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: In Silico and In Vitro Analysis of α-Glucosidase Inhibition by Ethanol Extract of Red Ginger (Zingiber officinale var.  Rubrum) from Sukabumi
Abstrak: Indonesia menempati peringkat kelima penderita diabetes melitus terbanyak di dunia sehingga perlu adanya pengobatan antidiabetes yang efektif salah satunya dengan mekanisme penghambatan enzim α-glukosidase. Obat antidiabetes sintetik dalam jangka waktu panjang dapat memberikan efek samping. Oleh karena itu, penggunaan obat herbal perlu dilakukan karena dinilai lebih aman. Jahe merah telah banyak dimanfaatkan dalam bidang medis dan diharapkan berpotensi menghambat aktivitas enzim α-glukosidase. Penelitian ini bertujuan mengukur aktivitas inhibisi enzim α-glukosidase oleh ekstrak etanol jahe merah asal Sukabumi dan menentukan ligan terbaik melalui studi in silico. Penelitian ini dilakukan dengan maserasi dalam etanol 70% dan dilakukan pembacaan absorbansi inhibisi enzim, sedangkan studi in silico dilakukan dengan molecular docking. Hasil penelitian menunjukkan nilai IC50 penghambatan enzim α-glukosidase sebesar 50.139,719 ± 0,481 μg/mL dan didapatkan dua ligan terbaik yaitu 6- shogaol dan 6-gingerol yang memiliki nilai ΔG dan Ki mendekati akarbosa (ligan pembanding terbaik), lolos uji toksisitas, serta berinteraksi dengan banyak situs pengikatan dan situs katalitik yang terletak di dalam poket situs aktif, Indonesia is in the fifth position with the most diabetes mellitus sufferers globally, so effective antidiabetic treatment is needed, such as the mechanism of inhibiting the α-glucosidase enzyme. Synthetic antidiabetic drugs, in the long term, can have side effects. Therefore, the use of herbal medicines is necessary because they are considered safer. Red ginger has been widely used in the medical field, and it has expected to have the potential to inhibit the activity of α-glucosidase. This study aimed to measure the inhibitory activity of α-glucosidase enzyme by the ethanol extract of red ginger from Sukabumi and determine the best ligand through in silico study. This research was carried out by maceration in 70% ethanol and reading the absorbance of enzyme inhibition, while in silico studies were carried out by molecular docking. The results showed that the IC50 value for inhibition of α-glucosidase enzyme was 50.139,719 ± 0.481 μg/mL. Two best ligands were obtained, namely 6-shogaol and 6-gingerol, which had ΔG and Ki values close to acarbose (the best comparison ligand), passed toxicity testing and interacted with many binding sites and catalytic sites that were located in active site pocket
Keyword: α-Glucosidase, Diabetes mellitus, Red Ginger

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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