Sirikul Thummajitsakul and Kun Silprasit

DOI: 10.14456/sjst-psu.2021.21

pp. 160 - 168

Abstract

The result showed total phenolic content, total flavonoid content and radical scavenging activity in ethanol extracts
higher than oil extracts and massage products of Boesenbergia rotunda, Alpinia conchigera, Alpinia galangal, and Alpinia siamensis. Fourier-transform infrared spectroscopy of the ethanol extracts provided specific peaks in a range of 4,000 to 550 cm^-1. Chemical differentiation between Alpinia sp. and Boesenbergia sp. was indicated by main peaks that corresponded to aromatic
and N-H in amino acids, O-H in phenyl group, and C-O in carbohydrates and glycoprotein. Chemical differentiation among three
Alpinia species were wavenumber ranges of C-O in acid or ester, C-O in carbohydrates and glycoprotein, and C-H in
isoprenoids. The cluster and PCA analysis showed good separation of chemical compositions and antioxidant activity among the
ethanol extract, massage solution and oil extract. Additionally, Ni, and Cd were found in all massage products, especially Ni above its maximum permission level.