Judul: Uji Inhibisi Senyawa Alami Kandidat Obat Alzheimer Menggunakan Metode Docking dan Density Functional Theory
Abstrak: Alzheimer’s Disease (AD) atau penyakit alzheimer merupakan penyakit neurogeneratif yang banyak menjangkit individu usia lanjut. Pengobatan AD dilakukan adalah penghambatan kerja enzim asetilkolinesterase agar tidak memperparah kondisi penderita AD. Penelitian ini dilakukan dengan menggunakan metode docking dan perhitungan density functional theory pada senyawa bilobalida, kaempferol, dan ternatin. Senyawa bilobalida memiliki kemampuan berikatan dengan asetilkolinesterase paling baik dibandingkan dengan senyawa alami lainnya dan asetilkolin. Hal ini dibuktikan dengan kedua metode yang dilakukan bahwa bilobalida selalu menjadi peringkat satu dalam kekuatan ikatan dengan asetilkolinesterase dengan energi gibbs docking sebesar -8,1 kcal/mol dan energi gibbs density functional theory sebesar -6496,382 kcal/mol., Alzheimer’s disease (AD) is a neurogenerative disease that affects many elderly individuals. AD treatment is carried out by inhibiting acetylcholinesterase enzyme. This research was conducted by docking method and calculation density functional theory on bilobalide, kaempferol, and ternatin. Bilobalide have the best ability to bind to acetylcholinesterase compared to other natural compounds and acetylcholine. This is poven by the two methods that bilobalide always in the first position in bond strength with acetylcholinesterase with gibbs energy from docking is -8,1 kcal/mol and from density functional theory is -6496,382 kcal/mol.
Keyword: Alzheimer's disease, Acetylcholinesterase, Docking method, Density Functional Theory

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: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite