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.