A new prenylated coumestan from the roots of Campylotropis hirtella.

A new prenylated coumestan, campylohirtin A (1), along with fifteen phenolic known compounds (2‒16) and four other known compounds (17‒20), was obtained from the 95% ethanol extract of roots of Campylotropis hirtella. Their structures were elucidated based on extensive spectroscopic analysis (1 D and 2 D-NMR, MS, UV and IR). In vitro antimalarial activities of compounds 1−3, 5−14 and 16 were evaluated by β-hematin formation inhibition assay. Compared with the positive control chloroquine diphosphate, compounds 8, 11 and 16 exhibited strong antimalarial activity with the IC₅₀ values of 69.9, 33.2 and 75.4 µM, respectively. Compounds 1−3, 5−7 and 12 showed moderate antimalarial activities with IC₅₀ values ranging from 134.6 µM to 578.6 µM. [ABSTRACT FROM AUTHOR]