Svalbamides A and B, Pyrrolidinone-Bearing Lipodipeptides from Arctic Paenibacillus sp

Two new secondary metabolites, svalbamides A ( ) and B ( ), were isolated from a culture extract of sp. SVB7 that was isolated from surface sediment from a core (HH17-1085) taken in the Svalbard archipelago in the Arctic Ocean. The combinational analysis of HR-MS and NMR spectroscopic data revealed the structures of and as being lipopeptides bearing 3-amino-2-pyrrolidinone, d-valine, and 3-hydroxy-8-methyldecanoic acid. The absolute configurations of the amino acid residues in svalbamides A and B were determined using the advanced Marfey's method, in which the hydrolysates of and were derivatized with l- and d- forms of 1-fluoro-2,4-dinitrophenyl-5-alanine amide (FDAA). The absolute configurations of and were completely assigned by deducing the stereochemistry of 3-hydroxy-8-methyldecanoic acid based on DP4 calculations. Svalbamides A and B induced quinone reductase activity in Hepa1c1c7 murine hepatoma cells, indicating that they represent chemotypes with a potential for functioning as chemopreventive agents.