Judul: Inhibition Activity to Cyclooxygenase-2 by The Active Compound of White Teak (Gmelina arborea) Bark In Silico as Anti-Inflammatory
Abstrak: Siklooksigenase-2 (COX-2) berperan mengubah asam arakidonat menjadi prostaglandin yang dapat menimbulkan berbagai tanda inflamasi sehingga dikatakan sebagai mediator inflamasi. Sebanyak enam senyawa kulit kayu jati putih berhasil diisolasi. Beberapa senyawa tersebut memiliki peran antiinflamasi berdasarkan uji in vitro dan in vivo. Penelitian ini bertujuan menganalisis penghambatan COX-2 oleh senyawa kulit kayu jati putih melalui uji in silico dengan metode penambatan molekuler menggunakan YASARA Structure. Hasil penambatan molekuler terhadap enam senyawa sebagai ligan uji menunjukkan bahwa (+)-balanophonin merupakan senyawa yang paling potensial dalam menghambat COX-2 secara selektif. Energi pengikatan (+)-balanophonin bernilai lebih negatif dari energi pengikatan ibuprofen, yaitu bernilai -7,562 kkal/mol dan konstanta disosiasi (Kd) sebesar 2,864 µM. Senyawa (+)-balanophonin menghasilkan berbagai interaksi, seperti ikatan hidrogen, interaksi elektrostatik, interaksi hidrofobik, dan van der Waals dengan residu-residu situs aktif COX-2, serta sifat senyawa tersebut telah memenuhi aturan Lipinski, ADME, dan toksisitas., Cyclooxygenase-2 (COX-2) plays a role in converting arachidonic acid into prostaglandins that can cause various inflammatory signs so it is said to be an inflammatory mediator. Six compounds of white teak bark were successfully isolated. Some of these compounds have anti-inflammatory roles based on in vitro and in vivo tests. This study aims to analyze the inhibition occurs COX-2 by white teak bark compounds through in silico test with molecular docking method using YASARA Structure. The molecular docking results of six compounds show that (+)-balanophonin is the most potential compound in selectively inhibiting COX-2. This is based on a binding energy (+)-balanophonin value more negative than ibuprofen, which is -7,562 kcal/mol and the dissociation constant (Kd) value is 2,864 μM. (+)-Balanophonin produces a variety of interactions, such as hydrogen bonds, electrostatic interactions, hydrophobic interactions, and van der Waals with COX-2 active site residues, and the properties of (+)-balanophonin have complied with Lipinski, ADME, and toxicity rules.
Keyword: (+)-balanophonin, COX-2, inflammation, white teak bark compound

Judul: Prediction of Anti-inflammatory Compounds in Okra Pods (Abelmoschus esculentus L.) in Inhibition of Cyclooxygenase-2
Abstrak: Siklooksigenase-2 (COX-2) mengkatalisis pengubahan asam arakidonat menjadi senyawa mediator inflamasi, seperti prostaglandin (PG). Buah okra memiliki aktivitas antiinflamasi berdasarkan studi in vitro dan in vivo, namun belum diketahui senyawanya yang dapat menginhibisi COX-2. Penelitian ini bertujuan memprediksi aktivitas antiinflamasi senyawa aktif buah okra yang dapat menghambat COX-2 berdasarkan interaksinya dengan residu asam amino sisi aktif, katalitik dan selektif. Perangkat lunak YASARA Structure digunakan untuk penambatan molekuler, sementara Discovery Studio Visualizer dan Pymol digunakan untuk analisis interaksi ligan-reseptor. Penambatan dilakukan pada ukuran gridbox 2,0 Å. Penapisan virtual menghasilkan 16 senyawa aktif buah okra hasil studi pustaka menghambat COX-2 dengan nilai energi bebas pengikatan (ΔG) di atas -6,0 kkal/mol. Hasil ini masih lebih rendah dari asam mefenamat sebagai ligan eksperimental. Kuersetin dan α-cubebene paling potensial menghambat COX-2, dengan nilai ΔG -7,887 dan -7,502 kkal/mol serta Ki 1,63 dan 3,13 μM, namun kelimpahannya rendah di buah okra. Senyawa yang paling melimpah adalah kuersetin-3-O-glukosida (-6,668 kkal/mol), berinteraksi selektif dengan His90, Val523 dan Arg513, sama halnya dengan celecoxib sebagai ligan pembanding., Cyclooxygenase-2 (COX-2) catalyzes the conversion of arachidonic acid into inflammatory mediator compounds, such as prostaglandins (PG). Okra pods has anti-inflammatory activity based on in vitro and in vivo studies, but the compounds that can inhibit COX-2 is not yet known. This study aimed to predict the anti-inflammatory activity of the active compounds of okra pods as COX-2 inhibitor based on their interactions with amino acid residues on the active, catalytic and selective sites. YASARA Structure software was used for molecular docking, while Discovery Studio Visualizer and Pymol were used for ligand-receptor interaction analysis. Molecular docking is done on a gridbox size of 2.0 Å. Virtual screening resulted in 16 active compounds of okra pods from literature study inhibiting COX-2 with binding free energy (ΔG) values above -6.0 kcal/mol. These values is still lower than mefenamic acid as an experimental ligand. Quercetin and α-cubebene were the most potent to inhibit COX-2, with ΔG -7.887 and -7.502 kcal/mol and Ki 1.63 and 3.13 μM, however their abundance was low in okra. The most abundant compound was quercetin-3-O-glucoside (-6,668 kcal/mol) and selectively bind to His90, Val523 and Arg513, similar to celecoxib as a reference ligand.
Keyword: anti-inflammation, COX-2, molecular docking, okra pods, selective

Judul: Analysis of M/M/1 Queue System with Continuous Service
Abstrak: Sistem antrean M/M/1 dengan pelayanan kontinu adalah sistem antrean di mana waktu pengiriman dan layanan secara independen dan menyebar secara eksponensial dengan satu server, sehingga server melayani pelanggan saat pelanggan berada di dalam sistem. Untuk mencapai karakteristik tersebut, diasumsikan di dalam sistem tersebut ada dua jenis pelanggan, yaitu pelanggan nyata dan pelanggan imajiner. dst..., The M/M/1 queueing system with continuous service is a queuing system where delivery and service times are independent and exponentially distributed with one server, so that the server serves the customer while the customer is in the system. To achieve the mentioned characteristics, it is assumed in the system there are two types of customers, namely real customers and imaginary customers. dst...
Keyword: expected value, exponentially, probability density function, queue