Abstract:
Six new
ent-abietane diterpenoids, abientaphlogatones A−F (
1 −
6 ), along with two undescribed
ent-abietane diterpenoid glucosides, abientaphlogasides A−B (
7 −
8 ) and four known analogs were isolated from the aerial parts of
Phlogacanthus curviflorus (
P. curviflorus). The structures of these compounds were determined using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), one-dimensional and two-dimensional nuclear magnetic resonance (NMR) spectroscopy, electronic circular dichroism (ECD) spectra, and quantum chemical calculations. Notably, compounds
5 and
6 represented the first reported instances of
ent-norabietane diterpenoids from the genus
Phlogacanthus. In the
β-hematin formation inhibition assay, compounds
2 ,
4 ,
7 −
10 , and
12 displayed antimalarial activity, with IC
50 values of 12.97−65.01 μmol·L
−1. Furthermore, compounds
4 ,
5 ,
8 , and
10 demonstrated neuroprotective activity in PC12 cell injury models induced by H
2O
2 and MPP
+.