TY - JOUR
T1 - Molecular properties of astaxanthin in water/ethanol solutions from computer simulations
AU - Karki, Khadga Jung
AU - Samanta, Susruta
AU - Roccatano, Danilo
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/9/8
Y1 - 2016/9/8
N2 - Astaxanthin (AXT) is a reference model of xanthophyll carotenoids, which is used in medicine and food industry, and has potential applications in nanotechnology. Because of its importance, there is a great interest in understanding its molecular properties and aggregation mechanism in water and mixed solvents. In this paper, we report a novel model of AXT for molecular dynamics simulation. The model is used to estimate different properties of the molecule in pure solutions and in water/ethanol mixtures. The calculated diffusion coefficients of AXT in pure water and ethanol are (3.22 ± 0.01) × 10-6 cm2 s-1 and (2.7 ± 0.4) × 10-6 cm2 s-1, respectively. Our simulations also show that the content of water plays a clear effect on the morphology of the AXT aggregation in water/ethanol mixture. In up to 75% (v/v) water concentration, a loosely connected network of dimers and trimers and two-dimensional array structures are observed. At higher water concentrations, AXT molecules form more compact three-dimensional structures that are preferentially solvated by the ethanol molecules. The ethanol preferential binding and the formation of a well connected hydrogen bonding network on these AXT clusters, suggest that such preferential solvation can play an important role in controlling the aggregate structure.
AB - Astaxanthin (AXT) is a reference model of xanthophyll carotenoids, which is used in medicine and food industry, and has potential applications in nanotechnology. Because of its importance, there is a great interest in understanding its molecular properties and aggregation mechanism in water and mixed solvents. In this paper, we report a novel model of AXT for molecular dynamics simulation. The model is used to estimate different properties of the molecule in pure solutions and in water/ethanol mixtures. The calculated diffusion coefficients of AXT in pure water and ethanol are (3.22 ± 0.01) × 10-6 cm2 s-1 and (2.7 ± 0.4) × 10-6 cm2 s-1, respectively. Our simulations also show that the content of water plays a clear effect on the morphology of the AXT aggregation in water/ethanol mixture. In up to 75% (v/v) water concentration, a loosely connected network of dimers and trimers and two-dimensional array structures are observed. At higher water concentrations, AXT molecules form more compact three-dimensional structures that are preferentially solvated by the ethanol molecules. The ethanol preferential binding and the formation of a well connected hydrogen bonding network on these AXT clusters, suggest that such preferential solvation can play an important role in controlling the aggregate structure.
UR - http://www.scopus.com/inward/record.url?scp=84986570933&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcb.6b06055
DO - 10.1021/acs.jpcb.6b06055
M3 - 文章
C2 - 27536854
AN - SCOPUS:84986570933
SN - 1520-6106
VL - 120
SP - 9322
EP - 9328
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 35
ER -