Blepharocalyxins C–E: three novel antiproliferative diarylheptanoids from the seeds of Alpinia blepharocalyx

Three novel diarylheptanoids, blepharocalyxins C–E (1–3), were isolated from an EtOH extract of seeds of Alpinia blepharocalyx, and their structures have been elucidated by the use of spectroscopic techniques. Blepharocalyxins D (2) and E (3) exhibited potent antiproliferative activity against murine colon 26-L5 carcinoma and human HT-1080 fibrosarcoma cells, with ED50 values of 3.61 and 9.02 μM, respectively.