New geranylated flavanones from the fruits of Paulownia catalpifolia Gong Tong with their anti-proliferative activity on lung cancer cells A549.

Three new geranylated flavanones, named as paucatalinone A (1), B (2), and isopaucatalinone B (3), were isolated from the fruits of Paulownia catalpifolia Gong Tong (Scrophulariaceae). Their structures were well determined by means of IR, MS, 1D and 2D NMR, and CD techniques. Paucatalinone A (1) is the first sample as a dimeric geranylated flavanone derivative isolated from natural products. Paucatalinone A (1) displayed good antiproliferative effects on human lung cancer cells A549 and resulted in a clear increase of the percentage of cells in G1 phase and a decrease in the percentage of cells in S and G2/M phases in comparison with control cells.