ISOLATION OF ANTIOXIDANT COMPOUNDS FROM SIRIH MERAH (Piper crocatum)
Antioxidants are compounds that can inhibit oxidation by reacting with reactive free radicals and form reactive molecule that relatively stable. Phenolic compounds such as alkaloids and flavonoids are source of natural antioxidants found in plants. Red betel leaf (Piper crocatum) is one of the...
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| Format: | Theses |
| Language: | Indonesia |
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| Online Access: | https://digilib.itb.ac.id/gdl/view/34630 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Antioxidants are compounds that can inhibit oxidation by reacting with reactive free radicals and form reactive molecule that relatively stable. Phenolic compounds such as alkaloids and flavonoids are source of natural antioxidants found in plants. Red betel leaf (Piper crocatum) is one of the treatment plant that contain phenolic compounds such as alkaloids, flavonoids, tannins and essential oils. Antioxidant activity test was reducted on red betel leaf since its contain alkaloid and flavonoids compounds. Expected results from this study is to get natural antioxidants. Soxhlet extraction was used for extraction method with increasing solvent polarity. Phytochemical test was conducted on alkaloids test, flavonoids test, saponin test, compounds terpenoids test, steroids, and phenolic compounds test. Separation of compounds was done by gravity chromatography and radial chromatography to obtain pure compounds. The antioxidant activity of red betel leaf (Piper crocatum) were determined qualitatively and quantitatively. TLC qualitative test performed by observing the spots that appear due to the spraying of 0.05 mM DPPH in TLC plate, while the quantitative test was conducted using DPPH (1,1-diphenyl-2-picrylhydrazyl) and IC50 (Inhibition Concentration 50%) determination. The standard used in this study is ascorbic acid (vitamin C). The result from extraction by used different solvent n-hexane, ethyl acetate and ethanol are 3.69%, 12.52% and 9.08% dry weight. n-hexane extract and ethyl acetate extract was obtained as green colour and ethanol was obtained as green brownish colour. Phytochemical analysis of ethyl acetate fraction shown positive fraction contains alkaloid and flavonoids compounds. Separation of ethyl acetate fraction (0.2 grams) by column chromatography was produced 24 fractions and futher purification by radial chromatography was obtained positif alkaloid on fractions to-19; 20; 23; 24. Second separation of ethyl acetate fraction (0.5 grams) by column chromatography was produce 37 fractions and futher purification by radial chromatography was obtained pure compound on fraction
24 to 28. Then, the structure of pure compound was elucidated by using spectroscopic methods such as UV-Vis, FT-IR, 1D (1H-NMR, 13C-NMR), 2D (HMBC, HMQC, COSY). The pure compound was obtained as 1-allyl -3.5- dimethoxy-7-methyl-4-oxo-6-(3,4,5-trimethoxyphenyl) bicyclo [3,2,1] oct-2-en-8-
yl acetate according to IUPAC name with molecular formula C25H32O8. The qualitative test on three crude extract with different solvent shom that its can inhibit free radical DPPH 0,05 mM. Beside that, the quantitative test on n-hexane , ethyl acetate and ethanol crude extract shows IC50 antioxidant activity are 134.29,
127.74, and 94.63 ppm and IC50 for ascorbic acid is 3.61 ppm. As conclusion, alkaloid compounds shows antioxidant activity 50.91 ppm and C25H32O8 from neolignan compounds do not active as antioxidant.
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