Qualitative and quantitative analysis of biologically active principles ...

Extraction of baicalein from Oroxylum indicum and related
species
The roots of the plants were dried and powdered. Approximately 15
g of sample was extracted with 300 ml ethyl acetate with a soxhlet
extraction system. The solvent of extract was evaporated in a rotary
evaporator (Buchi) at 60 0 C. The ethyl acetate extract was again
fractionated through medium pressure liquid silica gel (60 meshes)
column chromatography system with successive elution with
hexane, hexane and ethyl acetate (1:1) and ethyl acetate. The
collected elutes were subjected to Thin Layer Chromatography (TLC)
with various solvent system and the baicalein glycosides content
was detected by spraying Benedict’s Reagent and by
spectrophotometry.
Solvent system used for chromatographic separation
1. Chloroform: acetic acid (9:1)
2. Ethyl acetate: benzene (9:11)
3. Benzene: ethyl acetate (19:1)
4. Petroleum benzene: acetone: methanol (4:4:2)
5. Acetone: methanol: water (4:3:3)
6. Petroleum benzene: acetone: methanol: water (2:4:3:1)
Column chromatography
Approximately 1 ml ethyl acetate was added in the sample, mixed
and loaded on silica gel column (15 cm length) and eluted
successively with 50­74 ml each n­hexane, n­hexane & ethyl
acetate (3:1), n­hexane & ethyl acetate (2:2), n­hexane & ethyl
acetate (1:3) and ethyl acetate. Elutes 50 ml of each extract was
collected and evaporated to dryness.
11