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Kanker payudara merupakan suatu keadaan dimana sel telah kehilangan pengendalian dan mekanisme normalnya, sehingga terjadi pertumbuhan yang tidak normal, cepat, dan tidak terkendali pada jaringan payudara. Kanker payudara dapat menyebabkan kematian pada kaum wanita. Andrographolide merupakan salah satu senyawa antikanker yang terkandung pada tanaman sambiloto ( Andrographis Paniculata (Burm F) Ness.). Adapun reseptor Human Epidermal Growth Factor Receptor 2 (HER-2) merupakan resepor yang memiliki peranan penting pada kanker payudara. Tujuan pada peneitian ini adalah untuk mengetahui afinitas dan interaksi antara senyawa Andrographolide dan Dendronpholide G dengan reseptor HER-2 secara in silico . Pada penelitian ini dilakukan identifikasi sifat fisikokimia senyawa Andrographolide dan Dendronpholide G dengan menggunakan server swiss-ADME. Kemudian senyawa tersebut dioptimasi menggunakan software Avogadro. Setelah mendapatkan konformasi senyawa uji terbaik kemudian dilakukan tahap selanjutnya yaitu simulasi molecular docking menggunakan reseptor HER-2 terhadap senyawa uji menggunakan software MGL Tools 1.5.6 yang dilengkapi Autodock Tools 4.2. Adapun hasil penelitian yang diperoleh yaitu interaksi yang terjadi pada senyawa uji Andrographolide menghasilkan energi bebas ikatan sebesar −5,42 Kcal/mol dan nilai konstanta inhibisi 105,72 nM, sedangkan Dendranpholide G menghasilkan energi bebas ikatan sebesar −3,67 Kcal/mol dan nilai konstanta inhibisi 2,05 µM. Interaksi pada senyawa Andrographolide dan Dendranpholide G dengan reseptor HER-2 yaitu 1 ikatan hidrogen (MET801) dan terdapat 4 interaksi hidrofobik (MET801, LEU726, ALA751, LEU852). Hasil dari simulasi molecular docking dapat diprediksi bahwa senyawa Andrographolide memiliki afinitas yang baik dibandingkan senyawa Dendranpholide G maka dapat dinyatakan sebagai kandidat antikanker payudara.

The target for COVID-19 has been successfully crystallized along with its inhibitor, named SARS-CoV-2 main protease, making it easier for drug discovery and development. Sponge (Clathria Sp.) is a marine species that can be found in Indonesia and has a unique chemical structure that is still rarely explored in its properties. Therefore, this study aims to examined the potential of marine natural products from sponge (Clathria Sp.) as SARS-CoV-2 main protease inhibitor using in silico method. The ligand structures were obtained from the Knapsack database and the protein structure obtained from the RCSB site with the PDB code: 6LU7. The molecular docking method was validated by re-docked the native ligand and calculated the RMSD value. The compounds contained in Sponge were docked into the active site of the protein based on the validated methods. Afterward, the molecular dynamics were performed for 100 ns simulation, then analyzed its system complex stability. The RMSD 1.329 A was obtained by re-docked of native ligand which indicates that the docking method was valid. Molecular docking of the ligands showed mirabilin_G has binding energy -7.38 kcal/mol, compared to the native ligand N3 inhibitor that is -7.30 kcal/mol, and the ligand showed good stability from molecular dynamics simulation indicated by RMSD, RMSF and MM-PBSA binding free energy similar to the inhibitor during 100 ns simulation. Its indicated the potential of the compounds contained in the sponge as inhibitor of SARS-CoV-2 main protease.Communicated by Ramaswamy H. Sarma.

Resistensi antibiotika muncul sebagai polemik yang dapat mempengaruhi kesehatan manusia. Kemajuan teknologi membuka peluang dalam penemuan molekul senyawa baru yang mampu mencegah perkembangan mikroba patogen, seperti Pseudomonas aeruginosa yang resisten terhadap beberapa jenis antibiotika. Terapi fotodinamika dengan memanfaatkan penggunaan fotosensitizer yang berasal dari senyawa yang membentuk kompleks dengan besi merupakan salah satu pendekatan alternatif untuk mengatasi penyakit infeksi dengan risiko resistensi mikroba yang lebih rendah. Penelitian yang dilakukan secara in silico ini bertujuan untuk mengamati, mengeksplorasi, dan mengevaluasi mekanisme aksi berbasis struktural dari molekul senyawa yang membentuk kompleks dengan besi, yaitu besi-ftalosianina dan besi-salofen terhadap protein hemofor HasAp serta pengaruh molekularnya terhadap bagian situs aktif pengikatan dari protein hemofor HasR. Identifikasi interaksi molekuler dan afinitas antara molekul senyawa besi-ftalosianina dan besi-salofen terhadap protein hemofor HasAp dilakukan dengan simulasi ligan-protein docking mempergunakan software MGLTools 1.5.6 yang dilengkapi dengan AutoDock 4.2. Di samping itu, dilakukan juga simulasi protein-protein docking terhadap sistem kompleks ligan-protein untuk memastikan pengaruh molekularnya terhadap bagian situs aktif pengikatan dari protein hemofor HasR dengan mempergunakan software PatchDock. Berdasarkan simulasi ligan-protein docking diperoleh hasil bahwa senyawa besi-ftalosianina memiliki afinitas paling baik terhadap kedua protein hemofor HasAp, dengan nilai energi bebas pengikatan masing-masing sebesar −68,45 kJ/mol dan −65,23 kJ/mol. Menariknya, hasil simulasi protein-protein docking antara kompleks molekul senyawa besi-ftalosianina dan protein hemofor HasAp-besi-ftalosianina terhadap protein hemofor HasR memiliki nilai energi kontak atom yang positif sebesar 556,56 kJ/mol. Dari penelitian ini dapat diprediksikan bahwa perbedaan struktur molekul senyawa yang membentuk kompleks dengan besi mampu mempengaruhi mekanisme aksi berbasis structural terhadap protein hemofor target.

The COVID-19 pandemic has become a serious problem today, with its prevalence increasing every day. The SARS-CoV-2 main protease (MPro) is a promising therapeutic target to inhibit replicating and spreading the virus that causes COVID-19. The compounds contained in the Etlingera elatior plant has the potential. This study aimed to examine the compounds' activity in E. elatior against SARS-CoV-2 MPro using in silico methods. A total of seven compounds contained in E. elatior were obtained from the Knapsack database. The compounds were then docked into the SARS-CoV-2 MPro receptor's active site with the PDB ID 6LU7. Afterward, the biological activities were predicted by the PASS prediction webserver. The molecular docking results showed that ergosterol peroxide and sitostenone had the best binding energy with -10.40 kcal/mol and -9.17 kcal/mol, respectively. The in silico PASS prediction showed it has potential as antiviral therapy. It concluded ergosterol peroxide and sitostenone has the potential as SARS-CoV-2 MPro inhibitor candidate.

A pandemic coronavirus disease of 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now been declared a global pandemic by the World Health Organization. The search for new drugs, especially by utilizing antiviral peptides is a very potential area. Through this study, protein-peptide docking and protein-protein docking simulations were conducted using in silico methods to identify, evaluate, and explore the molecular affinity and interaction of dermaseptin peptide molecules produced by frogs of the genus Phyllomedusa against the SARS-CoV-2 spike protein macromolecule, and its effect on attachment to the surface of the ACE-2 (Angiotensin Converting Enzyme-2) receptor. Protein-peptide docking simulation results show that dermaseptin-S9 peptide molecule has the best affinity to the active site of SARS-CoV-2 spike protein macromolecule binding site, with a binding free energy value of −792.93 kJ/mol. Then the results of protein-protein docking simulations proved that dermaseptin-S9 peptide molecule was able to prevent the attachment of SARS-CoV-2 spike protein to the surface of the ACE-2 receptor, with a total energy value of 517.85 kJ/mol. Therefore, it is hoped that dermaseptin-S9 peptide molecule can be further studied in the development of novel antiviral peptide candidates for the control of COVID-19 infectious disease.

Background: The emergence of infectious diseases caused by SARS-CoV-2 has resulted in more than 90,000 infections and 3,000 deaths. The coronavirus spike glycoprotein encourages the entry of SARS-CoV-2 into cells and is the main target of antivirals. SARS-CoV-2 uses ACE2 to enter cells with an affinity similar to SARS-CoV, correlated with the efficient spread of SARS-CoV-2 among humans.Objective: In the research, identification, evaluation, and exploration of the structure of SARS-CoV and SARS-CoV-2 spike glycoprotein macromolecules and their effects on Angiotensin-Converting Enzyme 2 (ACE-2) using in silico studies.Methods: The spike glycoproteins of the two coronaviruses were prepared using the BIOVIA Discovery Studio 2020. Further identification of the three-dimensional structure and sequencing of the macromolecular spike glycoprotein structure using Chimera 1.14 and Notepad++. To ensure the affinity and molecular interactions between the SARS-CoV and SARS-CoV-2 spike glycoproteins against ACE-2 protein-protein docking simulations using PatchDock was accomplished. The results of the simulations were verified using the BIOVIA Discovery Studio 2020.Results: Based on the results of the identification of the macromolecular structure of the spike glycoprotein, it was found that there are some similarities in characteristics between SARS-CoV and SARS-CoV-2. Protein-protein docking simulations resulted that SARS-COV-2 spike glycoprotein has the strongest bond with ACE-2, with an ACE score of −1509.13 kJ/mol.Conclusion: Therefore, some information obtained from the results of this research can be used as a reference in the development of SARS-CoV-2 spike glycoprotein inhibitor candidates for the treatment of infectious diseases of COVID-19.

Citrus peels contain various phytochemical active compounds such as flavonoids that are useful for antiaging cosmetic products. This study was conducted to identify the anti-collagenase and anti-elastase activities of flavonoid compounds in citrus peel and to determine the molecular interaction mechanism using the molecular docking method. The study was carried out through several stages, including preparation of enzyme macromolecules, preparation of flavonoid compound molecules, validation of molecular docking, identification of binding-free energy, visualization of interaction conformations, and predictions of molecular skin toxicity. The result showed that the flavonoid compounds in citrus peel (hesperidin, naringin, nobiletin, and tangeretin) could bind to collagenase and elastase enzymes. Naringin has the highest affinity for the collagenase enzyme with the binding-free energy of −9.52 kcal/mol, while nobiletin has the highest affinity for the elastase enzyme with the binding-free energy of −6.44 kcal/mol. Compared to EGCG (epigallocatechin gallate), the flavonoid compounds have a lower affinity for the collagenase enzyme but a higher affinity for elastase enzymes. Hydrogen bonds and the hydrophobic interactions dominate the interaction between citrus peel’s flavonoids against the enzymes. When applied to the skin, flavonoid compounds are predicted to have no risk of skin toxicity. The flavonoid compounds of citrus peels are expected to have anti-collagenase and anti-elastase activities.

The main protease of the SARS-CoV-2 virus, SARS-CoV-2 Mpro, can be discovered as a promising target to treat the COVID-19 pandemic. The peptide-based inhibitors may present better options than small molecules for inhibits SARS-CoV-2 Mpro. Ziziphus spina-christi species reported have a peptide-based of alkaloids group, i.e. Amphibine that the analogues can be identified the potential as an inhibitor of SARS-CoV-2 Mpro. The compound structure was drawn and optimized using semi-empirical AM-1 method using Quantum ESPRESSO v.6.6, then the biological activity using PASS Prediction server and molecular docking simulation using MGLTools 1.5.6 with AutoDock 4.2 were performed. Afterward, the ADME profiles were predicted using the SWISS-ADME server. PASS server was predicting Amphibine B-F and H showed potency both as antiviral and as a protease inhibitor. The molecular docking simulation of Amphibine analogues showed lower binding energy than the native ligand. The binding energy of the native ligand was −7.69 Kcal/mol compared to the lowest binding energy of Amphibine analogues was −10.10 Kcal/mol (Amphibine-F). The ADME prediction showed, as an oral drug Amphibine-F has the best bioavailability, Amphibine-B, C, and D have good bioavailability, and Amphibine-E and H have poor bioavailability. Concluded, Amphibine B-F and H of Amphibine analogues showed potency as COVID-19 treatment targeting SARS-CoV-2 Mpro.

Nuclear receptor REV-ERBβ is an overexpressed oncoprotein that has been used as a target for cancer treatment. The metal-complex nature of its ligand, iron protoporphyrin IX (Heme), enables the REV-ERBβ to be used for multiple therapeutic modalities as a photonuclease, a photosensitizer, or a fluorescence imaging agent. The replacement of iron with cobalt as the metal center of protoporphyrin IX changes the ligand from an agonist to an antagonist of REV-ERBβ. The mechanism behind that phenomenon is still unclear, despite the availability of crystal structures of REV-ERBβ in complex with Heme and cobalt protoporphyrin IX (CoPP). This study used molecular dynamic simulations to compare the effects of REV-ERBβ binding to Heme and CoPP, respectively. The initial poses of Heme and CoPP in complex with agonist and antagonist forms of REV-ERBβ were predicted using molecular docking. The binding energies of each ligand were calculated using the MM/PBSA method. The computed binding affinity of Heme to REV-ERBβ was stronger than that of CoPP, in agreement with experimental results. CoPP altered the conformation of the ligand-binding site of REV-ERBβ, disrupting the binding site for nuclear receptor corepressor, which is required for REV-ERBβ to regulate the transcription of downstream target genes. Those results suggest that a subtle change in the metal center of porphyrin can change the behavior of porphyrin in cancer cell signaling. Therefore, modification of porphyrin-based agents for cancer therapy should be conducted carefully to avoid triggering unfavorable effects.

The emergence of multidrug-resistant Mycobacterium tuberculosis (MTB) has become a major problem in treating tuberculosis (TB) and shows the need to develop new and efficient drugs for better TB control. This study aimed to use in silico techniques to discover potential inhibitors to the Enoyl-[acyl-carrier-protein] reductase (InhA), which controls mycobacterial cell wall construction. Initially, 391 quercetin analogs present in the KNApSAck_3D database were selected, filters were sequentially applied by docking-based virtual screening. After recategorizing the variables (bond energy prediction and molecular interaction, including hydrogen bond and hydrophobic bond), compounds C00013874, C00006532, and C00013887 were selected as hit ligands. These compounds showed great hydrophobic contributions, and for each hit ligand, 100 ns of molecular dynamic simulations were performed, and the binding free energy was calculated. C00013874 demonstrated the greatest capacity for the InhA enzyme inhibition with ΔGbind = −148.651 kcal/mol compare to NAD (native ligand) presented a ΔGbind = −87.570 kcal/mol. These data are preliminary studies and might be a suitable candidate for further experimental analysis.

Glimepiride is often combined with metformin HCl as an oral antidiabetic in type II diabetes mellitus, which provides a complementary and synergistic effect with multiple targets for insulin secretion. Glimepiride includes class II of BCS, which solubility practically insoluble in water but high permeability, which will impact the drug's small bioavailability. In contrast, metformin HCl includes class III of BCS, which has a high solubility in water, but low permeability is absorbed approximately 50-60% in the digestive tract given orally. The co-crystallization method can be used to improve the glimepiride solubility properties and the permeability properties of metformin HCl by interrupting glimepiride with metformin HCl physically. This study aims to identify the physical interactions between glimepiride and metformin HCL using a thermal analysis of Differential Scanning Calorimetry (DSC) and then confirmed by a computational approach. Identifying the physical interactions between glimepiride and metformin HCL was carried out by plotting the melting points generated from the endothermic peaks of the DSC thermogram at various compositions versus the mole ratios of the two were further confirmed by the computational approach using PatchDock. The results of the phase diagram analysis of the binary system between glimepiride and metformin HCl show a congruent pattern, which indicates the formation of co-crystal or molecular compounds at a 1 : 1 mole ratio at 228°C. Computational approach results showed that the interaction between glimepiride and metformin HCl did not form new compounds but heterosinton formation that was stable in molecular dynamics simulations.

Anticoagulants are very important for the treatment and prevention of thrombotic disorders. The use of conventional anticoagulants like heparin and warfarin can cause bleeding complications. To find safer anticoagulant therapy agents, the development of isolation of new anticoagulant compounds has shifted towards natural sources. Bioactive peptides can be considered a better alternative because of their therapeutic potential in the treatment of various diseases. Several peptide molecules have been shown to inhibit the cytochrome P450 (CYP) 2C9 enzyme as a natural anticoagulant, such as bioactive peptides produced by yellowfin sole (Limanda aspera) and bioactive peptides in blue mussel (Mytilus edulis). This study aims to identify and evaluate the interactions that occur between peptide molecules with the cytochrome P450 (CYP) 2C9 enzyme using protein-peptide docking methods. Bioactive peptide sequencing was modeled using the PEP-FOLD software. The best conformation was chosen for an interaction study against the macromolecule of cytochrome P450 (CYP) 2C9 enzyme using PatchDock software. Further observations were made of interactions formed using BIOVIA Discovery Studio 2020 software. Based on the results of protein-peptide docking, the yellowfin sole peptide molecule has a good affinity against the macromolecule of cytochrome P450 (CYP) 2C9 enzyme, with an ACE score of −2527.01 kJ / mol. Therefore, the bioactive peptide is predicted to be used as a candidate for the cytochrome P450 (CYP) 2C9 enzyme inhibitor.

The new coronavirus (SARS-CoV-2), which caused the global pandemic Coronavirus Disease-2019 (COVID-2019), has infected nearly 206 countries. There is still little information about molecular compounds that can inhibit the development of infections caused by this disease. It is crucial to achieving the discovery of competent natural inhibitor candidates, such as antiviral peptides, because they have a variety of biological activities and have evolved to target biochemical machinery from different pathogens or host cell structures. In silico studies will be carried out, including protein-peptide docking and protein-protein docking, to identify, evaluate, and explore the affinity and molecular interactions of the Magainin-1 and Magainin-2 peptide molecules derived from frog skin (Xenopus laevis) to the main protease macromolecule (Mpro) SARS-CoV-2, and its effect on the ACE-2 receptor (Angiotensin Converting Enzyme-2 Receptor). Protein-peptide docking simulations show that both peptide molecules have a good affinity for the active site area of the SARS-CoV-2 Mpro macromolecule. These results were then confirmed using protein-protein docking simulations to observe the ability of the peptide molecule in preventing attachment to the ACE-2 receptor surface area. In silico studies show that Magainin-2 has the best affinity, with a bond free energy value of −3054.53 kJ/mol. Then the protein-protein docking simulation provided Magainin-2 was able to prevent the attachment of ACE-2 receptors, with an ACE score of 1697.99 kJ/mol. Thus, through in silico research, it is hoped that the Magainin peptide molecule can be further investigated in the development of new antiviral peptides for the treatment of infectious diseases of COVID-19.

Limbah kulit buah cokelat diketahui mengandung berbagai senyawa aktif, termasuk di antaranya adalah golongan flavonoid. Senyawa flavonoid diketahui berpotensi memiliki aktivitas inhibitor enzim tirosinase, suatu enzim yang menstimulasi proses pembentukan melanin. Penelitian ini bertujuan untuk mengevaluasi interaksi antara senyawa flavonoid dari kulit buah cokelat dengan enzim tirosinase menggunakan metode penambatan molekuler secara in silico. Pengujian dilakukan dengan beberapa tahapan yakni preparasi makromolekul enzim, pemodelan molekul senyawa uji, identifikasi sisi aktif molekul enzim, identifikasi dan evaluasi penambatan molekuler, serta simulasi dinamika molekuler senyawa uji dengan molekul enzim. Hasil simulasi penambatan molekuler antara molekul enzim dengan ligan alaminya yakni tirosin memberikan energi ikatan sebesar -4,91 kkal/mol. Senyawa flavonoid dari kulit buah cokelat yakni apigenin, epikatekin, katekin, kaemferol, kuersetin, dan kuersitrin diketahui memiliki afinitas pada sisi aktif enzim tirosinase dengan energi ikatan berturut turut -6,14; -6,17; -6,01; -5,89; -6,13; -6,81 kkal/mol. Hasil simulasi dinamika molekuler menunjukkan kuersitrin memiliki stabilitas yang baik dengan nilai RMSD rata-rata dan nilai energi bebas ikatan MM/PBSA masing-masing sebesar ±1,73 Å dan -80,12 kJ/mol. Hasil penelitian menunjukkan bahwa senyawa turunan flavonoid tersebut mampu berikatan dengan sisi aktif enzim tirosinase dengan afinitas yang lebih baik dibandingkan dengan ligan alaminya diamati dari nilai energi ikatannya. Senyawa turunan flavonoid yang terkandung dalam kulit buah cokelat berpotensi menjadi inhibitor kompetitif dari enzim tirosinase.Identification of In Silico Tyrosinase Inhibitory Activity of Flavonoid Derivative Compounds in Cocoa Pod Husk (Theobroma cacao L.). Cocoa pod husk was known to contain several active compounds, such as flavonoids. Flavonoid compounds are known to potentially have inhibitory activity of the tyrosinase, the enzyme which stimulates melanin synthesis.This study was conducted to evaluate the molecular interaction between flavonoids from cocoa pod husk with tyrosinase enzyme using in silico molecular docking method. The study was carried out through several stages, including preparation of enzyme macromolecules, modeling the molecule of the test compound, identifying the active site of the enzyme molecule, identifying and evaluating molecular docking, and molecular dynamics simulations of the test compound with the enzyme molecule. Molecular docking simulation between the enzyme and its natural ligand (tyrosine) produces binding energy of -4.91 kcal/mol. Flavonoid compounds from cocoa pod husk, including apigenin, epicatechin, catechin, kaempferol, quercetin, dan quercitrin, have an affinity on the active site of the enzyme with binding energy were -6.14; -6.17; -6.01; -5.89; -6.13; -6.81 kcal/mol, respectively. Then the molecular dynamics simulation shows quercitrin has good stability interaction with the average RMSD value and the MM/PBSA binding-free energy values of ±1.73 Å and -80.12 kJ/mol, respectively. The results showed that flavonoids of cocoa pod husc extract have an affinity to the active site of the enzyme, with a stronger binding energy than the original ligand. The flavonoid compounds of cocoa pod husk potential as a competitive inhibitor of the tyrosinase enzyme.

Bakteri patogen seperti Pseudomonas aeruginosa membutuhkan zat besi untuk dapat mempertahankan kelangsungan hidupnya. HasAp merupakan suatu protein yang dihasilkan oleh bakteri patogen sebagai sumber zat besi tersebut. Protein HasAp selanjutnya akan berikatan dengan protein membran luar yaitu HasR untuk dapat meneruskan sinyal pada sel bakteri. Penyerapan zat besi pada bakteri patogen ini dapat menjadi strategi pengembangan metode terapi dalam mengendalikan dan mencegah penyakit infeksi yang disebabkan oleh bakteri patogen Pseudomonas aeruginosa, salah satunya dengan memanfaatkan ftalosianina sebagai photosensitizer pada terapi fotodinamika. Penelitian ini bertujuan untuk mengidentifikasi, mengevaluasi, dan mengeksplorasi mekanisme aksi senyawa ftalosianina terhadap protein HasAp, serta pengaruhnya pada bagian sisi aktif HasR dengan menggunakan studi in silico. Studi ligan-protein docking dilakukan dengan menggunakan perangkat lunak MGLTools 1.5.6 yang dilengkapi dengan AutoDock 4.2 untuk mengamati afinitas dan interaksi molekuler antara molekul senyawa Fe-ftalosianina (Fe-Pc) dan Ga-ftalosianina (Ga-Pc) terhadap makromolekul protein HasAp. Selanjutnya, studi protein-protein docking dilakukan terhadap sistem kompleks ligan-protein untuk mengamati pengaruhnya terhadap area pengikatan dari makromolekul protein HasR dengan menggunakan perangkat lunak PatchDock. Berdasarkan hasil ligan-protein docking, senyawa Fe-ftalosianina (Fe-Pc) memiliki afinitas paling baik terhadap kedua protein HasAp, yaitu dengan nilai masing-masing -68,45 kJ/mol dan -69,16 kJ/mol. Kemudian, hasil studi protein-protein docking antara kompleks senyawa Fe-ftalosianina (Fe-Pc) dan protein HasAp terhadap protein HasR memiliki nilai Atomic Contact Energy (ACE) positif, yaitu 556,56 kJ/mol. Perbedaan struktur molekul senyawa ftalosianina terbukti mampu mempengaruhi mekanisme aksi terhadap protein target, sehingga hasil studi ini dapat menjadi acuan dalam mendesain struktur senyawa ftalosianina sebagai kandidat photosensitizer dalam terapi fotodinamika.Identification of the Molecular Mechanism of Phthalocyanine Compounds as Photosensitizer Candidates in Photodynamic Therapy by In Silico. Pathogenic bacteria including Pseudomonas aeruginosa need iron elements to be able to maintain their survival. HasAp is a protein produced by pathogenic bacteria as a source of iron. The HasAp protein will then bind to the outer membrane protein, namely HasR, to be able to forward signals in bacterial cells. Absorption of iron in these pathogenic bacteria can be a strategy for developing therapeutic methods in controlling and preventing infectious diseases caused by pathogenic bacteria Pseudomonas aeruginosa, one of which is by using phthalocyanine as a photosensitizer in photodynamic therapy. This study aims to identify, evaluate, and explore the mechanism of action of phthalocyanine compounds against HasAp proteins, and their effects on the active site of HasR through in silico studies. Ligand-protein docking studies were performed using MGLTools 1.5.6 with AutoDock 4.2 to observe the affinity and molecular interactions between molecules of Fe-phthalocyanine (Fe-Pc) and Ga-phthalocyanine (Ga-Pc) against HasAp protein macromolecules. Furthermore, a protein-protein docking study of the ligand-protein complexes system was simulated to observe its effect on the binding area of the HasR protein macromolecules using PatchDock. Based on the ligand-protein docking results, Fe-phthalocyanine (Fe-Pc) compounds have the best affinity for both HasAp proteins, with a binding energy value of -68.45 kJ/mol and -69.16 kJ/mol, respectively. The protein-protein docking study results between the complex compound Fe-phthalocyanine (Fe-Pc) and HasAp protein against HasR protein have a positive Atomic Contact Energy (ACE) value, with an ACE value of 556.56 kJ/mol. Differences in the molecular structure of phthalocyanine compounds are proven to be able to influence the mechanism of action against the target protein. Therefore, the results of this study can be a reference in designing the structure of phthalocyanine compounds as photosensitizer candidates in photodynamic therapy.

Arabian bidara leaves ( Ziziphus spina-christi , L.) are known to have strong antimicrobial activity against microorganisms that cause infection in the female genital area, namely Staphylococcus aureus bacteria and Candida albicans fungi. They contain main secondary metabolites such as flavonoids, alkaloids, and saponins. Christinin is a saponin glycoside derivative compound which consists of four types, namely christinin-A, B, C, and D. The role of computational studies in the discovery of new drugs is crucial and interesting nowadays because it is relatively cheap, effective, fast, and precise with a reliable level of accuracy. This computational study result will later be used to confirm in vitro test results which are carried out using experimental microbiological testing methods in the laboratory. This study identified, evaluated, and explored the interactions between christinin-A, B, C, and D compounds with Penicillin Binding Protein (PBP) from Staphylococcus aureus and Dihydrofolate Reductase from the fungus Candida albicans using computational study were carried out using the molecular docking. The christinin-A, B, C, and D compounds were modeled into 3D conformation using GaussView 5.0.8 and Gaussian09 software. The best conformation was selected for molecular interaction studies on Penicillin Binding Protein (PBP) from Staphylococcus aureus bacteria and Dihydrofolate Reductase from Candida albicans using MGLTools 1.5.6 software with AutoDock 4.2. The molecular interactions that occurred were further observed using the BIOVIA Discovery Studio 2020 software. Based on the molecular docking results, the christinin-B compound had the highest affinity for Penicillin Binding Protein (PBP) from Staphylococcus aureus bacteria, with a binding-free energy value of −7.67 kcal/mol. Meanwhile, the christinin-A compound has the highest affinity for Dihydrofolate Reductase from the fungus Candida albicans , with a binding-free energy value of −8.38 kcal/mol. Thus, it is predicted that christinin compounds can be chosen as the main component in feminine hygiene preparations to maintain the female genital area's health.

Objective: Prostate cancer is the second most common cancer in men. One of the efforts in the treatment of prostate cancer is by inhibiting histone lysine demethylase. Derivative compounds of coumarine, N-oxalylglycine, organoselenium, organosulfur, and pyridine have been reported to be active against two types of histone lysine demethylase (KDM) enzymes, KDM4E and KDM5B. This study aims to study the interactions of these derivatives with KDM.Methods: In this study, we performed computational studies, including molecular docking and molecular dynamics (MDs) simulations, and toxicity prediction, to assess the compounds’ activities toward three other KDM enzymes, KDM1A, KDM4A, and KDM4C.Results: Molecular docking simulations showed that a derivative compound of N-oxalylglycine, (R)-3-(4-[benzyloxy]phenyl)-2-(carboxyformamido) propanoic acid, and a derivative compound of pyridine, 3-(4-methoxybenzylamino)pyridine-2,4-dicarboxylic acid, has the highest affinity toward KDM. These results were confirmed in MDs studies which showed strong interactions at the active site of the five receptors. Toxicity prediction results show that the derivative compounds of coumarine, N-oxalylglycine, organoselenium, organosulfur, and pyridine are classified in category (high class), which suggests that the safety is not guaranteed, but is likely, not carcinogenic and nongenotoxic.Conclusion: Several coumarin, N-oxalylglycine, organoselenium, organosulfur, and pyridine derivative compounds are predicted to be able to interact strongly with KDM. The results in this study are useful for further studies in the development of novel anticancer drugs that target KDM.