SKRINING AKTIVITAS DAN ISOLASI SENYAWA PENANGKAP RADIKAL 2,2-DIFENIL-1-PIKRIL HIDRAZIL DARI DAUN KENIKIR (Cosmos caudatus, H.B.K)
| Main Authors: | , FARISYA NURHAENI, , Prof. Dr. Subagus Wahyuono, M.Sc., Apt |
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| Format: | Thesis NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2012
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/118156/ http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=57739 |
Daftar Isi:
- Searching for antioxidants from natural sources has become concern and it has attempted to identify compounds that can act as suitable antioxidants to replace synthetic antioxidants. Vegetables have known having many natural antioxidants such as vitamin E, vitamin C, beta carotene and flavonoids. Many vegetables have been traced having antioxidant properties, but it has not been much research on the isolation and structural identification of compounds responsible for antioxidant activity. This study perform a screening of antiradical activity on 10 species of vegetables and perform an isolation of active compound in the Cosmos caudatus, H.B.K. The ten of vegetables studied were Amaranthus lividus L.sensu Thell., Cichorium endivia L.var.crispum Lam., Brassica juncea (L.) Czern., Sauropus androgynus (L.) Merr., Ocimum bassilicum L. forma citratum, Brassica oleracea var.botrytis L., Brassica oleracea L. var.botrytis subvar cauliflora DC., Brassica oleracea L. var.capitata, Brassica oleracea L. var.capitata forma rubra, Cosmos caudatus H.B.K. Extraction of the simplicia dry powder made by the maceration method using 96% ethanol. The Ten of extract vegetable further tested the activity of radical by DPPH methode (2,2-diphenyl-1-pikril hidrazil). The extracts of Cosmos caudatus has the highest radical activity with IC50 about 19,43 ± 0,317 Âμg /ml. It also analyzed the content of total phenolic and flavonoid. Cosmos caudatus have the highest total phenolic content (18,68% w/w EAG) and the high flavonoid content (55,48% w/w ER). Extracts fractionation of Cosmos caudatus done by decanteer with petroleum benzen solvent. Active fraction is the fraction of insoluble petroleum benzen which fractionated again by Vacuum Liquid Chromatography (VLC) and obtained n-hexane subfraction: ethyl acetate (1:1), ethyl acetate 100%, and methanol 100%. Further, isolation of active compounds of ethyl acetate subfraction by Preparatif Thin Layer Chromatography (preparative TLC) method and obtained two isolates, isolates 1 (Rf = 0,53), isolate 2 (Rf = 0,31). The identification show that isolates 1 and 2 is a flavonoid glycoside. Hydrolysis of the isolates were then performed to obtain aglikon isolates. Aglikon isolate be identified using TLC (3 phase) compared with standard, spectrophotometry with the addition of shift reagent for flavonoids, IR spectrophotometry, and using High Pressure Liquid Chromatography (HPLC) which is also compared with the standard. The identification show that pure aglikon isolate is quercetin compounds, which value of IC50 is 2,35 Âμg/ml.