The HPLC analysis of the diethyl ether extract (Supplementary
data, Figure 1S) revealed a major peak at Rt = 20.34 min that
presents the TLC characteristics of the artifact-generating compound.
After scaling-up to preparative HPLC, the compound of
interest was isolated, and its purity verified by analytical HPLC
(96.5% at UV 254 nm; Supplementary data, Figure 2S).