Engineering Headway Vol. 9

Abstract: HDAC proteins play a role in epigenetic changes in cancer-causing gene expression. Previous research reported that hyptolide and its derivatives inhibited several cancer cell growths in vitro. However, the potential of this anticancer compounds in preventing HDAC protein activity has not yet been evaluated. This study aims to determine the site-related inhibitory activity and binding affinity produced by hyptolide against HDAC class IIa protein compared to its derivative complexes. Hyptolide and its derivatives have previously been optimized using ORCA software with B3LYP/6-31G** functional DFT theory. The optimization results on the hyptolide molecule show that the partial charge values of O4, O5, O6, and O7 atoms in the OAc group are -0.437; -0.444; -0.436, and -0.431 with a dipole moment 5.47363 Debye, while the partial charges of hyptolide derivatives on the same atom for epoxy-hyptolide are -0.465; -0.454; -0.448, and -0.415 with dipole moment value 8.57293 Debye and dimethylphenylamine-hyptolide molecules are -0.456; -0.442; -0.559 and -0.418 and dipole moment value 8.86020 Debye. The pharmacokinetics and class toxicity test of ligand compound show that the dimethylphenylamine-hyptolide has highest class toxicity, and it is more toxic than hyptolide and epoxy-hyptolide. The molecular docking process was conducted using AutoDock Vina software. The active site of amino acid residue that interacts with each ligand is Asp B 801 and Val B 708. In line with the partial charge value of the optimized hyptolide compound and its derivatives, binding affinity value complex with dimethylphenylamine-hyptolide ligand compound had the lowest binding affinitiy value in first conformation of -11.00. These results confirm that prediction of hyptolide derivative compounds with nitrogen group as alkylating agents will decrease the binding affinity between ligands and proteins. These results motivate researchers to conduct further studies on the activity of hyptolide derivative compounds in dimethylphenylamine-hyptolide against cancer cell growth in vitro and how to decrease its toxicity.

Abstract: The xynBTN63D gene sub-cloned on the plasmid shuttle vector pESC and pYHM1 in the host Escherichia coli BL21 (DE3) was successfully expressed and characterized. The xynBTN63D gene in the soluble fraction of each plasmid is expressed at induction temperatures of 25, 30, 35, 37, and 40 °C with a molecular weight of ±30 kDa. The soluble fraction of the xynBTN63D gene in both plasmids was expressed at induction temperatures of 25, 30, 35, 37, and 40°C with a molecular weight of ±30 kDa. The recombinant XynBTN63D, purified using the fast protein liquid chromatography (FPLC) method also has a molecular weight of ±30 kDa, observed using the sodium dodecyl polyacrylamide sodium electrophoresis (SDS-PAGE) method. The recombinant XynBTN63D has a temperature of 40 °C and an optimum pH of 5.5. It shows stability from 4 to 40 °C after preincubation for 1 hour with relative activity on the pCES and pMH1 plasmid of more than 50%. Recombinant XynBT63D also showed pH stability after being preincubated for 24 hours by showing relative activity of 86-100% at pH 5.0 to 6.0 for each plasmid

Abstract: This research aims to design anticancer molecules using the hybridization concept based on molecular derivatives of salicylic acid. The investigation explores structures with and without linked amino acid alanine through an in-silico docking approach. The research conducts screenings of the designed salicylic acid derivative molecules against receptors, including MMP9, MMP2, CDK2, P53, BAK EGFR, and ADP Ribose Polymerase. The most promising docking results for multitarget cancer compounds were observed in salicylic acid derivatives with amino acid linkages, specifically salicylic acid-curcumin, salicylic acid-benzyl alcohol, and salicylic acid-eugenol. These derivatives exhibited binding affinities towards MMP9 of -9.6, -9.6, and -8.9 kcal/mol, towards EGFR of -9.0, -7.6, and -7.9 kcal/mol, and ADP Ribose Polymerase of -11.2, -9.0, and -9.4 kcal/mol, respectively. The outcomes of the docking results highlight the significantly improved efficacy of multitarget anticancer compounds designed from salicylic acid derivatives with amino acid linkages, attributing this superiority to the enriched functional groups in the amino acid structure that enhance ligand-receptor interactions. This research contributes to identifying potential drug molecules as effective multitarget anticancer agents.

Abstract: Isoeugenol (2-methoxy-4-[(E)-prop-1-enyl] phenol) is a compound resulting from the isomerization of eugenol contained in clove oil (Syzygium aromaticum). Isoeugenol can be used as a precursor for vanillin biosynthesis through the biotransformation pathway. In this research, the biotransformation of isoeugenol was carried out using Pseudomonas aeruginosa as an enzyme- biocatalyst agent. The parameters used in this research include the effect of substrate concentrations of 0.5; 1; 1.5; and 2% v/v, incubation times of 24; 48; 72; and 96 hours, as well as extracting solvents with ethyl acetate and chloroform. The determination of substrate concentration was carried out at an incubation time of 24 hours, and then the characterization results with the best product concentration were used to determine the incubation time. The results of qualitative identification and characterization show that with increasing the substrate concentration, it can cause decreasing the target biotransformation results. The 1% concentration treatment with the most concentrated magenta-purple color intensity from the Schiff reagent test and the most concentrated intensity of the TLC stain has more potential to produce vanillin products with an area of 0.51% (ethyl acetate) and 0.36% (chloroform), as well as vanillyl methyl ketone with an area of 1.38% (ethyl acetate) and 4.91% (chloroform). On the other hand, increasing the incubation time can reduce the target biotransformation product. The 72 hours incubation time treatment produced vanillin 0.19% (ethyl acetate) and 0.74 (chloroform), as well as vanillyl methyl ketone 1.96% (ethyl acetate), and no vanillyl methyl ketone was produced in the chloroform solvent. In the biotransformation carried out, the substrate concentration was 1% and the incubation time was 24 hours in the chloroform extracting solvent, which became a more potential condition to produce the target biotransformation product with a substrate conversion of 5.27%, which was selective for vanillyl methyl ketone at 93.17% and vanillin at 6.83%.

Abstract: Shrimp waste contains a high content of chitin which is potential to be used as a chitosan’s precursor. Synthesis of chitosan is usually done by deproteination, demineralization, and deacetylation process. Deacetylation of chitin from shrimp waste isolated by autolysis, has been a few reported before. The chemicals involved in autolysis are less harmful and easier to treat before their disposal. Hence, this paper investigates the effect of base type and concentration on the degree of deacetylation of chitosan from chitin isolated by autolysis. Autolysis was carried out by an incubation at pH 2 using sulfuric acid for 10 d. Demineralization was performed by immersion in hydrochloric acid pH 1 for 24 h. The deacetylation of chitin was carried out at 120 °C for 120 min using two different bases, which are NaOH and KOH, respectively. The determination of chitosan’s degree of deacetylation (DD) was carried out using a semi-quantitative method from IR spectra. The use of KOH resulted in the obtained DD of less than 20%, while the NaOH usage produced around 50% of DD. Then, the NaOH was chosen and studied further to obtain a suitable DD for film applications, which is 40 – 99%. The deacetylation of chitosan was carried out by varying NaOH concentration from 60 to 70% (w/v). High concentration of NaOH tends to increase chitosan’s DD and slightly decrease the yield. The optimum concentration of NaOH was obtained at 70% (w/v) producing DD of 53.50±0.83% and yield of 47.66±0.28%. Chitosan synthesized using 70% concentration of NaOH produced a relatively homogeneous thin film. Polyaniline was then introduced to the film to obtain a prototype of smart packaging. This smart packaging was able to detect the pH changes proven by the change of its color.

Abstract: Along with the increasing population in Indonesia, there has been an increase in domestic waste production. It is necessary to treat wastewater before it goes to the environment to prevent pollution of the environment. This research was conducted to investigate the potential of isolates A, B, and L from the Biology Department Universitas Negeri Malang as a bacterial consortium in decomposing domestic waste with the aerobic system to remove Chemical Oxygen Demand using a batch system. Experimental trials were carried out using synthetic domestic waste with variations in bacterial formulation treatments and starter doses. The results show that a more stable COD reduction performance was obtained in the batch test process. Sequentially, the COD reduction data efficiency includes B 20% (88.65%), L 20% (84.2%), A 10% (80%), A 20% (79.92%), ABL 10% (72.3%), B 10% (25.67%), ABL 20% (-10.87%), with the greatest efficiency occurring in the L10% treatment at 89.76%. The genotype analysis shows that A, B, and L isolates were identified as Alcaligenes ammonioxydans

Abstract: Indonesia is the fifth ranked country with plastic waste that is not managed properly. Over time, plastic breaks down into microplastics (MPs) less than 5 mm in diameter, which in water can cause damage. One method of removing MPs that is considered efficient is MPs microfiltration using membrane technology. To obtain an adequate membrane in removing MPs particles, it is necessary to modify the membrane both in the material and the membrane manufacturing process itself. So this study aims to study the effect of immersion time in the manufacturing process on the characteristics and performance of microfiltration membranes to remove MPs in water. In this study, the membrane will be made using the phase inversion method with a flat sheet membrane finish. The membrane is made using Cellulose Acetate (CA) polymer with n-Methyl Pyrolidone (NMP) solvent and aquadest as its non-solvent. The selected variable is the membrane immersion time for 10; 17,5; and 25 minutes and operating pressure at membrane performance test 0,3; 0,5; and 0,7 bar. Furthermore, the resulting membrane will be analyzed for its characteristics through porosity and water content analysis, contact angle analysis, and SEM analysis. In addition, membrane performance tests are carried out to determine the ability of membranes when separating microplastics in water. CA/NMP flat sheet membrane fabrication produces white membrane flatsheet. The results of the experiments that have been carried out, obtained CA/NMP (15:85) membrane with a variable immersion time of 25 minutes has the best characteristics and performance. The membrane is white, has a thickness of 126μm, and is hydrophilic. The membrane also has a supporting layer with a finger-shaped pore structure and sponge. In addition, CA/NMP (15:85) membranes have a %microplastic rejection value in water reaching 99%.