ALCHEMY Jurnal Penelitian Kimia is a peer-reviewed, open-access journal publishes original research articles or review articles both theoretical and experimental studies on all aspects of fundamental and applied chemistry, including organic, inorganic, analytical, physical, computational chemistry, sustainable, green, and environmental. ALCHEMY Jurnal Penelitian Kimia covers studies in emerging fields of current innovative chemistry. Moreover, ALCHEMY Jurnal Penelitian Kimia pays special attention to the studies related to the exploration research of minerals and natural materials, including plant extracts that grow in Southeast Asia. ALCHEMY Jurnal Penelitian Kimia published twice a year in March and September. Bibliographic Information Journal abbreviation Editor-in-Chief Print ISSN Online ISSN Publisher DOI : : : : : : ALCHEMY J. Pen. Kim. Assoc. Prof. Dr. Teguh Endah Saraswati. 1412-4092 2443-4183 Sebelas Maret University, Surakarta, INDONESIA 10.20961/alchemy View Publication Information in Current Issue. View complete Statistics Information in Journal Metrics and Sinta.
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Phloroglucinol Compounds and Their Derivatives: Comparison of FTIR, NMR, and Bioactivity Characterization as Antibacterial, Antioxidant, and Anticancer Agents
Research on phloroglucinol (PG) and its derivatives has been extensively pursued over the past three decades. PG compounds are found in many plants, such as in the genus Callopyillum, the genus Hypericum, Eucalyptus kino, and brown algae. PG compounds have a symmetrical compound structure and contain many electrons distributed across three active sites, making them very advantageous for electrophilic aromatic substitution. PG has biological activities, such as antibacterial, antioxidant, anticancer, antiviral, anti-inflammatory, and others. PG bioactivity can be increased by synthesizing PG derivatives using various synthetic methods. The addition of an active group to PG can affect its bioactivity, properties, and characteristics, as well as its polarity and lipophilicity. This study aims to collect data on (1) Comparison of Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) characterization of various PG derivative compounds, (2) Comparison of PG bioactivity and its derivatives as antibacterial, antioxidant, and anticancer compounds. PG compounds and their derivatives have been shown to exhibit antibacterial effects against several bacteria, including Staphylococcus aureus, Escherichia coli, and MRSA. Furthermore, PG derivatives exhibit antioxidant properties, as evidenced by their low IC50 values, and have demonstrated anticancer activity against cancer cell lines such as A549, MCF-7, and HTC-116. The findings of this study have the potential to assist researchers in developing new drugs.
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Recent Developments of Biopolymer-Based Composite Membranes as Sustainable Separators for Lithium-Ion Batteries
The increasing adoption of electric vehicles and large-scale energy storage systems has intensified demand for high-performance and sustainable lithium-ion battery separators. This review summarizes recent progress in biopolymer-based separators as environmentally friendly alternatives to conventional polypropylene/polyethylene membranes. Fourteen research articles published between 2020 and 2026 are analyzed, focusing on biopolymers such as bacterial cellulose, chitosan, lignin, alginate, silk fibroin, and poly(L-lactic acid). The discussion covers material classification, membrane fabrication techniques, and modification strategies, including composite formation and crosslinking. Overall, the reviewed studies indicate that biopolymer-based separators generally exhibit improved electrolyte wettability, enhanced ionic conductivity, and adequate thermal stability, leading to competitive electrochemical performance and good cycling stability. In addition to performance benefits, the use of biomass-derived materials and water-based fabrication processes offers sustainability and potential biodegradability advantages. This review highlights current research trends and outlines key challenges related to testing standardization and manufacturing scalability for future lithium-ion battery applications.
Chemical Composition and Aromatherapy-Based Relaxation Potential of Selected Indonesian Herbal Essential Oils
Aromatherapy, an alternative treatment approach, is gaining popularity in Indonesia due to its ability to provide psychological and physiological relaxation. The use of Indonesian herbal plants, especially Syzygium polyanthum (bay leaf), Camellia sinensis (green tea), Cymbopogon citratus (lemongrass), Lavandula angustifolia (lavender), and Citrus limon (lemon) in aromatherapy has long been recognized for its distinctive, refreshing aroma and diverse secondary metabolites. This scientific literature review is presented to reveal the relationships between the presence and diversity of chemical composition of selected Indonesian herbal plants and various influencing factors, such as plant origin and the extraction method used. The aroma-defining properties of eugenol, geraniol, linalool, citral, and limonene in essential oils, when combined, can synergistically trigger bioactivities, including antioxidant, antibacterial, anti-inflammatory, and relaxing effects. Scientifically, the relaxing effects of aromatherapy are produced through stimulation of the olfactory system, which connects to the limbic system in the brain, including the amygdala and hypothalamus, which are responsible for improving mood and enhancing emotional regulation. Based on this review, the metabolite profile of essential oils plays a role in determining their potential bioactivity, especially in selected herbal plants as sources of natural relaxation therapy.
In Silico Study of Moringa Leaf (Moringa oleifera L.) Compounds as an Antiproliferative in Hepatocellular Carcinoma against TGF-β Receptor
Liver cancer is a condition in which liver cells grow uncontrollably. Liver cancer, also known as hepatoma, occurs when cells proliferate and acquire malignant properties. Liver cancer is among the types of cancer with a high contribution to global mortality rates each year. This study aims to predict and identify the activity of compounds isolated from Moringa leaves (Moringa oleifera L.) against liver cancer by targeting the TGF-β receptor using molecular docking. The research was conducted using software tools including LigandScout, ADMETlab 2.0, BIOVIA Discovery Studio Visualizer, and AutoDock Tools. The results showed that ten out of eleven test compounds from Moringa oleifera L. leaves met Lipinski's Rule of Five, indicating their potential as good oral drug candidates. Pharmacophore screening yielded an AUC100 value of 0.94 with three hit compounds: rutin, kaempferol, and isorhamnetin. In the molecular docking stage, the compound with the lowest binding energy was Isorhamnetin, with a binding energy of -8.18 kcal/mol against the TGF-β receptor, and it also demonstrated a favorable ADMET profile.
Organic Waste Management Innovation through Composting Technology with Local Bio-Activators
This research is part of a strategic research program in environmental technology and renewable energy focused on climate change mitigation. Organic waste management through composting technology is a strategic approach to reduce waste generation and the potential for methane (CH₄) emissions from anaerobic decomposition. This study aimed to analyze the effectiveness of local microorganism (MOL) bioactivators, namely rice MOL (P1), banana mob MOL (P2), and fruit MOL (P3), in accelerating composting, compared to controls (without the addition of MOL). The results showed that fruit MOL (P3) is the most effective bioactivator for accelerating decomposition and improving compost quality. This treatment achieves the fastest maturity in 40 days with the lowest C/N ratio and the highest macronutrient content (Nitrogen (N), Phosphorus (P), Potassium (K)) compared to other treatments. These findings confirm that the application of local bioactivators can significantly improve the efficiency of campus organic waste management and support environmental sustainability.
Optimization Depolymerization of Tilapia Fish Scale Chitosan by Oxidative Degradation with H2O2 using Central Composite Design (CCD)
Tilapia fish scales are among the fishery wastes that have not been optimally utilized, even though they have economic potential when processed into chitosan. Chitosan is a poly(2-amino-2-deoxy-β-D-glucose) obtained by deacetylation of chitin, with a high molecular weight ranging from 100 to 1.200 kDa, making it difficult to dissolve in water. To increase its solubility, chitosan can be depolymerized into oligochitosan with a lower molecular weight, around 5 – 10 kDa. This depolymerization process is influenced by temperature, time, and concentration factors. This study aims to determine the optimal conditions for the depolymerization of chitosan from tilapia fish scales using a central composite design (CCD). The stages of chitosan production include demineralization, deproteinization, and deacetylation, yielding a white powder with a molecular weight of 264.214 kDa and a degree of deacetylation of 74.24%. Based on CCD optimization, the optimal conditions for the depolymerization of tilapia fish scale chitosan were 3.6 M H2O2, 50 °C, and 2 hours, yielding a molecular weight of 3093 kDa. Fourier transform infrared (FTIR) characterization showed a peak shift from wave number 3267 cm-1 to 3303 cm-1. Oligochitosan also showed 100% solubility in water at neutral pH
Synthesis, Characterization, and DFT Computational Study of Cu(II) Complex with 3-Hydroxybenzoate
This study focuses on the synthesis, characterization, and density functional theory (DFT) computational study of Cu(II) complexes with 3-hydroxybenzoic acid ligands. The synthesis process was carried out by reacting CuCl₂·2H₂O with 3-hydroxybenzoic acid ligands in methanol, refluxing for 3 hours, and allowing the mixture to stand until complex precipitation formed. The complex formula was determined by atomic absorption spectrometry (AAS), thermogravimetric analysis (TGA), and molar conductivity measurements (41 S·cm2·mol-1), indicating that Cl⁻ acts as a counterion and that the complex formula is [Cu(3-hydroxybenzoate)2]Cl2·4H2O. The complex exhibits a single electronic absorption peak at 914 nm, indicating ligand-metal charge transfer (LMCT) and d-d transitions, consistent with a distorted square-planar geometry. The infrared spectrum shows a phenolic –OH band, indicating that –OH is not deprotonated. Computational methods were used to reveal the electronic structure and molecular geometry, and to verify the experimental data. This complex forms a distorted square planar structure.
Modification of Chroman Derivative Compounds and Their In Silico Antibacterial Activities
This study reports the alkaline reflux synthesis of 6-chloro-4-chromanone (Ch) with the secondary amine dimethylamine (DA) to obtain chromanone-derived compounds with potential antibacterial activity. Spectroscopic analyses confirmed that 6-chloro-3-((dimethylamino)methyl)chroman-4-one (Ch-DA) was successfully formed in 46.37% yield and corresponded to the targeted structure. In silico antibacterial studies were performed to evaluate the interaction between the synthesized compound and the target protein (PDB ID: 3VOB). Molecular docking results indicated that Ch-DA exhibits antibacterial potential through the formation of hydrogen bonds with key amino acid residues at the active site. The standard ligand (9PC) showed a CDOCKER energy of-46.4867 kcal/mol with seven hydrogen bonds involving residues VAL310, ASN263, VAL207, ASN208, GLY205, LEU209, and GLY196. Meanwhile, Ch-DA demonstrated a CDOCKER energy of -34.3506 kcal/mol with three hydrogen bonds at GLY196, THR265, and ASP199. The positive control, chloramphenicol, produced a CDOCKER energy of -48.0224 kcal/mol and formed three hydrogen bonds with THR309, GLY205, and GLY196, whereas the precursor compound (Ch) showed lower activity (-27.546 kcal/mol) without hydrogen bond formation. These results indicate that the incorporation of a secondary amine group enhances antibacterial activity, with docking performance comparable to the positive control, suggesting that Ch-DA has potential as antibiotic drugs.
Kitolod (Isotoma longiflora Presi) Leaf Extract as a Bioreductor in Silver Nanoparticle Synthesis
Silver nanoparticles (AgNPs) were synthesized using kitolod (Isotoma longiflora Presi) leaf extract as a bioreductor. This research aims to investigate the ability of extracts to act as reducing agents in the formation of AgNPs and to characterize the resulting AgNPs. The synthesis was carried out under the following conditions: pH of extract 12, reaction time 90 minutes, silver nitrate concentration 2 × 10-4 M, and extract concentration 0.08%. Fourier transform infrared (FTIR) spectra confirmed the involvement of phytochemicals in the reduction of Ag+ to Ag0. The synthesized AgNPs were spherical, with an absorption peak at around 420 nm, an average particle size of 67.38 nm, a zeta potential of -23.6 mV, and a polydispersity index (PDI) of 0.697. Stability testing showed that the synthesized AgNPs remained stable for two months at room temperature.
Determination of Tetracycline Antibiotic Residue Levels in Goldfish (Cyprinus carpio) using High Performance Liquid Chromatography (HPLC)
The method for determining residual levels of tetracycline antibiotics in goldfish (Cyprinus carpio) was validated using High Performance Liquid Chromatography (HPLC). The HPLC method has advantages, including high accuracy, efficiency, ease of operation, and high selectivity and sensitivity. This research aims to develop a method for determining tetracycline residues and tetracycline levels in goldfish meat obtained from eight markets in Bandar Lampung City. The analytical method carried out was optimized for the composition and flow rate of the mobile phase. Optimization results show a composition of acetonitrile:water = 35:65 and a flow rate of 0.5 mL/minute. The method validation parameters carried out are linearity, precision, accuracy, selectivity, Limit of Detection (LoD), and Limit of Quantitation (LoQ). The linearity results obtained from this research were R2 = 0.9980. This method has repeatability precision with a Relative Standard Deviation (%RSD) value of 1.35%, and reproducibility precision with %RSD values of 0.96% and 1.14%, respectively. The %recovery method value is 101.05%. The LoD and LoQ values for this method are 0.27 and 0.90 ppm. Measurement of tetracycline antibiotic residue levels in carp samples from 8 market locations in Bandar Lampung showed values of 21.77 – 38.58 ppm, with uncertainties of ±0.87 – ±1.42. The method validation results show that the method can be used for routine analysis of tetracycline antibiotic levels in the laboratory.
Copyright (c) 2026 ALCHEMY Jurnal Penelitian Kimia http://creativecommons.org/licenses/by-nc/4.0
The Effect of Co-Processed Excipient and Mannitol on Physical Properties and Release Test of Flavonoid Total of Bajakah Root (Spatholobus littoralis Hassk.) Water Extract in Effervescent Granule
Bajakah root is traditionally used in herbal medicine and exhibits notable antioxidant activity (IC₅₀ = 0.155 mg/mL) with a total flavonoid content of 32.49 ppm. However, conventional consumption by boiling is limited by poor taste, odor, and low stability. To overcome these limitations, this study developed effervescent granules to enhance acceptability and absorption. The effect of combining co-processed excipients (lactose–manihot starch in a ratio of 64.32:35.68) with mannitol on granule characteristics and flavonoid release was investigated. Bajakah root extract was prepared by hot water infusion (90 °C, 15 min; ratios 1:10 and 1:20) followed by freeze-drying. Phytochemical contents were analyzed using UV–Vis spectrophotometry. Co-processed excipients were prepared via wet granulation and characterized by SEM. Formulations with co-processed excipient–mannitol ratios of 3:1, 2:2, and 1:3 were evaluated for physicochemical properties and flavonoid release. Results showed total flavonoid and tannin contents in the extract of 2.19% and 9.04%, respectively. Excipient ratios significantly affected flow rate, angle of repose, moisture content, and disintegration time (p < 0.05), but not pH. All formulations met pharmacopoeial requirements for ≥80% flavonoid release within 60 min. The optimal formulation (1:3) demonstrated excellent properties, supporting its potential as an effective herbal delivery system.
Synthesis and Characterization of Carrageenan-Chitosan Milkfish Scales-Based Hydrogel for Slow-Release Fertilizer
This study aims to develop a superabsorbent hydrogel as a slow-release fertilizer based on a combination of carrageenan-glucomannan and carrageenan-chitosan derived from milkfish (Chanos chanos) scale waste. The hydrogel was synthesized by chemical crosslinking with glutaraldehyde concentrations of 2%, 4%, 6%, and 8%. Hydrogel characterization included swelling ratio tests, gel fraction analysis, Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), urea absorption (Xo), and urea release kinetics in both aqueous and soil media. The results indicate that a 8% glutaraldehyde concentration yielded optimal performance in both hydrogel systems, achieving the highest gel fractions (>90%) and maximum urea absorption capacities of 8.05 g/g for carrageenan-glucomannan and 13.31 g/g for carrageenan-chitosan. The carrageenan-glucomannan hydrogel exhibited a higher swelling ratio of 630% at 2% glutaraldehyde concentration and slower urea release in soil, ranging from 0.192% to 4.113% over 7 days. In contrast, the carrageenan-chitosan hydrogel demonstrated stronger chemical affinity for urea but released it more rapidly, ranging from 1.037% to 7.092% over the same period. SEM and FTIR analyses confirmed the formation of a three-dimensional network structure and chemical interactions among the components.
Synthesis and Characterization of an Adsorbent from Chicken Eggshell and Its Application for Methyl Orange
Eggshell is a part that protects egg components from various external threats, including chemical, physical, and biological factors. This study aimed to obtain an adsorbent from chicken eggshells using physical and chemical activation techniques. The quality of the eggshell-derived adsorbent was assessed and compared with the Indonesian National Standard (SNI) 1995, with a focus on parameters such as ash content, moisture content, and iodine absorption. The adsorbent obtained was applied to a solution of methyl orange, and Fourier transform infrared spectroscopy (FTIR) analysis was conducted before and after the adsorption process. Furthermore, the study stages include adsorbent preparation, activation, and adsorption. The adsorbent weight for this process was 17 grams, with time intervals of 15, 30, 45, 60, and 75 minutes. The results showed that both physically activated as well as physical and chemical activated adsorbents met the SNI 1995 standard, based on the parameters of water content (1.73% and 2.86%), ash content (8.18% and 6.745), and iodine absorption (761.40 mg/g and 774.09 mg/g). FTIR analysis confirmed the presence of a hydrocarbon and an OH group in the structure before and after adsorption. The optimum methyl orange adsorption capacity was achieved at an adsorbent mass of 17 grams and a contact time of 60 minutes, resulting in removal efficiencies of 20.38% for physical activation and 24.11% for physical and chemical activation.
Formulation and Stability of Miana Leaf Extract Spray Gel with Antioxidant
The extract of Miana leaves (Coleus scutellarioides L.) is recognized for possessing potent antioxidant Action. This research aimed to develop a physically stable spray gel incorporating miana leaf extract and to evaluate its antioxidant potential through the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Three formulations with different proportions of Carbopol and hydroxypropyl methylcellulose (HPMC) were evaluated for stability under room-temperature storage and during cycling tests, with organoleptic characteristics and viscosity as assessment parameters. The extract alone exhibited very strong antioxidant Action (IC₅₀ = 47.71 ppm). In comparison, the spray gel formulations showed IC₅₀ values of 141.18 ppm (FE1, 1%), 113.72 ppm (FE2, 3%), and 80.90 ppm (FE3, 5%), corresponding to moderate, moderate, and strong Action, respectively. Among these, FE2 (3% extract) demonstrated the most favorable physical stability.
Physical and Chemical Properties of Bacterial Cellulose-Based Bioplastic Innovation from Sago Liquid Waste for Eco-Friendly Secondary Food Packaging
The increasing demand for plastic food packaging has raised concerns over the environmental impact of plastic waste. Previous research has used sago liquid waste as a primary food packaging material, namely, edible coatings on tomatoes and edible films on sausages. However, research on secondary food packaging has not been conducted. The method used in this research involves a series of stages, from synthesizing bacterial cellulose to make bioplastics. The bioplastics were made with bacterial cellulose fermented from sago liquid waste and mixed with varying compositions of carboxymethyl cellulose (CMC), zinc oxide (ZnO), polyvinyl alcohol (PVA), and glycerol. Chemical characteristics, as determined by functional group analysis, showed that bioplastics still exhibited the typical functional groups of bacterial cellulose, as well as additional groups from glycerol, CMC, PVA, and ZnO, indicating the success of chemical structure modification in bioplastics. The crystallinity level of bioplastics also increased with the concentration of the mixture, with the highest crystallinity value of 37.084% in bioplastic sample A4. The physical characteristics of bioplastics, such as transparency, thickness, moisture content, water solubility, water uptake, and water vapor transmission rate, increased with increasing bioplastic mixture.
Free Radical Scavenging, Cytotoxic Activity, and Antioxidant-Targeted Molecular Docking Analysis of Akar Kusim Besar (Artabotrys sp.) Methanolic Extract from Ketambe, Indonesia
Akar Kusim Besar (Artabotrys sp.), a vine from the Annonaceae family and an orangutan food source in Ketambe (Indonesia), is known to contain diverse bioactive metabolites. This study evaluated the phytochemical profile, antioxidant activity, cytotoxicity, and molecular docking of its methanolic leaf extract. Phytochemical screening confirmed the presence of alkaloids, steroids, terpenoids, saponins, flavonoids, phenolics, and tannins. The extract showed strong radical scavenging activity (IC50 = 100.816 µg/mL) and cytotoxicity against Artemia salina larvae (LC50 = 57.702 µg/mL), indicating potential bioactivity attributable to flavonoids and phenolic compounds. Gas Chromatography-Mass Spectrometry (GC-MS) analysis detected 30 compounds, of which 12 were subjected to molecular docking against human glutathione peroxidase 7 (2P31). Stigmasta-3,5-diene exhibited the strongest binding affinities, while several compounds complied with Lipinski's Rule of Five, supporting their potential druglikeness. Together, these findings suggest that Artabotrys sp. exhibits promising antioxidant and cytotoxic activities, and that molecular docking provides mechanistic insight into its anticancer potential.
Identification of Antioxidant Compounds using the DPPH Radical Scavenging Method from Ethanol and Methanol Extracts of the Leaves and Fruits of the Renggak Plant (Ammomum dealbatum R.)
This study aims to screen antioxidant compounds from the renggak plant (Amomum dealbatum R.). Screening of phytochemicals was carried out on the leaves and peel of the renggak fruit by the extraction method using ethanol and methanol solvents. Extraction was carried out by maceration, and the antioxidant potential test was carried out by measuring the extract's scavenging activity against DPPH radicals. In the fruit peel, both ethanol and methanol extracts tested positive for all phytochemicals, while in the leaves, ethanol extract was positive only for tannins and alkaloids, and methanol extract for flavonoids, saponins, tannins, and alkaloids. The difference in results was caused by differences in solvent polarity. The results of the antioxidant test showed that the leaf extract had an IC₅₀ value of 44.31 µM, while the fruit peel extract had an IC₅₀ value of 144.57 µM. The lower IC₅₀ value in the leaf extract indicates that the bioactive compounds contained therein have higher antioxidant potential than the fruit peel, as they can inhibit 50% of free radical activity at lower concentrations. The results of this study provide additional phytochemical and antioxidant sources from plant sources, for use as raw materials in the pharmaceutical and cosmetic industries.
The Influence of Solvent and Heating Time Toward the Percent Yield of Sumbermanjing Pyrophyllite-Polyethylene Glycol (PEG) 6000 Composites
The synthesis of clay-polymer composites has attracted considerable interest due to their promising potential properties. The composites were prepared from Sumbermanjing pyrophyllite and polyethylene glycol (PEG) 6000. This research aims to evaluate the influence of solvent and heating time on the percent yield of the composites. Pyrophyllite-PEG composites were synthesized via the casting and sol-gel methods with variations in solvent (demineralized water, methanol, acetone) and heating time (1, 1.5, and 2 hours). The highest yield (37.7239%) was achieved by a composite synthesized with acetone and a 2-hour heating treatment. The composite prepared with demineralized water showed poorer PEG diffusion into the pyrophyllite structure than did those prepared with methanol or acetone. A 2-hour treatment produced a more uniform, relatively smaller porous structure, despite subtle differences across various heating conditions. Statistical analysis revealed a significant difference among solvent treatments, but no significant difference among heating times. The melting points of the 1-hour and 2-hour composites were 120.7667 °C and 116.0333 °C, respectively, suggesting a successful composite synthesis. The successful composite synthesis was further confirmed by Fourier Transform Infrared (FTIR) spectra, which showed characteristic functional groups (O–H stretching, 3673.92 cm-1; C–H stretching, 2882.37 cm-1; Al–OH stretching, 1146.67 cm-1).
Synthesis of Ni2+/Natural Zeolite by Electro-Ion Exchange
Electro-ion exchange was carried out to synthesize Ni2+/natural zeolite at room temperature using various concentrations of Ni(NO3)2 of 0.05, 0.1, 0.15, and 2.0 M, zeolite wetting times of 0 and 24 hours, electrolysis times of 1, 2, and 3 hours, and voltages of 7.5, 15, and 28.4 V. The amount of Ni2+ that can be impregnated in the zeolite was monitored with Atomic Absorption Spectroscopy (AAS). The Ni2+/zeolite formed was characterized for its total acidity. The optimum conditions for this process are 28.4 V, 3 hours, and 0.1 M Ni(NO3)2. Under these optimum conditions, the Ni2+ content of the natural zeolite was 0.04 mmol/g, with a total acidity of 2.5 mmol/g. The increasing trend in the amount of Ni2+ content matched the trend in the total acidity. The synthesized Ni²⁺/natural zeolite is expected to be applied as a catalyst in reactions such as hydrogenation and hydrocracking.
Synthesis of Carbamate-Modified Cellulose Biocoagulant from Jengkol (Archidendron pauciflorum) Peel via Crosslinking Method for Lead Removal from Wastewater
Heavy metal pollution poses a serious environmental and health threat. An effective and environmentally friendly solution to mitigate this issue is the use of cellulose-based coagulants derived from jengkol (Archidendron pauciflorum) peel waste modified with carbamates. Cellulose isolated from jengkol peel was successfully modified with carbamate derived from urea through a crosslinking method. The formation of cellulose and carbamate crosslinks was confirmed by Fourier transform infrared (FTIR) spectroscopy, which showed new absorption peaks corresponding to amide (–NH2) and nitrile (CN) functional groups. Morphological observations using a scanning electron microscope (SEM) showed changes in the shape of cellulose fibers after modification with carbamate, where carbamate cellulose exhibited a denser fiber morphology with larger pore sizes. Elemental analysis revealed the presence of nitrogen in carbamate-crosslinked cellulose, indicating that the cellulose has successfully bonded with the carbamate derived from urea. The decrease in heavy metal lead (Pb) concentration in wastewater samples was achieved by adding 1.5 g of carbamate-modified cellulose, resulting in 96.87% Pb removal. These results show that the cellulose-based biocoagulant from jengkol peel waste, modified with carbamate via crosslinking, has been successfully synthesized and significantly reduced the concentration of the heavy metal Pb.
Preparation and Optimization of Coal Fly Ash-Based Geopolymer and Its Application as an Adsorbent for Basic Yellow 2 and Methylene Blue Dyes
The preparation of geopolymer from coal fly ash (CFA) solid waste of Jepara PLTU has been carried out by activating CFA using a 10 M NaOH solution and Na2SiO3. Characterization of CFA and geopolymer using X-ray fluorescence (XRF), X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infra-Red (FTIR) spectroscopy. The adsorption process was studied under parameters including pH, geopolymer mass, contact time, and initial adsorbate concentration. The optimum conditions for the adsorption process of basic yellow 2 dye with fly ash-based geopolymer were optimum at solution pH of 11; adsorbent mass of 0.15 g; contact time of 120 minutes; and initial concentration of 80 ppm, while methylene blue adsorption was at solution pH of 11; adsorbent mass of 0.15 g; contact time of 120 minutes; and initial concentration of 60 ppm. Coal fly ash, a solid waste product from the Jepara PLTU, can be used to produce geopolymers through geopolymerization in the presence of activators such as NaOH and Na₂SiO₃. The adsorption capacities of these geopolymers for basic yellow 2 and methylene blue dye solutions are 26.55 and 19.825 mg/g, respectively.
Phytochemical Examination, GC-MS Analysis, and Antibacterial Activity of Methanol Extract of Dadap Leaves (Erythrina variegata L.) Against Staphylococcus aureus and Escherichia coli Bacteria using Disc Diffusion Method
This study examines the antibacterial activity of a methanol extract from the leaves of Dadap (Erythrina variegata L.) against Staphylococcus aureus and Escherichia coli. Bacterial infections are a major health issue in Indonesia, so the development of plant-based natural medicines is being pursued. The Dadap plant has the potential to treat bacterial infections. This study aims to identify the types of secondary metabolites in the methanol extract of Dadap leaves, analyze the active compounds using Gas Chromatography-Mass Spectroscopy (GC-MS), and evaluate their antibacterial activity. Extraction was performed by maceration with methanol, and antibacterial testing was conducted by disk diffusion on Mueller-Hinton Agar with extract concentrations of 5, 10, 20, and 40% (w/v). The extracts were diluted in sterile distilled water. The results exhibited antibacterial activity against S. aureus and E. coli, with inhibition zones of 14 mm (strong) and 8.8 mm (moderate) at a 40% concentration, respectively. These activities might be linked to the active compounds found in the Dadap leaves extract using phytochemical and GC-MS analysis. The phytochemical analysis showed that the E. variegata L. leaf extract contains alkaloids, steroids, terpenoids, saponins, flavonoids, phenols, and tannins. Furthermore, the GC-MS chromatogram identified 11 compounds, including 7 with antibacterial activity, such as neophytadiene, 3,7,11,15-tetramethyl-2-hexadecen-1-ol, hexadecanoic acid, methyl ester, n-hexadecanoic acid, phytol, methyl stearate, and stigmasterol. Overall, the crude extract of Dadap leaves showed a potential candidate for development as an antibiotic.