Dependence of 1H NMR chemical shifts of geminal protons of glycosyloxy methylene (H2‐26) on the orientation of the 27‐methyl group of furostane‐type steroidal saponins

This is the authors' abstract. We don't add key points for this paper.

An approach based on the difference (Delta(ab) = delta(a) - delta(b)) between the 1H NMR chemical shifts (delta(a), delta(b)) of the geminal protons of glycosyloxy methylene (H2-26) (Delta(ab) = <0.48 for 25R; Delta(ab) = >0.57 for 25S) is proposed for ascertaining 25R/25S orientation of the 27-methyl group of furostane-type steroidal saponins. These studies suggested the 25R-orientation of the 27-Me group for the furostanol glycosides isolated by Wu et al. from Tribulus terrestris.