Material and Method
Plant materials
Fresh calyces of Hibiscus sabdariffa L.
(Roselle) were obtained from Amphur Jana, Songkhla
province, Thailand in April 2004. The plant material
was authenticated and a voucher specimen (No. SKP
1090819) has been deposited in the herbarium of the
Faculty of Pharmaceutical Sciences, Prince of Songkla
University, Hat Yai, Songkhla, Thailand.