Homoisoflavanones, Alkaloid, and Norsesquiterpenoid from Polygonatum cyrtonema and Their Immunomodulatory Effects

A chemical investigation of the rhizome of cultivated P. cyrtonema yielded six previously undescribed compoundsone norsesquiterpenoid (<b>1</b>), one pyridine alkaloid (<b>2</b>), and four homoisoflavanones (<b>3a</b>, <b>4a</b>, <b>5a</b>, <b>6a</b>)together with 9 known compounds (<b>3b</b>, <b>4b</b>, <b>5b</b>, <b>6b</b>, <b>7</b>–<b>11</b>).

Their structures were established on the basis of extensive spectroscopic data and quantum chemical calculations, including NMR, HRESIMS, and calculated ECD. The enantiomers of the C-6-methylated homoisoflavanones (<b>3a</b>/<b>3b</b>–<b>6a</b>/<b>6b</b>) were successfully isolated via chiral HPLC. All compounds were evaluated for their immunomodulatory activity using RAW264.7 macrophages at concentrations ranging from 3.125 to 25 μM. Only compounds <b>8</b> and <b>11</b> enhanced the proliferation and phagocytosis of RAW264.7 macrophages and upregulated the secretion of NO, IL-6, and TNF-α.