Aquilarinenside D (4) [17] gave the molecular formula of
C24H28O13 on the basis of the detected peak at m/z 523.1442
[MH] (calcd. for C24H27O13, 523.1457) in HRESIMS spectrum
(Fig. S30 in Supporting information). The 1H NMR and 13C NMR
spectra of 1 and 4 displayed near-identical similarity for all signals,
and the main difference observed was that outer a-L-rhamnopyranoside
unit was replaced by a b-D-xylopyranoside unit. It was
confirmed by GC analysis of the hydrolyzed product and by the
coupling constant of the anomeric proton Xyl H-1000 (d, J = 7.7 Hz).
Therefore, aquilarinenside D (4) was determined as iriflophenone
2-O-b-D-xylopyranosyl-(1 ! 4)-O-a-L-rhamnopyranoside.