Withaphysalins from Medicinal and Edible Physalis minima and Their Anti-inflammatory Activities

Physalis minima is a medicinal and
edible plant in China. In this study, 22 new withaphysalins, including
a novel 1(10 → 6)abeo-14β-hydroxy one
(1) and other 15 unusual 14β-hydroxy ones (3–4, 6–17, 19), were
isolated from the whole herbs of P. minima together with two known analogues (23–24). Their structures were established
by extensive analysis of high-resolution electrospray ionization mass
spectrometry, IR, and 1D and 2D NMR spectroscopic data. Their absolute
configurations were determined by electronic circular dichroism (ECD)
spectra and single-crystal X-ray crystallographic analyses, together
with DFT NMR calculations. All isolated compounds were evaluated for
their anti-inflammatory activity via measuring the colorimetric reporter
of the secreted embryonic alkaline phosphatase gene driven by an IFN-β
minimal promoter fused to five copies of the NF-κB consensus
transcriptional response element and three copies of the c-Rel binding
site in LPS-stimulated human THP1-Dual cells. Compounds 2, 5, 6, 9, 10, 11, and 20 showed significant anti-inflammatory
effects with IC50 values in the range of 3.01–13.39
μM. Among them, compounds 2 and 10 showed better anti-inflammatory effects to inhibit the secretion
of IL-6, IL-1β, and TNF-α in LPS-stimulated THP1-Dual
cells.