Direct determination of E and Z configurations for double bond in bioactive meroterpenoids from Ganoderma mushrooms by diagnostic 1H NMR chemical shifts and structure revisions of previous analogues
Fu‐Ying Qin, Jiaojiao Zhang, Dawei Wang, Te Xu, Dan Cai, Yong‐Xian Cheng
Abstract
Ganoderma mushrooms are not only traditional Chinese medicine, but also dietary supplements and functional foods worldwide. In this work, six new meroterpenoids, ganodercins A − F (2, 3, and 6–9), and three known compounds ganomycin C (1), cochlearin I (4), and fornicin D (5) were isolated from Ganoderma mushrooms. An approach characteristic of the chemical shift for H-8 to assign the geometry of meroterpenoids was developed and successfully used for structure revisions of 1, 5, and previous analogues. Biological evaluation found that 4 selectively inhibits Smad3 phosphorylation in TGF-β1-induced NRK-52E cells. Moreover, 1 and 7 could increase glucose uptake in a dose dependent manner in palmitic acid induced C2C12 cells. Further, 1 was found to activate AMPKα(Thr-172) and AKT(Ser-473) phosphorylation, while 7 could activate AKT(Ser-473) phosphorylation. This study demonstrates the potential of Ganoderma to be developed as new anti-renal fibrosis and improve insulin resistance functional food and medicine.