Characterization of gingerol analogues in supercritical carbon dioxide (SC CO2) extract of ginger (Zingiber officinale, R.,).

Organically grown ginger rhizome (Zingiber officinale Roscoe) SC CO2 extract obtained at 280 bar and 40 °C and its column chromatographic fractions are characterised for its composition. The components in the extract and fractions are identified by HPLC and LC based MS and are used as standard for the estimation of gingerol analogues in the extract. HPLC and mass analysis of the extracts confirmed the various forms of gingerol constituents [4]-, [6]-, [10]-gingerols and [6]-, [8]-, [10]-shogaols in ginger extracts. SC CO2 extract of organic ginger was found to show 6-gingerol around 25.97 % of total extract. The estimation of [6]-gingerol, [6]-shogaols, [4]gingerol, [10]-gingerol and 6-gingediol content of the SC CO2 purified ginger extract was found to be 75.92 ± 1.14, 1.25 ± 0.04, 4.54 ± 0.04, 13.15 ± 0.30 and 0.37 ± 0.00 % respectively. Antioxidant activity was measured by 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) and the assay have shown 652 ± 0.37 mg TE/g and 3.68 ± 0.18 mg TE/100 g respectively, are significantly higher results with SC CO2 organic ginger extract. Paradol analogues are not detected in this study. Small quantities of [4]-, [10]gingediol and [6]-gingediacetate are also found in ginger extract.