Total Phenolic and Flavonoid Test of Gleichenia linearis Leaf Extract as Antioxidant Using Microwave Assisted Extraction

Abstract

Exposure to ultraviolet (UV) rays from sunlight and radiation exposure from devices such as mobile phones, laptops, and others can be factors in the formation of free radicals. Excessive exposure to free radicals can cause oxidative stress, thus requiring defense mechanisms to prevent damage, one of which is the use of antioxidants. One source of antioxidants is the resam leaves. Resam leaf extract is known to contain flavonoids, alkaloids, tannins, saponins, steroids, and triterpenoids. This research aims to determine the influence of solvents and extraction time variations on the yield, total phenolic content, total flavonoid content, and antioxidant activity of resam leaf extract. Additionally, it aims to explore the relationship between the total phenolic content and total flavonoid content in relation to antioxidant activity. The testing comprises the determination of total phenolic content using the Folin-Ciocalteau method, total flavonoid content using the AlCl3 method, and antioxidant activity using the DPPH method. This research consists of 2 factors, namely the type of solvent and variations in extraction time. The solvents used are acetone and ethanol, while the extraction time durations are set at 5, 10, 15, and 30 minutes. The results of the analysis using ANOVA and post hoc test DMRT at the 5% significance level indicate that the type of solvent and extraction time variations used have a significant influence on the produced content. The highest yield, total phenolic content, total flavonoid content, and antioxidant activity in this research were obtained from ethanol as the solvent with a MAE time of 10 minutes, with respective values of 62.21%, 172.9 mg EAG/g, 110.60 mg EQ/g, and 24.12 µg/mL. The correlation testing showed that total phenolic content contributes 95.5%, while total flavonoid content contributes 56.5% to the generated antioxidant activity (IC50). Phenolic compounds are the most dominant compounds in the resam leaf extract, which play a role as antioxidants.