin-Derived Cyclopentenone Macrolactams from an Eastern Kentucky Abandoned Coal Mine Microbe.

Four cyclopentenone-containing ansamycin polyketides (mccrearamycins A-D), and six new geldanamycins (Gdms B-G, including new linear and mycothiol conjugates), were characterized as metabolites of Streptomyces sp. AD-23-14 isolated from the Rock Creek underground coal mine acid drainage site. Biomimetic chemical conversion studies using both simple synthetic models and Gdm D confirmed that the mccrearamycin cyclopentenone derives from benzilic acid rearrangement of 19-hydroxy Gdm, and thereby provides a new synthetic derivatization strategy and implicates a potential unique biocatalyst in mccrearamycin cyclopentenone formation.