New Ethylated Derivatives of Sulfur- and Nitrogen-Containing Artifacts from Tenodera Sinensis Egg Pod and Their Anti-Renal Fibrosis

Three pairs of enantiomers and one achiral molecule that are new ethylated derivatives of sulfur and nitrogen-containing compounds named mantidisamides E–H (1–4), along with twenty known ones (5–24), were derived from the ethanol extract of Tenodera sinensis Saussure. The structures of these new compounds and their absolute configurations were assigned on the basis of spectroscopic analyses and computational methods. The assessment of activities in NRK-52e cells induced by TGF-β1 demonstrated that the previously undescribed compounds 1 and 2 exhibited a significant capacity to inhibit the expression of proteins (fibronectin, collagen I, and α-SMA). Moreover, the biological activity of these compounds was found to increase with rising concentrations. Notably, compounds 1–4 should be artifacts; however, undescribed compounds 1 and 2, which possessed obvious biological activity, might be attractive for chemists and biologists due to the potential for more detailed exploration of their properties. It is worth mentioning that compounds 1 and 2 remain novel structures even in the absence of the ethoxy group.