Judul: Identification of Active Compounds and Antibacterial Activity of Bandotan Leaves (Ageratum conyzoides) Ethanol Extract against Staphylococcus aureus and Escherichia coli
Abstrak: Resistensi antibiotik menimbulkan dampak negatif pada berbagai bidang. Perlu dilakukan penelitian bandotan (Ageratum conyzoides) yang memiliki kandungan metabolit sekunder yang bersifat antibakteri. Penelitian ini bertujuan mengidentifikasi kelompok senyawa metabolit sekunder dan senyawa aktif dan menganalisis ekstrak etanol daun bandotan sebagai antibakteri Staphylococcus aureus dan Escherichia coli. Tahapan penelitian terdiri atas ekstraksi menggunakan pelarut etanol 96%, identifikasi kualititatif kelompok senyawa metabolit sekunder, identifikasi senyawa aktif ekstrak dengan LC-MS ACQUITY UPLC®H-Class System, dan uji aktivitas antibakteri metode cakram kertas. Serbuk daun bandotan dimaserasi, sehingga menghasilkan rerata rendemen ekstrak 4,45%. Identifikasi kualititatif menunjukkan sampel mengandung flavonoid, saponin, kumarin, alkaloid, terpenoid, dan tanin. Identifikasi LC-MS menunjukkan sampel mengandung 16 senyawa dugaan yang berasal dari kelompok senyawa yang bersifat antibakteri. Uji metode cakram kertas menunjukkan bandotan dapat menghambat Staphylococcus aureus dan Escherichia coli.
Keyword: bandotan, ethanol extract, Escherichia coli, Staphylococcus aureus, antibacterial

Judul: Characterization Antibacterial Compounds from Ethyl Acetat Fraction of Bandotan Leaf (Ageratum conyzoides L.)
Abstrak: Utilization of Ageratum conyzoides L. leaf for wound healing and digestion disorders are often associated with its antibacterial activities. However, information of this plant as antibacterial agent still limited on the polar and nonpolar fraction. Therefore, the objective of this study was to evaluate and identify the antibacterial activity of semipolar fraction extract of A. conyzoides L. leaves to Staphylococcus aureus and Eschericchia coli. Overall antibacterial activity results of ethyl acetate extract, fractions and subfractions Ageratum conyzoides L. leaves showed broad-spectrum antibacterial activity because it can prevent bacterial growth of S. aureus and E. coli. Subfractions 4b has the highest antibacterial activity for S. aureus compared to other subfractions. The minimum inhibition concentration for subfractions 4b against S. aureus was 25 mg/ml and 50 mg/ml for E. coli. Based on UV-Vis spectrophotometer, infra red and gas chromatograpy-mass spectroscopy, this fraction contain coumarin compounds, 2 chromen (prekosen II and 7-methoxy-2,2-dimethyl-6-vinyl-2H-chromene), and 2 derivative palmitic acid (9, 12-heksadecanoic acid and 9,12 octadecanoic acid, neophytadiene and 5,11,14,17-methyl eicosatetraenoate.
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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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