Three major compounds showing significant antioxidative, α-glucosidase inhibition, and antiglycation activities in Robusta coffee brew

Abstract

ABSTRACT The objective of this study was to separate and identify the bioactive compounds in the Robusta coffee brew. The coffee brew showed significant potential for antioxidant, anti-α-glucosidase, and antiglycation activities, as well as effectiveness in managing type 2 diabetes mellitus (T2DM). Indonesian Lampung Robusta coffee beans were roasted at the first crack level, followed by grinding and brewing. The bioactive compounds of the coffee brew were separated and isolated using the bioassay-guided approach. The isolated compounds were further identified using NMR and LC-MS. The highly bioactive compounds in the coffee brew were highly polar and present in large amounts. Furthermore, the three major compounds with the most potent bioactivities were identified as 5-O-caffeoylquinic acid (5-CQA), 4-O-caffeoylquinic acid (4-CQA), and 3-O-caffeoylquinic acid (3-CQA). This study also demonstrated that caffeine had little influence on the abovementioned bioactivities. These results are important for the isolation of bioactive compounds in coffee brew for further applications of coffee-based functional foods to overcome T2DM.