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: Bioactive Compounds Screening of Cinnamon (Cinnamomum burmannii) as Inhibitor of Acetylcholinesterase Enzyme In Silico
Abstrak: Alzheimer merupakan penyakit progresif dan neurodegeneratif yang banyak menyerang populasi lansia di atas 65 tahun. Patofisiologi Alzheimer dapat terkait dengan penipisan neurotransmitter asetilkolin (ACh) yang disebabkan karena adanya plak beta amiloid dan neurofibrillary tangles. Metabolit sekunder yang terdapat pada kulit kayu manis (Cinnamomum burmannii) berpotensi sebagai antikolinesterase untuk menangani gejala Alzheimer. Penelitian ini bertujuan menapis senyawa bioaktif yang berasal dari kulit kayu manis (Cinnamomum burmannii) secara in silico dengan metode virtual screening dan molecular docking melalui analisis energi ikatan, konstanta inhibisi, dan jenis interaksi. Penelitian menunjukkan bahwa senyawa aktif epicatechin dan medioresinol memiliki potensi terbaik dalam inhibisi AChE dengan afinitas mendekati dengan ligan alami atau pembanding. Epicatechin memiliki energi bebas ikatan sebesar -10,0 kkal/mol dan konstanta inhibisi sebesar 0,0459 μM dengan empat ikatan hidrogen dan tujuh ikatan hidrofobik. Sementara medioresinol memiliki energi bebas ikatan sebesar -9,9 kkal/mol dan nilai Ki sebesar 0,0543 μM dengan satu ikatan hidrogen dan tiga belas ikatan hidrofobik., Alzheimer is a progressive and neurodegenerative disease that mainly affects the elderly population over 65 years. The pathophysiology of Alzheimer's may be related to the depletion of the neurotransmitter acetylcholine (ACh) caused by the presence of beta amyloid plaques and neurofibrillary tangles. Secondary metabolites found in cinnamon (Cinnamomum burmannii) have potential as anticholinesterases to treat Alzheimer's symptoms. This study aims to screen bioactive compounds derived from cinnamon (Cinnamomum burmannii) in silico with virtual screening and molecular docking methods through analysis of bond energies, inhibition constants, and types of interactions. Research shows that the active compounds epicatechin and medioresinol have the best potential for AChE inhibition with affinity close to that of natural or comparison ligands. Epicatechin has an affinity energy of -10,0 kcal/mol and an inhibition constant of 0,0459 M with four hidrogen bonds and seven hydrophobic bonds. Meanwhile, medioresinol has an affinity energy of -9,9 kcal/mol and a Ki value of 0,0543 M with one hidrogen bond and thirteen hydrophobic bonds.
Keyword: Alzheimer, acetylcholinesterase, cinnamon, molecular docking

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