Determination of Total Flavonoid Content from Extract and Fractions of Mangrove Leaves (Rhizopora mucronata)

Indonesia is an archipelagic country with a very wide coastal area. Lombok Island has a coastal area with quite extensive mangrove forest areas. Rhizopora mucronata was the most dominant species found in the region. The Rhizopora mucronata species was a plant from the Rhizoporaceae family reported to have antibacterial, antifungal, and antioxidant activity. These biological activities were caused by the presence of secondary metabolite compounds in R. mucronata, one of which is flavonoids. Research regarding the flavonoid content of R. mucronata leaves has not been explored. Therefore, the study aimed to determine the total flavonoid content in extracts and fractions of R. mucronata leaves using the spectrophotometric UV-Vis method. R. mucronata mangrove leaves simplicia were extracted using the sonication method using 96% ethanol solvent, then fractionated using the liquid-liquid extraction method with n-hexane, ethyl acetate, and water. The percentage yield of 96% ethanol extract, water fraction, ethyl acetate fraction, and n-hexane fraction respectively were 42.33%; 43.147%; 40.49%; 9.74%; and 32.49%. The TLC test showed the presence of flavonoid compounds detected in the extract and fractions which were marked with blue spots. The total flavonoid contents in the 96% ethanol extract, water fraction, ethyl acetate fraction, and n-hexane fraction were respectively (12,980; 14,160; 23,880; and 25,350) mg Quercetin equivalent/gram sample (mg QE/ g). The total flavonoid content of the extract and fractions of R. mucronata leaves were analyzed using the One-way ANOVA test method. The total flavonoid content in the n-hexane fraction and ethyl acetate fraction was significantly higher than the 96% ethanol extract and water fraction. The total flavonoid content of R. mucronata leaves was relatively high, which contributes to several of its biological activities.