화학공학소재연구정보센터
Applied Biochemistry and Biotechnology, Vol.180, No.7, 1286-1300, 2016
Structural Characterization of a Novel Antioxidant Pigment Produced by a Photochromogenic Microbacterium oxydans Strain
The Microbacteriaceae family, such as Microbacterium, is well known for its ability to produce carotenoid-type pigments, but little has been published on the structure of such pigments. Here, we isolated the yellow pigment that is responsible for the yellowish color of a Microbacterium oxydans strain isolated from a decomposing stump of a resinous tree. The pigment, which is synthesized when the bacterium is grown under light, was purified and characterized using several spectroscopic analyses, such as ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), H-1 and C-13 nuclear magnetic resonance (H-1 NMR, C-13 NMR), and high-resolution mass spectrometry (HRMS). From these analysis, a molecular formula (C27H42O2) and a chemical structure (8-hydroxymethyl-2,4,12-trimethyl-14-(2,6,6-trimethyl-cyclohex-2-enyl)-teradeca-3,7,9,11,13-pentan-2-ol) were deduced. The chemical properties of the pigment, such as aqueous stability at different pH, stability in different organic solvents, and antioxidant capacity, are also reported. Together, these data and previous studies have resulted in the identification of a new antioxidant pigment produced by M. oxydans. To the best of our knowledge, this is the first thorough investigation of this carotenoid-like pigment in the Microbacterium genera.