Six new resin derivatives from flowers of <i>Humulus lupulus</i> L. with anti-osteoporosis activities

Six new resin derivatives, humuluslupulus A-F (<b>1</b>-<b>6</b>), were isolated from flowers of <i>Humulus lupulus</i> L., together with thirteen known compounds (<b>7</b>-<b>19</b>). The structures of isolated compounds were identified by IR, HRESIMS, NMR analysis, and compared with data from the literature. The anti-osteoporosis activities of compounds <b>1</b>-<b>6</b> were evaluated by MTT assay and Western blot analysis in osteoblasts. Among them, compounds <b>2</b>, <b>3</b>, <b>4</b>, <b>6</b> could increase the osteoblastic proliferation. Compounds <b>1</b>-<b>6</b> could all improve the expressions of bone formation related proteins, including Runx2, OPN and BMP-2. It can be confirmed that new resin derivatives of hop have potentialities for promoting osteoblastic bone formation.