Judul: Uji Potensi Inhibisi Ekstrak Daun Sirih Merah terhadap Lipase Pankreas sebagai Antiobesitas secara In Silico
Abstrak: Obesitas menjadi pemicu munculnya berbagai penyakit degeneratif, seperti stroke, jantung, diabetes tipe 2, dan resistensi insulin. Inhibitor lipase pankreas merupakan agen obat antiobesitas dengan kerja menginhibisi enzim lipase pankreas. Penelitian ini bertujuan melakukan pencarian dan prediksi aktivitas inhibisi terhadap lipase pankreas dari senyawa aktif daun sirih merah. Penelitian dimulai dengan penapisan virtual 60 ligan uji, prediksi stabilitas dan toksisitas ligan, validasi penambatan molekuler, penambatan molekuler, dan visualisasi 2D serta 3D. Hasil menunjukkan bahwa benzethonium octyloxyacetate, hydroxybenzoic acid β-D-glucosyl ester, dan anthocyanins memiliki potensi terbaik dalam menginhibisi enzim lipase pankreas berdasarkan penapisan virtual, stabilitas ligan, toksisitas ligan, energi afinitas, jumlah ikatan hidrogen dengan sisi aktif, jarak ikatan, dan konstanta inhibisi (Ki). Benzethonium octyloxyacetate memiliki nilai afinitas sebesar -8 kkal/mol, memiliki interaksi ikatan hidrogen pada residu His349 sisi aktif reseptor lipase pankreas (6KSM) dengan jarak ikatan 2,94 Å, dan nilai Ki sebesar 1,347 μM., Obesity triggers the emergence of various degenerative diseases, such as stroke, heart disease, type 2 diabetes, and insulin resistance. Pancreatic lipase inhibitors are anti-obesity drug agents that work by inhibiting pancreatic lipase enzymes. This study aims to search and predict the inhibitory activity of pancreatic lipase from the active compound of red betel leaf. The research began with virtual screening of 60 test ligands, prediction of ligand stability and toxicity, validation method of molecular docking, molecular docking, 2D and 3D visualization. The results showed that benzethonium octyloxyacetate, hydroxybenzoic acid β-D-glucosyl ester, and anthocyanins had the best potential in inhibiting pancreatic lipase enzymes based on virtual screening, ligand stability, ligand toxicity, energy affinity, number of hydrogen bonds with active site, bond distance, and constants inhibition (Ki). Benzethonium octyloxyacetate has an affinity value of -8 kcal/mol, has a hydrogen bond interaction on the His349 residue on the active site of the pancreatic lipase receptor (6KSM) with a bond distance of 2,94 Å and Ki value of 1,347 μM.
Keyword: molecular docking, pancreatic lipase, obesity, red betel

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: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
Keyword: