A 1-O-acylglycoside, isolated from pods of Acacia sieberana var. woodii, was shown to be 1-(6-O-α-L-arabinopyranosyl-β-D-glucopyranosyl)-(S)-2-methylbutyrate by chemical and spectroscopic methods. In the assignments of the signals in the ¹³C NMR spectrum, advantage was taken of isotope-induced chemical shift changes and off-resonance decouplings at different frequencies. CD established the absolute configuration of the aglycone.