Jurnal Beta Kimia

In Silico Study of the YAKRCFR Peptide Structure and Its Interaction with Human Peroxiredoxin-5

2025-11-08T04:58:14+00:00

The identification of bioactive peptides with therapeutic potential is an emerging focus in drug discovery. In this study, we evaluated the structural stability and binding affinity of the oyster-derived peptide YAKRCFR through molecular modeling and docking simulations against the human peroxiredoxin receptor. Structural prediction using the PEP-FOLD4 server revealed a consistent α-helical conformation across all models, stabilized by key intramolecular hydrogen bonds and favorable sOPEP energy values. Molecular docking was validated with a root mean square deviation (RMSD) of 0.273 Å, confirming the reliability of the docking protocol. The YAKRCFR peptide exhibited a strong binding affinity with the 1HD2 receptor (ΔG = –8.1 kcal/mol), outperforming both ascorbic acid (–6.1 kcal/mol) and the native ligand (–4.862 kcal/mol). Detailed interaction analysis indicated that YAKRCFR forms stable hydrogen bonds and van der Waals interactions with critical residues such as ILE A119 and PHE A120, contributing to its thermodynamic stability and binding specificity. These findings suggest that YAKRCFR holds promise as a lead compound for further development in peptide-based therapeutic strategies, particularly for targets involving the human peroxiredoxin receptor.

Development of Student Worksheets on Thermochemistry Material Based on Problem-Based Learning (PBL) for Phase F

2025-11-08T04:58:15+00:00

This study aims to evaluate the validity of Student Worksheets (LKPD) in thermochemistry material designed using a Problem-Based Learning (PBL) approach, assess the implementation of learning using the PBL model, and examine students’ responses to the developed worksheets. The research employed the 4-D development model, although it was limited to the development stage only. The study involved 26 students from class XI.3 at SMA Negeri 1 Semau Selatan as the research subjects. Data collection methods included interviews, validation, and the distribution of questionnaires. The results of the study revealed that: (1) the developed Student Worksheets was considered highly valid, with average scores from material expert validators I and II at 93,05% and 98,6%, respectively, and from media expert validators I and II at 91,65% and 94,45%, respectively; (2) all aspects of classroom learning using the PBL model were implemented successfully; and (3) students’ responses to the LKPD were very positive, with an average score of 90%.

Surface Modification of Paper-Based Analytical Devices Using Polymer Inclusion Films as Optical Sensors for The Detection of Cu(II) Ions in Water

2025-11-08T04:58:15+00:00

This study presents the development of a microfluidic paper-based analytical device (µPAD) modified with a polymer inclusion film (PIF) for the detection of Cu(II) ions in aqueous samples. The PIF formulation comprised of polyvinyl chloride (PVC), bis(2-ethylhexyl)phosphoric acid (D2EHPA), and Aliquat-336, while sodium zincon salt served as the colorimetric reagent. The optimization was conducted by systematically varying several key parameters such as PIF composition and volume, reaction time, sample volume, and sample pH. The resulting color intensity was digitally quantified using smartphone, and the results were validated against UV–Vis spectrophotometry as the reference method. The optimized conditions were established at a composition of 50% PVC, 30% D2EHPA, 20% Aliquat-336 and 0.1% zincon, with a PIF volume of 20 µL, a reaction time of 40 minutes, a sample volume of 30 µL, and an optimal pH of 5. Under these conditions, the µPAD demonstrated excellent analytical performance, exhibiting strong linearity (R² = 0.9993), high precision (0.36%), good accuracy (0.368%), recovery rates between 98.18% and 102.44%, a limit of detection (LOD) of 0.143 mg/L, and a limit of quantification (LOQ) of 0.476 mg/L. Furthermore, selectivity assessments indicated that D2EHPA effectively reduced interference from Zn(II) ions, confirming the robustness of the developed sensing platform.

Characterization of Pineapple Peel Activated Carbon (Ananas comosus) as an Iron (Fe) Heavy Metal Adsorbent with NaOH and NH4OH Activators

2025-11-08T04:58:16+00:00

The purpose of this study was to investigate the effect of strong and weak base activators on the adsorption properties of activated carbon derived from pineapple peel waste. Activated carbon prepared with NaOH and NH₄OH activators exhibited different physical characteristics; NaOH-activated carbon appeared darker and had a rougher texture compared to NH₄OH-activated carbon. The NaOH-activated carbon contained a moisture content of 8.2%, an ash content of 2.22%, and an iodine adsorption capacity of 393.75%. In contrast, the NH₄OH-activated carbon contained a moisture content of 9.9%, an ash content of 2.68%, and an iodine adsorption capacity of 382.41%. Atomic absorption spectrophotometry (AAS) analysis showed an adsorption capacity of 0.17 mg/L for NaOH-activated carbon and 0.18 mg/L for NH₄OH-activated carbon. Fourier Transform Infrared (FTIR) spectroscopy revealed that NaOH-activated carbon contained O–H (hydroxyl), C=C (aromatic), C–H (alkane), C–O (alcohol), and C=H (alkene) functional groups, while NH₄OH-activated carbon exhibited O–H (hydroxyl), C=C (aromatic), C–H (alkane), and C=H (alkene) groups.

Isolation and Identification of Halotolerant Bacteria in Saline Soils from the Coastal Areas of Oebelo White Sand Beach and Pariti Beach

2025-11-09T03:49:32+00:00

A study has been conducted to isolate and identify halotolerant bacteria in saline soils from the coastal areas of Oebelo White Sand Beach and Pariti Beach. The sampling method used was random sampling. During sampling, pH, electrical conductivity (EC), and soil temperature were also measured. Bacterial isolation was performed using a serial dilution technique, resulting in three pure isolates from each beach sand sample. The isolates were cultured on Nutrient Agar (NA) medium and incubated at 37°C for 24 hours. The colonies obtained were small, round, and white. The isolates were then purified using the streak plate method. The halotolerant test was conducted using Tryptic Soy Agar (TSA) medium without added salt. The results showed that the bacterial colonies were halotolerant, as indicated by growth after 24 hours of incubation. Further biochemical tests, including motility, citrate utilization, urease, and sugar hydrolysis, revealed that all isolates from Oebelo White Sand samples showed positive results for all tests, whereas isolates from Pariti Beach exhibited some variations. These findings indicate that the isolates were capable of hydrolyzing urea into ammonia, utilizing citrate as a carbon and energy source, and fermenting sugars present in the medium.

Analysis of Total Hardness Levels in Water Around the Trunojoyo Campus using the Complexometric Method

2025-11-20T08:30:30+00:00

Water hardness, primarily caused by dissolved calcium (Ca²⁺) and magnesium (Mg²⁺) ions, affects the suitability of groundwater for domestic use and may have adverse health and operational effects when concentrations are high. Indonesia’s clean water quality standard (PERMENKES No. 492/MENKES/PER/IV/2010) sets a maximum hardness of 500 mg/L as CaCO₃. This study determined the total hardness of well water in three villages surrounding the Universitas Trunojoyo Madura campus (Telang, Gili Timur, and Labang) using complexometric titration with 0.01 M EDTA. Samples were collected by simple random sampling and titrated in triplicate. Results showed pronounced spatial variation: Telang village exhibited very high total hardness average 715.7 mg/L, Gili Timur had moderate hardness 146 mg/L, and Labang had low hardness 101.3 mg/L. The elevated hardness in Telang exceeds the national standard and likely reflects local geology (limestone contact and calcareous soils). We recommend pretreatment of well water used for drinking in areas with very high hardness.

Formulation and Evaluation of Balm Stick Preparations from the Essential Oil of Eucalyptus resinifera Leaves

2025-11-21T12:37:35+00:00

Balm is one of the pharmaceutical products with an ointment base that uses essential oils as one of the ingredients in its formulation. One of the essential oils found in Indonesia is Eucalyptus resinifera essential oil. In Indonesia, the use of E. resinifera leaf essential oil in balm stick formulations has not yet been reported. The purpose of this study was to formulate and characterize a balm stick preparation from E. resinifera leaf essential oil for the development of health products. The methods used included the formulation of E. resinifera essential oil balm with four essential oil concentrations (0%, 15%, 20%, and 25%) and evaluation of the preparations through homogeneity, spreadability, adhesion, pH, and skin irritation tests. The results showed that the best formula was Formula III, containing 20% essential oil, which met the requirements for a good balm preparation based on the results of the homogeneity test (homogeneous), spreadability test (3.9 cm), adhesion test (>1 minute), pH test (4.6), and skin irritation test (no irritation observed), and was also the most preferred according to the organoleptic test.