The Structural Characteristics of Sustainable Nanomelanin Derived from Lasiodiplodia theobromae

Abstract

Natural melanin is a sustainable and environmentally friendly pigment. The structural properties of melanin are of great significance for its functional applications. In this study, the preliminary composition and structure of melanin extracted from the induced cultures of Lasiodiplodia theobromae were qualitatively characterized by ultraviolet-visible (UV) spectrophotometer, elemental analysis (EA), Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The results showed that the secreted melanin contained many functional groups such as hydroxy groups, alkanes and aromatic rings, which belonged to benzoquinone structure and aliphatic structure. The melanin secreted by Lasiodiplodia theobromae can be identified as a type of allomelanin. This research work is expected to provide a reference for the application of melanin in various fields in the future.