Determination of quercetin and rutin in the ethyl acetate fraction of etlingera elatior (Jack) R.M. Smith flower by reversed-phase liquid chromatography-mass spectroscopy

Abstract

Etlingera elatior (Jack) R.M. Smith (Zingiberaceae), has been reported to possessing various pharmacological activities. Secondary metabolites, e.g. kaempferol-3-O-glucoside, kaempferol, and quercetin have been identified within the flower. Our work determined the flavonol content, e.g. quercetin and rutin in particular, in the ethyl acetate fraction of E. elatior flower. Initially, the flowers were macerated with 70% ethanol at 29°C for 3x24 hours and filtered. The filtrates were collected and rotary-evaporated at 65 rpm (equals to 20440 relative centrifugal force) 45oC and the resulted E. elatior flower viscous extract was subjected to spectrophotometric identification and liquid-liquid partitioned using ethyl acetate. For identifying the flavonols, shift reagents (aluminium chloride and sodium acetate) were used. The ethyl acetate fraction was injected separately into an octadecylsilane column (1.7 µm; 2.1 x 100 mm) of liquid chromatography-mass spectroscopy. Mobile phase employed was a mixture of double-distilled water 99.9% and formic acid 0.1%; at a flow rate of 0.2 mL/minute; source temperature 100oC; desolvation temperature 350oC; cone gas flow 15 L of nitrogen/hour. Based on the retention profile and mass fragmentation, quercetin (retention time at 7.94 minutes; m/z 301.1423) and rutin (retention time at 5.97 minutes; m/z 609.2082) were detected in the ethyl acetate fraction with the former’s concentration 1.16% w/w and the latter’s 0.61% w/w.