ISOLATION OF ANTIOXIDANT COMPOUNDS FROM N-HEXANE EXTRACT OF ITCH LEAVES (LAPORTEA DECUMANA (ROXB.) WEDD.)

• Main Author: Laureent, Felicia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/82551
• Institution: Institut Teknologi Bandung

Free radicals are compounds that have one or more unpaired electrons, so they tend to be highly reactive and capable of damaging molecules in the human body. The accumulation of free radicals can lead to complications of health problems, such as premature aging and various degenerative diseases. Antioxidants are compounds that are able to protect body cells from damage caused by free radicals by stopping harmful chain reactions that can damage important biological molecules. Itchy leaf plant (Laportea decumana (Roxb.) Wedd.) is one of the plants known to have potential as an antioxidant producer. This study aims to determine the antioxidant activity of itchy leaf extract by 2,2-diphenyl-1-picrylhydrazyl (DPPH) silencing method and isolate and characterize compounds that have antioxidant activity in itchy leaves. Simplisia of itchy leaves were extracted by maceration method using solvents with graded polarity (n-hexane, ethyl acetate, and ethanol). Determination of antioxidant activity was carried out using the DPPH silencing method at a wavelength of 517 nm with ascorbic acid as a positive control. The results of qualitative and quantitative tests of DPPH inhibition showed that antioxidant active compounds were present in the n-hexane extract and ethanol extract. The n-hexane extract was fractionated by vacuum liquid chromatography (VLC) method, followed by subfractionation by classical column chromatography (CCC) method. Subfractions containing the target compounds were then continued to subfractionation stage 2 by Medium Pressure Liquid Chromatography (MPLC) method. The results were purified by preparative thin layer chromatography (TLC) method. Isolates were tested for purity by single development chromatography method using three mobile phases and two-dimensional TLC. The TLC results were scanned by TLC Spectrophotodensitometer. Antioxidant activity of itchy leaf extract (Laportea decumana (Roxb) Wedd.) was ranked from the strongest to the weakest, namely ethanol extract, n-hexane extract and ethyl acetate extract with IC50 values of 114.104 ± 1.263 ?g/mL, 895.705 ± 1.734 ?g/mL, and > 5000 ?g/mL, respectively. Based on the results of characterization by KLT Spectrophotodensitometry method, it is known that the isolate obtained from n-hexane extract is a compound of terpenoid group, with carotenoid subgroup. The isolate has a percent DPPH silencing value of 32.961 ± 0.227 at a concentration of 1000 ?g/mL.