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: Analysis Potency of Red Betel Active Compund as an Inhibitor of Acetylcholinesterase Enzyme Through In Silico
Abstrak: Alzheimer merupakan penyakit yang menyebabkan terjadinya penurunan fungsi kognitif dan merupakan penyebab kematian ketujuh terbesar di dunia. Inhibitor enzim asetilkolinesterase (AChE) merupakan pengobatan alzheimer yang paling banyak berkembang hingga saat ini, namun pengonsumsiannya masih memberikan banyak efek samping. Sirih merah, tanaman yang telah banyak digunakan dalam pengobatan herbal mengandung banyak senyawa aktif yang diharapkan dapat berpotensi sebagai inhibitor AChE. Penelitian ini bertujuan menemukan senyawa aktif sirih merah yang berpotensi dalam menginhibisi enzim AChE secara in silico menggunakan teknik penambatan molekuler. Potensi inhibisi terbaik dimiliki oleh copaene, auron, dan 1,1’-(6,6’-Dihydroxy-5,5’-dimethoxy3,3’-biphenyldiyl)di(1-propanone) dengan nilai ΔG dan Ki berturut-turut sebesar - 7,738; -7,658; dan -5,348 kkal/mol serta Ki 2,045; 2,498; dan 118,9 µM. Ketiga ligan tersebut juga berinteraksi dengan sisi aktif CAS (Catalytic Active Site) atau PAS (Peripheral Aromatic Site) yang berperan penting dalam penghambatan enzim AChE untuk terapi antialzheimer., Alzheimer is a disease that causes the decline of cognitive function and considered as the seventh biggest cause of death in the world. Acetylcholinesterase (AChE) enzyme inhibitors are the most established treatment for alzheimer until now despite its possible side effects. Red betel, a widely used plant in herbal medication, contains many active compounds which are expected to be potential for AChE inhibitors. The study aims to research the active compound of red betel that has the potential to inhibit the AChE enzyme in silico through molecular docking techniques. The finest inhibitory potentials were possessed by copaene, aurone, and 1,1’-(6,6’ -Dihydroxy- 5,5’ -dimethoxy- 3,3’ -biphenyldiyl)di(1- propanone) indicated correspondingly by the value of ΔG and Ki values -7.738; - 7,658; and -5.348 kcal/mol and Ki 2,045; 2,498; and 118,9 µM. Those three ligands also interacted with the active site CAS (Catalytic Active Site) or PAS (Peripheral Aromatic Site) that plays a fundamental role to inhibit the AChE enzyme for antialzheimer therapy.
Keyword: acetylcholinesterase, alzheimer, molecular docking, red betel

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