Biopigment of the Tropical Marine Microalgae Porphyridium cruentum as an Antioxidant

• Main Author: Rachmawati, Mulki
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/37955
• Institution: Institut Teknologi Bandung

Antioxidants are species that can reduce the activity of free radicals. The antioxidant activity of Porphyridium cruentum biopigments remains unknown. The present study aimed to determine the antioxidant activity of P. cruentum biopigments against radicals DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2-Azino-bis(3-etilbenzotiazolin-6- sulfonic acid). The research methods included cultivation of P.cruentum cells in Walne medium for 9 d, extraction of nonpolar biopigments with acetone and polar biopigments with 0.1 M phosphate buffer pH 5.5 and 7.1, purification of the biopigments, and determination of antioxidant activity of the biopigments. The results showed that the density of wet biomass of P.cruentum was 3.14 ± 1.29 g/L. Nonpolar biopigments of P. cruentum were identified as ?-carotene, pheophytin a, chlorophyll a, and chlorophyll c, meanwhile polar biopigment was phycoerythrin. Crude extract of P. cruentum (5 g wet biomass/80 mL acetone) contained 5.58 µg/mL chlorophyll and 10.13 µg/mL carotenoid compounds. Crude extract of P. cruentum (2 g wet biomass/28 mL phosohate buffer) contained 266.04 µg/mL (pH 7.1) and 76.68 µg/mL (pH 5.5) phycobilin. The qualitative test results showed that ?-carotene, chlorophyll a and phycobilin of P. cruentum exhibited antioxidant activity. The IC50 value of ?-carotene against DPPH radical and chlorophyll a against ABTS was 113.05 and 91.63 ppm, respectively.