Svalbamides A and B, Pyrrolidinone-Bearing Lipodipeptides from Arctic <i>Paenibacillus</i> sp.

• Main Authors: Young-Eun Du, Eun-Seo Bae, Yeon-Jung Lim, Jang-Cheon Cho, Sang-Jip Nam, Jong-Heon Shin, Sang-Kook Lee, Seung-Il Nam, Dong-Chan Oh
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Marine Drugs
• Subjects: <i>Paenibacillus</i>; Arctic; Svalbard; Marfey’s method; DP4 calculation; quinone reductase
• Online Access: https://www.mdpi.com/1660-3397/19/4/229

Two new secondary metabolites, svalbamides A (<b>1</b>) and B (<b>2</b>), were isolated from a culture extract of <i>Paenibacillus</i> 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 <b>1</b> and <b>2</b> as being lipopeptides bearing 3-amino-2-pyrrolidinone, <span style="font-variant: small-caps;">d</span>-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 <b>1</b> and <b>2</b> were derivatized with <span style="font-variant: small-caps;">l</span>- and <span style="font-variant: small-caps;">d- </span>forms of 1-fluoro-2,4-dinitrophenyl-5-alanine amide (FDAA). The absolute configurations of <b>1</b> and <b>2</b> 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.