Judul: In Silico Screening of Active Compounds of Sembung  Leaves (Blumea balsamifera DC) as Antihypertensives
Abstrak: Hipertensi adalah perubahan struktural atau fungsional pada pembuluh darah arteri dan/atau organ yang disuplai, yang disebabkan oleh peningkatan tekanan darah. Hal ini terjadi karena angiotensin converting enzyme (ACE) dapat meningkatkan tekanan darah dengan cara mengubah angiotensin I yang tidak aktif menjadi angiotensin II yang aktif. Kaptopril merupakan obat hipertensi yang dapat menghambat aktivitas ACE. Salah satu tanaman obat, yaitu daun sembung (Blumea balsamifera DC) merupakan tanaman yang berpotensi memiliki aktivitas sebagai antihipertensi. Penelitian ini bertujuan mengidentifikasi potensi senyawa aktif daun sembung dalam menghambat ACE melalui uji in silico berdasarkan parameter farmakodinamika dan farmakokinetika dengan menggunakan dua software penambatan. Hasil penelitian menunjukkan bahwa Luteolin adalah ligan uji terbaik karena selain memiliki ΔG dan Ki yang rendah dari ligan kontrol, serta Kd yang lebih tinggi dari ligan kontrol. Luteolin teridentifikasi memiliki interaksi dengan Zn dan memiliki interaksi ikatan hidrogen pada sisi aktif, serta memenuhi kriteria dalam analisis Lipinski, ADME dan toksisitas. Oleh karena itu, senyawa ini relatif aman digunakan sebagai kandidat obat untuk pengobatan penyakit hipertensi., Hypertension is a structural or functional change in the arterial blood vessels and/or supplied organs caused by increased blood pressure. The change happens because angiotensin angiotensin converting enzyme (ACE) can increase blood pressure by converting inactive angiotensin I to active angiotensin II. Captopril is a commercial hypertension drug that can inhibit ACE activity. One of the medicinal plants, namely sembung leaves (Blumea balsamifera DC) is a plant that can potentially have antihypertensive activity. This study aims to identify the potential of active compounds of sembung leaves in inhibiting ACE through an in silico test based on pharmacodynamic and pharmacokinetic parameters using two docking software. The results showed that Luteolin was the best test ligand because besides having lower ΔG and Ki than control ligands, and higher Kd than control ligands. Luteolin was identified to have interactions with Zn and hydrogen bond interactions at the active site, and met the criteria in the Lipinski, ADME, and toxicity analysis. Therefore, this compound is relatively safe to be used as a drug candidate for the treatment of hypertension.
Keyword: ACE, captopril, docking, hypertension, sembung leaves

Judul: In Silico Analysis of Bioactive Compounds in Black Cumin Seed as Inhibitor of Angiotensin-I Converting Enzyme (ACE)
Abstrak: ACE merupakan salah satu reseptor utama dalam regulasi tekanan darah serta paling umum dihambat untuk mengatasi hipertensi. Biji jintan hitam dipercaya memiliki banyak manfaat, salah satunya menurunkan tekanan darah. Penelitian ini bertujuan mengidentifikasi interaksi molekuler serta menyeleksi dan memprediksi potensi inhibisi senyawa bioaktif biji jintan hitam terhadap ACE sebagai obat antihipertensi. Penelitian dilakukan dengan penapisan virtual 97 ligan uji menggunakan PyRx Virtual Screening Tool dan penambatan molekuler menggunakan AutoDock Tools. Hasil analisis interaksi ligan-reseptor menunjukkan 14 dari 20 ligan yang diuji pada tahapan tersebut memiliki potensi sebagai inhibitor ACE. Epicatechin menjadi ligan dengan potensi terbaik (ΔG -7.00 kkal/mol; BSS 62.50%) serta memenuhi pendekatan keberadaan interaksi terhadap Zn. Meskipun tidak menjadi ligan terbaik, terdapat tiga senyawa khas biji jintan hitam yang diidentifikasi juga berpotensi sebagai inhibitor ACE, yaitu trans-4-methoxy-thujane (ΔG -5.20 kkal/mol; BSS 68.75%) yang memenuhi pendekatan keberadaan interaksi terhadap Zn serta thymoquinone (ΔG -5.50 kkal/mol; BSS 43.75%) dan thymohydroquinone (ΔG -5.20 kkal/mol; BSS 50.00%) yang memenuhi pendekatan keberadaan ikatan hidrogen pada sisi aktif., ACE is one of the main receptors in the regulation of blood pressure and is the most commonly inhibited to treat hypertension. Black cumin seeds are believed to have many benefits, one of them is lowering blood pressure. This study aims to identify molecular interactions as well as to select and predict the ACE inhibition potential of bioactive compounds from black cumin seeds as an antihypertensive drug. The research began with virtual screening of 97 ligands using the PyRx Virtual Screening Tool and molecular docking using AutoDock Tools. The results of the ligand-receptor interaction analysis showed that 14 of the 20 ligands tested at that step had potential as ACE inhibitors. Epicatechin became the ligand with the best potency (ΔG -7.00 kcal/mol; BSS 62.50%) and qualify to the approach of the presence of an interaction with Zn. Although not the best ligand, there are three unique ligands of black cumin seeds that were identified as potential ACE inhibitors, those are trans-4-methoxy-thujane (ΔG -5.20 kcal/mol; BSS 68.75%) which qualify to the approach of the presence of an interaction with Zn, also thymoquinone (ΔG -5.50 kcal/mol; BSS 43.75%) and thymohydroquinone (ΔG -5.20 kcal/mol; BSS 50.00%) which qualify the approach of the presence of hydrogen bonds on the active site.
Keyword: ACE, Black cumin seed, Hypertension, Molecular docking

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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