Supercritical Fluid Extraction of Phytoconstituents fluid Extraction of Phytoconstituents from Buchanania Lanzan Spreng and their Identification by Hyphenated Technique

Abstract

Since ancient times, plants have been used as medicine. Different extraction techniques are used for the extraction of phytoconstituents from plants. The present study involves the extraction of flavonoids from the seeds of Buchanania lanzan Spreng. by conventional extraction techniques and supercritical fluid extraction. The supercritical fluid extraction parameters were optimized at a temperature of 35 °C, pressure of 19.61 MPa, co solvent percentage (ethanol) of 5.66 % and at a carbon dioxide flow rate of 3.0 mL/min. The extraction yield of supercritical fluid extract was 20.50 ± 0.47 % and for cold macerated and soxhlet extracts were 6.07 ± 0.10 % and 2.04 ± 0.10 % respectively. Qualitative tests and thin layer chromatography of all the three extracts showed the presence of phenolic and flavonoid compounds. Further, quantitative estimation of phenols and flavonoids showed that the supercritical fluid extract had higher flavonoid and phenolic content compared to the other two extracts. Further, the in vitro antioxidant activity of the extracts was determined by DPPH free radical scavenging activity, ABTS method, ferric reducing ability and total antioxidant capacity assays. The antioxidant activity of the supercritical fluid extract was high as compared to cold macerated and soxhlet extract. Isolation of phyotoconstituents responsible for the high antioxidant activity of the supercritical fluid extract was done using preparative thin layer chromatography using the optimized solvent system of thin layer chromatography. Four fractions were isolated from the supercritical fluid extract. The isolated fractions were analysed by high performance liquid chromatography using Inertsil ODS 3V, 250 x 4.6 mm, 5 and#956; column and the mobile phase was 0.1 % formic acid in water: Acetonitrile in the ratio of 70: 30 at a flow rate of 0.5 mL/min. Out of the four fractions isolated, fraction 2 and fraction 3 did not show any UV Visible absorbance. Identification of the fractions was done by LC MS/MS analysis.