A novel diarylheptanoid-flavonol dimer (1), named officinin C, was isolated from the rhizomes of Alpinia officinarum Hance. The structure elucidation was accomplished by HR-ESI-MS and 1D and 2D NMR methods. Its xanthine oxidase inhibitory activity was tested along with officinin A (2). At the concentration of 25 mu M, compounds 1 and 2 can reach 57 ...