Biological and chemical guided isolation of 3,4-secograyanane diterpenoids from the roots of Pieris formosa

Abstract

Seventeen new 3,4-secograyanoids (1–17), together with seven known compounds (18–24), were isolated from the roots of Pieris formosa. Their structures with absolute configurations were characterized by a series of spectroscopic methods and X-ray diffraction. Compounds 1, 2, 4–8, 10–13, and 16–24 exhibited significant analgesic activity at 5.0 mg kg⁻¹ (ip) compared to vehicle-injected mice (p < 0.05). In particular, compounds 16 and 17 showed highly potent activities with inhibition rates of 63.5% and 69.9%, respectively.