Key Engineering Materials Vol. 840

Abstract: Ocimum basilicum essential oil has many uses, however, it is still difficult to get the maximum results, in terms of both quantity and quality due to some reason. Thus, it is necessary to study the factors affecting the extraction in order to give the maximum output, in terms of yield and quality, respectively. The method used in this study was the most commonly used one, which is called hydro-distillation method. The highest yield in this study goes as high as 1.4%, which was obtained when 1 cm-sized of material, 2100 Watt of power, and solvent to material ratio of 0.025 was operated. With regards to the resulting composition and chemical analysis results, it shows the best condition for extraction using HD method is at 2100 W power, ratio F/S is 0.025 and material size 1 cm.

Abstract: Scurrula atropurpurea known as benalu is a medicinal plant that has been used for the treatment of various diseases such as antibacterial. Plants with ethnomedicine history use to cure pathogenic bacterial infections and their endophytic fungi is a promising source of antibacterial compounds. This study aimed to compared the antibacterial activity of S. atropurpurea leaves and their endophytic fungi. The secondary metabolites were isolated from the leaves of S. atropurpurea and their endophytic fungi by the chromatography method. The antibacterial activity test was carried out by Kirby Bauer method against Salmonella typhi (IPCCCB.11.669) and Escherichia coli (ATCC 25922) as Gram (-) and Bacillus subtilis (ATCC 6633) and Staphylococcus aureus (ATCC 25923) as Gram (+). The antibacterial compound from S. atropurpurea was determined by spectroscopy analysis as Quercetin-3-O-α-L-Rhamnopyranoside, while the antibacterial compound from endophytic fungi (strain BB1) as a lactone. Phylogenetic tree of strain BB1 has the highest homology with Neopestalotiopsis surinamensis strain CBS 450.74.

Abstract: Caulerpa lentillifera belong to Caulerpa genus which is commonly found in tropical and subtropical water. The biggest constituent of seaweed is polysaccharide that has some biological activities as a potential medicine. Therefore, this research aimed to extract and evaluate the antioxidant activity from Caulerpa lentillifera polysaccharide. The extraction was carried out by using water extraction. First, the sample was added with ethanol and soaked overnight at room temperature. On the following day, the sample was added with aquades and put in a water bath at 75°C for three hours. After that, ethanol was added to precipitate the extract. The crude polysaccharide extract percent yield obtained 4.16 %. The crude extract purified by using a column with DEAE-Sepharose with percent yield obtained 14.8 %. Both crude and pure extracts were characterized by analyzing the total carbohydrate and sulfate by using spectrophotometer, functional group by using FT-IR spectroscopy and sugar component by using HPLC. Antioxidant activity was analyzed by using the FRAP method for both crude and pure extract. Moreover, the polysaccharide crude extract gives higher antioxidant activity than the purified extract.

Abstract: Dengue is one of the crucial diseases in human-caused by dengue virus (DENV) infection. However, the development of DENV antiviral is often facing a problem because no effective drug to treat infection caused by all DENV serotypes. The inhibition of host protein involved in DENV life cycle can be a potential approach in dengue drug discovery, and also avoiding antiviral resistance. Endoplasmic Reticulum (ER) α-glucosidase II is one of the target host protein in DENV endoplasmic reticulum that plays an important role in the maturation process of DENV envelope glycoprotein. Natural products have been known as an essential source of a lead compound for drug discovery due to their therapeutic potency. In this research, pharmacophore-based virtual screening and molecular docking simulations were performed to find ligand that has potential to inhibit α-glucosidase II activity. About 67,609 natural products from InterBioScreen (IBS) database were used in the simulation as ligands with α-glucosidase II as the protein target. After subjected to Lipinski’s Rule of Five, druglikeness, nasty functions, and toxicity screening using DataWarrior software, 17,462 ligands were obtained. The pharmacophore features for molecular docking simulation was obtained from Protein-Ligand Interaction Fingerprint (PLIF) analysis using eight α-glucosidase II protein with different ligands. Based on virtual screening, rigid, and flexible docking simulations using Molecular Operating Environment (MOE) software, 32 ligands have lower Gibbs free binding energy (ΔG_binding) compared to the standards. Two best ligands, namely STOCK1N-85545 and STOCK1N-86400 which belong alkaloid derivatives, showed the exceptional ligand interaction and had the lowest ΔG_binding of-11.204 and-10.276 kcal/mol, respectively. The ligands were identified to have a binding interaction with amino acid Asp564 and Asp640 in α-glucosidase II catalytic site. STOCK1N-85545 and STOCK1N-86400 were also identified to have a good pharmacological properties after subjected to ADME-tox test using Toxtree, SwissADME, admetSAR, and pkCSM software.

Abstract: Breast cancer has become one of the leading cause of women’s death around the world. Breast cancer can be caused by genetic or environmental factors. Human epidermal growth factor receptor 2 (HER2) is one of the main causes of breast cancer. The HER2 tyrosine kinase plays a significant role in the dimerization reaction which causes auto-phosphorylation of tyrosine residues in the cytoplasmic domain that triggers growth of the cancer cells. Inhibition of HER2 protein activity can be a potential alternative for breast cancer treatment. Flavonoids have become an important scaffold in medicinal chemistry due to its bioactivity and availability. Therefore, flavonoids were used as the database on this in silico research. Fragment-based drug design was applied to determine novel drug candidates. Three potential candidates were obtained in this research. VC-962 was selected as the best inhibitor candidates for HER2 tyrosine kinase.

Abstract: Diabetes is one of the top causes of death in the world, with 425 million sufferers reported in 2017. About 90% of diabetics suffer from Type 2 Diabetes Mellitus (T2DM). Recent studies show that inhibiting the α-amylase enzyme can significantly decrease the postprandial blood glucose levels through blocking carbohydrate hydrolysis. Therefore, it can be a promising strategy for T2DM treatment. This research was aimed to find the new potential inhibitor for the α-amylase from lead-like compounds Molecular Operating Environment (MOE) database through fragment-based drug design, combining with structure-based pharmacophore design method to obtain new drug candidate for T2DM. There were 653,214 lead-like compounds which were obtained from MOE database and screened based on the Astex Rules of Three along with toxicity filter to gain lead-like fragments. The filtered fragments were docked into the binding site of the α-amylase utilizing MOE 2014.09 software. Potential lead-like fragments were grown to generate 25,600 new ligands by utilizing DataWarrior v5.0.0 software, based on the Lipinski’s Rule of Five and toxicity filter. Molecular docking simu-lation and pharmacological test was performed on the ligand libraries to acquire the best ligand, namely BGOJI which were chosen according to the lowest ΔG binding score, RMSD value < 2, good molecular interaction, ADME/T test result.

Abstract: The synthesis of 1,5-diphenyl-3-styryl-4,5-dihydro-1H-pyrazole (B1) and 5-(3,4-dimethoxyphenyl)-3-(3,4-dimethoxystyryl)-1-phenyl-4,5-dihydro-1H-pyrazole (B2) have been conducted from 1,5-diphenylpenta-1,4-dien-3-on (A1) and 1,5-bis(3,4-dimethoxyphenyl)penta-1,4-dien-3-one (A2). Heme polymerization inhibitory activity (HPIA) assay of the synthesized compounds has also been carried out. The first step of reaction was Claisen-Schmidt condensation of benzaldehyde derivatives and acetone using NaOH 20% and ethanol as solvent. Dibenzalacetone derivatives were reacted with phenylhydrazine using acetic acid to form N-phenylpyrazoline. The structure of products was characterized by FT-IR, GC-MS, DI-MS, ¹H- and ¹³C-NMR The result of heme polymerization inhibitory activity assay showed that IC₅₀ of B1 and B2 1.26 and 0.79 mM while quinine 1.26 mM. The result indicated that compound B2 was more potent as antimalarial than quinine.

Abstract: Oxindole derivatives were efficiently synthesized from diazoamides derived from aniline derivatives in the presence of a Ru(II)-Pheox catalyst. Ru(II)-Pheox was found to be one of the most efficient catalysts so far for the synthesis of oxindole derivatives from the diazoamides in high yields (up to 99%) with high regioselectivity. Furthermore, the reaction was rapid and no substituent effects on the aromatic ring.

Abstract: Symmetrical Amino Azine derivative compound of 6,6'-((1E,1'E)-hydrazine-1,2-diylidenebis (methanyl-ylidene)) bis (3,4-dimethoxyaniline) TM has been synthesized through an unusual reaction route employed benzylidine derivative with some electron withdrawing groups as intermediate compounds. The targeted TM compound was prepared by one pot reaction of the intermediate 2-(4,5-dimethoxy-2-nitrobenzylidene) malononitrile 3 or (E)-1,2-dimethoxy-4-nitro-5-(2-nitrovinyl)-benzene 4 or nitrohydrazone 5 with excess 80% hydrazine hydrate and 10% Pd/C catalyst. However, direct synthesis to produce TM using nitro aryl aldehyde derivatives with 80% hydrazine hydrate and 10% Pd/C catalyst failed to obtain the target compound of TM.

Abstract: Curcumin, a diarylheptanoids compound which isolated primary from Curcuma longa, exhibits a variety of exciting biological activities, including as an antibacterial agent. In the present study, a sulfanilamide-contained curcumin compound was synthesized and characterized to investigate the antibacterial activity against gram-positive bacteria S. aureus, B. subtilis and gram-negative bacteria E. coli. The characterization of the synthesized compound was determined by analysing peak absorbance, functional group, and molecular weight using mass spectroscopy, UV/Vis and FTIR spectrophotometry. Curcumin-sulfanilamide compound exhibited the best antibacterial activity against gram-negative bacteria compared to curcumin and the curcumin-derived compound containing isoxazole with inhibitory zone of 11 mm.