Synthesis of antioxidant agents based on improvement of hydroxyl groups prepared from lawsone compounds

Phenolic compounds are important group of plant-based biologically active compounds that have a particularly antioxidant capacity, which is closely related to the health effects. Based on the beneficial effect of phenolic compounds in humans, it is appropriate to perform the preparation of antioxidant agents by focusing on the structure-activity relationship study based on hydroxyl groups. This research aims to enrich the hydroxyl groups preparation from naphthoquinone (lawsone) to enhance the power of antioxidant activity. The synthesis of naphthoquinones dimeric derivative compounds was conducted by varying aromatic aldehydes: lawsone (1: 2 mmol) using l-proline as the catalyst. The synthesized products were confirmed for its absorbance, vibration of the functional group, and molecular weight using UV-Vis, FTIR, and GC-MS. The results of the analysis showed three lawsone derivatives named as: 2,2'- (Phenylmethylene)bis(3-hydroxy-1,4-naphthoquinone); 2,2'-[(4-hydroxy-phenyl)-methyl]bis(3-hydroxy-1,4-naphtho quino- ne); and 2,2'-(3-phenyl-allyl)bis(3-hydroxy-1,4-naphthoquinone) as compound 1, 2, and 3, respectively. The compound 2 has the best antioxidant scavenging activity among the two other compounds. The percent inhibition of compounds 1, 2, and 3 has an IC₅₀ amount of 1452.90; 664.25; and 1504.03, respectively.