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This study aims to improve critical thinking skills and Wasaka characteristics through the development of a problem-based learning-based reaction rate e-module and to assess the validity, practicality, and effectiveness of the e-module. This research uses the ADDIE model (Analysis, Design, Development, Implementation, and Evaluation). In the analysis stage, researchers assess the needs of teaching materials, characteristics of students, and learning objectives. The design stage includes material collection, outline preparation, and e-module prototype design. At the development stage, the author conducted e-module development and validation with expert validators. In the implementation stage, the learning application using the e-module was carried out in class XI B SMA Negeri 10 Banjarmasin with as many as 34 students, which involved practicality and effectiveness tests. At this stage, students learn via e-modules that are accessed via their respective cellphones. The evaluation stage is carried out with 2 types, namely, summative evaluation through pretest and posttest and formative evaluation, by evaluating each stage by revising the e-module. The results showed that the e-module was very valid (score of 4.85), very practical (score of 92.75), and effective in improving critical thinking skills (N-Gain of 0.78) and Wasaka characteristics (N-Gain of 0.72). The indicators used in the critical thinking ability variable are the FRISCO (focus, reason, inference, situation, clarity and overview). In addition, the Wasaka character indicators used are responsibility, hard work and resilience. The results of this analysis indicate that the e-module is very valid, very practical, and very effective in applying the reaction rate material to improve critical thinking skills and Wasaka characteristics.

Deep eutectic solvents (DESs) are promising alternatives to traditional electrolytes in electrochemical devices because of their favorable properties, including low volatility, biodegradability, and ease of preparation. This study aimed to optimize a DES composed of choline chloride and urea by investigating the effects of molar ratios and short-chain alcohol additions on viscosity, ionic conductivity, and electrochemical stability. The DES was prepared at 80°C at four molar ratios of choline chloride to urea (1:1, 1:2, 1:3, and 1:4), with a 1:2 ratio optimal for achieving a stable, homogeneous solution. Short-chain alcohols (methanol, ethanol, 1-propanol, and 1-butanol) were added to reduce viscosity and enhance conductivity. The addition of methanol and ethanol effectively lowered the viscosity and increased the ionic conductivity because of their ability to integrate into the DES matrix and disrupt hydrogen bonding. Electrochemical analysis confirmed that the oxidative stability of DESs remained unaffected by these alcohol additions, with oxidation onset consistently at approximately 1 V. These findings demonstrate that methanol and ethanol are suitable additives for improving the performance of DESs as electrolytes in electrochemical applications, enhancing both their conductivity and stability.

Learning media refers to equipment designed and developed to convey information, facilitating the effective transmission of knowledge. Molecular structure is a complex chemical concept containing abstract ideas, which can challenge student comprehension. To address this, the development of 3D hologram learning media for molecular structures aims to provide students with a visual representation for enhanced understanding. This research aims to (1) understand the process of developing 3D hologram learning media for molecular structures via the ADDIE development model and (2) assess the validity and practicality of the developed media. The supporting instruments for this research include product and instrument validation sheets, product readability questionnaires, and question items. The study involved six students from the 12th grade. Descriptive analysis of the data reveals that the developed product aligns with the ADDIE model, achieving a validation rate of 90%. The practicality of the product is determined to be 89%. Therefore, the developed product can be utilized as a learning media for molecular structures via 3D holograms.

Learning chemistry materials using 2D media is currently unable to provide a clear picture of some abstract and microscopic chemical content. Several studies show that many students have difficulty with chemistry because they cannot visualize structures and processes at the submicroscopic level and relate them to other levels of chemical representation. The purpose of this study was to determine the teachers' understanding of new technology that can be used to help students translate 2D into 3D in real form, namely using FabLab. This research is descriptive qualitative research with the research subjects 39 high school teachers and vocational school teachers in West Java. There are three stages in this research, data reduction, data presentation and conclusion drawing. The results showed that all teachers do not know or understand FabLab, although there are teachers who have attended training related to FabLab.Only 23% of teachers are aware of 3D printing but they do not know what is meant by FabLab. There are two schools that have 3D printing facilities, but they are not utilized, one of the reasons being the lack of technological mastery. This research is useful in designing professional development training for chemistry teachers in the field of technology, specifically in the utilization of FabLab.

The relatively high content of free fatty acids in crude palm oil inhibits the direct synthesis of biodiesel. The use of a bifunctional solid heterogeneous catalyst allows for simultaneous transesterification-esterification reactions and facilitates the purification of the final product from the reaction mixture. This study aimed to synthesize biodiesel from crude palm oil via the use of a Sn-K/metakaolinite catalyst in a simultaneous transesterification-esterification reaction. Biodiesel synthesis was carried out using crude palm oil before and after pretreatment. The optimum conditions were determined by the reaction time (1–5 hours), reactant molar ratio (1:2, 1:4, 1:6, 1:8, 1:10, 1:12), and catalyst concentration (1,3, 5,7 and 9%), and the resulting methyl esters were measured for density, viscosity, and free fatty acids and analyzed via GC‒MS. The results obtained indicate that biodiesel synthesis was successfully carried out with completely converted methyl esters via treated crude palm oil. The optimum conditions for the reaction included a reaction time of 3 hours, a catalyst concentration of 5% and a reactant molar ratio of 1:10. The resulting methyl ester product has a density of 0.86 g/mL, a viscosity of 3.02 cSt and a free fatty acid content of 0.059%. The results of the GC‒MS analysis revealed that the dominant methyl ester components were methyl oleate and methyl palmitate. The synthesis of biodiesel from crude palm oil with a Sn-K/metakaolinite catalyst has been proven to be carried out in simultaneous transesterification-esterification reactions with good catalytic activity.

Cadmium is one of the heavy metals with high toxicity that can harm human health and the environment. A commonly used method to remove heavy metals is adsorption. One of the widely used adsorbents is zeolite, which is composed primarily of silica and alumina. Palm oil fly ash (POFA) is a waste from palm oil mills that is rich in silica and alumina so that it can be used as a basic material for zeolite. This research aims to study the factors that affect the adsorption process of Cd metal using zeolite synthesized from POFA and determine the kinetics and isotherms of adsorption. The factors observed were pH (3, 4, 5, 6; 7), adsorbent dosage (1, 1.5, 2, 2.5, 3 g/l), contact time (5, 10, 15, 30, 60, 90, 120, 150, 180 min), and initial concentration of Cd metal (2, 4, 6, 8, 10, 15 mg/L). Adsorbent characterization was performed by XRF and XRD analysis. The results showed that pofa-based zeolite can remove Cd metal with an efficiency above 95%. The adsorption process can follow well the pseudo-second-order kinetics model and both Langmuir and Freundlich isotherm models with a maximum adsorption capacity of 64.58 mg/g. The zeolite synthesized from POFA can remove Cd metal well and has the potential to be developed into an adsorbent

This research focuses on the utilization of natural materials such as textile dyes, which are environmentally friendly and safe for the health of living things. The natural ingredients used are pandan wangi leaves (Pandanus amaryllifolius Roxb.), especially chlorophyll compounds, which are green pigments. The types of fabrics tested consisted of cotton fabrics, linen fabrics, and drill fabrics. The purpose of this study was to extract chlorophyll from pandan wangi leaves via the maceration extraction method with ethanol and maceration for 36 hours. The particle size of the pandan wangi leaves was made up to 60 mesh to obtain the optimum extraction yield. Fabric coloring begins by washing the fabric with Turkish Red Oil (TRO) solution and then mordanting it with various concentrations of 1% and 0.6% alum mordant. Fabrics that have been dyed are then tested for color fastness to sunlight and rubbing. The results of maceration of the ethanol extract produced a yield value of 40.22%. The chlorophyll a and b contents were calculated from the absorbance values obtained via ultraviolet‒visible (UV‒Vis) spectroscopy, namely, 3.7223 µg/mL and 1.1362 µg/mL, respectively. Fourier transform infrared (FTIR) characterization revealed the presence of methyl, ketone, amine, and ester functional groups. The values of the test results for color fastness to sunlight and rubbing were 4 (good) and 4‒5 (very good), respectively.

Protein plays a crucial role as a biocatalyst in various industries, particularly in breaking down proteins into amino acids. The demand for proteases capable of functioning under extreme conditions, such as high salinity, temperature, and pH, is increasing. To address this, the exploration of bacteria that produce stable proteases in such environments is essential. Bacillus clausii J1G-0%B, a halophilic bacterium isolated from Madura salt ponds, thrives in salinity levels of 0-20% NaCl. This study aims to obtain and characterize the protease produced by Bacillus clausii J1G-0%B, focusing on its activity and stability under extreme conditions. The research involved screening, production, and purification of the protease using ammonium sulfate fractionation and dialysis. Protease activity was measured using the Kunitz method, and protein content was determined using the Lowry method. Characterization included optimizing enzymatic conditions (pH, temperature, NaCl concentration), identifying metalloprotease types, and analyzing enzyme kinetics and thermodynamics. The study successfully produced protease using a halophilic medium with casein and 5% NaCl. After 96 hours of incubation, the protease exhibited a specific activity of 654.737 U/mg. Optimal activity was observed at pH 7, 50°C, and 10% NaCl, with stability between 2.5% and 15% NaCl concentration. Enzyme kinetics revealed a high affinity for casein, with a KM value of 0.164 mg/mL and Vmax of 13.182 µmol/mL·min. Thermodynamic analysis indicated high stability, as shown by a positive ΔGi value (+105.84 kJ/mol), a low inactivation constant (ki = 0.0031 min-1), and a long half-life (t½ = 223.548 minutes). EDTA chelation tests confirmed that the protease is a metalloprotease. The halostable protease from Bacillus clausii J1G-0%B shows significant potential for industrial applications and bioremediation in high-salinity environments.

The KCaF3 perovskite catalyst was successfully synthesized by reacting limestone (natural-CaCO3) with potassium fluoride (KF). The synthesis of the KCaF3 catalyst was conducted with several variations in the mole ratio of CaCO3 to KF (1:1, 1:2, and 1:3). The research results showed that the addition of KF can affect the characteristics of the catalyst. The optimal catalyst is the KCaF3 catalyst with a mole ratio variation of 1:3. X-ray diffractometer analysis revealed that the highest KCaF3 phase composition reached 74.05%, while thermogravimetric analysis indicated a CaCO3 concentration of 34.50%. Surface Area Analyzer analysis shows that KCaF3 has the largest surface area, which is 187.1 m2/g. This catalyst efficiently facilitated the transesterification of palm oil, yielding 93.4% biodiesel.

This study evaluates the degradation of methylene blue through photocatalysis using BiVO4/g-C3N4 material with the help of visible light. Material characterization was conducted using X-ray diffraction, scanning electron microscopy, and UV-Vis diffuse reflectance spectroscopy data. The characterization results show that the crystal structure of BiVO4/g-C3N4 is a heterojunction between monoclinic BiVO4 and hexagonal g-C3N4, with a crystal size of about 10.16 nm and a band gap energy value of about 2.16 eV. The morphology formed is a combination of sheet and rod-like. This study optimized the photocatalytic activity of the composite by analyzing the variation of g-C3N4 concentration, degradation time, and methylene blue pH. The results show that the BiVO4/g-C3N4 sample has optimal photocatalytic and adsorption properties in sample B (1:3) with pH 7 and a degradation time of 150 minutes. Under these conditions, the BiVO4/g-C3N4 composite successfully degraded methylene blue by 94.14%. The rate kinetics of the photocatalytic reaction followed first order, with *OH species playing the most role in the degradation mechanism. These findings highlight the potential of BiVO4/g-C3N4 as an effective photocatalyst material for organic pollutant degradation applications, offering a sustainable solution for wastewater treatment.

Chemical dyeing and finishing processes used in the clothing and textile industries are among the main contributors that can increase the impact of climate change. Photocatalysis using nanosized titanium dioxide (TiO2) has been continuously developed as a promising technology for purifying dye wastewater into simpler and environmentally friendly components. In addition, the decoration of iron cations (Fe2+) and (Fe3+) increases the reusability of the photocatalyst due to their magnetic properties, which are easy to collect for the recycling process. Magnetic Fex+/TiO2 microfibers have been successfully prepared using a hydrothermal method using titanium dioxide in an alkaline solution. Cations were added into the solution with the different molar ratios of Ti/Fex+ to produce Fe2+/TNW and Fe3+/TNW, respectively. Photocatalysis activity test using magnetic Fex+/TNW was carried out using methylene blue in a reactor equipped with an incandescent bulb lamp representing solar light. The results showed that adding the cations resulted in a new shape of palm tree leaves, like titanate microfibers. Controlling the cation’s molar ratio produces the magnetic Fex+/TNW with a 50-150 µm length. SEM images of each material presented the uniformly elongated shape and aggregated on one side morphology. In addition, paramagnetic properties indicate that magnetic Fex+/TNW can be easily separated from the dispersion in less than 1 minute using an external magnet. A photocatalysis activity test of magnetic Fex+/TNW was performed by calculating the percent degradation of methylene blue with variations in irradiation time in visible light conditions. The result showed the effectiveness of photodegradation of methylene blue was significantly increased in materials with 3.3 molar ratios of both Ti/Fe2+ and Ti/Fe3+ with a percent degradation reaching 79% and 70%, respectively, in 5 hours. In conclusion, magnetic Fex+/TNW is introduced as an alternative dye wastewater treatment technology that has reusable properties and works well on sustainable energy sources of solar light.

Fluorouracil (5-Fu, 1) is an antimetabolite cancer drug and the first-line drug of anticancer administration by WHO that has been widely used worldwide for more than 50 years. The development of 5-fluorouracil is an effort to obtain higher activity, decrease side effects, and create a specific target receptor compared to 5-fluorouracil. In this research, a series of novel 5-Fluorouracil (5-Fu) derivatives has been synthesized based on a benzoylation reaction (Schotten-Baumann reaction) of N1-hydroxylated 5-Fu called compound 2, 5-fluoro-1-(hydroxymethyl)-uracil. The benzoyl chloride substituents used in this research, including 3-chlorobenzoyl (4a), 2-chlorobenzoyl (4b), 3-nitrobenzoyl (4c), 4-methoxy benzoyl (4d), 4-trifluoromethylbenzoyl (4e), 3,4-dichlorobenzoyl (4f), and 4-nitrobenzoyl (4g) chloride become (4a-4f)-5Fu. This research meticulously examined the conditions (time and reaction temperature) at the second step of the synthesis reaction (esterification), ensuring the reliability of the results. The best synthesis conditions for 4a, 4b, 4c, 4d, and 4g compounds were found to be reflux at 40°C for 6 hours, whereas 4e and 4f compounds reactions were performed in an ice bath for 11 and 17 hours, respectively. All product syntheses, 4a-4g compound, were purified using column chromatography and eluted using eluent hexane: acetone (6:4), and the yields of 4a-4g compounds were around 61-79%. The pure compounds were characterized using FTIR and 1HNMR spectrometer, further validating the research. Based on these findings, it can be concluded that all 5-Fu derivatives can be synthesized using the Schotten-Baumann reaction method.

The green synthesis method is an economical and eco-friendly approach to synthesizing materials. This study effectively synthesized magnetic NiFe2O4 by Artocarpus altilis extract leave for the photocatalytic degradation of Methylene blue dye and exhibited antibacterial properties. The phytochemical compounds found in plants act as agents for reducing and stabilizing NiFe2O4. The synthesized NiFe2O4 was examined using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), and vibrating sample magnetometry (VSM). The variables in degradation include solution pH, dye concentration, catalyst dose, and irradiation time. The synthesized NiFe2O4 has a 12.4 nm crystallite size, a saturation magnetization (Ms) of 44.56 emu/g, and a band gap of 1.68 eV. The degradation efficiency of methylene blue dye was 98.2% under the following conditions: a solution pH of 10, a concentration of 10 mg/L, a dose of 0.1 g/L, and an irradiation time of 90 min. The degradation mechanism of Methylene blue dye may be accurately described by pseudo-first-order kinetics, with a kapp value of 0.0443 min-1. NiFe2O4 has high stability; after five degradation cycles, the degradation efficiency decreased by 4.45%. Additionally, NiFe2O4 demonstrates significant antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria.

In this research, gold nanoparticles were synthesized using the green synthesis method with the bioreduction extract of Basella alba leaf infusion. This research aims to characterize gold nanoparticles synthesized using UV-Vis spectroscopy and TEM and assess their antioxidant activity, which is quantified by the IC50 value. The UV-Vis spectrophotometric characterization of the gold nanoparticles revealed an absorption peak at a maximum wavelength of 543 nm. TEM characterization indicated a particle diameter of 9.463 ± 2.273 nm. The antioxidant activity was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) reduction method with concentration variations of 2.5, 5, 10, and 20 ppm, resulting in reduction percentages of 40.6%, 44.3%, 57.4%, and 77.9%, respectively, and an IC50 value of 7.05 μg/mL, indicating very strong antioxidant activity. Based on these findings, it can be concluded that Basella alba leaf infusion extract is effective as a biological reducing agent in synthesizing gold nanoparticles, and the resulting nanoparticles show significant potential as antioxidants for reducing free radicals.

Many industries in Indonesia have switched to using coal fuel. The use of coal at PT PLTU Paiton has reached 250 tons per hour and produces 4% of waste by-products of combustion contained from bottom ash by 25% and fly ash by 75%. Fly ash waste will harm the environment and health. Fly ash contains many components, including SiO2 52%, Al2O3 31.86%, Fe2O2 4.89%, CaO 2.68%, and MgO 4.66%. This research aims to synthesize and characterize zeolite X from PT Paiton fly ash using a low-temperature synthesis method. Zeolite X synthesis in this study has 3 steps: The pretreatment process, silica synthesis process, and zeolite synthesis process. The results of silica synthesis obtained SiO2 55.54%. The resulting zeolite product has a typical peak at 2ϴ 28.72. Zeolite x has a wavelength of 430, 570, 695,7, and 965,7, which respectively indicates Si-O-Si and Si-O-Al bonds, double ring bonds, T-O ring symmetric strain (internal), and asymmetric (internal). The results of zeolite X crystal synthesis in this study could not be formed in the variable of adding time of 3-5 hours with a variation of moles of Al2O3 0,5-1,5 moles.

Anthocyanin compounds as natural coloring substances contained in Clitoria ternatea flowers have higher antioxidant activity than anthocyanins from other flower extracts. Obtaining anthocyanin extract from Clitoria ternatea flower can be done using the solid-liquid extraction method. The objectives of this study include making a leaching equilibrium diagram of Clitoria ternatea flowers and determining the optimum L/S ratio and the number of equilibrium stages in the counter current horizontal screw extractor. In the maceration process, a leaching equilibrium diagram is produced, which is then used to design and determine the number of equilibrium stages. The equilibrium diagram of anthocyanins from Clitoria ternatea flowers with a gradient slope to the right is in accordance with the literature so that the equilibrium diagram can be used in the design of the extraction unit and the calculation of the theoretical stage of the multi-stage extraction unit. Based on the equilibrium diagram, the Number of Transfer Units (NTU) of 4 stages and the Height of the Transfer Unit value of this process is 0.105 m.

Speciation and bioavailability of mercury in the sediments of Palu Bay after the earthquake and tsunami were conducted using fractionation and Diffusion Gradient in Thin Films (DGT). This method has been conducted using sediment samples from the estuary of the Pondo River, Palu. Heavy metal speciation of mercury ions was conducted by looking at the distribution of mercury ions in various species by sequential extraction and heavy metal bioavailability of mercury ions. This method was conducted by looking at the migration of mercury ions from sediments into the seawaters using a Diffusive Gradient in Thin Films (DGT). The speciation of mercury ions concentration with sequential extraction as EFLE (easily, freely, leachable, exchangeable) fraction is about < 0.0005 ppm, the oxidizable fraction is about < 0.0005 ppm and the resistant fraction is between < 0.0005 ppm to 0.0063 ppm. The results of DGT experiments to study the migration of mercury ions from sediments into the seawaters during 3 days of immersion is between 0.01003 ppm and 0.01748 ppm. The availability of mercury ions concentration in the sediments allows for the migration of mercury ions into water.

The Citarum River is included in the category of the most polluted river in the world because it contains chemicals that can reduce air quality. This pollution not only affects air quality but also threatens public health and the surrounding ecosystem. Heavy metals, especially Cu(II), are one of the contaminants that have exceeded the threshold and can cause serious health impacts, including organ damage and nervous system disorders. Hydrogel is an alternative adsorbent that is widely used in various fields, especially in the field of air purification. Hydrogel has the ability to absorb and adsorb contaminants. In particular, Carboxymethyl Cellulose (CMC) hydrogel and pectin hydrogel have attracted much attention for safe water purification because they are non-toxic and have good biodegradability and biocompatibility. The researchers conducted a study on the adsorption of Cu(II) metal using a Carboxymethyl Cellulose (CMC) hydrogel adsorbent and pectin in a 2:1 composition through the Freeze-thaw method. FTIR analysis of the CMC/pectin hydrogel confirmed the presence of C-O-, O-H, C=O, C-H, OH bending, and COOH stretching vibrations. Based on BET analysis, the hydrogel has micropores, a type 1 isotherm, and a surface area of ​​1,889 m2/g. The Langmuir isotherm model was used to determine the ideal adsorption conditions to be a concentration of 298 ppm, an adsorption capacity of 1,0918 mg/g, and an adsorption efficiency of 13,485%.

Biofoam is a plant-based alternative packaging. The biofoam was prepared by using the extrusion method and baking process. This research aims to determine the lowest ratio of PVA and glycerol in absorbing water and testing the mechanical properties of biofoam (tensile strength, biodegradation test and FTIR analysis. The best biofoam composition in absorbing water was obtained at a ratio of PVA: glycerol 8%. The results of biofoam characteristics obtained by the water absorption test were 9.76%, maximum bending strength was 9.20 MPa and biofoam can be degraded 100% on day 15. The results of FTIR analysis showed the presence of absorption spectra at wave numbers 3410,15 cm-1, which is a typical region of O-H functional groups (strong and broad) carbohydrates and polyphenols. Modification of starch with fiber and plasticizer in research improves the physicochemical characteristics of biofoam in terms of increasing water absorption and biofoam biodegradation. In contrast, in terms of mechanical properties, the bending strength of biofoam requires further research referring to the characteristics of biofoam mechanical properties toward SNI standards.

Grasshoppers are insects that are pests for agriculture. In recent years, humans have begun to realize the broader economic value of insects, which are not only used as animal feed but also as sustainable biopolymers, such as chitin and chitosan. Grasshoppers' body organs contain chitin, including the digestive tract (intestine), trachea system, and exoskeleton (outer skeleton). Currently, the chitin extraction process using the green method with Deep Eutectic Solvent (DES) is more popular because it reduces the use of dangerous chemicals, reduces waste, and is overall more environmentally friendly than using chemical and biological methods. In the chitin extraction process, process parameters, such as reaction time, temperature, and particle size of the raw material, are adjusted to obtain the desired properties of chitin. This research aims to determine the effect of particle size and temperature on chitin yield and degree of acetylation (DA). The research results show that the yield values ​​and DA values ​​produced in this research are not by similar references which have described the characteristics of chitin. However, there is one sample showing that the most optimal DA value is the BSC 7 150 mesh 90°C sample, at wavelengths of 1560 cm-1 and 2875 cm-1, producing a DA value of 55.79514% and DD 44.20485933%. The best yield value was BSC 2 110°C 50 mesh, with a value of 22.1%.

Water pollution from settlements, agriculture, and industry is a significant issue, as it introduces pollutants like heavy metals into water bodies, harming both humans and aquatic ecosystems. Phytoremediation is a cost-effective, eco-friendly technology for reducing heavy metals in water bodies. This study aimed to assess Azolla filiculoides plants' ability to absorb heavy metals nickel and mercury. The plants were grown in a hydroponic solution contaminated with 0.25 ppm of nickel and 0.5 ppm of mercury. The growth of the plants was measured based on their wet and dry weight, and the nickel and mercury content in the plant tissue was analyzed using Atomic Absorption Spectrophotometry (AAS). The study found that the growth of A. filiculoides plants was unaffected by the concentration of either nickel or mercury. The amount of nickel absorbed by the plants was 0 µg/g plant dry weight, while for mercury, it was 1654.82 µg/g. Based on the results, A. filiculoides plant is more promising for use as a phytoremediation agent for water bodies contaminated with mercury heavy metals rather than nickel heavy metals.

The leachate produced at the Kawatuna landfill, managed without proper waste treatment systems, has been found to contain heavy metals like cadmium (Cd), which contaminate groundwater and pose significant health risks. This study investigates the reduction of Cd ions in leachate through adsorption using activated carbon (AC) waste. The AC waste was reactivated via thermal methods, including phosphoric acid immersion, heating, and washing. Morphological analysis was conducted using scanning electron microscopy (SEM), and adsorption efficacy was evaluated with atomic absorption spectroscopy (AAS). The findings indicate that AC waste with a pore diameter of 2.95 µm can be effectively reused as an adsorbent through thermal reactivation. Specifically, AC treated with H3PO4 immersion and heating exhibited a pore diameter of 3.24 µm, while heating and washing resulted in a pore diameter of 2.29 µm. The Cd concentration in leachate treated with AC immersed in H3PO4 followed by heating showed a modest reduction, whereas the heating and washing treatment led to a significant decrease in Cd levels, achieving an adsorption capacity of 3.92 mg/L within 50 min. This method presents a viable alternative for managing landfill leachate at the Kawatuna site.

Numerous ZnO nanoparticles have been successfully synthesized using diverse plant extracts, yet research utilizing B. rotunda extract as a capping agent with microwave assistance has been lacking. Hence, this study aimed to employ microwave-assisted B. rotunda extract to produce ZnO nanoparticles and test their antibacterial activity. By utilizing 10 mL of 1% (m/v) B. rotunda extract at pH 12.5 and calcinating for 3.8 hours at 200°C, coupled with 20 minutes of microwave treatment, ZnO nanoparticles averaging 78.78 nm in diameter were synthesized. Particle size was determined using the ImageJ software to analyze TEM images. UV-Vis absorption spectroscopy indicated a peak wavelength at 360 nm, while FTIR analysis identified compounds from B. rotunda extract crucial in nanoparticle formation. Antibacterial testing revealed the nanoparticles' ability to create an inhibition zone against E. coli growth.

Restrictions on synthetic antioxidants in several countries have caused the global community to switch to using natural antioxidants. One source of natural antioxidants is mistletoe leaves (Loranthus ferrugineus Roxb.).The presence of mistletoe in a place and host is an important aspect to pay attention to to get the best antioxidants. This research aims to determine the effect of different altitudes and host types on the antioxidant activity and phytochemical content of mistletoe leaves. This research was structured in a split-plot design with 2 factors, namely altitude (lowland and medium land) and host types (avocado, lime, cocoa, and dogfruit). Antioxidant activity test using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method and phytochemical screening using reagents. Variables observed included extract yield percentage, antioxidant activity (IC50 value), and phytochemical screening. The results showed that altitude and host type significantly affected the antioxidant activity of mistletoe leaves. Mistletoe leaves in avocado hosts in the lowlands and medium land showed the best antioxidant activity, namely 155,94 µg/mL and 156,25 µg/mL in the weak antioxidant category, and the highest phytochemical content, namely flavonoids, alkaloids, tannins, saponins, and steroids.

Teak wood (Tectona grandis L.f.), a high-quality wood commonly used in Indonesia, specifically in the Cilegon area, has the potential to be used as an alternative to reduce environmental pollution. This research aimed to test teak wood sawdust waste as an adsorbent for cobalt heavy metal, create activated charcoal from the sawdust waste for the same purpose, and determine the optimal conditions for treatment with and without chemical activation. Industrial waste samples were found to contain 50.7 ppm of cobalt metal through ICPS testing. Activated chemical adsorption, without activation and with industrial wastewater mixture, resulted in a decrease in cobalt metal concentration by 78.2% or 11.08 ppm. The optimal conditions for activated chemical adsorption were found at a pH of 5, an adsorbent mass of 600 mg, and a time of 40 minutes, resulting in decreases of 60.9% (21.2751 ppm), 71% (15.7821 ppm) and 67.7% (17.5812 ppm), respectively. The results show that teak wood sawdust waste can effectively adsorb cobalt heavy metal, providing a potential solution for industrial wastewater treatment.

Green chemistry is currently included in 10th-grade chemistry in Indonesia’s Merdeka curriculum. However, the learning implementation is still limited to the knowledge of approximately 12 principles of green chemistry, but its relevance to real-world applications is less discussed. The process of organic compound synthesis is a problem that is closely related to the application of green chemistry. This research aims to produce context-based green chemistry teaching materials for senior high school students on the basis of experiments using an ionic liquid and microwave-assisted organic synthesis (MAOS) method in the synthesis of an organic compound named dehydrozingerone (DHZ) from vanillin and acetone. The instructional material development method follows the Research & Development (RnD) method via a 4D model and includes the Define, Design, Develop, and Deliver stages. The guided-inquiry student worksheets developed in this research were tested in a classroom setting with 31 10th grade students from Al Ma’soem Senior High School in Bandung, West Java, Indonesia. The evaluation of the teaching materials received a positive response from the students, with a score of 78.29%, indicating a “good” classification. The findings of this study highlight the potential of these contextual teaching materials to enhance students’ engagement and understanding in learning green chemistry concepts and applications.

Penelitian ini merupakan Implementasi model pembelajaran contextual teaching and learning (CTL) dalam meningkatkan hasil belajar siswi kelas XI pada materi sistem koloid di SMA Islam Darul Muhibbien Binuang bertujuan untuk meningkatkan aktivitas siswi, hasil belajar dan tanggapan siswi terhadap penerapan model pemebelajaran contextual teaching and learning (CTL). Pendekatan yang digunakan adalah kuantitatif dan quasi ekperimen. Subjek penelitian adalah siswa kelas XIB sebanyak 20 siswi sebagai kelas eksperimen dan kelas XIC sebanyak 20 siswi sebagai kelas kontrol. Aktivitas siswi tergolong sangat tinggi dengan persentase rata-rata 91,25%, hasil penelitian menunjukkan bahwa hasil belajar meningkat dengan persentase hasil belajar yang diperoleh 15% nilai sebelum menggunakan model CTL, sedangkan siswi telah menggunakan model CTL persentase yang diperoleh 95%. Tanggapan siswi adalah positif sebanyak 94%, sedangkan yang bertanggapan negatif 6%. Hasil penelitian ini menyimpulkan bahwa penerapan model pembelajaran CTL dapat meningkatkan aktivitas siswi, hasil belajar, dan minat belajar siswi.

Karakteristik alami zeolit alam sangat mempengaruhi kemampuannya untuk mengadsorpsi logam aktif di dalam kerangkanya. Oleh karena itu, penelitian ini bertujuan mengetahui konsentrasi logam titanium oksida yang sesuai untuk memodifikasi zeolit alam Ende menjadi bahan fotokatalis. Berdasarkan hasil penelitian, disimpulkan bahwa konsentrasi logam titanium oksida (TiO2) adalah sebesar 0,2 M untuk diimpregnasikan ke dalam kerangka zeolit alam Ende. Zeolit alam Ende merupakan jenis mordenit dan tidak mengalami perubahan struktur setelah diimpregnasikan dengan logam titanium ke dalam kerangkanya, tetapi terjadi pergesaran sudut 2θ° sebanyak 0,02 ke arah yang lebih besar. Luas permukaan terbesar berada perlakuan konsentrasi titanium oksida (TiO2) sebanyak 0,2 M yaitu 23,365 m2/gram, dengan penampakan morfologi yang lebih padat dan rapi, serta peningkatan rasio Si/Al. Perlakuan 0,2 M larutan titanium oksida (TiO2) merupakan konsentrasi terbaik yang mampu memberikan 16,40% logam titanium ke dalam kerangka zeolit alam Ende.

Air limbah merupakan bahan buangan yang berbentuk cair yang mengandung bahan kimia. PT Sucofindo cabang Semarang menerapkan International Organization for Standarization (ISO) 17025 bahwa Laboratorium harus mengidentifikasi kontribusi terhadap ketidakpastian pengukuran, sehingga diperlukan estimasi ketidakpastian penetapan kadar nitrit pada air limbah. Percobaan ini bertujuan untuk mengestimasi ketidakpastian penetapan kadar nitrit dalam air limbah hasil yang diperoleh dibandingkan dengan spesifikasi standar keberterimaan perusahaan yang mengacu pada SNI 06-6989.9-2004. Penelitian ini menggunakan pengukuran dengan alat spektrofotometri sinar tampak pada λ 543 nm. Pelaporan hasil uji diperoleh sebesar (0,029 ± 0,004) mg/L, (0,042±0,005) mg/L, dan (0,044 ± 0,005) mg/L. Nilai tersebut memberikan rentang nilai ketidakpastian yang diperkirakan terdapat nilai benar berada sekitar (0,025 – 0,033) mg/L untuk sampel A, (0,037– 0,047) mg/L untuk sampel B, dan (0,039–0,049) mg/L untuk sampel C. Nilai ketidakpastian dari setiap sampel diperoleh yaitu ≤ 15% kadar yang diperoleh atau sesuai dengan syarat keberterimaan yang telah ditetapkan perusahaan.

Penggunaan minyak goreng merupakan salah satu kebutuhan pokok pada kehidupan masyarakat yang sangat dibutuhkan setiap hari. Minyak goreng yang tidak bisa dipakai akan menghasilkan limbah berupa minyak bekas (jelantah). Salah satu upaya untuk mengurangi limbah minyak jelantah yaitu dengan pembuatan biodiesel. Pada Pengerjaan biodiesel dapat melakukan analisa transesterifikasi minyak dan metanol dengan bantuan katalis homogen seperti katalis KOH, NaOH dan NaOCH3. Tujuan penelitian ini adalah untuk mengetahui pengaruh jenis katalis KOH 1%, NaOH 1% dan NaOCH3 1%. Minyak jelantah dan metanol perbandingan (1:9) ditransesterifikasi pada suhu 65°C dan waktu reaksi transesterifikasi 120 menit dengan menggunakan 0,896 gram katalis KOH, NaOH dan NaOCH3. Hasil biodiesel terbaik pada katalis NaOCH3 dengan yield terbanyak 78,67%, densitas 40°C 875,4 kg/m3, viskositas kinematik 40°C 5,68 cSt, kadar air 0,049 %, bilangan asam 0,727 mgKOH/g dan kadar metil ester 51,19%. Semua parameter biodiesel telah memenuhi SNI 7182:2015, kecuali untuk kadar metil ester belum memenuhi SNI 7182:2015.

Karbohidrat merupakan salah satu bahan makanan utama yang diperlukan oleh tubuh. Beras merupakan makanan yang banyak mengandung karbohidrat dan juga merupakan sumber gula bagi penderita diabetes, sehingga sebaiknya dibatasi. Tujuan penelitian ini adalah untuk mengetahui kandungan karbohidrat pada nasi yang diperoleh dari berbagai perlakuan dengan menggunakan metode Luff Schoorl. Hasil penelitan menunjukkan pada sampel nasi tanpa perlakuan memiliki kadar karbohidrat sebesar 0,016%, sedangkan sampel nasi yang mengandung daun pandan memiliki kadar karbohidrat sebesar 0,014%, dan sampel nasi yang mengandung minyak kelapa memiliki kadar karbohidrat sebesar 0,011%. Dari hasil menunjukkan bahwa perbedaan kadar karbohidrat pada sampel tidak menunjukkan perbedaan yang cukup signifikan.

Jumlah penduduk yang semakin meningkat berdampak pada peningkatan jumlah limbah kulit buah-buahan. Tidak hanya daging buah yang kaya akan nutrisi, namun kulit buah-buahan juga mengandung berbagai senyawa bioaktif yang dapat diaplikasikan dalam bidang pangan, farmasi, dan lain-lain. Tanin yang termasuk ke dalam golongan polifenol juga ditemukan pada berbagai jenis tanaman. Penelitian ini bertujuan untuk menentukan kadar tanin pada ekstrak etanol kulit buah naga dan kulit buah semangka. Ekstraksi kulit buah dilakukan dengan metode maserasi menggunakan pelarut etanol. Pengujian secara kualitatif dilakukan dengan skrining fitokimia dan penentuan kadar tanin ditentukan dengan metode Spektrofotometri UV-Vis. Hasil skrining fitokimia adalah kedua ekstrak mengandung tanin dan saponin. Sementara itu, kadar tanin pada ekstrak etanol kulit buah naga (BN) dan kulit buah semangka (SMK) berturut-turut adalah 0,3817±0,0000 μg TAE/g dan 0,2681±0,0004 μg TAE/g.

Limbah industri merupakan salah satu sumber pencemaran logam berat seperti timbal (Pb) yang menimbulkan dampak berbahaya bagi ekosistem dan kesehatan. Tanaman gonda (Sphenoclea zeylanica gaertn) merupakan komoditi lokal Kota Cilegon yang belum banyak dieksplor manfaatnya. Penelitian ini bertujuan untuk mengetahui efektivitas tanaman gonda terhadap penurunan kadar logam Pb pada limbah cair industri. Metode yang digunakan adalah metode analisis deskriptif kuantitatif rancangan acak lengkap desain faktorial 2x3x3 dengan variable bebas berupa jumlah tanaman yaitu, 5,10 dan 15 tangkai dan waktu fitoremediasi yaitu, 2,4 dan 6 hari. Penurunan konsentrasi Pb diukur dengan Spektrofotometri Serapan Atom (AAS). Hasil penelitian menunjukan tanaman gonda dapat menyerap logam berat timbal (Pb) dengan hasil efesiensi optimum yaitu pada hari ke-6 dan jumlah tanaman sebanyak 15 tangkai dengan persentase sebesar 92,43 %. Dapat disimpulkan bahwa hubungan antara waktu dan jumlah tanaman gonda berpengaruh dalam penurunan kandungan logam berat timbal (Pb) menggunakan metode fitoremediasi.

Penelitian didasari oleh pernyataan Kemendikbud, bahwa kurikulum merdeka diharapkan dapat mempersiapkan siswa dalam menghadapi abad 21 dengan membangun Metakognisi siswa. Oleh karena itu tujuan penelitian ini adalah, untuk mendeskripsikan aktifitas yang dapat membangun metakognisi siswa dalam pembelajaran kimia yang ditinjau dari perbedaan akademik masing-masing gender. Penelitian ini merupakan penelitian dengan pendekatan kualitatif, dengan partisipan berjumlah 56 siswa. Data dikumpulkankan menggunakan lembar wawancara dan lembar observasi metakognisi melalui aktifitas belajar siswa. Penelitian dilaksanakan di salah satu madrasah aliyah negeri di kabupaten pesisir selatan tahun ajaran 2023/2024. Hasil penelitian menunjukkan metakognisi siswa dengan kemampuan akademik tinggi, sedang, dan rendah ditemukan perbedaan dalam mepembelajaran kimia. Siswa kemampuan akademik tinggi cenderung lebih baik dalam memahami materi kimia dibandingkan siswa kemampuan akademik rendah. Berdasarkan tinjauan perbedaan gender, perempuan cenderung lebih baik untuk membangun metakognisinya dibandingkan siswa laki-laki. Oleh karena itu, aktifitas membangun metakognisi dapat dilakukan melalui tahap perencanaan pembelajaran, monitoring dan evaluasi.

Sintesis senyawa 4-(5-bromo-4-hidroksi-3-metoksifenil)-3-buten-2-ol dan uji potensi sebagai atraktan lalat buah telah dilakukan. Penelitian ini bertujuan untuk mensintesis senyawa 4-(5-bromo-4-hidroksi-3-metoksifenil)-3-buten-2-ol dan uji potensi sebagai atraktan lalat buah hama yang baru. Sintesis senyawa 4-(5-bromo-4-hidroksi-3-metoksifenil)-3-buten-2-ol tersebut dilakukan melalui tiga tahap, tahap pertama yaitu reaksi brominasi terhadap vanilin dengan menggunakan KBrO3 dan HBr dalam kondisi asam. Tahap kedua yaitu reaksi kondensasi aldol terhadap 5-bromovanilin dengan aseton menggunakan katalis NaOH 20%. Tahap ketiga yaitu sintesis senyawa 4-(5-bromo-4-hidroksi-3-metoksifenil)-3-buten-2-ol melalui reaksi reduksi produk kondensasi aldol dengan NaBH4. Senyawa produk hasil reaksi dianalisis dengan GC-MS dan FT-IR. Hasil sintesis 4-(5-bromo-4-hidroksi-3-metoksifenil)-3-buten-2-ol berupa cairan dengan rendemen 48,77%. Uji potensi sebagai atraktan lalat buah hama menunjukkan bahwa senyawa hasil 4-(5-bromo-4-hidroksi-3-metoksifenil)-3-buten-2-ol dapat berpotensi sebagai atraktan lalat buah (Bactrocera spp).

Mata pelajaran kimia merupakan suatu mata pelajaran yang memerlukan strategi agar lebih mudah untuk dimengerti oleh siswa terutama pada materi redoks. Salah satu model pembelajaran yang dapat memudahkan siswa dalam menerima konsep yang diberikan oleh guru adalah model pembelajaran inkuiri terbimbing. Penelitian ini bertujuan untuk mengetahui apakah terdapat perbedaan hasil belajar kimia kelas X SMA Islam Darul Muhibbien pada materi redoks dengan menggunakan model pembelajaran inkuiri terbimbing. Dalam penelitian ini penulis menggunakan metode eksperimen (quasi experimen) dan menggunakan pendekatan kuantitatif dengan desain penelitian yang digunakan yaitu pretest-posstest control grup design. Hasil penelitian menunjukkan bahwa pada uji hipotesis hasil nilai signifikan yang didapat adalah 0,000 < 0,05 yang artinya terdapat perbedaan hasil belajar siswa pada kelas eksperimen dengan kelas kontrol dengan penggunaan model pembelajaran inkuiri terbimbing dan konvensional, dengan persentase nilai belajar kelas eksperimen 80% dan 55% pada kelas kontrol.

Diabetes mellitus (DM) is a chronic metabolic disorder posing a significant health risk. Effective treatments are continually sought. Coumarin derivatives with oxime ester groups have shown potential as antidiabetic agents by inhibiting the α-glucosidase enzyme, a key player in glycoprotein metabolism and postprandial hyperglycemia control. This makes lysosomal α-glucosidase a promising therapeutic target. A study used 28 coumarin derivatives with known α-glucosidase inhibitory IC50 values for computer-assisted drug design (CADD) through quantitative structure-activity relationship (QSAR) analysis, yielding a statistically robust equation for guiding new compound development. Subsequently, eleven new coumarin derivatives with oxime ester groups were synthesized, showing enhanced α-glucosidase inhibitory activity compared to the initial set. Molecular docking assays indicated that compounds 32, 37, 38, and 39 had lower free energy values than the native ligand, suggesting higher stability in target protein interactions. Notably, compound 38 had the lowest free energy (-8.351) and demonstrated lower root mean square deviation (RMSD) and root mean square fluctuation (RMSF) than the original ligand, indicating greater stability. The QSAR equation derived is: Log IC50 = 2.886 - 0.054 (LUMO) + 0.073 (μ) – 0.148 (α) – 0.046 (RD) + 0.046 (BM) + 0.001 (Vvdw) – 0.421 (qC2) + 1.138 (qC8) – 0.092 (qC9) + 2.61 (qC10) + 1.354 (qN1) (Eq 1) n=28; R=0.918; R2=0.843; SD=0.196; F hit/F tab=3.169; Sig =

The complex compound dithiocarbamate exhibits various biological activities, including anticancer, antibacterial, antifungal, and antioxidant properties. Dibutyl tin (IV) N-ethyl benzyl dithiocarbamate was synthesized to overview its structure and evaluate its antibacterial activity against Salmonella typhimurium ATCC 14028 and Propionibacterium acnes. This compound was synthesized via an in situ method by adding dibutyl tin (IV) dichloride, N-ethylbenzylamine, and carbon disulfide, forming a precipitate, which was then dried to yield a white powder. This powder can also be crystallized. The compound was characterized using FTIR, 1H NMR, and 13C NMR spectroscopy, along with antibacterial activity testing using the disc diffusion method. The FTIR analysis revealed characteristic absorption bands at 1111.00 cm-1 (C-N), 731.02 cm-1 (C-S), 2954.95 cm-1 (C-H), 1602.85 cm-1 (C=C), 360.69 cm-1 (Sn-S), and 567.07 cm-1 (Sn-C). The 1H NMR spectrum showed chemical shifts at 0-3.8570 ppm (δ CH3), 5.0032-5.1472 ppm (δ N-CH2), and 7.2780-7.3607 ppm (δ C6H5). The 13C NMR spectrum displayed signals at 0-34.5610 ppm (δ CH3), 48.6398-56.9247 ppm (δ N-CH2), 127.6651-135.7665 ppm (δ C6H5), and 201.7568 ppm (δ CS2). The antibacterial activity of dibutyl tin (IV) N-ethyl benzyl dithiocarbamate was assessed, revealing inhibition zones against Salmonella typhi of 6.78 mm (100 ppm), 7.36 mm (120 ppm), and 7.76 mm (140 ppm), categorizing the activity as moderate. Against Propionibacterium acnes, inhibition zones were 1.8 mm (100 ppm), 1.88 mm (120 ppm), and 2.13 mm (140 ppm), categorizing the activity as weak. Based on these findings, it can be concluded that dibutyl tin (IV) N-ethyl benzyl dithiocarbamate can be synthesized to form an octahedral structure and exhibits antibacterial activity. However, it is not yet suitable for use as a new antibiotic.

Heavy metal waste, such as lead (Pb), released into the environment negatively affects ecosystems and human health due to its toxic properties. Consequently, it is imperative to develop methods to remove Pb from the environment. One widely used method is adsorption. Synthesizing adsorbents via electrospinning offers several advantages: simplicity, the ability to produce nano-sized fibers, lightness, chemical stability, and reusability. This research aims to determine the optimum conditions for synthesizing cellulose acetate (CA) nanofibers modified with zeolite (CA-Zeolite) by electrospinning to characterize them and evaluate their adsorption capacity. The research results showed that the optimum conditions for the synthesis of cellulose acetate nanofibers were a solution concentration of 14% (w/v), a voltage of 10.5 kV, a flow rate of 0.02 mL/hour, and a tip-to-collector distance of 10 cm. The FTIR spectrum of CA-Zeolite revealed a new peak in the 400-610 cm-1 wavelength range, indicative of O-Si-O bonds, characteristic of zeolite functional groups, confirming the successful incorporation of zeolite into the CA nanofibers. From the SEM data, it can be seen that the addition of 6% (w/w) zeolite reduced the average membrane fiber diameter from 662.4 nm to 353.1 nm. EDX results show the presence of Si and Al elements in the CA-Zeolite nanofiber membrane. Incorporating zeolite into CA nanofibers decreased the contact angle from 125.49° to 111.66°, enhancing hydrophilicity. The modified CA nanofibers with 6% (w/v) zeolite demonstrated an adsorption capacity of 1.595 mg/g.

In December 2019, the first COVID-19 cases were in Wuhan, China. This case is a global concern and a threat to public health. Based on previous research using molecular docking methods, it was found that flavonoids exhibit strong inhibitory activity in SARS-CoV-2 main proteases. The study aims to determine the flavonoid compound Syzygium cumini (L.) Skeels can interact with the SARS-CoV-2 main protease receptor and can be used as a candidate for COVID-19 therapy with virtual screening. Myricetin 4”-O-acetyl-2-O-gallate has the lowest Gibbs free energy (ΔG) of -9.82 kcal/mol. The molecular dynamics of the best compound, Myrcetin 4-O-acetyl-2-O-gallate, RMSD, and RSMF values are quite stable. As a result of pharmacokinetic prediction and toxicity, the best compounds have a relatively good pharmacokinetic profile and are non-toxic. Thus, it can be concluded that the compound Myricetin 4”-O-acetyl-2-o-gallate in the Syzygium cumini (L.) Skeels is predicted to interact with the SARS-CoV-2 main protease receptor (7C6S) as a potential drug candidate for COVID-19 therapy.

In this research, the preparation of lipoamide through direct amidation of fatty acid and via amidation of fatty acid methyl ester (FAME) was compared. The reactivity of aromatic amines and cyclohexylamine for the synthesis of lipoamide was investigated in this research. The performance of saturated and unsaturated fatty acids was also compared. The synthesis of lipoamides via direct amidation was conducted under reflux using a Dean-Stark trap and silica gel as the catalyst. On the other hand, the amidation of FAME was carried out without catalysts and solvent. Both reactions were run simultaneously for 18 hours at the same temperature. The reaction was monitored using TLC, and then the product was purified using column chromatography and characterized using FTIR and 1H NMR. The TLC data, FTIR, and 1H NMR spectra confirmed that both reaction pathways produced the same lipoamide as the product. Both reaction pathways were compatible with aromatic and nonaromatic amines and saturated and unsaturated fatty acids. The reaction yield of lipoamide from direct amidation was around 70-80% and two-fold higher than lipoamide synthesis via amidation of FAME. Therefore, direct amidation of fatty acid was preferred for the synthesis of lipoamides compared to via amidation of FAME.

Natural products and their structural analogs are the main sources of pharmacotherapy. Various Aglaia species have been investigated since the 1960s for their phytochemical constituents and biological properties. This research focuses on isolating the terpenoid group from Aglaia shawiana, to provide a basis for further research to identify lead compounds for drug development. The hexane extract of Aglaia shawiana leaves was isolated using vacuum liquid chromatography and gravity column chromatography, employing solvents with varying polarities. The isolation process yielded two compounds: compound 1 and compound 2. A total of 15 mg of a pure isolate was obtained for compound 1, and 4.5 mg for compound 2. Their structures were characterized using 1D NMR (¹H, 13C, DEPT 135) and 2D NMR (HMQC, HMBC, 1H-1H COSY) and by comparing them with previously reported spectral data. It was concluded that compound 1 has the molecular formula C30H50O3, is a triterpenoid type cycloartane, and is named cycloartan-3β,29-diol-24-one, while compound 2 has the molecular formula C30H52O, is a steroid compound, and is named 23a-homostigmast-5en-3β-ol. These compounds were discovered for the first time in this species.

ABSTRACT. The interaction between herbal remedies and drugs is a fascinating phenomenon that might cause therapeutic complications in patients. Warfarin is an anticoagulant drug that provides anti-blood-clotting effects by inhibiting the formation of vitamin K-dependent coagulation factors, and warfarin interacts with the nuclear receptor PXR, subsequently modulating cytochrome P450 during the metabolism process. St. John's wort, an herbal medicine with antidepressant effects, can alter the pharmacokinetics of warfarin. Thymoquinone is one of the active compounds in N. sativa and has pharmacological activities such as anticoagulant, antidiabetic, diuretic, antidepressant, and anti-inflammatory effects. In this study, we investigated the compounds in Nigella sativa (N. sativa) against pregnane X receptor (PXR) and evaluated the impact of thymoquinone (TQ) administration on PXR expression in HepG2 cells. The molecular docking analysis was conducted utilizing the Molecular Operating Environment (MOE) with the PXR (PDB ID: 7AXJ). At the same time, the PXR gene expression was measured using RT-PCR instruments. The RMSD value in docking represents the deviation criteria between the native ligand position and the redocking position result, indicating the capability of MOE and PDB qualification for performing molecular docking. The docking analysis showed that warfarin had the strongest binding energy (7AXJ -6.0507) by forming hydrogen binding type on Arg410. Despite TQ being the major component, it also displayed a high affinity for the two PDB IDs (7AXJ -4.5962). Furthermore, the concurrent administration of warfarin and TQ (19.27 μM) in HepG2 cells showed a significant reduction in the relative mRNA expression of the PXR gene. Given the above-mentioned findings, our study adequately enables us to predict the mechanism behind herb-drug interactions (HDIs) implicating N. sativa, specifically the TQ compound to warfarin metabolism via the activation of the PXR receptor. Keywords: Thymoquinone, expression mRNA, PXR, molecular docking, HepG2 cells.

ABSTRACT. Azadirachta excelsa is a plant belonging to the same genus as the Indian neem (Azadirachta indica) which is expected to have similar biological activities. However, its active components and pharmacological effects are limited. The composition and quantity of these metabolites in A. excelsa may differ due to different polarities of extracting solvents, so selecting an effective extractive solvent with a high level of biological activity is important. Therefore, in this study, we examined differences in the metabolite finger printing using FTIR-based metabolomics, as well as evaluated their antibacterial activity against Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739). A. excelsa was extracted using chloroform, ethyl acetate, ethanol p.a., 70% and 50% ethanol. Extracts obtained were analyzed using FTIR and the inhibition zones were then determined. The results showed that principal component analysis (PCA) could distinguish each sample based on the extraction solvent. In this study, we found 50% and 70% ethanol extracts had similar metabolite compositions and concentrations based on their respective FTIR spectrum. The inhibition zone of A. excelsa extracts ranged from 12.37-17.20 mm and 13.88-15.89 mm against S. aureus and E.coli, respectively. The chloroform extract was more effective against both bacteria. Duncan's further test showed that chloroform extract reduced E. coli similarly to ethyl acetate but not S. aureus. While 50%, 70%, and ethanol p.a. extracts inhibited S. aureus and E. coli equally. Based on these results, the polarity of the extracting solvent had an important influence on the metabolite profile and antibacterial activity of A. excelsa. Keywords: Azadirachta excelsa, antibacterial activity, metabolite fingerprinting, FTIR.

ABSTRACT. Paracetamol's (PCT) Paracetamol's (PCT) presence in water bodies poses a risk to both aquatic life and humans. This study aims to examine the effect of salinities on PCT removal in water using powder and supported photocatalysts. ZnO powder is a superior photocatalyst to TiO2, where the rate constant can be 18 times higher. Salinity boosted the PCT removal up to 2.7 times for TiO2 at lower concentrations but decreased the PCT removal for TiO2 and ZnO at higher values. Immobilizing the powder photocatalysts on a nonwoven polyester support (NPS) dropped the photocatalytic activity, especially for ZnO, whose performance was 36 times lower than its powder counterpart. The passivation of the photocatalysts by the silica binder necessary for attaching the photocatalyst to the support can be linked to the decline in the performance of TiO2 and ZnO composites. The silica and TiO2 formed homogeneous layers on the NPS, unlike the silica and ZnO layers. High salinity reduced the performance of TiO2 composites by 20 times but showed no significant effect on ZnO composites. The performance of the ZnO composite was further reduced when real seawater was used as feed. Keywords: Titanium dioxide, zinc oxide, polyester, paracetamol, salinity.

ABSTRACT. Sesquiterpenoids are a class of terpenoid compounds with a remarkable diversity of structures and biological activities. Sesquiterpenoids are primarily found in higher plants, such as the Meliaceae family's Aglaia genus. Aglaia cucullata is a species of Aglaia that is still rarely explored and can potentially contain sesquiterpenoid compounds with cytotoxic activity. Hence, the research intended to isolate sesquiterpenoids from the n-hexane extract of A. cucullata stem bark and evaluate their cytotoxic effect against A549 lung cancer cells. Compounds 1 and 2 were isolated and purified from n-hexane extracts utilizing various chromatographic techniques. The structure of compounds 1 and 2 was determined by analyzing various spectroscopic methods (IR, MS, and NMR) and comparing them to previously reported spectral data. Compound 1 was identified as an isodaucane-type sesquiterpenoid, 10-hydroxy-6,10-epoxy-7(14)-isodaucane, and was first reported in Meliaceae family. Compound 2 was confirmed as an eudesmane-type sesquiterpenoid, eudesm-4(15)-ene-1β,6α-dihydroxy, and was first reported in Aglaia cucullata. Cytotoxic activity of 1 and 2 were investigated in vitro against A549 lung cancer cells using the PrestoBlue assay and resulted in inactive and low cytotoxicity with IC50 values of 292.77 and 90.55 μM, respectively. Key words: Aglaia cucullata, , A549 cell lines, cytotoxic activity, Meliaceae, sesquiterpenoids.

ABSTRACT. Butanol-HCl4 (Bu-HCl4) and Protein-Precipitation (P-P) are methods that proposed to determine the content of free tannins, protein-bound tannins, and fiber-bound tannins. This study aims to determine the feasibility of tannin measurements by both methods and validation of Analytical Methods (VMA) evaluates specific parameters like accuracy, precision, specificity, and linearity through lab testing. The material used was twenty C. calothyrsus leaves which collected randomly from different trees. The samples were measured by both methods in triplicates for qantification and validation. The obtained data were analyzed by descriptive and t-test to compare both methods. The analysis of VMA shows that the P-P method yields higher accuracy compared to the Bu-HCl method in percentage recovery rates. The quantification of free tannins, protein-bound tannin, tannin fiber, and total tannin by the Bu-HCl4 method versus the P-P method showed significantly higher values (p

ABSTRACT. Silica xerogel from corn husks shows potential to be applied as an adsorbent for cationic dye removal due to its high adsorption capacity. However, the study regarding its performance in a continuous operation is still very limited, which hinders its application as a commercial adsorbent. To answer that problem, we investigate the adsorption of methylene blue (MB) and crystal violet (CV) dye using silica xerogel from corn husk in a continuous fixed-bed column. A breakthrough curve analysis was carried out with flow rate and bed height variations in an up-flow mode. The column effluent concentration was analyzed using a UV-Vis Spectrophotometer. The experimental data shows good agreement with the Thomas/Bohart-Adams and Yoon-Nelson model at different flow rates but has less correspondence for increasing bed height. Maximum adsorption capacities for methylene blue were 1.977 mg/g (Thomas/BA) and 1.743 mg/g (experimental). While for crystal violet the maximum adsorption capacities were 3.400 mg/g (Thomas/BA) and 4.573 mg/g (experimental). Keywords: adsorption, cationic dyes, silica xerogel, fixed-bed column, mathematical model.

ABSTRACT. This investigation delineates the fabrication, comprehensive characterization, and electrochemical evaluation of a one-dimensional Cobalt-based Metal-Organic Framework (Co-MOFs), constructed from 4,4’-Bipyridine ligands and Cobalt (II) ions. The study aimed to perfect the synthesis protocol, elucidate the structural and compositional attributes of the resultant MOF, and probe its electrochemical performance. Utilizing the reflux method, renowned for its efficacy and eco-compatibility, we synthesized the MOF and affirmed its formation through a suite of analytical techniques, including Infrared (IR) spectroscopy, Ultraviolet-Visible (UV-Vis) spectroscopy, Atomic Absorption Spectroscopy (AAS), and electrical conductivity measurements. The synthesized Co-MOFs, chemically notated as [Co2(4,4'-bpy)2(SO4)(H2O)2]SO4·H2O, manifested as a one-dimensional coordination polymer. X-ray Diffraction (XRD) analysis unveiled its monoclinic crystallinity within the C2 space group. Electrochemical characterization uncovered a reversible redox system, evidenced by a robust peak current ratio (IPa/IPc = 7.5), indicative of efficient electron transfer processes. Furthermore, the Co-MOFs significantly augmented the kinetics of the oxygen evolution reaction (OER) in an alkaline aqueous solution, highlighting its potential as a superior catalyst in energy-related electrochemical applications. This work not only contributes to the field of MOF synthesis but also sets the stage for future explorations into their practical applications in sustainable energy systems. Keywords: Electrochemical properties, metal-organic framework, oxigen evolution reaction catalyst, 4,4’-bipyridine.

ABSTRACT. The biological method for silver nanoparticle synthesis emphasizes green synthesis, which is faster, environmentally safer, facile, energy-efficient, and cost-effective. It provides good alternatives to physical and chemical methods. In this research, we have synthesized silver nanoparticles using D. vitifolius ethanolic extract. The 38 natural compounds of flavonoid, phenolic or polyphenol compositions have been determined by LC-MS/MS-QTOF which is carried out using UNIFI software equipped with a mass spectrum library of active substances from natural ingredients from the Waters database. Silver nanoparticle (Dv-AgNP) was characterized by using TEM and SEM where the average diameter of nanoparticle was seen