BACE1 Inhibitory Meroterpenoids from Aspergillus terreus

Sixteen 3,5-dimethylorsellinic acid–based
(DMOA-based) meroterpenoids,
including 10 new compounds, asperterpenes D–M (1–10), were obtained from Aspergillus
terreus. The structures and absolute configurations
of the new compounds were confirmed by extensive spectroscopy, single-crystal
X-ray diffraction analysis, and experimental electronic circular dichroism
(ECD) measurements. Compounds 2, 3, and 7 are the first 3,5-dimethylorsellinic acid-based meroterpenoids
possessing a unique cis-fused A/B ring system. These
new compounds were evaluated for their inhibitory activity against
β-site amyloid precursor protein-cleaving enzyme 1 (BACE1).
Compounds 2, 3, and 7, the
first 3,5-dimethylorsellinic acid-based meroterpenoids possessing cis-fused A/B rings, exhibited significant inhibitory activities
against BACE1 with IC50 values of 3.3, 5.9, and 31.7 μM,
respectively.