MOESM4 of Protective effects of ten oligostilbenes from Paeonia suffruticosa seeds on interleukin-1β-induced rabbit osteoarthritis chondrocytes

Additional file 4. Spectrograms of structure identification of ten compounds. 1H- and 13C-NMR spectra of ten compounds were measured on a Bruker Avance DRX-500 spectrometer (1H at 500 MHz and 13C at 125 MHz) in MeOH-d4. Chemical shifts are given in δ values (ppm) relative to tetramethylsilane (TMS) as an internal standard. 1 suffruticosol A, 2 suffruticosol B, 3 suffruticosol C, 4 trans-resveratrol, 5 cis-ε-viniferin, 6 trans-ε-viniferin, 7 cis-suffruticosol D, 8 cis-gnetin H, 9 trans-suffruticosol D, and 10 trans-gnetin H.