2.1. Preparation of concrete and absolute
Fresh flowers (500 g) were collected from the campus of the
Institute of Minerals and Materials Technology, Bhubaneswar
(21◦15E, 85◦15N), Orissa, India. The flowers were taken in an aspirator
bottle and contacted with distilled pentane (3 L) for 6 h. After
draining the extract, the raffinate flowers were again contacted
with fresh pentane (2.5 L) for 6 h followed by a quick wash with
pentane (1 L). Removal of pentane from the combined extracts in a
rotary evaporator under vacuo below 35 ◦C afforded a deep yellow
waxy residue, the so called concrete (7.9±0.2 g). Methanol (40 mL)
was added to the concrete, warmed to 50 ◦C for 5min to get a homogeneous
mixture, which was then refrigerated for 24 h at −15 ◦C,
when most of the waxes got precipitated. Filtration of the precipitate
through a sintered funnel followed by evaporation of methanol
below 40 ◦C afforded a light yellow partially dewaxed absolute.