Plant part such asleaves, stems, branches, twigs, and roots possess different therapeutic functions and activities. Besides that, development stages, either young or mature could cause several effects to the bioactive compounds as well as the antioxidant properties of the plant. Thus, an experiment was conducted using a nested design, with three replications, involved young and mature development stages and three different plant parts, namely the leaves, stems, and aerial parts. The main objective of this experiment was to study and compare the phytochemical properties from different parts of A. paniculata plant when harvested at young and mature development stages. The bioactive compounds were A. paniculata analysed by using high-performance liquid chromatography (HPLC) and antioxidant properties were determined using a spectrophotometer. According to the findings of this study, the extraction yield, andrographolide, neoandrographolide, and 14-deoxy-11, 12-didehydroandrographolide contents were significantly affected by the development stage of the plant. Most of the antioxidant properties were at their highest during the young development stage, whereas the ferric reducing ability of plasma , and reducing power are the highest when the plants harvested at the mature development stage. No significant differences were recorded among the total phenolic content and hydrogen peroxide scavenging activity when the plants were harvested at both young and mature developmental stages. The leaves possess the richest phytochemical properties among all the anatomical plant parts analysed at the young development stage and then followed by the aerial parts, while the lowest contents of these beneficial health substances were found in the stems.

Keywords: andrographolide, correlation, extraction yield, flavonoids