Affiliation:
1. Institute of Bioproduct Development, School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Johor, Malaysia
Abstract
Background:
Orthosiphon aristatus is a popular medicinal herb because of its pharmacological
significance. Therefore, a lot of products formulated from the plant extract are available in
the market. However, many phytochemicals in the plant extract are still remained to be unknown.
Objective:
The objective of this study was to profile phytochemicals from the plant extracts prepared
using water and ethanol in a reflux system for comparison.
Method:
The commonly used analytical techniques of acetone precipitation (gravimetry) and vanillin
assay (colorimetry) were used to estimate total saponin in the plant extracts. The low dielectric
constant of acetone (20.7) was used to precipitate saponins. The phytochemicals in the plant extracts
and their respective precipitates were then identified by LC-MS/MS.
Results:
Higher amount of precipitate was formed from ethanol extract than water extract. The results
of LC-MS/MS revealed that not only saponins, but other phytochemicals, such as phenolic acids,
flavonoids, terpenoids and aliphatic acids were also detected in the precipitates. In particular,
ethanol extract and its precipitate were found to have higher flavonoids. Acetone precipitation could
significantly increase the content of sagerinic acid and rosmarinic acid, as well as polyhydroxylated
and polymethoxylated flavones from the water extract.
Conclusion:
Acetone precipitation is not specific for saponin, but also any phytochemicals which
have lower solubility due to the lack of hydrogen bonding in high dipole moment medium of acetone.
Gravimetric acetone precipitation had successfully profiled the phytochemicals in both highly
complex water and ethanol based crude extracts.
Publisher
Bentham Science Publishers Ltd.
Subject
Complementary and alternative medicine,Drug Discovery