Isolation and preliminary identification of active components from the leaves of leea indica (memali) using chromatographic technique / Fatin Azieyati Baharom

This study was conducted to focus on isolation of the Leea Indica leaves extract and to reveal the
antioxidant activity of L. indica. Different crude extract of L. Indica leaves extract have been
prepared based on different polarities of solvent which were non-polar, medium polar and polar.
Two crude extracts which was PE and DCM extract were proceed with the separation by using
thin layer chromatography to isolate the biological antioxidant active compound. Different solvent
system has been used for each extraction to obtain the best separation using thin layer
chromatography. Solvent system for petroleum ether extraction was 30:70 (v/v); PE:DCM, while
for DCM extraction was 96:4 (v/v); DCM: Methanol. Results showed that two separated
compounds from petroleum ether extract have been detected at retention factor of 0.14 and 0.85.
While for dichloromethane extract, one separated compound has been detected at retention factor
0.66. All three separated compounds were further analyzed for antioxidant screening with
preparative thin layer chromatography (p-TLC). The isolated compounds were analyzed using GCMS
and NMR for the preliminary structural identification. Three compounds from retention factor
0.14 and four compounds from retention factor 0.85 were positively detected as antioxidant
compounds in PE extract. While four compounds from retention factor 0.66 was detected as
antioxidant compound in DCM extract. The crude extract were proceed with the antioxidant
scavenging on DPPH radicals to assess the antioxidant activity of the crude extracts quantitatively.
The result revealed that MeOH extract as the strongest antioxidative extract followed by DCM and
PE extract. These quantitative antioxidant result established the antioxidant screening test from
dot blot method conducted previously. From the spectroscopic analysis, the antioxidative
compounds were suggested as Palmitic acid and Phthalic acid.