Bioactive Phenolic Components from the Twigs of Atalantia buxifolia

Five new compounds named buxifoximes
A–C (1–3), buxifobenzoate
(4), and 7-O-(7′-peroxygeranyl)
coumarin (5), together
with 25 known compounds, were identified from the twigs of Atalantia buxifolia. Compounds 1–3 are unique secondary metabolites with the aldoxime functionality.
The structures of the isolates were determined on the basis of spectroscopic
data analyses, and the structure of 1 was confirmed by
an X-ray single-crystallographic analysis. With respect to bioactivity,
antidengue virus, anti-inflammatory, and cytotoxic activities of all
purified compounds were tested and evaluated. Compound 1 showed a significant anti-inflammatory effect by inhibiting superoxide
anion generation with an IC50 value of 4.8 ± 0.7 μM.
Among the acridone alkaloids, 5-hydroxy-N-methylseverifoline
(23) exhibited antidengue activity (IC50 =
5.3 ± 0.4 μM), and atalaphyllinine (20) demonstrated
cytotoxicity (IC50 = 6.5 ± 0.0 μM) against the
human liver cancer cell line, HepG2.