Optimized Synthesis and Antioxidant Activity of Anthocyanins Delphinidin-3- O -glucoside and Petunidin-3- O -glucoside.

The chemical synthesis of anthocyanins, especially delphinidin-3- O -glucoside and petunidin-3- O -glucoside, is preferable due to the challenges associated with their extraction and purification. However, the reported methods for the synthesis are scarce and intricate. Our research focused on exploring a one-step ester-to-ketone process and optimizing the ring formation reaction, simplifying and improving the overall synthesis strategy. Through these attempts, we were able to achieve higher production yields of delphinidin-3- O -glucoside and petunidin-3- O -glucoside. According to the results of DPPH, ABTS, and FRAP, the antioxidant activity of anthocyanins was increased with the number of B ring hydroxyl substituent. Additionally, both delphinidin-3- O -glucoside and petunidin-3- O -glucoside exhibited no cytotoxicity effects, highlighting their potential for safe application in various fields.