Five flavan dimers which showed lipase-inhibiting effects were isolated from fruits of Cassianomame (Leguminosae). Structures of two new compounds among them were determined to be (2S)-3′,4′,7-trihydroxyflavan-(4β → 8)-catechin and (2S)-3′,4′,7-trihydroxyflavan-(4α → 8)-catechin. Fouf flavan dimers structurally related to these two compounds were also synthesized for spectral comparison. Among 10