Aryl-enclosed polyketides from mangrove sediment associated bacterium Bacillus amyloliquefaciens attenuating pro-inflammatory 5-lipoxygenase

Two aryl-enclosed polyketides were identified from the ethyl acetate extract of mangrove sediment associated bacterium Bacillus amyloliquefaciens , and were characterized as 1-(8-hydroxy-1-oxoisochroman-3-yl)propyl 4′-(6′-hydroxy-8′-oxotetrahydrofuran-5′-yl)acetate (compound 1 ) and 6′a-(3′-(1′-(8-hydroxy-1-oxoisochroman-3-yl)propoxy)-3′-oxoethyl)-8′-oxotetrahydrofuran-6′-yl butyrate (compound 2 ) by detailed spectroscopic techniques encompassing two-dimensional nuclear magnetic resonance and mass spectroscopic experiments. Polyketide compound 2 bearing oxotetrahydrofuran-6′-yl butyrate moiety exhibited potential antioxidant activities against the free radicals, 2,2-diphenyl-1-picrylhydrazyl radical and 2,2′-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC 50 1.01 and 1.22 mM, respectively), and were found to be significantly greater than those displayed by polyketide 1 and standard ( α -tocopherol IC 50 1.45–1.63 mM, p