Comparison on Total Phenolics and Flavonoids and Antioxidant Activities of Methanol Extract of Horseshoe Crab (Tachypleus gigas) Eggs

The marine environment can be a source of abundant bioactive compounds. One of the horseshoe crab species scattered in Indonesian sea waters is Tachypleus gigas. It was reported that the eggs of T. gigas contained flavonoids, saponins, alkaloids, and steroids. Flavonoids are polyphenol compounds that have the ability as natural antioxidants. In this study, total phenolics, flavonoids, and antioxidant activity tests were carried out on the methanol extract of T. gigas eggs. The total phenolics content used the Folin Ciocalteu method, the total flavonoids used the aluminum chloride colorimetric method, and the antioxidant activity test used the FRAP and DPPH methods. The test results showed that the total phenolics and flavonoids were 0.53506 ± 0.001335 mg GAE/g extract and 0.52067 ± 0.000731 mg QE/g extract, respectively. Meanwhile, the results of the antioxidant activity test with the FRAP method obtained a total antioxidant capacity of 29.85 μmol in the medium category and antioxidant activity with the DPPH method obtained an IC50 value of 597.0397 μg/mL in the very weak category.