Standardised herbal extract of chlorogenic acid from leaves of Etlingera elatior (Zingiberaceae)

Abstract

Background: Chlorogenic acid (CGA) or 5-caffeoylquinic acid, was found to be the dominant phenolic compound in leaves of Etlingera elatior (Zingiberaceae). The CGA content of E. elatior leaves was significantly higher than flowers of Lonicera japonica (honeysuckle), the commercial source. In this study, a protocol to produce a standardised herbal CGA extract from leaves of E. elatior using column chromatography was developed.

Materials and methods: Freeze-dried leaves of E. elatior were extracted with 30% ethanol, and sequentially fractionated using Diaion HP-20 and Sephadex LH-20.

Results: The CGA fractions, which yielded extracts of 10% and 40% w/w purity, possessed antioxidant, tyrosinase inhibition, and antibacterial properties. The entire fractionation process took only 6.5 hours, using gravity flow. From 50 g of leaves, the final yield of CGA extract was 0.2 g (0.4%). The CGA content of the standardised herbal extract from leaves of E. elatior (40%) is 1.6 times that of commercial extracts from honeysuckle flowers (25%).

Conclusion: With high CGA content, the standardised herbal extract has a great potential to be developed into functional food and other health products. Leaves of E. elatior, which currently have no economic value, could serve as an alternative source of CGA. Leaves are large, available in abundance, and harvesting is non-destructive to the plants.

Keywords: Chlorogenic acid; column chromatography; fractionation; standardised extract.

Figure 1

High-performance liquid chromatography chromatograms at 280 nm of Etlingera elatior leaves showing chlorogenic acid peaks at 5.74 minutes retention time of crude extract (a), Diaion HP-20 fractionated extract (b), and Sephadex LH-20 fractionated extract (c)