Isolation and Structural Determination of Cyclic Dipeptides Produced by Arthrobacter sp.

Introduction: Arthrobacter is a genus of bacteria that has gained recent attention due to its unique ability to produce bioactive compounds that possess potential antimicrobial properties. Method: In this study, we isolated two cyclic dipeptides (CDPs) from Arthrobacter sp. obtained from a soil sample. Result: The isolated Arthrobacter sp. exhibited inhibitory activity against a filamentous indicator bacterium and a violacein-producing Janthinobacterium sp. Cultivation of Arthrobacter sp. TAJX1902 was carried out using rich medium broth and agar to facilitate the extraction of metabolites. The isolated compounds were characterized through spectroscopic techniques. GCMS analysis of the crude extract revealed the presence of bioactive cyclic dipeptides. Conclusion: The structures of the isolated CDPs were determined as acylated cyclo(Dphenylalanine- 4-hydroxy-D-proline) (1) and cyclo(D-phenylalanine-D-proline) (2). Furthermore, two additional metabolites, 2,4-dihydroxypyrimidine (3) and 2,4-dihydroxy-5-methylpyrimidine (4), were identified and verified through NMR spectral analysis.