Materials and methods
Preparation of Red Kwao Krua crude extract
The Red Kwao Krua crude extract was modified from Chainarong et al.,
(2005). The tuber roots of Red Kwao Krua were cleaned, sliced and minced
into small pieces, dried at 45 ๐
C and grinded to fine powdered particles. The
powder was successively extracted using 75 % ethanol (1/4 w/v) in 250 ml
Eelenmeyer flasks then agitated for 48 hr using mechanical shaker at 250 rpm.
The total extracted volume was filtrated using filter cloth. The filtrate was kept
in deep freezer for one day before it was crystallized by Freeze-Dryer until