Abstrak

Finally i've had my second graduation at sabuga at 18 april 2009 ago. Here i share some of my study abstract. Being a graduated student was something really great and also tiring, we can sponge many science and skill. Here i share my abstract, actually i haven't found my goals in this research, but the study continue even after i have graduated.

Abstrak

Tiga senyawa aromatik dan satu senyawa yang diketahui sebagai 4’,6-dihidroksi-4-metoksibenzofenon-2-O-glukosida telah diisolasi dari fraksi etil asetat dan n-butanol ekstrak etanol buah mahkota dewa (Phaleria macrocarpa (scheff.) Boerl) dan diuji aktivitas penangkap radikal bebas secara in vitro.

Uji aktivitas penangkap radikal bebas mengikuti metode Blois menggunakan DPPH (1,1-diphenyl-2-picryl Hydrazyl) secara spektrofotometri. Ekstrak etanol, fraksi n-heksana, fraksi etil asetat, fraksi n-butanol, fraksi sisa air, dan asam askorbat sebagai pembanding memberikan IC₅₀ secara berurutan : 82,93; 217,38; 56,48; 111,12; 180,55 dan 3,22 mg/ml. Sementara isolat PM 1, PM 2, PM 3, dan PM 4 memberikan IC₅₀ secara berurutan 492,92; 626,60; 102,96; dan 285,85 mg/ml.

Dari data spektrum Ultraviolet, IR, NMR-H dan NMR-C, isolat PM 1 merupakan suatu glukosida yang memiliki kerangka benzena yang tersubstitusi para, tidak memiliki ikatan karbonil sebagaimana 3 isolat lainnya. Isolat PM 3 merupakan suatu senyawa aromatik dengan rantai samping alkil. Dari spektrum UV dan IR Isolat PM 4 diduga merupakan suatu flavonol.

Kata kunci : Mahkota dewa, Phaleria macrocarpa, DPPH.

Abstract

From the ethyl acetate and n-buthanol fraction of ethanol extract of mahkota dewa (Phaleria macrocarpa (scheff.) Boerl), 3 aromatic compounds and 1 known compound (4’,6-dihydroxy-4-metoxybenzofenone-2-O-glucoside) were isolated. To estimate the activity of antioxidant from the isolated compounds, the use of the stable free radical 1,1-diphenyl-2-picryl Hydrazyl (DPPH) spectrophotometrically was applied.

The IC₅₀ for ethanol extract, n-hexane, ethyl acetate, n-buthanol, water fraction, and ascorbic acid as standard were shown respectively by 82.93; 217.38; 56.48; 111.12; 180.55, and 3.22 mg/ml. While IC₅₀ of PM 1, PM 2, PM 3, and PM 4 were 492.92; 626.60; 102.96; and 285.85 mg/ml.

Based on the ultraviolet, infrared, ¹H-NMR and ¹³C-NMR spectra, PM 1 was characterized as a glucoside with p-substituted benzene and no carbonyl. An aromatic compound with an alkyl chain was characterized for PM 3. while PM 4 was pressumed as flavonol.

Keywords : Mahkota dewa, Phaleria macrocarpa, DPPH