Judul: Penambatan Molekuler Senyawa Aktif Sirih Merah (Piper  crocatum) sebagai Inhibitor Angiotensin Converting Enzyme
Abstrak: Hipertensi merupakan penyakit yang disebabkan tekanan arteri tinggi yang tidak normal yaitu diatas 140/90. Dua pertiga orang dewasa di dunia menderita penyakit ini dan di Indonesia sudah semakin meningkat dari umur di atas 18 tahun. Lisinopril (Angiotensin Converting Enzyme inhibitor) menjadi obat pilihan di lini pertama dalam menangani hipertensi, namun obat tersebut masih memberikan banyak efek samping. Sirih merah telah banyak digunakan dalam pengobatan herbal dan diharapkan berpotensi menghambat aktivitas ACE (Angiotensin Converting Enzyme). Penelitian ini bertujuan menemukan senyawa aktif yang berpotensi menginhibisi ACE secara in silico dengan metode penambatan molekuler. Hasil penelitian menunjukkan 8 dari 83 senyawa aktif sirih merah. Senyawa aktif 3S, 5R, 8R, 9R, 10R, 12R, 13R, 14R, 17S)-17-[(2S)-5-[2-(3,4-dimethoxyphenyl) ethylamino]-2-hydroxypentan-2-yl]-4,4,8,10,14-pentamethyl-2, 3, 5, 6, 7, 9, 11, 12, 13, 15, 16, 17-dodecahydro-1H-cyclopenta[a]phenanthrene-3,12-diol adalah metabolit sekunder berjenis alkaloid yang berpotensi dalam inhibisi ACE dengan nilai energi bebas ikatan (∆G) 9.958 kkal/mol dan berinteraksi dengan 17 residu asam amino. Hasil penelitian dapat digunakan sebagai acuan dalam studi lebih lanjut., Hypertension is a disease caused by abnormally high arterial pressure above 140/90. Two thirds of adults in the world suffer from this disease and in Indonesia has been increasing from the age of 18 years. Lisinopril (Angiotensin Converting Enzyme (ACE) inhibitor) is the drug of choice in the first line in treating hypertension, but the drug still has many side effects. Red betel has been widely used in herbal medicine and is expected to potentially inhibit ACE activity. This study aims to find the active compound that has the potential to inhibit ACE in silico through molecular docking method. The results showed 8 out of 83 active compounds of red betel. The active compound 3S,5R,8R,9R,10R,12R,13R,14R, 17S)-17-[(2S)-5-[2-(3,4-dimethoxyphenyl) ethylamino]-2-hydroxypentan-2-yl]-4,4,8,10,14-pentamethyl-2, 3, 5, 6, 7, 9, 11, 12, 13, 15, 16, 17-dodecahydro-1H-cyclopenta[a]phenanthrene-3,12-diol is an alkaloid type secondary metabolite that has the potential for ACE inhibition with a bond free energy value (∆G) of 9.958 kcal/mol and interacts with 17 amino acid residues. The research results can be used as a reference in further studies.
Keyword: Hipertensi, Angiotensin Converting Enzyme, Sirih Merah

Judul: Penambatan molekuler senyawa bioaktif sirih merah (Piper crocatum) terhadap lipoksigenase dan penghambatan malondialdehid in vitro
Abstrak: Penyakit degeneratif terjadi karena beberapa faktor risiko yang berhubungan langsung dengan peradangan. Salah satu agen penyebab inflamasi adalah enzim lipoxygenase (LOX) yang dapat membentuk malondialdehid (MDA) sehingga dibutuhkan obat antiinflamasi yang terbuat dari tanaman herbal salah satunya daun sirih merah (Piper crocatum). Penelitian ini bertujuan menentukan senyawa asal dari ekstrak dan fraksi etanol 70% daun sirih merah yang memiliki penghambatan terbaik terhadap enzim lipoksigenase penyebab terbentuknya malondialdehid (MDA) melalui simulasi penambatan molekuler serta menentukan aktivitas antioksidan tertinggi dari 4 daerah berbeda di pulau Jawa dengan metode thiobarbituric acid (TBA). Senyawa daun sirih merah yang mampu menghambat enzim lipoksigenase yakni ligan nandrolone phenylpropionate dan sofalcone dengan energi afinitas sebesar -10.4 kkal/mol dan -9.1 kkal/mol dengan nilai Ki sebesar 0.0023 µM dan 0.021 µM. Aktivitas antioksidan daun sirih merah terbaik dari daerah asal Bogor ekstrak etanol 70% dengan nilai IC50 sebesar 0.432 µg/mL. Perbedaan kekuatan antioksidan tiap daerah dilakukan analisis PCA dengan hasil tidak terbentuk kluster sehingga antar daerah memiliki karakteristik yang sama, Degenerative diseases occured due to several risk factors which directly related to inflammation. One of the causative agents of inflammation is the lipoxygenase (LOX) enzyme which can form malondialdehyde (MDA) so that anti-inflammatory drugs are needed made from herbal plants such as red betel leaf (Piper crocatum). This study aimed to determine the origin of the compound from the 70% ethanol extract and fraction of red betel leaf which had the best inhibition of the lipoxygenase enzyme that causes malondialdehyde (MDA) formation through molecular docking simulations and to determine the highest antioxidant activity from 4 different areas in Java islands with thiobarbituric acid (TBA) method. Red betel leaf compounds that can inhibited lipoxygenase enzymes are nandrolone phenylpropionate and sofalcone ligands with affinity energies of -10.4 kcal/mol and -9.1 kcal/mol with Ki values of 0.0023 µM and 0.021 µM, respectively. The best antioxidant activity of red betel leaf came from Bogor of 70% ethanol extract with an IC50 value of 0.432 µg/mL. The difference in antioxidant strength of each region was carried out by PCA analysis with the results no clusters were formed so that between regions had the same characteristics.
Keyword: Antioksidan, Daun Sirih Merah, Lipoksigenase, Malondialdehid

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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