Judul: The Potential of Roselle (Hibiscus sabdariffa L.) Active Compounds as Alzheimer's Therapy Through In-Silico Inhibition of BACE1
Abstrak: Ekstrak rosela telah ditemukan memiliki senyawa aktif yang berpotensi sebagai terapi alzheimer, namun belum ada diketahui mengenai senyawa aktif rosela yang memiliki aktivitas penghambatan terhadap BACE1 (beta-site APP cleaving enzyme 1). BACE1 merupakan salah satu enzim yang berperan dalam patogenesis alzheimer. Penelitian ini bertujuan menganalisis interaksi molekuler metabolit dari rosela terhadap sisi aktif BACE1 melalui virtual screening secara in-silico. Hasil virtual screening didapat energi bebas Gibbs (ΔG) dan KD yang menggambarkan interaksi protein dengan ligan. ΔG paling rendah berdasar interaksi protein dan ligan dimiliki oleh senyawa cyanidin 3-(6”-(E)-caffeylsambubioside) dengan nilai sebesar -10,6480 kkal/mol dan nilai konstanta disosiasi (KD) sebesar 15,90 nM. Ligan terseleksi memiliki ΔG lebih negatif dari ligan pembanding Verubecestat. Semua ligan terseleksi tidak lolos uji Lipinski, tetapi memiliki skor bioavailabilitas cukup baik. Metabolit dari tanaman Rosela atau Hibiscus sabdariffa L. kurang berpotensi menginhibisi protein BACE1 pada sisi aktif dan sebagai terapi Alzheimer., Roselle extract has been found to contain active compounds with potential as therapeutic agents for Alzheimer's disease, but nothing is known about the compound which have inhibitory activity against BACE1 (beta-site APP-cleaving enzyme 1). BACE1 is one of the enzymes involved in the pathogenesis of Alzheimer's disease. This study aims to analyze the molecular interactions of roselle metabolites at the active site of BACE1 by virtual screening. Virtual screening results yielded the Gibbs free energy (ΔG) and KD that describe the protein-ligand interaction. The lowest ΔG based on protein-ligand interactions is cyanidin 3-(6"-(E)-caffeylsambubioside) with a value of -10.6480 kcal/mol and a dissociation constant (KD) value of 15.90 nM. All selected ligands have ΔG more negative than Verubecestat. All selected ligands didn’t pass the Lipinski test, but had good bioavailability values. Metabolites of Roselle or Hibiscus sabdariffa L. are less likely to inhibit the active site of BACE1 protein and as Alzheimers’ therapy.
Keyword: alzheimer, BACE1, Hibiscus sabdariffa L., rosela, roselle

Judul: Molecular Docking of the Active Compound of Red Betel (Piper crocatum) on Butyrylcholinesterase as an Antialzheimer's Candidate
Abstrak: Jenis demensia yang sering dialami oleh orang lanjut usia (lansia), salah satunya yaitu penyakit Alzheimer. Penderita penyakit Alzheimer ditandai dengan penurunan fungsi kognitif, memori, dan perubahan perilaku secara permanen. Komponen aktif yang terkandung dalam daun sirih merah memiliki keterkaitan dalam menghambat enzim butirilkolinesterase (BChE). BChE adalah salah satu enzim yang berperan penting dalam penanganan penyakit Alzheimer yang dikaitkan dengan patologis Alzheimer, yaitu hipotesis kolinergik. Penelitian ini bertujuan menguji daya inhibisi senyawa aktif yang terkandung dalam daun sirih merah terhadap aktivitas enzim BChE melalui pendekatan simulasi penambatan molekuler. Metode yang digunakan pada penelitian melalui penggabungan metode penapisan virtual dan penambatan molekuler sebagai tahapan awal pengembangan daun sirih merah melalui penghambatan enzim BChE. Hasil yang telah diperoleh pada penelitian ini, yaitu daya inhibisi terbaik dimiliki oleh 1,2,3,4,5,6,7- heptazacycloicosane sebesar 0,4888 µM dan diperoleh energi bebas pengikatan sebesar -8,6 kkal mol-1 . Residu yang terlibat pada pengikatan substrat oleh ligan uji dengan enzim BChE, yaitu Tyr-332 dan Trp-82., Alzheimer’s disease is a type of dementia experienced by a significant portion of the world’s population. Alzheimer’s is characterized by a permanent decline in cognitive function, memory, and behavioral changes. The active components contained in red betel leaf are linked to inhibiting the butyrylcholinesterase (BChE) enzyme. According to the cholinergic hypothesis, BChE is an enzyme that may play an important role in the etiology and treatment of Alzheimer’s disease. The aim of the study was to test the inhibitory power of the active compound contained in red betel leaf against BChE through a molecular docking simulation approach. The method used in this research was a combination of virtual screening and molecular docking. The result obtained with the best inhibition were 1,2,3,4,5,6,7-heptazacycloicosane of 0,4888 µM and a binding free energy of -8,6 kkal mol-1. The amino acids involved in binding the substrate by the test ligand to BChE were Tyr-332 and Trp-82.
Keyword: antialzheimer, butirilkolinesterase, sirih merah, antialzheimer, butyrylcholinesterase, Piper crocatum

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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