Renoprotective Glycoside Derivatives from Zingiber officinale (Ginger) Peels

As a widely consumed spice and traditional Chinese medicine, Zingiber officinale Roscoe (ginger) has been used in the treatment of nausea, coughs, and colds. In this article, 18 new glycosides (1–18) and six known analogues (19–24) were isolated from the peel of ginger. The planar structures of these compounds were determined by using HR-ESI-MS and extensive spectroscopic techniques (UV, IR, 1D-NMR, and 2D-NMR). Their relative and absolute configurations of the stereogenic centers in the new natural products were determined by analysis of NMR data, using a quantum mechanical NMR approach and time-dependent density functional theory based electronic circular dichroism calculations. The renal fibrosis activities of the isolated natural products together with those of 6-gingerol (6-Gi), 8-gingerol (8-Gi), and 10-gingerol (10-Gi) were evaluated in TGF-β1 induced NRK-52E cells. Compounds 9, 10, 15, 22–24, 6-Gi, 8-Gi, and 10-Gi were found to be active toward extracellular matrix, indicating that they have potential renal fibrosis activities.