Judul: In Silico Study of Chemical  Constituent in Lemongrass (Cymbopogon citratus) Against Monoamine Oxidase A
Abstrak: Inhibitor dari salah satu isoform enzim monoamin oksidase, yakni monoamin oksidase A (MAO-A), memiliki pengaruh terhadap beberapa kondisi psikiatris seperti kecemasan, sehingga inhibitor MAOA dijadikan sebagai salah satu jenis obat antidepresan. Beberapa penelitian pada tanaman serai menunjukkan adanya efek antidepresan. Penelitian ini bertujuan mendeteksi adanya potensi senyawa senyawa aktif tanaman serai (Cymbopogon citratus) dalam menghambat aktivitas enzim MAO-A yang merupakan salah satu pengobatan yang bersifat antidepresan dengan metode docking atau penambatan molekuler. Penelitian ini menggunakan metode penambatan molekuler dengan perangkat lunak YASARA Structure, preparasi protein dan visualisasi tiga dimensi menggunakan Discovery Studio, dan visualisasi dua dimensi menggunakan LigPlus. Dari 56 senyawa yang ditemukan, sebanyak 5 senyawa bioaktif pada tanaman serai berpotensi sebagai inhibitor monoamin oksidase A, yakni limonene, linalool, neral, beta-myrcene, dan trans citral setelah melalui tahap penapisan virtual, analisis farmakokinetik dan prediksi toksisitas. Berdasarkan analisis penambatan molekuler, limonene dengan energi bebas ikatan sebesar -4.921 kkal/mol dan konstanta inhibisi sebesar 244.83 µM memiliki potensi terbaik untuk menginhibisi aktivitas monoamin oksidase A., Monoamine oxidase A (MAOA) inhibitors have an effect to several psychiatric condition such as anxiety, so that MAOA inhibitor could be used as antidepressant drug. This research aims to detect potential bioactive of lemongrass (Cymbopogon citratus) in order to inhibit MAOA enzyme activity that is served as one of antidepressant treatment. This research used YASARA Structure as molecular docking software, Discovery Studio as protein preparation and three dimensional visualization, and LigPlot as three-dimensional visualization. Based on 56 constituent found in lemongrass, 5 constituents had found to be potential on inhibiting MAOA, namely limonene, linalool, neral, beta-myrcene, and trans-citral after conduting virtual screening, pharmacokinetic and toxicity prediction. Based on molecular docking analysis, limonene is found to be the most potential ligand to inhibit MAOA activity with -4,921 kkal/mol binding free energy and 244.83 µM inhibition constant.
Keyword: antidepresan, limonene, MAOA, penambatan molekuler, tanaman serai

Judul: Analisis In Silico Potensi Antidepresan Senyawa Aktif Kemangi  (Ocimum basilicum L.) melalui Inhibisi Monoamin Oksidase A (MAOA)
Abstrak: Depresi merupakan kondisi gangguan emosi yang secara klinis disebabkan oleh defisiensi neurotransmiter monoamin (serotonin, noreprinefrin dan dopamin). Monoamin oksidase A (MAOA) berperan sebagai regulator utama homeostasis ketiga neurotransmiter tersebut. Kemangi mengandung senyawa flavonoid dan minyak atsiri yang berpotensi sebagai inhibitor MAOA. Penelitian ini bertujuan mengidentifikasi senyawa aktif kemangi yang memiliki potensi terbaik sebagai antidepresan melalui inhibisi MAOA berdasarkan nilai energi bebas ikatan (∆G), konstanta disosiasi (Kd), interaksi ligan-reseptor dan bioavailabilitas. Penelitian dilakukan secara in silico melalui metode penambatan molekuler menggunakan aplikasi YASARA Structure. Hasil penelitian menunjukkan bahwa terdapat 11 senyawa aktif kemangi yang berpotensi sebagai inhibitor MAOA dengan nilai ∆G lebih rendah dibandingkan moclobemide (obat komersil) yaitu naringenin, kaempferol, apigenin, genkwanin, quercetin, zingiberene, beta-bisabolene, alpha-farnesene, beta-sesquiphellandrene, nepetodin A dan hesperitin. Naringenin merupakan senyawa aktif kemangi yang memiliki potensi inhibisi MAOA terbaik dengan nilai ∆G sebesar -9.325 Kkal/mol dan Kd 0.146 μM., Depression is an emotional disorder condition that is clinically caused by a deficiency of monoamine neurotransmitters (serotonin, norepinephrine, and dopamine). Monoamine oxidase A (MAOA) acts as a major regulator of the homeostasis of these three neurotransmitters. Basil contains flavonoid and essential oil compounds that have the potential as MAOA inhibitors. This study aims to identify the active compound of basil which has the best potential as an antidepressant through MAOA inhibition based on the value of free energy of binding (∆G), dissociation constant (Kd), ligand-receptor interaction and bioavailability. The research was conducted in silico through the molecular docking method using the YASARA Structure application. The results showed that there were 11 active compounds of basil that had the potential as MAOA inhibitor with ∆G value lower than moclobemide (commercial drug), there were naringenin, kaempferol, apigenin, genkwanin, quercetin, zingiberene, beta bisabolene, alpha-farnesene, beta-sesquiphellandrene, nepetodin A dan hesperitin. Naringenin is the active compound of basil which has the best MAOA inhibition potential with a free energy of binding value of -9.325 Kcal/mol and Kd 0.146 M.
Keyword: Depresi, Kemangi, Monoamin Oksidase A, Penambatan molekuler

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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