AKTIVITAS ANTIOKSIDAN, TOTAL FENOL, TOTAL FLAVONOID, TOTAL KAROTENOID DARI BERBAGAI EKSTRAK BUAH PARIA (MOMORDICA CHARANTIA L.) DAN ISOLASI SENYAWA ANTIOKSIDAN

• Main Author: Raina Nasution, Halimah
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45488
• Institution: Institut Teknologi Bandung

Recently various degenerative diseases in people due to the oxidative damage in body’s cells which attacked by free radicals. Antioxidants are compound that can inhibit negative impact of free radicals in body. Antioxidant can inhibit the oxidation reaction by binding to free radicals. Bitter gourd (Momordica charantia L.) is a plant that can grow well in Indonesia and is believed to have many benefits. Based on several studies, bitter gourd fruit was known to have the effect of antioxidant. In addition, bitter gourd fruit have been used by people for treating various diseases. This research aimed to determine IC50 DPPH scavenging activity; determine total phenolic, total flavonoid, and total carotenoid of each extracts; analyze correlation of total phenolic, total flavonoid, and total carotenoid with IC50 DPPH scavenging activity; and isolation antioxidant compound of bitter gourd fruit extract. Crude drug of bitter gourd fruit was extracted by reflux apparatus using three solvents with increasing polarity, n-hexane, ethyl acetate and ethanol. Each extract was monitored by TLC. IC50 DPPH scavenging activity, total phenolic, total flavonoid, and total carotenoid of each extract was determined by ultraviolet-visible spectrophotometry and their correlation with IC50 DPPH scavenging activity by Pearson’s method. Ethyl acetate fruit extract was fractionated by vacuum liquid chromatography. Fraction 4 was subfractionated by column chromatography. Subfraction 28 was purified by washing and recrystallization method. Purity test was performed by TLC. Characterization of isolate was performed by using specific spray reagent, ultraviolet-visible spectrophotometry, two dimentional paper chromatography, and infrared spectrophotometry. Fruit crude drug of bitter gourd (Momordica charantia L.) contained alkaloid, flavonoid, phenolic, terpenoid, steroid/triterpenoid groups. Ethanol fruit extract of bitter gourd (density of its 1 % extract 0.75 g/mL) showed the highest antioxidant activities with the lowest value of IC50 DPPH scavenging activity (1.01 µg/mL). The highest total phenolic content, total flavonoid content, and total carotenoid content values were given by ethanol fruit extract (1.66 g GAE/100 g), ethyl acetate fruit extract (3.41 g QE/100 g), and n-hexane fruit extract (0.88 g BE/100 g), respectively. An antioxidant compound H was obtained from ethyl acetate fruit extract. Ethyl acetate and ethanol of bitter gourd fruit extracts were very strong antioxidant. Total phenolic content of bitter gourd fruit extracts showed negative and high correlation with IC50 DPPH scavenging activity (p<0.01). Phenolic compounds were the major contributor in bitter gourd fruit extract using DPPH assay. Antioxidant compound H was flavonol aglycone that had free -OH group in C-3 and expected had free -OH in ring A and or ring B.