Response Surface Optimization of Extraction of Bioactive Constituents and Antioxidant Activity of Codiaeum variegatum Leaves
Adewole O.A1*, Adewole S.A2, Adaramola F.B3, Ukangwa N.A4, Akintunde
A.O5, Adeoye B.K6
1,4Department of Biochemistry, School of Basic Medical Sciences, Benjamin S. Carson (Snr.) College of Health and Medical Sciences, Babcock University, Ilishan-Remo, Nigeria.
2,5,Department of Agriculture and Industrial Technology, Babcock University, Ilishan-Remo.
3Department of Basic Sciences, Chemistry unit, Babcock University, Ilishan-Remo, Nigeria.
6Department of Nutrition and Dietetics, School of Basic Medical Sciences, Benjamin S. Carson (Snr.) College of Health and Medical Sciences, Babcock University, Ilishan-Remo.Corresponding author: Adewole, OA.; E-mail: adewoleo@babcock.edu.ng
ABSTRACT
The study aimed at optimizing the yield of extraction of flavonoids, phenolics, and DPPH (2, 2- diphenyl-1-picrylhydrazyl free radical scavenging activity) of Codiaeum variegatum leaves as a function of drying temperature (60-100 ºC) and ethanol concentration (50-80 v/v %) at constant drying time (80 minutes) using Response Surface Methodology (RSM). FT-IR (Fourier Transform Infrared Spectrophotometer) and proximate analyses of the leaves were also carried out using standard methods. From the results, linear term was significant for phenolic content, while quadratic term was significant for both flavonoid content and DPPH. The coefficient of determination (R2) for flavonoids, phenolics and DPPH were 0.9116,
0.9155, and 0.9612 respectively, showing a good fit model. The model terms were significant (P<0.05) for all the responses which provided its suitability for prediction purposes. The coefficients of variation (CV) were less than 10 %. Using desirability function, the optimum operating conditions to obtain higher extraction of flavonoids, phenolic and DPPH was found to be 72.72 °C and 75.61 v/v ethanol concentrations.The FT-IR results of the optimum processing conditions confirmed the presence of alkanes, alkenes, alcohol, amines, phenol, nitro compounds, and sulfoxides in the ethanol extracts of Codiaeum variegatum The study revealed that Codiaeum variegatum leaves have significant antioxidant potential and can therefore be used in
various medicinal applications. Keywords: RSM, flavonoid, phenolic, DPPH, optimization, FT-IR
