Satyajit Roy Rony, Md. Anwar Hossain, Shammi Akhter, Md. Hossain Sohrab, Farhana Afroz, Mst. Nadira Begum, Optimization for the Extraction of Antioxidant Compounds from Justicia adhatoda Leaves Using Response Surface Methodology, Research Journal of Pharmacology, Volume 14,Issue 4, 2020, Pages 49-57, ISSN 1815-9362, rjp.2020.49.57, (https://makhillpublications.co/view-article.php?doi=rjp.2020.49.57) Abstract:

In this study, the response surface methodology (RSM) constructed on a central composite design (CRD), was applied to control optimization for the extraction  of  antioxidant  compounds  from Justicia  adhatoda leaves. Two extraction parameters were assessed at high and low levels (13  experimental  designs): Methanol (30-80%) and the extraction time (4-6 days). Using RSM, a quadratic polynomial equation was used by multiple regression analysis to predict the optimization of the extraction process. Analysis of variance (ANOVA) was applied and the significant effect of the factors and their interactions were tested at a 95% confidence interval. The antioxidant extract (AE) yield was significantly influenced by solvent composition and time. The maximum AE was obtained at methanol (55%) and time (6.41 days) 6.48 g/100 g at run 13. The minimum radical scavenging activity (IC50) values were obtained at (methanol/45% water and extraction time 3.59 days) 1.28 μg mL‾1. It was found that the antioxidant extract yields and radical scavenging  activity  (IC50) of Justicia adhatoda leaves could be optimized at 3.10 g/100 g and 17.10 μg mL‾1 at the optimum condition at a time of 6.06 days and solvent concentration of 69.24%. The results of the antioxidant properties of Justicia adhatoda leaves by using response surface methodology (RSM) confirm this technique's usefulness.

Keywords: Central composite design; experimental designs; quadratic polynomial equation; analysis of variance; antioxidant extract; radical scavenging activity