Judul: Penapisan Virtual Senyawa Polifenol Alami sebagai Inhibitor Beta-Laktamase untuk Penanganan Resistensi Antibiotik BetaLaktam
Abstrak: Pemakaian antibiotik yang tidak sesuai dengan indikasinya dapat menyebabkan resistensi. Beta-laktamase dapat menurunkan efektivitas betalaktam dan menyebabkan resistensi antibiotik. Senyawa polifenol adalah senyawa metabolit sekunder yang banyak ditemukan pada berbagai tanaman dan beberapa diketahui dapat menghambat aktivitas enzim beta-laktamase. Penelitian ini bertujuan menyaring senyawa polifenol alami di data bank molekul yang memiliki potensi terbaik sebagai inhibitor beta-laktamase menggunakan penapisan virtual, pengujian interaksi molekuler, prediksi druglikeness, farmakokinetika, serta toksisitas ligan. Berdasarkan analisis pada 112 ligan uji polifenol alami, didapatkan 6 ligan yang diprediksi potensial sebagai inhibitor beta-laktamase. Trans-resveratrol 3-O-glucuronide memiliki pengikatan paling stabil dengan nilai energi bebas ikatan (ΔG) sebesar -8,1 kkal/mol dan konstanta inhibisi (Ki) sebesar 1,137 µM. Namun, keenam ligan uji terpilih dapat dikategorikan baik dan tidak toksik sehingga dapat menjadi kandidat inhibitor CTX-M beta-laktamase.
Keyword: ADMET, beta-laktamase, natural polyphenolic, virtual screening

Judul: Potensi Senyawa Aktif Sungkai (Peroema canescens) dalam Menginhibisi Enzim Beta-Laktamase Secara In Silico.
Abstrak: Kasus resistensi bakteri terhadap antibiotik menjadi ancaman serius bagi kesehatan manusia karena menurunkan efektivitas obat untuk mencegah dan menyembuhkan infeksi bakteri. Resistensi dapat disebabkan oleh pengobatan yang tidak tuntas. Salah satunya yaitu bakteri Escherichia coli yang menghasilkan enzim CTX-M yang merupakan jenis dari beta-laktamase yang menghambat kerja antibiotik golongan beta-laktam. Sungkai merupakan salah satu tanaman obat tradisional dan terbukti menghambat pertumbuhan bakteri Escherichia coli. Penelitian ini bertujuan mengidentifikasi senyawa aktif sungkai yang berpotensi menginhibisi beta-laktamase serta analisis interaksi yang terjadi secara in silico. Senyawa aktif daun sungkai ditambatkan ke reseptor beta-laktamase, kemudian dianalisis interaksinya serta diprediksi bioavailabilitas dan toksisitas. Hasil penelitian menunjukan sebanyak 6 dari 19 ligan uji lolos penapisan hingga akhir dan berpotensi menjadi inhibitor beta-laktamase. Senyawa tersebut antara lain, beta-sitosterol, 3,4’,5-thrihydroxy-3,’,7-dimenthoxyflavanone, physcion, isorhamnetin, chrysoeriol, quercetin 3,3 dimetly ether, dan vintexin-2-O rhamnoside., Cases of bacterial resistance to antibiotic has become a serious threat for human health because they reduce the effectiveness of drugs in preventing and treating bacterial infections. Resistance can be caused by uncomplete treatment. One of example is Escherichia coli bacteria which produces the CTX-M enzyme, that is a type of of beta-lactamase that inhibits the action of beta-lactam antibiotics. Sungkai is one of the traditional medicinal PLANTS and it is proved inhibiting the growth of Escherichia coli. This research aims to identify the active compounds of sungkai that have the potential to inhibits beta-lactamase and analyze interactions of molecular docking. The active compounds of sungkai leaves are docked to the beta-lactamase receptor, then their interactions are analyzed, predicting bioavailability, and toxicity. The results showed that 6 of the 19 tested ligands pass the screening and have the potential to become beta-lactamase inhibitors. The compounds are beta-sitosterol, 3,4’,5-thrihydroxy-3’7-dimenthoxyflavanone, physcion, isorhmaetin, chrysoeriol, quercetin 3,3 dimetly ether, and vintexin-2-O-rhamnoside.
Keyword: resistent, beta-lactamase inhibitors, sungkai

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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