Comparison of different extraction methods for the extraction of bioactive compounds from Chromolaena odorata

Chromolaena odorata is believed to have great potential in the pharmaceutical industry due to the presence of phytochemical components such as alkaloids, flavonoids, and phenolics. In this study, four extraction methods which are conventional extraction, enzyme-assisted extraction (EAE), ultrasound-assisted extraction (UAE) and ultrasound-assisted enzymatic extraction (UAEE) procedure were performed to extract quercetin, berberine, gallic acid and tannic acid from Chromolaena odorata. The effect of different extraction methods was observed in the extraction yield involving three important parameters which were cellulase concentration, extraction time and duty cycle. The analysis of bioactive compounds was done using High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). In this study, the interaction effect between the extraction process parameters (i.e cellulase concentration, extraction time and duty cycle) was investigated by employing Response Surface Methodology (RSM). Phytochemical screening result showed the presence of the bioactive compounds. Next, it was found that the quercetin and tannic acid were suitable with UAEE while berberine and gallic acid were suitable with UAE. The optimum extraction conditions were as follows: 1) 4% cellulase concentration, 40 minutes sonication time, 75% duty cycles for quercetin and tannic acid, 2) 40 minutes sonication time, 75% duty cycles for berberine, and 3) 40 minutes sonication time, 90% duty cycles for gallic acid. The optimum yield obtained for quercetin, berberine, gallic acid, and tannic acid was 1.0687±0.0112%, 2.7228±0.0707%, 2.8130±0.0123%, and 1.7982±0.0711%, respectively. The FESEM image of the UAE and UAEE sample shows that the plant's cell wall was greatly ruptured, and more void was produced compared to other methods. Quadratic model found as the best-fit model for the extraction yield of quercetin and tannic acid with the value of R² was 0.8799 and 0.9240, respectively. From the model, the interaction effect of AB, AC and BC was found to be significant towards the extraction yield of quercetin and tannic acid. Compared with the conventional and EAE methods, the UAE and UAEE methods were superior in terms of percentage yield and shorter extraction time. The result shows that UAE and UAEE were effective methods to extract bioactive compounds such as quercetin, berberine, gallic acid and tannic acid from Chromolaena odorata plant.