Carotenoid composition and investigation of the antioxidant activity of Phormidium sp

Abstract

Microalgae metabolites are used for the health, feed additives, cosmetic industries, food and biodiesel production. Phormidium species have an important position in medical studies because they contain essential components. In this study, carotenoid profile and content were analyzed using HPLC method. Antioxidant activities for Phormidium sp. were determinated using DPPH and FRAP assays. BHT and ASC were used as control samples in antioxidant assays. The saponified extract to seperate a range of carotenoids, verified a suitable separation as inferred from the retention factor (k) among 0.54 - 3.83 and the separation factor (α) values more than 1. Resolution peaks appointed to carotenoids (16) for Phormidium sp. was attained within the period time of 45 min. In the specie, main carotenoids identified were cis-Lutein, All-trans-lutein, All-transzeaxanthin, 13-or 13’-β-carotene, All-trans-β-carotene and 9-or 9’-cis-β-carotene. Auroxanthin and cisneoxanthin were identified as epoxy-containing compounds. It is also understood that considering the DPPH assay, the extract of Phormidium sp. (IC50:127.6 mg/L) exhibited clearly low radical scavenging activity compared to the standards ASC (IC50: 0.02 mg/L) and BHT (IC50: 0.19 mg/L). In the FRAP antioxidant experiment, the mean ASC and BHT equivalent amounts were determined as 828.6 and 124.6 mg/L, respectively. Quantitatively, Phormidium sp. was predominated by cis-Lutein as a major constituent, being 41.35 % (3.02 mg/g) in total carotenoids (Tc). The antioxidant capacity of Phormidium sp. that considering the DPPH and FRAP were compared to control standards were showed considerably low effects.