Judul: Potential of Bioactive Compounds in Fig (Ficus carica L.) as Selective Estrogen Receptor Modulator (SERMs) In Silico
Abstrak: Kasus kanker payudara terbanyak didominasi jenis positif hormon reseptor, yang terkait pada keberadaan reseptor estrogen-α (ERα). Selective estrogen receptor modulator (SERMs) mampu mengikat ERα agar proliferasi terhambat. Tanaman tin memiliki aktivitas antikanker payudara positif estrogen, namun belum diketahui interaksi antagonisnya terhadap ERα. Penelitian ini bertujuan menentukan senyawa aktif yang berpotensi berperan sebagai antagonis terhadap reseptor ERα pada tanaman tin. Penambatan molekuler menggunakan AutoDock Vina. Jenis interaksi molekuler ligan-reseptor ditentukan melalui parameter energi afinitas (ΔG), konstanta inhibisi (Ki), dan binding site similarity (BSS). Hasil penambatan mendapatkan 13 ligan uji yang bersifat antagonis terhadap ERα. Potensi pengikatan antagonis terbaik terdapat pada ligan epikatekin (ΔG -8,4 kkal/mol dengan Ki 0,696 μM) dan apigenin (ΔG -8,1 kkal/mol dengan Ki 1,154 μM). Hasil penelitian menunjukkan bahwa epikatekin merupakan ligan dengan potensi terbaik dalam berikatan antagonis terhadap ERα berdasarkan energi afinitas, konstanta inhibisi, serta interaksi residu asam amino., Most of breast cancer cases is hormone receptor positive type of breast cancer. Selective estrogen receptor modulator (SERMs) can binding an estrogen receptor α (ERα) and inhibit proliferation. Fig has anticancer breast activity, but their antagonist’s interaction with the ERα still unknown. This study aims to determine the bioactive compounds on figs that potentially block the ERα as an antagonist. Molecular docking using AutoDock Vina. The type of ligand-receptor molecular interaction is determined by the parameters such as affinity energy (ΔG), inhibition constant (Ki), and binding site similarity (BSS). The result of molecular docking is 13 ligands from leaves, fruit, and latex fig that can block the ERα. Epicatechin (ΔG -8,4 kcal/mol with Ki 0,696 μM) and apigenin (ΔG -8,1 kcal/mol with Ki 1,154 μM) are compounds that have the best potential antagonist activities to ERα. The results showed that epicatechin is the test ligands with the best potential antagonist compound to the ERα based on affinity energy, inhibitory constant, and amino acid residues’s interaction.
Keyword: Estrogen receptor α, Fig, Molecular docking, SERMs

Judul: Activity of breast anticancer of active compound from Spatholobus suberectus stem’s by in silico
Abstrak: Sekitar lebih 70% kasus kanker payudara adalah tipe positif hormon reseptor. Kasus kanker payudara tipe ini lebih banyak terjadi pada wanita post menopaus. Pengobatan yang efektif kasus ini adalah pemberian inhibitor enzim aromatase. Senyawa isoflavonoid batang Spatholobus suberectus telah teruji secara in vitro memiliki aktivitas sitotoksik terhadap sel kanker payudara MCF-7 yang banyak mengekspresikan reseptor estrogen dan enzim aromatase. Perlu dilakukan pencarian senyawa lain batang Spatholobus suberectus yang berpotensi memiliki aktivitas antikanker payudara. Penelitian ini bertujuan memprediksi potensi senyawa-aktif batang Spatholobus suberectus sebagai antikanker payudara melalui mekanisme penghambatan enzim aromatase secara in silico dengan metode penambatan molekular. Simulasi penambatan molekuler dilakukan melalui parameter energi ikat (ΔG), konstanta inhibisi (Ki), jenis interaksi dan binding site similarity (BSS). Senyawa aktif yang diprediksi memiliki potensi adalah prestegane B, 2R,3R-3,7-dihidroksiflavanon, dihidrorobinetin, asam protokatekuat etil ester, liquiritigenin, naringenin, 7,4’-dihidroksi-8-metoksi-isoflavone, asam protokatekuat, glisirosida, dulcisflavan, butein, hesperetin, plathymenin, isoliquiritigenin, dan medioresinol., Approximately over 70% of breast cancer cases are positive types of hormone receptors. Cases of this type of breast cancer are more common in post menopausal woman. An effective treatment of this case is the administration of aromatase enzyme inhibitors. The stem isoflavonoid compound Spatholobus suberectus has been tested in vitro has cytotoxic activity against MCF-7 breast cancer cells that expressed a lot of estrogen receptors and aromatase enzymes. It is necessary to search for other compounds of Spatholobus suberectus stem that have the potential to have anticancer activity of the breast. This study aimed to predict the potential of compound-active stem Spatholobus suberectus as an anticancer breast through the mechanism of inhibition of aromatase enzymes in silico by molecular docking method. Molecular tethering simulation is done through binding energy parameters (ΔG), inhibition constants (Ki), types of interaction and binding site similarity (BSS). Active compounds that was predicted to have potential are prestegane B, 2R,3R-3,7-dihydroxyflavanon, dihydrorobinetin, protocatechuic acid ethyl ester, liquiritigenin, naringenin, 7,4’-dihidroksi-8-metoksi-isoflavone, protocatechuic acid, glyciroside, dulcisflavan, butein, hesperetin, plathymenin, isoliquiritigenin, and medioresinol.
Keyword: molecular docking, inhibitor, aromatase

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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