solation of Antioxidant Compound from Papaya Seeds (Carica papaya L.)

• Main Author: Krishnamoorthy, Rachna
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45065
• Institution: Institut Teknologi Bandung

Antioxidant is a compound with its ability to trap or to neutralize free radicals. One of the antioxidant sources is papaya fruit, whereas its seeds as a waste were traditionally used for antidiabetics remedies. The aim of this study was to isolate and characterize antioxidant compound from papaya seeds extract under optimized conditions. The crude drug was extracted by the maceration method using solvents of increasing polarity (n-hexane, ethyl acetate, ethanol). Every extraction with each type of solvent was carried out three times in order to obtain the maximum yield. The rendemen yield for the n-hexane extract is 20.02 %, yield for the ethyl acetate extract is 8.01 % and the yield for the ethanol redistillate extract is 2.46 %. Antioxidant activity was then assessed quantitatively by the determination of IC50 value. The reference standard used was ascorbic acid with value IC50 7.24 µg/ml. As for the determination of IC50 for the extracts, the n-hexane extract had the lowest value of IC50 scavenging activity of DPPH which was 350 µg/ml followed with the ethyl acetate extract which was 654.13 µg/ml and finally the ethanol extract with IC50 831.76 µg/ml. Hence, the n-hexane extract clearly had the strongest antioxidant activity and continued to further process. The n-hexane extract was then fractionated by the vacuum liquid chromatography (VLC) using gradient eluent composition from n-hexane, ethyl acetate and ethanol resulting in 21 fractions. The fractions were monitored using the Thin Layer Chromatography method, observed under visible light, under UV ?254 nm, under UV ?366 nm, as well as sprayed with H2SO4 10% in methanol and DPPH 0.2% in methanol. Fraction 4 was chosen to continue subfractionation based on the chromatogram pattern. Subfractionation in this case was an approach aimed to separate as well as purify the target compounds. The non-polar fraction 4 was then subfractionated by the classical column chromatography (CCC) using isocratic elution with the eluents composition of n-hexane : ethyl acetate (9.5 : 0.5). Each subfraction was collected by volume of 5ml which produced total of 101 subfractions. Based on the chromatogram pattern from the subfraction monitoring, subfraction 27 looks pure with only one spot that matches the Rf of target isolate which is 0.6230. Thus, the subfraction 27 was chosen to carry out the next step which is purity test. The purity test was observed by the one-dimension and two-dimension thin layer chromatography. The pure isolate was then tested for its antioxidant activity. The value of IC50 scavenging activity of DPPH was 290 µg/ml. Hence, the isolate had stronger antioxidant activity compared to the n-hexane extract. Characterization using specific spray reagents showed positive presence for alkaloid, flavonoid, and phenol. The compound isolated was presumed to be alkaloid substituted with phenol structure.