Hierarchical Superstructures of l-Glutathione

The formation of hierarchical structures of organic crystals has great potential for many chemical and medical applications in various areas such as pharmaceuticals, food, pigments, and organic catalysis. In this paper, we describe the synthesis of l-glutathione spherical hierarchical structures using an anti-solvent precipitation method. The crystallization of l-glutathione hierarchical structures under various experimental parameters such as temperature, solvent composition, and l-glutathione concentrations is thoroughly studied. The hierarchical organic structures are studied using several techniques including X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. It is found that the hierarchical structures and the polymorphs of l-glutathione depend mainly on the anti-solvents used during the anti-solvent precipitation process. On the basis of these results and on kinetic measurements of the crystallization course, we propose a possible mechanism for the formation of the l-glutathione superstructures based on the self-assembly principle. In this work, we investigate the formation of l-glutathione spherical hierarchical structures as a model system of crystallization of organic hierarchical crystals. We believe that the results of this study and the synthesis described here, for the formation of organic hierarchical structures, can be further extended to numerous organic hierarchical crystal systems.