1Department of Natural Sciences, Faculty of Applied and Computer Sciences, Vaal University of Technology, Private Bag X021, Vanderbijlpark, 1900, Gauteng, South Africa
2Institute of Chemical and Biotechnology, Faculty of Applied and Computer Sciences, Vaal University of Technology, Private Bag X021, Vanderbijlpark, 1900, Gauteng, South Africa
3Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Florida Campus, Johannesburg, South Africa
*Corresponding author e-mail: pillam@unisa.ac.za
Online Published on 12 February, 2026.
Cotyledon orbiculata L. is a South African medicinal plant used to treat a variety of health conditions. This study aimed to use the maceration technique to optimize the methanolic extraction of phytochemicals from the leaves of C. orbiculata. A 23 full factorial design was used to assess the effect of three variables (solvent concentration, temperature and extraction time) on extraction yield. Their influences were assessed by multiple regression analysis, and a mathematical model with numerical optimal values for each variable was developed. The study also evaluated the extraction conditions in terms of total phenolic, tannin and flavonoid content. The optimum extraction conditions were 50% methanol, 25°C, and 168 h, which resulted in an extraction yield of 33.6%. The analysis of variance analysis showed that solvent concentration was the most significant variable in the extraction of total phenolics (TP) (p < 0.0001) and total flavonoids (TF) (p < 0.0001), whereas the interaction between the solvent concentration and temperature (p < 0.0001) affected the extraction of total tannins (TT) the most.
Cotyledon orbiculata, Extraction yield, 23 factorial design, Phytochemical analysis
