Studies on green corrosion inhibitors is one of the emerging research field in recent days. From our lab, methanolic extract of 2 different Aquilaria species (Aquilaria malaccensis & Aquilaria subintegra) leaf was successfully reported as a green corrosion inhibitor for mild steel in 1 M HCl medium and their corresponding active constituents namely mangiferin and adenosine were identified as well. Current manuscript emphasises, in-depth analysis on Aquilaria leaf extract and test solution before and after the corrosion measurements. The ideology was proceeded via high-performance liquid chromatography (HPLC) analysis over corrosion inhibitor as well as all the tested solutions, which is for quantifying the amount of mangiferin and adenosine in the leaf extracts. This (HPLC) method was successfully validated for the quantification of active ingredients consumed during adsorption of Aquilaria's phytoconstituents and the results obtained were correlated with corrosion inhibition performance. © 2019 Elsevier B.V.