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I W. G. Gunawan
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Chemistry

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STUDI PERBANDINGAN HASIL SINTESIS METIL-N(2,3-XILIL)ANTRANILAT DENGAN PEREAKSI DIAZOMETANA DAN BF3-METANOL I W. G. Gunawan
Jurnal Kimia (Journal of Chemistry) Vol. 3, No. 1 Januari 2009
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

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N(2,3-xylyl)antranilic acid is an analgesic drug which works by inhibiting synthesis of prostaglandin.Through this mechanism N- (2,3-xylyl)antranilic acid causes gastro iritation. Therefore, this research aims tosynthesise N- (2,3-xylyl)antranilic ester derivatives using BF3-methanol and diazomethane methods, and to findwhich methods will give the best result.Diazomethane used for methylation reaction needs to be fresh because it is an unstable gas, while BF3-methanol needs refluxing for 10-15 hours. The physico chemical properties of methylation product werecharacterised using colour reaction testing, melting point, and Rf value, while the structure was identified using UVvis,FT-IR and 1HNMR.It was found that diazomethane method gave better yield (68%) compared to BF3-methanol (52%). N- (2,3-xylyl)antranilic methyl ester obtained using both methods was found as a yellowish-white shiny crystal having thesame degree of purity. In addition, both product revealed the same physico chemical properties such as meltingpoint, colour, and Rf value. Hence, the products obatined using both methods were identical which was N- (2,3-xylyl)antranilic methyl ester.
ISOLASI DAN IDENTIFIKASI SENYAWA GOLONGAN TRITERPENOID DARI EKSTRAK n- EKSANA DAUN KEPUH (Sterculia foetida L.) SERTA UJI AKTIVITAS ANTIRADIKAL BEBAS I. A. R. Astiti Asih; I W. G. Gunawan; N. M. Desi Ariani
Jurnal Kimia (Journal of Chemistry) Vol. 4, No. 2 Juli 2010
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

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Kepuh leaves can be used as traditional medicine to cure various diseases. Maseration of ± 1000 g drypowder of Kepuh leaves with n-hexane as the solvent resulted in 2,10 g n-hexane concentrated extract. Separation ofthis extract with column chromatography gained two yellow amorphous crystal isolates of F3.1 and F3.2 with 0,0195 gand 0,0032 g in weight, respectively.The result of phytochemical test of isolate F3.1 with Liebermann-Burchard reagent showed that the isolatepositively contained triterpenoid. Identification of isolate F3.1 with spectrophotometer UV-Vis showed one broadpeak at 265 nm. The transition occured probably was n *, that was caused by C=O chromophor. Infraredspectrum showed characteristic groups of OH at 3294,42 cm-1, aliphatic CH at 2924,09 cm-1 and 2854,65 cm-1, C=Oat 1743,65 cm-1, bending CH2 and bending CH3 at 1458,18 cm-1 and 1381,03 cm-1 and alcoholic CO at 1172,72 cm-1.Free antiradical activity test against isolate F3.1 was carried out by spectroscopy UV-Vis method. Isolate F3.1 hadcharacteristic as a free antiradical with DPPH damping percentage at the 5th minute was 85,33% and at the 60thminute was 88,52%.According to phytochemical tests and spectrophotometry analysis, isolates from kepuh leaves was expectedto contain true triterpenoid group compounds with free antiradical activity OH group, aliphatic CH, C=O andalcoholic C-O as the functional groups.
ISOLASI DAN IDENTIFIKASI SENYAWA TERPENOID YANG AKTIF ANTIBAKTERI PADA HERBA MENIRAN (Phyllanthus niruri Linn) I W. G. Gunawan; I G. A. Gede Bawa; N. L. Sutrisnayanti
Jurnal Kimia (Journal of Chemistry) Vol. 2, No. 1 Januari 2008
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

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Abstract

Isolation and identification of terpenoid, antibacterial compounds meniran herb (Phyllanthus niruri Linn) by GasChromatography – Mass Spectroscophy were carried out. Two kinds of extraction, i.e. maseration using methanoland the sochlet using n-hexane were employed.The extract obtained were contains terpenoids basedon fitochemical test of Liberman-Burchard n-hexaneextract was tested for antimicrobial activity against Escherichia coli ATCC® 25292 and Staphylococcus aureusATCC® 25293. In this study we obtained that n-hexane extract by sochlet extraction showed greater activitycompared to the extract by maseration with methanol, as indiated by disc diameter of inhibition zone. Diametricinhibition zone for these two extract are 1 mm for Escherichia coli and 0,5 mm for Staphylococcus aureus, formethanol extract, and where are 10 mm for Escherichia coli and 12 mm for Staphylococcus aureus for n-hexaneextract.The n-hexane extract was then purified using column chromatography. The pure extract was analyzed usingGas Chromatography - Mass Spectroscophy. Gas Chromatography - Mass Spectroscophy data indicated that theextract contains two compounds, i.e. phytadiene [ M+ ] 278 and 1,2 seco – cladiellan m/z 335 [ M+ - H ].
Co-Authors I Gusti Agung Gede Bawa I. A. R. Astiti Asih N. L. Sutrisnayanti N. M. Desi Ariani