Effects of green extraction methods on the chemical profile of Schisandra chinensis fruit extracts and on their tyrosinase inhibitory activity

The fruits of Schisandra chinensis (Turcz.) Baill. are a well-known food with health benefits for the central nervous system. This study was aimed at comparing green extracts of the fruits to select an environmentally friendly process providing a product rich in bioactives. S. chinensis fruits were extracted by decoction, macerations, ultrasound-assisted (UAE), and dynamic solid-liquid (SLDE) extraction using EtOH/H2O mixtures. The extract's chemical profiles were established by an integrated LC-MS and NMR approach. The LC-MS analysis revealed the presence of 70 metabolites, some of which never reported before in S. chinensis fruits, and the NMR analysis highlighted the occurrence of both primary and specialized metabolites. LC-MS and NMR data were processed by multivariate statistical analysis to highlight differences in the extraction methods. The extracts obtained with 100% EtOH by UAE and SLDE resulted the richest ones in lignans. Furthermore, the tyrosinase inhibitory activity of the extracts was tested (IC50 range 122.6–181.4 μg/ml). The extracts obtained with 100% EtOH showed the highest tyrosinase inhibitory activity, suggesting how the activity could be ascribed both to lignans, reported as responsible for the biological properties of S. chinensis and compounds as coumaric acid, 3,4,5-trimethoxycinnamic acid, gallic acid, known as tyrosinase inhibitors.