Jurnal Pendidikan Kimia
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Molecular Docking Study of Nutmeg (Myristica Fragrans) Constituents as Anti-Skin Cancer Agents
Get PDFMolecular docking analysis was carried out to understand better the interaction between DHODH and inhibitor from nutmeg in this series. The nutmeg constituent binding orientations in the active site of DHODH was seen in a molecular docking analysis and helped design a potentially new inhibitor. This work aimed to study the molecular docking of nutmeg constituents with the DHODH inhibitor using a computer-aided drug design. Molecular docking using AutoDock 4.2 was done to explore the models of binding complexes. The 3D structure was derived using Discovery Studio to investigate the essential chemical interaction of complex structures. Dihydroguaiaretic acid was the most potent ligand having a docking score of -9.3 kcal/mol. This value was better than the standard drug 5-FU. The dihydroguaiaretic acid structure interacted with Tyr365 and Thr63 through a hydrogen bond similar to the native ligand. These results suggest that nutmeg seed could serve as the lead compound for potent DHODH inhibitors against skin
Optimizing of Competitive Adsorption Methylene Blue and Methyl Orange using Natural Zeolite from Ende-Flores
Get PDFWaste from the textile industry is considered a potential source of environmental pollution, especially water, because it contains dangerous dyes. In this research, natural zeolite is an effective and efficient alternative to overcome pollution caused by methylene blue and methyl orange dyes. Activation of natural zeolite was carried out with 3 M HCl solution and was characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Simultaneously, the methylene blue and methyl orange adsorption processes were studied in variations in the weight of the adsorbent, contact time, and pH. The concentration of dyes left in the solution was observed with UV-Vis Spectrophotometer. The results showed that the adsorption capacity of natural zeolite in absorbing methylene blue was 21.189 mg / g and methyl orange was 18.208 mg / g. The optimum conditions of dyes adsorption are achieved with successive adsorbent weights 0.3 g and 0,4 g, following contact times 60 minutes and 90 minutes, and successive pH 6 and 2. The adsorbent weight factor, contact time, and pH affect the adsorption of dyes by natural zeolite from Ende
Synthesis and Photoluminescence Properties of Alkylbromoporphyrin
Get PDFThe usage of porphyrin as a light-harvesting chromophore is considered as one of the keys to obtaining low-cost and high-efficiency dye-sensitized solar cell (DSSC). In this paper, a novel porphyrin, 5,10,15-tris(nitrophenyl)-20-(p-(11-bromo)dodecoxyphenyl))porphyrin, having a long alkyl chain and three nitro groups was synthesized. The nitro groups serve as anchoring groups to TiO2 surfaces and long alkyl chain prevents unwanted dye aggregation. The porphyrin was synthesized by condensation of p-(12-Bromododecoxy)benzaldehyde and pyrrole in propionic acid according to an adaptation of the general Rothemund method [1]. p-(12-Bromododecoxy)benzaldehyde was synthesized by nucleophilic substitution reaction between 4-hydroxybenzaldehyde and 1,12-dibromododecane in acetone. The reaction products were analyzed by 1H-NMR and mass spectroscopy. The absorption and fluorescence spectra of the porphyrin were also recorded. As results, the absorption spectrum of the porphyrin consists of a strong Soret and four weak Q-band. Compared to 5,10,15-tris(nitrophenyl)-20-(p-(11-bromo)dodecoxyphenyl))porphyrin spectrum, there is no wavelength shifting because of the incorporation of the alkyl chain. The fluorescence spectrum of the porphyrin shows two characteristic emission bands and the intensity ratio of those emission bands is always constant when irradiated by different excitation wavelength related to Soret and Q-band
Virtual Practicum Guideline Development Based on 5E Learning Cycle
Get PDFThe research purpose was to develop chemistry practicum guidelines based on the 5 E (Engagement, Exploration, Explanation, Elaboration, Evaluation) learning cycle and determine the student's responses. This development research adapted from Borg and Gall model. Data were obtained from interviews, validation questionnaires from content and media experts, readability questionnaires, and student's responses after used the product. Results validation of the chemistry practicum guidelines shows that the content expert validation scores 4.42 while media expert validation scores 4.65 with a range> 4.2, classified as very good. The average readability test showed a score of 4.28. A product trial to determine the student's response toward developed guidelines had an average of 4.28, which was included in an exciting classification. There was an increase in student learning outcomes with average pretest scores of 50, average posttest scores of 85, and the N-gain value data obtained was 0,7 in the high category. Thus, the study concluded that the chemistry learning guidelines with salt hydrolysis topic based on the 5E learning cycle using the virtual program developed in this study were feasible to be applied in the learning process
The Effect of Energy Minimization on The Molecular Docking of Acetone-Based Oxindole Derivatives
Get PDFIn silico study by molecular docking, drug discovery, and virtual screening are useful for obtaining compounds with promising biological activity. The force fields energy minimization in molecular docking is the overall process to produce better geometry estimation and ligand-receptor affinity. In this study, the divide and conquer algorithm based on the Mikowski matrix in MarvinSketch and the conjugate gradient algorithm of Open Babel were used to minimise acetone-based oxindole derivatives in indoleamine 2,3-dioxygenase 1 (IDO1). The results showed that the binding energy produced by MarvinSketch was generally better than the binding energy obtained with Open Babel. The visualization of molecular docking results indicated that the poses and hydrogen bonding, halogen bonding and π-π interactions are different between MarvinSketch, Open Babel, and no energy minimization. The results revealed that energy minimization affects the molecular docking results.
Biofilm Chitosan as Modern Dressing for Ulcers
Get PDFModern dressing techniques as open wound dressings are still effective and suitable for use, especially for people with open wounds such as ulcers, but they still have disadvantages, such as the high prices and need for other antibiotics to prevent inflammation. Previous studies reported an increase in the number of antibiotic resistance, which sparked the idea of producing new dressing materials that have strong antimicrobial and biocompatible properties. The material suitable for the idea of a wound dressing is chitosan biofilm because it has strong antibacterial properties and has a similar structure to the skin tissue. This study aims to produce chitosan biofilm using the deacetylation method using a strong base. The physicochemical characterization results of biofilms showed a deacetylation degree of 87.13 with a voltage of 1.15 ± 0.00 and a polycationic group of biofilms that appeared at a wavenumber of 2.1714 ± 0.0000 nm. From the measurement of the antibacterial power of chitosan biofilm against skin surface bacteria, the inhibition zone diameter was 18.93 ± 0.12; 19.50 ± 0.17; 20.20 ± 0.23; 20.13 ± 0.03 and 22.53 ± 0.09 against S. aureus, S. epidermidis, P. aeruginosa, E. colli, Bacillus sp. Overall, it can be concluded that biofilm chitosan has the opportunity to be applied as a dressing in wound care
Impact of Forest Fires in Sumatra and Kalimantan to Atmospheric Pollution During Period Of 2010-2015
Get PDFcontribute significantly. Pollutant emissions caused by forest fires comprising CO, SO2 and dust (PM10). This paper will be analyzed estimates of pollutant emissions in both Kalimantan and Sumatra using the estimation method based on the amount of material burned. Estimates of the emissions and dispersion of pollutants such as particulates, sulfur dioxide, carbon monoxide were investigated. Distribution and concentration of pollutants used time series of monthly data and spatial map based on satellite data. Extensive data from the 2010-2014 forest fires data from the ministry of the environment and forestry (KLHK) and forest fire data period 2015 from LAPAN. Pollutant concentration data used AIRS on satellite data, OMI satellite and MERRA during 2010-2011 and in 2014-2015, adjusted to the data in situ vast wildfires for both regions. The results of estimation of pollutant emissions in Sumatra shows emissions from forest fires for the period of 2010 greater than in 2011, reaching 9 tons of CO per year, while emissions from fires and plantations during 2011 were higher than in 2010 with a very high value of 150 Tons/year for pollutants CO. In Kalimantan, emissions from forest fires during 2010-2011 CO emissions highest in West Kalimantan 11.13 tons/year and South Kalimantan 12.14 tons of CO per year. Emissions from fires and plantations in South Kalimantan reached 32.11 tons/year.
Development of Authentic Assessment Based on Creative Thinking Skills in A Carbohydrates Qualitative Analysis Project-Based using Local Material
Get PDFLaboratory activities can improve creative thinking skills. This study aims to develop an authentic assessment based on creative thinking skills. This research is development research with the Rowntree development model. The research stages consist of the planning stage, the development stage and the evaluation stage. Data were analyzed using CVR and test description. This study was conducted with 33 participants. This research has produced an authentic assessment instrument consisting of learning indicators, written tests, test rubrics, product rubrics and psychomotor assessment rubrics. An authentic assessment developed in the qualitative analysis of carbohydrates with a CVR value obtained is +0.70, which can be considered valid for all validated components. The authentic assessment reliability test resulted in an average score of 56.56, a standard deviation of 25.06, and test reliability of 0.82. from the analysis, it was determined that the authentic assessment based on creative thinking skills of qualitative analysis of carbohydrates with local material developed had met the valid and reliable criteria.
XRF and XRD Investigation for the Results of the Extraction of Mud Volcano from Napan Village into Silica
Get PDFSilica powder was obtained from the mud volcano of Napan Village following the co-precipitation method. This research aimed to determine the phase changes that occur in calcined silica with various temperatures. This research was carried out in three stages, there are the preparation of a mud volcano using the pre-treatment method, extraction of silica with sodium hydroxy solution, and calcination of silica with temperature variations. By analysis of XRF and XRD results, the mud volcano samples showed a high percentage of SiO2 minerals. The results of silica characterization using XRD showed that uncalcined and calcined silica at 600oC had an amorphous structure with broading peaks. Tridymite and cristobalite phases were detected in calcined silica at 800oC and 1000oC. Calcined silica at a temperature of 1000oC transformed the tridymite phase to cristobalite with a decrease in the intensity of the tridymite phase while the cristobalite phase increased
Synthesin and Characterization Chitosan Film with Silver Nanoparticle Addition As A Multiresistant Antibacteria Material
Get PDFThe synthesis of chitosan films with the addition of silver nanoparticles (AgNps) has been carried out in 2 stages. The first stage is to make colloidal silver nanoparticles with chitosan as a stabilizer and a reducing agent with NaOH as an accelerator and assisted by microwave irradiation. The second stage is to make a film from colloidal silver nanoparticles-chitosan by casting method. The formation of silver nanoparticles was identified using a UV-Vis spectrophotometer and TEM. Chitosan films with the addition of AgNps were characterized by chemical, physical and mechanical properties. Furthermore, the antibacterial activity was tested against multi-resistant bacteria ESBL and MRSA. The results showed that the formation of AgNps was indicated by the appearance of an absorption band at 400-413 nm with a size of less than 6 nm. The FTIR spectra showed that there was a slight shift at the 1604 cm-1 peak which indicated that the AgNps interacted with the NH2 group on D-glucosamine of chitosan. The films morphology with addition Ag NPs tends to be rough in surface and cross-sectional. The presence of AgNps tends to increase the swelling value, tensile strength and film elasticity. Chitosan film with the addition of silver nanoparticles has antibacterial activity against multi-resistant bacteria ESBL and MRSA. The anti-bacterial activity of the film was derived solely from the silver nanoparticles