Three new bioactive metabolites, 1,6-dihydroxy- 2-methyl-heptan-4-one (1), 4-hydroxy-1-(2-methyl-oxiranyl)- pentan-2-one (2), and 2-(2-hydroxy-propyl)-4-methylfuran- 3-carboxylic acid amide (3) were isolated from the terrestrial Streptomyces sp. isolate ANK245, along with the new microbial constituent p-vinylanisol (4a) and the known metabolites p-vinyl-phenol (4b) and phenethyl alcohol. Analysis of the nonpolar part of the extract by gas chromatography/mass spectrometry (GC-MS) provided further evidence for tetradecanoic acid, 9-octadecenoic acid, hexadecanoic acid, 2-methoxy-4-vinylphenol (4c), 4-hydroxy-3-methoxy-benzaldehyde, o-hydroxybiphenyl, and 1,5,9-trimethyl-4,8,13-cyclotetradecatrien-1,3-diol (5). Structures 1–3 of the new compounds were elucidated by nuclear magnetic resonance (NMR) and NMR spectroscopy, but mass spectrometry (MS) techniques and their absolute configuration were determined by density functional theory (DFT) calculations and Mosher derivatisation. Their antimicrobial and cytotoxic activities were evaluated in comparison with the crude bacterial extract.
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Zeitschrift für Naturforschung B is an international scientific journal which publishes original papers, microreviews, and letters from all areas of inorganic chemistry, solid state chemistry, coordination chemistry, molecular chemistry, and organic chemistry.