Jurnal Kimia Sains dan Aplikasi
ISSN / EISSN : 1410-8917 / 2597-9914
Published by: Institute of Research and Community Services Diponegoro University (LPPM UNDIP) (10.14710)
Total articles ≅ 532
Latest articles in this journal
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 126-135; doi:10.14710/jksa.24.4.126-135
The bandgap energy (Egap) of TiO2 material modified with metal-chlorophyll complex compounds (M = Cu2+, Fe3+) was observed. Chlorophyll (Chl) was isolated from cassava leaves, and its UV-Vis spectra showed absorption peaks in the Soret band region (410 nm) and in the Q band region (665 nm), which is the typical peak of chlorophyll. Copper(II)-chlorophyll complex was prepared from the reaction between chlorophyll and CuSO4.5H2O, while the iron(III)-chlorophyll was synthesized from chlorophyll and FeCl3.6H2O in methanol solvent under reflux at 65°C. The presence of copperand iron metals in the chlorophyll metal complexes was identified using Atomic Absorption Spectroscopy in methanol solution. The absorption of copper measured in Cu2+-Chl was 0.0488 (0.4805 mg/L), while the iron atom in Fe3+-Chl was 0.0050 (0.0195 mg/L). The UV-vis spectra demonstrate the hypsochromic shift of the Soret band to 405 nm (Cu2+-Chl) and 402 nm (Fe3+-Chl). The Infrared spectra of chlorophyll after being complexed with copper(II) shows the increase of vibrational absorption wavenumber of the C=N group from 1225.06 cm-1 to 1241.94 cm-1 indicates the coordination of the metal ion on the N atom in the pyrrole ring. The shift in the absorption band on the Fe3+-Chl spectrum was seen for the C=O ester group from 1720.49 cm-1 to 1721.10 cm-1 indicating the metal ion bonding in the C=O group of esters. The DR-UVis analysis of TiO2/metal-chlorophyll shows a bathochromic shift towards the visible light region. By using the Tauc plot method, it was observed that the Egap of TiO2 reduces from 3.08 eV to 2.89 eV and 2.93 eV in the compound of TiO2/Cu2+-Chl and TiO2/Fe3+-Chl, respectively.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 120-125; doi:10.14710/jksa.24.4.120-125
The use of motorized transportation in Indonesia is now proliferating. The higher the use of motorized vehicle-based transportation in an area, the higher the potential for air pollution. One of the air pollutants is a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX). This study examines the effect of coconut shell-derived activated carbon adsorbent mass which is adjusted with different thicknesses on its adsorption ability for BTEX. The adsorbent is used to adsorb the emissions of the 1990 GL-Pro motorcycle with premium fuel. The results of gas chromatography-mass spectroscopy (GC-MS) show that motor vehicle emissions contain BTEX and other hydrocarbons. ANOVA variant analysis showed that the difference in mass of activated carbon in the range of this study did not provide a significant difference in BTEX adsorption.Keywords: adsorbent; motor vehicle emissions; BTEX pollutants; coconut shell
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 108-113; doi:10.14710/jksa.24.4.108-113
Stigmasterol and Stigmasterone from Methanol Extract of Calophyllum soulattri Burm. F. Stem Bark. Calophyllum soulattri Burm. F. has been widely used for herbal medicine. Phytochemical investigation of C. soulattri contains a secondary metabolite of the steroid class. Steroid compounds have various biological activities, such as anti-inflammatory, antioxidant, antiproliferative, antibacterial, antimalarial, and anticancer. Two secondary metabolites steroids have been isolated and identified from the stem bark extract of C. soulattri. Isolation was carried out through the extraction (maceration), fractionation, and purification stages. Maceration is carried out using methanol as a solvent. Fractionation was carried out by vacuum liquid chromatography (VLC), and purification was by flash column chromatography. Identification of combined fractions and determination of pure isolates were used through thin-layer chromatography (TLC). The solvent used in the chromatography methods was a mixture of n-hexane and ethyl acetate. The structure isolates were identified by FTIR, 1H NMR, and 13C NMR and compared with literature data. Secondary metabolites steroids that have been isolated are identical compounds to stigmasterol and stigmasterone.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 85-90; doi:10.14710/jksa.24.3.85-90
Coronavirus is a pandemic in the world. It requires researchers and scientists to work hard to find a vaccine or drug to inhibit the development of the coronavirus. Many drugs have been used, such as remdesivir, lopinavir, and chloroquine. However, how effective is the use of these drugs for inhibiting the coronavirus’s growth? There is no research has been done. Curcumin is now known as one of the compounds that have some biological activities, and it is also can potentially be used as a CoV-2 inhibitor. The computational study, i.e., molecular docking and molecular dynamic, can help researchers to predict which compounds have the potential as an inhibitor against the CoV-2 coronavirus. In this study, lopinavir was used as a positive control. Lopinavir and 45 curcumin analog compounds were docked against the main protease protein with 6LU7 PDB ID. Based on the docking results, it was discovered that compound 1, compound 2, and compound 4 have the same binding orientation as lopinavir. Molecular dynamic simulation with the lowest binding free energy conformation was used to check these compounds’ stability. Only compound 4 was maintained to observe hydrogen bonding with Lys5 and Lys137 with a distance of 2.9 Å. The distance of hydrogen bonds and binding free energy over simulation time is essential to elucidate the potential compound’s affinity. For then, compound 4 can be used as a potential inhibitor against the CoV-2 coronavirus.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 91-100; doi:10.14710/jksa.24.3.91-100
Diclofenac sodium is a non-steroidal anti-inflammatory drug with a relatively short release time. This short release time promotes a more frequent drug consumption and could lead to side effects in the stomach, e.g., gastrointestinal disorders, gastrointestinal bleeding, and gastric ulcers. A drug delivery system with a slow-release activity is one of the promising technologies to control the drug amount released to the stomach. A surfactant-modified natural zeolite as a carrier for diclofenac sodium has been used in this study. This study focused on the preparation, characterization, and slow-release performance of HDTMA-modified natural zeolite as a carrier for diclofenac sodium. The zeolite underwent chemical and physical activation, as well as milling prior to use. It was proven that the zeolite used was dominated by mordenite and clinoptilolite with high stability properties towards acid treatments, as indicated by the XRD patterns. A modification of the zeolite surface using HDTMABr was also successfully performed, indicated by the appearance of peaks at wavenumbers of 2923.05 cm-1 and 2853.39 cm-1 (symmetrical and asymmetrical CH2 strains of HDTMA molecules, respectively) in the FTIR spectra. The synthesized HDTMA-modified natural zeolite also showed an excellent surface property such as surface area, pore-volume, and size, as indicated by the BET-BJH isotherms on the nitrogen adsorption. The slow-release performance of the zeolite-based drug delivery system was studied by investigating the adsorption-desorption behavior of HDTMA-modified zeolite towards diclofenac sodium. The HDTMA-modified zeolite adsorbed the diclofenac sodium of 54.01% at a pH of 7.5, the contact time of 60 min, and the initial concentration of 100 ppm. The adsorbed diclofenac sodium of 73.95% could be released from the HDTMA-modified adsorbent for 8 h, mimicking the time length of drug metabolism in the human body.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 114-119; doi:10.14710/jksa.24.4.114-119
β-sitosterol is an essential bioactive phytosterol naturally present in plant cell membranes. It has a coincident structure with animal cholesterol. This investigation reported isolation, structure analysis, and an antimicrobial assay of β-sitosterol from the root bark of Bakau Minyak (Rhizophora apiculata) from Lampung coastal. The isolation of β-sitosterol was carried out through maceration using methanol, separation by vacuum liquid chromatography (VLC), and purification by column chromatography (CC) using ethyl acetate/n-hexane (2:8) as eluent. The structure of β-sitosterol was determined using spectroscopic analysis (UV-Vis, FT-IR, 13C-NMR, 1H-NMR, DEPT, and GC-MS). The pure β-sitosterol has 107.4 mg of white needle crystalline compound, the compound melting point about 140.7-141.2oC, the molecular mass confirmed by m/z 414, and UV absorption detected at λ 203.9 nm. The β-sitosterol antimicrobial bioactivity assay has shown potential activity to be developed as a lead compound against E. coli.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 136-145; doi:10.14710/jksa.24.4.136-145
Research on the isolation, toxicity test, antimalarial test, and identification of the active compound from the ethyl acetate fraction of Stylissa massa sponge from Oenggae waters, Rote Island, has been conducted. This study aimed to investigate the antimalarial activity of the ethyl acetate fraction of the Stylissa massa sponge. Isolation was carried out by the extraction method using a mixed solvent of methanol: dichloromethane of 3: 2 (v/v), then the extract was partitioned in a solvent mixture of ethyl acetate: water of 1: 2 (v/v). The ethyl acetate extract obtained was separated by column chromatography using the gradient polarity system method. The toxicity test of each fraction was carried out by the Brine Shrimp Lethality Test (BSLT) method, and the antimalarial test was carried out by the haematin polymerization inhibition method. Identification of compounds from the active fraction in the antimalarial test was carried out using Liquid Chromatography-Mass Spectrometry (LC-MS). The extraction yield was 1.14 g (0.23%) of the ethyl acetate extract in the form of a dark brownish-yellow oily solid. Separation by column chromatography resulted in 15 fractions. Toxicity test results showed the four most active fractions with LC50 values, which are very promising for new drug discovery. The IC50 value in the antimalarial activity test of the four fractions indicated that the Stylissa massa sponge ethyl acetate extract was more active than the standard chloroquine compound (115 μg/mL). The LC-MS analysis indicates that fraction 11 contains two compounds that have been reported, and 1 compound is unknown. In contrast, fraction 14 indicates that it contains three compounds that have been reported and one unknown compound.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 101-107; doi:10.14710/jksa.24.3.101-107
Cholesterol plaque buildup in artery walls occurs due to oxidation of Low-Density Lipoprotein (LDL) molecules by free radicals, which are a risk factor for coronary heart disease. Piper crocatum contains active compounds that can act as HMG-CoA reductase inhibitors, such as flavonoids, alkaloids, polyphenols, tannins, and essential oils. This study aimed to predict the potential of Piper crocatum extract and fraction compounds as HMG-CoA reductase inhibitors by investigating the ligand affinity to the HMG-CoA reductase enzyme. Ligand and receptor preparation was conducted using BIOVIA Discovery Studio Visualizer v188.8.131.5250 and AutoDock Tools v.1.5.6. Molecular docking used AutoDock Vina, while ligand visualization and receptor binding used PyMOL(TM) 184.108.40.206.Edu. The receptor used was HMG-CoA reductase (PDB code: 1HWK) with atorvastatin as a control ligand. Catechin, schisandrin B, and CHEMBL216163 had the highest inhibition with affinity energies of -7.9 kcal/mol, -8.2 kcal/mol, -8.3 kcal/mol, respectively. Amino acid residues that played a role in ligand and receptor interactions were Ser684, Asp690, Lys691, Lys692.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 77-84; doi:10.14710/jksa.24.3.77-84
Li7La3Zr2O12 (LLZO) is a garnet-type electrolyte for all-solid-state lithium-ion batteries (ASSB). It has good chemical and electrochemical stability against lithium and a relatively high ionic conductivity. However, the ionic conductivity needs to be further increased to provide a high specific capacity of the ASSB. Element doping into LLZO is an effort to increase molecular defect, known to enhance the conductivity. This research studied the effect of the Na2B4O7 addition on the LLZO synthesis, producing LLZBO(A). The investigation aims to understand whether the sodium ions dope into the LLZO structure during synthesis, or it is only B ions to enter into the structure. Therefore, another synthesis with B2O3 of B precursor was conducted for comparison (LLZBO(B)). The precursors were mixed stoichiometrically by following the formula of Li7-xLa3-xZr2-xBxNaxO12 (LLZBO, x= 0.15; 0.20; 0.30). XRD analysis equipped with Le Bail refinement found that LLZBO(A) and LLZBO(B) mainly consist of cubic and tetragonal LLZO with a %mol of 69.06 – 69.84 %, and the main secondary phase is La2Zr2O7. The surface morphology of LLZBO(A) and LLZBO(B) is almost similar to the irregular form of large aggregates. The particles become more dispersed when 0.3 %mol dopant was submitted. Impedance analysis found a high ionic conductivity of LLZBAO(A)0.3 1.042x10-3 Scm-1.
Jurnal Kimia Sains dan Aplikasi, Volume 24, pp 70-76; doi:10.14710/jksa.24.3.70-76
The focus of this study was to compare the antimicrobial activity of silver nanoparticles (AgNPs) synthesized using ethanol extracts (AgNPE) and water extracts (AgNPA) from four o’clock flowers (Mirabilis jalapa) against Staphylococcus aureus. AgNPs were characterized by UV-Vis diffraction, FTIR, SEM, and X-rays. UV-Vis analysis showed that AgNPA has an SPR band of about 460 nm and 530 nm for AgNPE, which proves the characteristics of the absorbance area of AgNPs. SEM images of AgNPE and AgNPA show a cuboid shape with a mean diameter of 80 and 30 nm, respectively and well dispersed. The response to the presence of polysaccharide biomolecules involved in forming AgNPs was analyzed using a Fourier transform infrared spectrometer. The result was that AgNPA and AgNPE have different reducing agents. The plant extracts, AgNPE and AgNPA, were studied for their antimicrobial activity against Staphylococcus aureus. The result was that both AgNPA and AgNPE showed good activity and showed that AgNPA with less inhibition was more effective than AgNPE.