Antibacterial colorants: characterization of prodiginines and their applications on textile materials

A strain of Vibrio sp. isolated from marine sediments produced large quantities of bright red pigments that could be used to dye many fibers including wool, nylon, acrylics, and silk. Characterization of the pigments by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) revealed three prodiginine-like structures with nonpolar characteristics and low molecular mass. UV-visible spectra of the major constituent in methanol solution showed absorbance at lambda max 530 nm wavelength. The accurate mass result showed that the main isolated product has a molecular mass of m/z 323.1997. Further analysis using mass fragmentation (MS/MS), 1H NMR, COSY, HMQC NMR and DEPT confirmed the detailed structure of the pigment with an elementary composition of C20H25N3O. Fabrics dyed with the microbial prodiginines demonstrated antibacterial activity.