Judul: Aktivitas Antagonis Senyawa Aktif Kayu Secang (Caesalpinia sappan L.) Terhadap Reseptor Androgen In Silico Sebagai Antikanker Prostat
Abstrak: Kanker prostat merupakan pertumbuhan sel yang tidak normal akibat mutasi gen yang meregulasi proses proliferasi pada sel epitel prostat, serta dipengaruhi oleh hormon androgen dan reseptornya. Penelitian ini bertujuan menentukan senyawa aktif kayu secang (Caesalpinia sappan L.) yang berpotensi sebagai antikanker prostat melalui penghambatan reseptor androgen secara in silico. Sebanyak 35 senyawa aktif kayu secang diperoleh dari publikasi, kemudian ditambatkan secara molekuler pada reseptor androgen menggunakan perangkat lunak PLANTS. Hasil penelitian menunjukkan senyawa aktif sappanone B menjadi senyawa yang paling potensial sebagai antikanker prostat karena memiliki aktivitas antagonis dengan tidak membentuk ikatan hidrogen pada Asn705 dan Thr877 serta memiliki nilai penambatan -93,1328. Nilai tersebut lebih negatif dibandingkan ligan alami dihidrotestosteron dengan nilai penambatan -92,2929 dan ligan pembanding bikalutamida dengan nilai penambatan -83,2453, sehingga berpotensi memiliki afinitas ikatan antagonis terhadap reseptor androgen yang lebih kuat., Prostate cancer is an abnormal cell growth due to gene mutations that regulate the proliferation process in prostate epithelial cells, and is influenced by androgen hormone and its receptors. This study aims to determine the active compounds of sappan wood (Caesalpinia sappan L.) that have potential as prostate anticancer through androgen receptor inhibition in silico. A total of 35 active compounds of sappan wood were obtained from publications, then molecularly docked to androgen receptors using PLANTS software. The results showed that sappanone B is the most potential compound as a prostate anticancer because it has antagonistic activity by not forming hydrogen bonds on Asn705 and Thr877 and has a docking score of -93.1328. This value is more negative than the natural ligand dihydrotestosterone with a docking score of -92.2929 and the comparative ligand bicalutamide with a docking score of -83.2453, so it has the potential to have a stronger antagonistic binding affinity to androgen receptors.
Keyword: Androgen, Caesalpinia sappan L., Kanker Prostat, Penambatan Molekuler, Sappanone B

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: Utilization of terra/MODIS L1B data for analysis of horizontal wind profile in the troposphere
Abstrak: This study was concerned with horizontal wind derived from data collected with the Moderate-resolution Imaging Spectroradiometer (MODIS) on board the NASA’s Earth Observation System (EOS)-Terra satellite. The aim of this study is to develop a method for the estimation of horizontal wind movement in the troposphere based on Navier-Stokes equation. The method was applied to a calibrated and geolocated Terra/MODIS L1B 1 km data set. The data inputs to estimate surface temperature are retrieved from TIR (Thermal Infrared) bands 31 (10.780 μm to 11.280 μm) and 32 (11.770 μm to 12.270 μm). The obtained surface temperatures were later used to approximate geopotential height on a constant-pressure surface by using the modified Poisson equation. The main assumptions used are the hydrostatic equilibrium, ideal gas law, constant lapse rate and constant acceleration of gravity. Based on the distribution of geopotential height, the pressure gradient force is measured by the gradient of geopotential on an isobaric coordinate to present the horizontal wind profile. For certain topographic areas especially in the mountain ranges, there was a disadvantage of using pressure as a vertical coordinate which lead to inaccuracy. In spite of that, Terra/MODIS L1B data with 1 km spatial resolution can be used to estimate the horizontal wind movement in the troposphere.
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