Fig. 4 in Oleanane hemiacetal glycosides from Gymnema latifolium and their inhibitory effects on protein tyrosine phosphatase 1B

Fig. 4. Key NOESY correlations of compounds 1 (a: the aglycone, b: sugar moiety), 5 and 6. Fig. 4 c showed the chemical shifts and coupling constants of the protons on the glycosides. HMBC correlations bridging two sugar moieties were measured. All the discussions about COSY, NOESY and the coupling constant rules to identify the relative configuration of the sugar moiety were suggested at Results and discussion of compound 1.