Phenolic profile of crude extracts derived from a red alga, Corallinaelongata Ellis and Solander

Abstract

In the present chapter, we have evaluated the total phenolic contents and antioxidantactivities of crude extracts from a red alga, Corallinaelongata. The phenolic compoundsin the extracts have been identified and quantified by reverse-phase high-performance liquid chromatography. Phloroglucinol was by far the predominant polyphenol found in the extracts, followed by catechin and epicatechin. Extracting solvents such as water, methanol and water/methanol (1/1) significantly affected the total phenolic amounts determined using the Folin-Ciocalteu method. The total phenolic contents ranged from 443.0 to 487.4 mg gallic acid equivalents per 100 g of dry plant material. The antioxidant efficiency of the extracts was evaluated by measuring the ability to scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl, finding that it ranged from 37.0 % to 66.4% (inhibition percentage). The high correlationbetween the yield of extraction, the total phenolic content and the radical scavenging activity was found, allowing us to conclude that phenolic constituents are mainly responsible for the observed antioxidant activity in the extracts. Because of the wide range of biological activities of phloroglucinol and the other polyphenols detected in the extracts, Corallinaelongate appears to have many potential industrial uses.