Judul: Essential oil of temu hitam (Curcuma aeruginosa Roxb.)„s rhizomes, stems, and leaves as antibacterial toward Streptococcus mutans and biofilm degradator on teeth
Abstrak: Rimpang temu hitam banyak digunakan sebagai antibakteri. Penelitian ini membandingkan kemampuan minyak atsiri rimpang, batang, dan daun temu hitam sebagai antibakteri Streptococcus mutans dan pendegradasi biofilm pada gigi menggunakan metode mikrodilusi. Minyak atsiri diisolasi dengan distilasi uap. Potensi antibakteri terbaik adalah minyak rimpang KHM=konsentrasi hambat minimum=15.63 μg/mL dan KBM=konsentrasi bunuh minimum=1000 μg/mL. KHM rimpang sama dengan tetrasiklin. Setelah difraksionasi dengan kolom maupun kromatografi lapis tipis preparatif, KHM dan KBMnya tidak lebih baik. Senyawa 2,2,5-trimetil-2‟(H)-5‟-6‟-dihidropirano[3‟,4‟,g]indan-1-on diduga paling berperan sebagai antibakteri S. mutans. Kemampuan degradasi biofilm minyak atsiri kasar temu hitam kurang kuat. Minyak atsiri batang lebih baik mendegradasi biofilm (IC50=1347 μg/mL) daripada rimpang dan daun. Setelah difraksionasi, beberapa fraksi minyak atsiri rimpang (F1, F2, dan F3) lebih baik kemampuan degradasinya tetapi IC50 lebih tinggi dari klorheksidin., Rhizomes of temu hitam are widely used as antibacterial. This research compare the potency of essential oil of rhizomes, stems, and leaves of temu hitam as antibacterial toward Streptococcus mutans and biofilm degradator on teeth. The essential oil was isolated by steam distillation. Rhizome‟s essential oil showed good potency as antibacterial with MIC=minimum inhibition concentration=15.63 μg/ml and MBC=minimum bactericidal concentration=1000 μg/ml. MIC of rhizome was same with tetracycline. MIC and MBC of rhizome‟s essential oil was smaller than fraction of column and preparative thin layer chromatography. The 2,2,5-trimethyl-2‟(H)-5‟-6‟-dihydropyrano[3‟,4‟,g]indan-1-one give better potency as antibacterial toward S. mutans. Essential oil of temu hitam was not stronger as biofilm degradator. Stem‟s essential oil was the better essential oil (IC50=1347 μg/mL) to degradate biofilm than rhizome and leave‟s essential oil, but some of fraction of rhizome‟s essential oil (F1, F2, and F3) have better potency than stem‟s essential oil but the IC50 was higher than chlorhexidine. Keywords: Antibacterial, biofilm degradator, essential oil, Streptococcus mutans
Keyword: antibakteri, minyak atsiri, pendegradasi biofilm, Streptococcus mutans

Judul: Hubungan Variasi Waktu Distilasi Kukus Rimpang Temu Hitam (Curcuma aeruginosa) dan Aktivitas Antibakteri Minyak Atsiri
Abstrak: Waktu distilasi dapat mempengaruhi ekstraksi minyak atsiri seperti pada rimpang temu hitam (Curcuma aeruginosa) yang telah dibuktikan memiliki aktivitas antibakteri. Oleh karena itu, penelitian ini bertujuan menentukan waktu distilasi yang optimum dalam menghasilkan minyak rimpang temu hitam dengan aktivitas antibakteri terkuat. Rimpang temu hitam didistilasi kukus dengan perbedaan lama waktu setiap 30 menit selama 4 jam untuk mendapatkan minyak atsiri dan ditentukan senyawa yang terdapat di dalamnya menggunakan gas chromatography-mass spectrometry. Aktivitas antibakteri ditentukan dengan difusi cakram terhadap bakteri Streptococcus mutans, Escherichia coli, dan Staphylococcus aureus. Senyawa yang terdapat pada minyak atsiri yang paling dominan adalah eukaliptol (34,89%), epikurzerenon (20,58%), dan kamfor (16,90%) berdasarkan rerata luas puncak pada total waktu distilasi. Potensi antibakteri terkuat didapatkan pada waktu distilasi 30 menit pertama untuk bakteri S. mutans dan E. coli, serta waktu distilasi 30 menit ketujuh untuk bakteri S. aureus., Distillation time can affect the extraction of essential oils such as the rhizome of temu hitam (Curcuma aeruginosa) which has been shown to have antibacterial activity. Therefore, this study aims to determine the optimum distillation time to produce temu hitam rhizome oil with the strongest antibacterial activity. The rhizomes of temu hitam were steam distilled with different lengths of time every 30 minutes for 4 hours to obtain essential oil and determined the compounds contained in them using gas chromatography-mass spectrometry. Antibacterial activity was determined by disc diffusion against Streptococcus mutans, Escherichia coli, and Staphylococcus aureus. The most dominant compounds present in essential oils are eucalyptol (34,89%), epicurzerenone (20,58%), and camphor (16,90%) based on the average peak of the total distillation time. The strongest antibacterial potency was obtained in the first 30 minutes of distillation for S. mutans and E. coli, and in the seventh 30 minutes of distillation for Staphylococcus aureus.
Keyword: antibacterial, essential oil, GC-MS, steam distillation

Judul: Analysis of Unequal Income Distribution with Cobb-Douglas Production Function
Abstrak: This paper studies the economic growth model by Moav (2002). Moav model shows the existence of unequal income distribution between low-income with high-income community. That kind of unequal income distribution is caused by uneven distribution of income. On this Moav model, there is one area called the threshold. Threshold becomes a benchmark to determining whether a society is categorized into low- or high- income community. The production function used in this paper is the Cobb-Douglas function. The dynamics of this model is described as difference equation of low-income, threshold, and high-income community. Simulation study on the model is carried out using Maple 13 and Mathematica 7.0 software. Overall, from the observed case, high-income community will reach a stable condition earlier, followed by the threshold, and then the low-income community.
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