Identification of the polar constituents of Potamogeton species by HPLC-UV with post-column derivatization, HPLC-MSn and HPLC-NMR, and isolation of a new ent-labdane diglycoside - Waridel,P.; Wolfender,J.L.; Lachavanne,J.B.; Hostettmann,K. (Phytochemistry, 2004)