. However, it is
difficult to identify whether or not the ingredients in extracts
(mixtures) have antagonistic or synergistic biological effects,
and it is also unclear what compound in extracts is mainly
responsible for the bioactivities, which makes the study of
structure–activity relationship difficult. Therefore, the use of a
purified triterpene is required to reveal the acting mechanism of
responsible compounds and to further screen and rationally
design structurally similar lead compounds