Figure 3.

Spectra, proposed or authenticated structures, and chiral HPLC data. APCI-MS/MS spectra of compounds 1, 2, and 3 were obtained in the negative-ion mode. The presented UV/Vis spectra for each of these products were taken between 200 and 450 nm. Based on MS/MS and UV/Vis spectra, molecular structures were proposed and subsequently synthesized for authentication for products 1 and 3. Two pairs of enantiomers were detected for both the natural product (N) and the synthesized (S) compounds 1a and 1b by chiral HPLC analysis. G, Guaiacyl; 5H, 5-hydroxyguaiacyl; G′, unit derived from coniferaldehyde; 5H′, unit derived from 5-hydroxyconiferaldehyde.