Thin Layer chromatography analysis of antioxidant
constituents
The antioxidant constituents were analysed using thin
layer chromatography (TLC) followed by DPPH (2, 2-
Diphenyl-1-picrylhydrazyl) technique24. About 100 μg
of extract of seagrass species was loaded on TLC
plates (Merck, 10 x 10 cm2). The plates were
developed in 10% chloroform in methanol and
Methanol:Chloroform:Hexane(7:2:1) to separate the
various constituents of the extracts. The developed
plates were air dried and observed under visible and
UV light (240 and 300 nm). Various separated spots
were noted as their Rf values. After this examination,
0.05% of DPPH solution in methanol was sprayed on
the surface of developed TLC plates and incubated for
10 min at room temperature. The active antioxidant
seagrass constituents were detected as yellowish white
spots produced by bleaching of DPPH by resolved
bands on the TLC plates. After visual comparison with
the intensity of bleached colour of the TLC band of
positive standard, the antioxidant strengths of seagrass
constituents were tentatively categorized as strong and
week activities. All detected active antioxidant
constituents were noted according to their Rf values.
Ascorbic acid and Gallic acid were used as positive
control, and blank TLC plate was taken as negative
control.