Judul: Compounds in Garlic (Allium sativum) and Black Garlic as Antigout Based on In Silico Analysis
Abstrak: Asam urat merupakan produk akhir dari katabolisme purin yang dihasilkan oleh kerja enzim xantina oksidase (XO), guanin deaminase (GDA), adenin deaminase (ADA), purin nukleosida fosforilase (PNP), dan 5-nukleotidase II (NT5C2). Gout merupakan penyakit yang disebabkan oleh akumulasi kristal monosodium urat yang diakibatkan oleh kelebihan asam urat. Bawang putih dilaporkan mengandung senyawa bioaktif yang berpotensi sebagai antigout. Fermentasi bawang putih menjadi bawang hitam menghasilkan perubahan komponen maupun konsentrasi senyawa dan hal ini berpengaruh terhadap potensinya sebagai antigout. Penelitian ini bertujuan untuk memilih jenis bawang putih lokal (Indonesia) atau bawang putih impor (Cina) serta memprediksi interaksi antara senyawa pada bawang dan lima protein target melalui pendekatan in silico, yaitu ensemble docking. Digunakan 14 senyawa terpilih hasil analisis UHPLC-Q-Orbitrap-MS/MS ekstrak bawang putih dan bawang hitam yang diperoleh dari lokal maupun impor sebagai ligan uji dan 5 reseptor target, yaitu XO, GDA, ADA, PNP, dan NT5C2. Hasil penelitian menunjukkan senyawa alliin, N-asetil-S-alil-L-sisteina, ajoena, asam p-kumarat, piridoksal, piridoksamina, asam 4-guanidinobutirat, dan Dglukosamina dapat dikembangkan sebagai kandidat antigout multi-target karena memiliki afinitas pengikatan yang paling kuat dibanding kontrol. Hampir semua senyawa uji ditemukan lebih banyak terdapat di bawang hitam dengan konsentrasi yang tidak berbeda pada lokal maupun impor., Uric acid is the end product of purine catabolism produced by the action of the xanthine oxidase (XO), guaninae deaminase (GDA), adenine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5-nucleotidase II (NT5C2). Gout is caused by the accumulation of monosodium urate crystals due to excess uric acid. Garlic contains bioactive compounds that have the potential to antigout. Fermentation of garlic into black garlic produces changes in components that affect its potential as antigout. The purpose of the study was to select the type of local garlic (Indonesia) or imported garlic (Cina) and predict the interaction between compounds in garlic and five target proteins through an in silico approach, namely ensemble docking. Fourteen compounds were used from analysis of UHPLC-Q-Orbitrap-MS/MS extracts of both local and imported garlic and black garlic as test ligands and five target receptors. In-silico study shows alliin, N-acetyl-S-allyl-L-cysteine, ajoene, pcoumaric acid, pyridoxal, pyridoxamine, 4-guanidinobutyric acid, and Dglucosamine compounds can be developed as candidates for multi-target antigout because of their binding affinity strongest than the control. Almost all compounds were found abundantly in black garlic extract with no different concentrations in local and imported black garlic.
Keyword: Antigout, bawang hitam, bawang putih, in silico, Antigout, black garlic, garlic, in silico

Judul: Penapisan Senyawa Aktif Daun Sirsak, Putri Malu, Alang-alang dan Pandan Wangi sebagai Inhibitor Xantina Oksidase secara in Silico
Abstrak: Gout adalah penyakit kronis yang disebabkan oleh pengendapan kristal natrium urat. Salah satu cara mengatasi penyakit ini adalah dengan menurunkan kadar asam urat melalui penghambatan kinerja enzim xantina oksidase (XO). Allopurinol yang merupakan analog purina adalah salah satu obat penghambat XO komersial. Upaya mencari senyawa baru yang berpotensi dapat menurunkan kadar asam urat dari tumbuhan berkhasiat obat telah lama dilakukan melalui isolasi senyawa murni dan turunannya sebagai bahan dasar pembuatan obat modern. Penelitian ini bertujuan mendapatkan informasi tanaman herbal yang berpotensi dapat menghambat kinerja XO dengan melakukan penapisan senyawa aktif yang berasal dari daun sirsak, putri malu, alang-alang, dan pandan wangi sebagai inhibitor enzim XO secara in silico dengan metode penapisan virtual dan penambatan molekuler. Parameter yang digunakan adalah energi ikatan (ΔG), konstanta inhibisi (Ki), dan ikatan yang terbentuk. Hasil penelitian menunjukkan senyawa (E,E)-pandanamina dari pandan wangi berpotensi paling tinggi sebagai inhibitor enzim XO dengan ΔG sebesar -9,28 kkal/mol, Ki 0,16 µM, dan nilai binding site similarity (%BSS) sebesar 88,89%. Selanjutnya, senyawa aktif ini dapat diisolasi dari daun pandan wangi untuk dijadikan kandidat obat pada pengobatan penyakit gout., Gout is a chronic disease caused by the deposition of sodium urate crystals. One of the treatments for this disease is to reduce uric acid levels through the inhibition of the enzyme xanthine oxidase (XO). Allopurinol which an analog of purines is one of the commercially available XO inhibitor drugs. Various studies have been carried out to find new potential compounds to reduce uric acid levels from medicinal plants, which have long been carried out through the isolation of pure compounds and their derivatives as basic ingredients for making modern medicines. This study aims to obtain the information on potential herbal plants to inhibit XO activity by screening active compounds derived from soursop leaves, mimosa, cogongrass, and pandanus as XO enzyme inhibitors in silico by virtual screening and molecular docking methods. The parameters analyzed are bond energy (ΔG), inhibition constant (Ki), and the bonds formed. The results of this study indicated that (E,E)-pandanamine from pandanus had the highest potential as XO enzyme inhibitor with ΔG of -9,28 kcal/mol, Ki of 0,16 µM, and the value of binding site similarity (% BSS) is 88,89%. Furthermore, this active compound can be isolated from pandanus leaves to be used as a drug candidate in the treatment of gout.
Keyword: gout, uric acid, virtual screening, molecular docking, xanthine oxidse

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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