Effect of Sun Drying on Phytoconstituents and Antiviral Activity of Ginger against Low-Pathogenic Human Coronavirus

Abstract

Rhizomes of ginger are commonly used as a spice and for home remedies in either fresh or dry form. This study aimed to assess the effect of sun drying on the volatile constituents, total phenolic and flavonoid content, and the antiviral activity of ginger against low-pathogenic human coronavirus. The antiviral effect of the major volatile compounds was predicted through molecular docking. GC/MS was employed for profiling the volatile constituents of both fresh and dry ginger oils. Moreover, chemometric analysis was applied to discriminate between fresh and dry ginger and to investigate the correlation between their volatile constituents and the antiviral activity using principal component analysis (PCA) and partial least-squares regression (PLS-R). GC/MS analysis revealed that the major effects of the drying process were an increase in α-curcumene and β-sesquiphellandrene. Moreover, total phenolic and flavonoid contents of dried ginger decreased considerably. A PCA score plot revealed significant discrimination between fresh and dry ginger, with α-curcumene and 4-thujanol identified as the main discriminating markers. These findings were validated by in silico molecular docking studies, which revealed that the compounds under consideration had good drug-like characteristics. Thus, ginger is rich in valuable phytoconstituents which showed promising therapy in viral infections such as COVID-19.