Spectroscopic studies on the antioxidant and anti-tyrosinase activities of anthraquinone derivatives

Objectives: Anthraquinones (9,10-dioxoantracenes) with a wide range of applications constitute an important class of natural and synthetic compounds. Moreover, there is an increasing interest in developing new anthraquinone derivatives with biological activity. These findings suggested that due to the qualities of anthraquinone, it may be employed in the pharmaceutical and food industries. Methods: The synthesis of anthraquinone derivatives (compound 1 and 2) was performed using the Mannich base reaction, and the compounds were characterised via FT-IR, 1H and 13C NMR spectra, and mass spectral analysis. Through the use of spectroscopic analytical techniques, the in vitro antioxidant capacity of anthraquinone was examined. These techniques included DPPH free radical scavenging, hydrogen peroxide (H2O2) scavenging, ABTS center dot+ scavenging activity, ferrous ion (Fe2+). Results: At a concentration of 100 mu g/mL, compound 2 shows that 65.2 % inhibited to DPPH assays compared with butylated hydroxyl toluene (BHT) at 45.7 % activity. Moreover, compound 2 shows that more potential of activity against DPPH, ABTS center dot+, hydrogen peroxide, ferric ion (Fe3+), and ferrous ion (Fe2+) chelating, reducing, and antioxidant properties when compared with compound 1 and standard BHT. The compounds 1 and 2 where checked for tyrosinase activity, the compound 2 shows that significant of activity compared with compound 1 and standard kojic acid. Conclusion: Kinetics studies were analysed compounds 1 and 2 through all antioxidant assays and activity of tyrosinase inhibition. The compound 2 was highly active against all the activities. Based on the aforementioned findings, it can be used to maintain nutritional quality, extend the shelf life of food and medicine, delay the development of hazardous oxidation products, and minimise or stop the oxidation of lipids in dietary items.