Judul: Analisis In Silico Senyawa Flavonoid Kayu Secang (Caesalpinia sappan L.) pada Reseptor α-amilase Sebagai Antidiabetes
Abstrak: Pengujian in vitro dan in vivo kayu secang (Caesalpinia sappan L.) sebagai antidiabetes sudah dilakukan sebelumnya dan memberikan hasil yang efektif, namun mekanismenya pada hewan belum diketahui. Penelitian ini bertujuan menganalisis mekanisme senyawa metabolit kayu secang (Caesalpinia sappan L.) yang dapat menghambat enzim α-amilase pada hewan melalui penambatan molekuler secara in silico. Profil farmakokinetik ligan diprediksi berdasarkan aturan Lipinski. Prediksi toksisitas dilakukan menggunakan admetSAR. Reseptor diperoleh dari basis data PDB (ID 1OSE). Ligan pembanding yang digunakan adalah akarbosa. Penambatan molekuler dilakukan dengan menambatkan ligan uji brazilin, protosappanin B, protosappanin C, dan sappanchalcone pada enzim α-amilase menggunakan Autodock Vina. Penambatan molekuler dianalisis dengan energi ikatan (ΔG), konstanta inhibisi, serta ikatan kimia. Hasil penambatan molekuler menunjukkan semua ligan uji memiliki potensi sebagai antidiabetes. Ligan uji brazilin memiliki aktivitas penghambatan enzim α-amilase lebih baik daripada akarbosa berdasarkan nilai ΔG dan %BSS., In vitro and in vivo assessments on secang wood (Caesalpinia sappan L.) as antidiabetic had been done before and given effective results, but the mechanism in the animals is unknown. This study aims to analyze the mechanism of secang wood (Caesalpinia sappan L.) metabolic compounds that can inhibit the α-amylase enzyme in animals through in silico molecular docking. Ligand pharmacokinetic profiles were predicted based on Lipinski’s rule. Prediction of ligand toxicity was performed using admetSAR. The receptor was obtained from the PDB database with ID 1OSE. The comparative ligand used was acarbose. Molecular docking was performed by tethering the test ligands brazilin, protosappanin B, protosappanin C, and sappanchalcone to the α-amylase enzyme using Autodock Vina. Molecular docking is analyzed by binding affinity (ΔG), inhibition constant, and chemical bonds. The molecular docking results showed that all of the tested ligands had the potential as antidiabetic. The brazilin-tested ligand had better α-amylase inhibitory activity than acarbose based on ΔG and % BSS values.
Keyword: α-amylase, Caesalpinia sappan L., diabetes, molecular docking

Judul: Potensi Senyawa Aktif Kayu Secang (Caesalpinia sappan L.) sebagai Inhibitor Lipase Pankreas In Silico
Abstrak: Obesitas merupakan kondisi abnormal karena adanya penumpukan lemak yang berlebih pada jaringan adiposa. Prevalensi obesitas di Indonesia meningkat dari 14,8% di tahun 2013 menjadi 21,8% di tahun 2018. Obat pelangsing sintetik seperti orlistat bekerja dengan menghambat penyerapan lemak, namun dapat menimbulkan efek samping sehingga diperlukan senyawa alami yang berpotensi sebagai antiobesitas. Penelitian ini bertujuan mengidentifikasi senyawa aktif dalam ekstrak etanol kayu secang (Caesalpinia sappan L.) dengan metode LC-MS/MS QToF dan menentukan senyawa yang berpotensi menginhibisi aktivitas lipase pankreas secara in silico dengan penapisan virtual menggunakan aplikasi YASARA Structure. Hasil penelitian menunjukkan sebanyak 14 senyawa aktif berhasil diidentifikasi dari ekstrak etanol 70% kayu secang dan juga sebanyak 49 senyawa hasil studi literatur digunakan sebagai ligan uji dalam penelitian ini. Simpulan penelitian adalah sebanyak 10 senyawa aktif kayu secang yang terbaik dalam penelitian ini berikatan dengan residu asam amino pada sisi katalitik lipase pankreas, baik itu pada residu Ser152 maupun His263.
Keyword: antiobesitas, Caesalpinia sappan L., in silico, inhibitor lipase pankreas, kayu secang

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