Judul: Penambatan Molekuler Senyawa Aktif Saga (Abrus precatorius) pada Enzim α-Glukosidase sebagai Kandidat Obat Antidiabetes Melitus
Abstrak: Diabetes melitus (DM) adalah penyakit degeneratif yang ditandai dengan tngginya konsentrasi glukosa dalam darah atau dikenal dengan kondisi hiperglikemia yang dalam jangka panjang dapat menyebabkan penyumbatan pada pembuluh darah besar seperti pada jantung dan ginjal. Kondisi hiperglikemia berkaitan dengan kerja enzim yang dapat menghidrolisis karbohidrat menjadi glukosa, yaitu enzim α-glukosidase. Untuk mengatasi kondisi hiperglikemia dibutuhkan inhibitor α-glukosidase. Dalam penelitian ini, tanaman saga dikaji sebagai inhibitor α-glukosidase. Saga merupakan tumbuhan yang mengandung flavonoid, triterpenoid, dan sterol yang dipercaya dapat menurunkan kadar glukosa darah. Penelitian ini bertujuan menentukan daya hambat α-glukosidase oleh senyawa aktif saga dengan menggunakan metode penambatan molekuler. Metode yang digunakan adalah preparasi ligan dan reseptor, prediksi toksisitas ligan, validasi penambatan molekuler, dan penambatan molekuler. Hasil penambatan molekuler menunjukkan bahwa isoorientin merupakan ligan dengan potensi terbaik dalam menghambat enzim α-glukosidase.
Keyword: Diabetes mellitus, α-glucosidase, molecular docking, saga

Judul: Hubungan Struktur dan Aktivitas Senyawa Biflavonoid Genus Araucaria sebagai Inhibitor Enzim α-Glukosidase secara In Silico
Abstrak: Diabetes melitus (DM) merupakan penyakit gangguan metabolik yang ditandai dengan tingginya kadar gula dalam darah. Indonesia menempati urutan ke-5 jumlah penderita DM tertinggi di dunia. Acarbose, agen antidiabetik komersial yang bekerja dengan menghambat α-glukosidase, penggunaannya dalam jangka panjang menimbulkan efek samping sehingga senyawa potensial dari bahan alam diperlukan sebagai alternatif. Pengembangan obat baru perlu diprediksi melalui metode in silico agar menghemat biaya dan waktu karena dapat dilakukan dengan cepat secara komputasi. Genus Araucaria, kelompok tanaman yang mengandung biflavonoid, diprediksi dapat menurunkan kadar glukosa darah melalui inhibisi α-glukosidase. Penelitian ini bertujuan mengkaji interaksi molekuler dengan teknik simulasi penambatan molekuler, serta menguji potensi senyawa biflavonoid genus Araucaria sebagai inhibitor α-glukosidase secara in silico berdasarkan struktur dan gugus fungsinya. Hasil penambatan molekuler menunjukkan bahwa ligan uji (5), diprediksi sebagai ligan yang paling berpotensi sebagai inhibitor α-glukosidase dengan nilai ∆G -8,6 kkal/mol, Ki 0,489 μM, dan Binding Site Similarity 68,75% terhadap keseluruhan residu sekitar reseptor., Diabetes mellitus (DM) is a metabolic disorder characterized by high blood sugar levels. Indonesia ranks 5th with the highest number of DM sufferers in the world. Acarbose, a commercial antidiabetic agent that works by inhibiting α-glucosidase, its long-term use often causes side effects, so potential compounds from natural ingredients need as alternatives. New drug development needs to be predicted through in silico method to save costs and time because it is done computationally fast. The genus Araucaria, a group of plants containing biflavonoids, is predicted to lower blood glucose levels through α-glucosidase inhibition. This study examines the molecular interactions with molecular docking simulation techniques and examines the potential of biflavonoid compounds of the genus Araucaria as α-glucosidase inhibitors using in silico analysis of their structure and functional groups. The molecular docking results showed that the test ligand (5), was predicted to be the ligand with the most potential as an α-glucosidase inhibitor with ∆G -8,6 kcal/mol, Ki 0,489 M, and Binding Site Similarity 68,75% of the total residue around the receptor.
Keyword: α-Glukosidase, Diabetes, Araucaria, Penambatan Molekuler

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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