Chimica et Natura Acta is published by the Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran. The major focus of the journal is to publish articles in the area of material chemistry, environmental chemistry, chemical separation and analysis, natural product and synthetic organic chemistry, biotechnology & biomolecular sciences and other topic that are highly related to chemical sciences. The journal publishes 3 times every years on April, August and December. Publication fee for every article published in CNA is IDR 1.000.000 for Indonesian authors or USD 100 for foreign authors, paid to this bank account after manuscript acceptance. As of January 1, 2025, all manuscripts submitted for consideration by CNA must be written in English and must be accompanied by a cover letter. Starting from January 2026, manuscript submissions should be directed to CNA via the website: https://journal.unpad.ac.id/cna/ Published by Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Padjadjaran Jln. Raya Bandung Sumedang km. 21 Jatinangor, Sumedang, Jawa Barat 45363 Phone/Fax: +62-22-7794391; e-mail: jcna@unpad.ac.id ISSN: 2355-0864 | e-ISSN: 2541-2574
Correlation between FTIR fingerprint spectra and inhibition of α-glucosidase activity of Andrographis paniculata using partial least squares regression analysis
Andrographis paniculata has been used empirically by people as traditional medicine to treat diabetes. In this study, we correlated the FTIR spectra and α-glucosidase inhibition by using chemometrics analysis to obtain a functional group from the metabolite present in A. paniculata herb exhibited α-glucosidase inhibitory activity. A. paniculata herb powder was extracted using water, ethanol, ethyl acetate, and n-hexane using ultrasonication method. The dried extract obtained was then measured for its FTIR spectra and determined for α-glucosidase inhibitory activity. Absorbance data from the FTIR spectra of A. paniculata herb extracts were used as a principal component analysis (PCA) variable for grouping extract based on the solvent extractor used. In addition, partial least square regression analysis (PLSR) is also used to predict functional groups from metabolites that cause inhibition of α-glucosidase. In the PLSR, we correlated using the FTIR spectrum's absorbance values and IC50 of α-glucosidase inhibitory activity. Before being subjected to PCA and PLSR, the FTIR spectrum was preprocessed using standard normal variate. PCA using the absorbance data from 1800–1000 cm-1 and 2800–3400 cm-1 could group the extract based on extracting solvent used with a cumulative percentage of the two principal components (PC), namely PC-1 and PC-2 are 86%. The PLSR analysis showed that OH, C=O, C=C, and C-O are the predicted functional groups related to the inhibition of α-glucosidase. So, those functional groups are present in the metabolites in A. paniculata herb extracts that contributed to the inhibition of α-glucosidase.
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Green Synthesis of Biodiesel from Pliek U Oil using Oyster Shell–Derived Calcium Oxide Modified with PVA: Structural Characterization and Catalytic Performance
The production of biodiesel from local resources is a strategic approach to support sustainable energy transition. This study aimed to synthesize and evaluate the performance of a heterogeneous catalyst derived from oyster shell-based calcium oxide (CaO) modified with polyvinyl alcohol (PVA) as a binder, for the transesterification of Pliek U oil into biodiesel. CaO was synthesized by calcining oyster shells at 800°C, followed by PVA modification to improve structural stability and catalytic activity. The catalyst was characterized using X-ray Diffraction (XRD) to observe crystal patterns, while the resulting biodiesel was analyzed by Gas Chromatography–Mass Spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FTIR) to identify methyl ester compounds. Physicochemical properties including density, viscosity, acid value, water content, and flash point were also evaluated. Transesterification was carried out at a methanol-to-oil molar ratio of 12:1, catalyst concentration of 2.29% w/w, reaction temperature of 60°C, and reaction time of 90 minutes. The results showed a biodiesel yield of 96%, with dominant components being methyl caprylate, methyl laurate, and methyl caprate. FTIR spectra confirmed the presence of characteristic functional groups of methyl esters. The biodiesel properties met the SNI 7182:2015.
The Chemistry Profile of Essential Oil of the Roots, Stems, and Leaves of The Plant Litsea firma (Blume) Hook F.
Indonesia, as an agrarian country rich in natural resources, holds enormous potential in the essential oil industry. There are approximately 150–200 species of essential oil-producing plants worldwide, 40 of which are found in Indonesia, including those from the Lauraceae family. The genus Litsea within the Lauraceae family is known for producing essential oils, with Litsea cubeba being the most popular. However, high demand for Litsea’s essential oils encourages the exploration of essential oils from other Litsea species, such as Litsea firma. This study used gas chromatography-mass spectrometry to look at the chemical profile of essential oils from the roots, stems, and leaves of L. firma grown in West Kalimantan. The chemical profile data is then compared with data from other studies. The analysis results indicated that the composition of essential oils from roots is similar to the stems but differs from the leaf. The stem and root essential oils primarily consist of 4,4-diethyl-spiro[2,3]hexan-5-on, whereas the leaf essential oils mostly contain 1-cyclohexyl-ethanone. This difference in chemical constituents suggests that different parts of L. firma may have different ecological roles or therapeutic benefits. Further research could explore the implications of these findings for the plant's potential use in traditional medicine or natural product development. Therefore, we should continue exploring L. firma's essential oil to maximize its potential.
Green Synthesis and Characterization Of Silver Nanoparticles using Dadap Serep (Erythrina lithosperma) Leaves Extract as a Bioreductor
Silver nanoparticles (AgNPs) had been widely applied in various fields such as health, food, environment, catalysts, optics, and electronics. The synthesis of silver nanoparticles can be carried using a bottom-up method using by bioreductants derived from natural extracts (green synthesis). This study aims to describe the green synthesis of silver nanoparticles using a bioreductants from dadap serep (E. lithosperma) leaves extract and to determine its characteristics. The synthesis was carried out by varying the volume ratio of dadap serep leaves extract to silver nitrate solution at ratios of 1: 1, 1: 2, 1: 3, and 1: 4, followed by optimization at pH 9, 10, and 11. Characterization of the synthesized AgNPs was carried out using Ultra Violet-Visible (UV-Vis) spectrophotometer, Fourier Transform Infrared (FTIR) spectrophotometer, Particle Size Analyzer (PSA), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The results showed that the optimum synthesis reaction conditions occurred at a volume ratio of 1: 4 and pH 10. The synthesized silver nanoparticles had an average particle size of 92 nm (DI = 0.3124). The FTIR spectrum showed the presence of hydroxyl groups (3242,88 cm-1), aromatic C=C (1568.35 cm-1), C-O (1033.25 cm-1 ), Ag-O. (519.23 cm-1). The results of XRD analysis showed typical peaks of silver atoms at 2 q: 37.71o (111), 43.84o (200), 64.07o (220), 77.04o (311). SEM analysis showed that the silver nanoparticles had an irregular surface morphology. Thus, dadap serep (E. lithosperma) leaves extract has the potential to be used as a bioreductor for the synthesis of silver nanoparticles.
The Role of Glu/Gly/Zif-8 Edible Film in Improving the Superior Rheological and Water Vapor Barrier Properties and Antibacterial Activity for Active Food Packaging
The low barrier to water vapor and gas is a critical limitation of glycerol-plasticized gluten-based edible films (GBEF) for food packaging applications. In this study, gluten (Glu) and glycerol (Gly) were cross-linked with 0.25–1.00% (w/v) zeolitic imidazolate framework-8 (ZIF-8) to improve interfacial compatibility and enhance the structural integrity of the film matrix. The formation of hydrogen bonds and electrostatic interactions between ZIF-8 and the Glu/Gly matrix strengthened the chemical network, resulting in increased tensile strength (TS). The water vapor transmission rate (WVTR) of Glu/Gly/ZIF-8 edible films (Glu/Gly/ZIF-8 EF) ranged from 1.085 to 1.453 g/m²/24 h, indicating significantly improved barrier properties. Mechanical testing showed TS and elongation at break (EAB) values of 32.18–60.58 MPa and 211.86–382.83%, respectively, meeting Japanese Industrial Standards for edible films (TS > 0.3 MPa, EAB > 70%, WVTR < 10 g/m²/24 h, thickness < 0.25 mm). Glu/Gly/ZIF-8 EF also demonstrated strong antibacterial activity, with inhibition zones of 25–26 mm for Gram-negative Escherichia coli and 25–34 mm for Gram-positive Staphylococcus aureus. These findings demonstrate that ZIF-8 effectively enhances both the mechanical and functional performance of gluten/glycerol films, providing a promising strategy to expand their application as bioactive packaging materials in the food industry.
Evaluation of Thrombotic Markers in Diabetic Septic Foot: A Study of Coagulation and Hematological Parameters in Khartoum State
Diabetes mellitus is a globally prevalent chronic disease. It is characterized by a metabolic dysregulation in insulin secretion, resulting in persistent hyperglycemia. Uncontrolled HbA1c levels may lead to various complications, including diabetic Septic foot (DSF), which in severe cases can progress to lower limb amputation. Therefore, this study aimed to evaluate coagulation profiles and hematological parameters as potential thrombotic and inflammatory markers associated with diabetic foot infections. Preventive measures, patient education, and proper diabetic foot care remain the cornerstone strategies for reducing the risk and progression of such complications. The Total of 120 participants were divided into three groups by 40 patients, diabetic septic foot, without foot complications and healthy individuals (control). Coagulation and hematological parameters were assessed. Our results PT, INR, MCV, MCH, and PDW were significantly elevated in the DSF group with control group. Males were more affected than females. A moderate positive correlation was observed between HbA1c and both RBC count and PDW. Patients with diabetic septic foot exhibit significantly higher coagulation and hematological markers, particularly PT, INR, MCV, MCH, and PDW. These markers, along with HbA1c levels, may serve as potential indicators of thrombotic risk in DSF patients, especially among males.
Synthesis of Cu2ZnSnS4 (CZTS) Semiconductor Thin Film with Variation of Sulfur Solution Concentration
The Cu2ZnSnS4 (CZTS) thin film is an alternative semiconductor material as a light absorbing layer in solar cells. The advantages of CZTS as a light absorbing layer are the availability of abundant materials in nature and high absorption coefficient values. The absorbent layer was prepared using the sol-gel and spin coating method on an indium tin oxide (ITO) glass substrate. Films were made with a sol-gel solution with varying concentrations of sulfur solution, namely with a concentration of 3M and 6M using a simple spin coating tool which was rotated for 30 seconds. The film formed was hardened at 550°C for 60 minutes under N2 gas. The results of X-ray diffraction analysis showed that the CZTS thin films formed from the two samples had a kesterite crystal structure with a small percentage. Samples with a sulfur solution concentration of 6M had a higher percentage of crystals with a percentage of 13.26% with a film thickness of 3.73-4.73 μm, while the sulfur solution concentration of 3M has a percentage of 7.54%. The CZTS thin film sample with 6M sulfur concentration has a bandgap energy of 1.88 eV and the absorption coefficient value obtained is 5 x 103cm-1 which is the best result. In conclusion, the spin coating method has the potential to be used to produce kesterite ZCTS under relatively high concentrations of sulfur solution.
Phytochemical Analysis and Flavonoid Content of Lempuyang Wangi (Zingiber aromaticum Val.) Rhizomes using Various Solvent Extractions
Lempuyang Wangi (Zingiber Aromaticum Val.) is a medicinal plant widely used in traditional medicine in Southeast Asia. This study aimed to extract and analyze the secondary metabolites from the rhizomes of Lempuyang Wangi using the maceration method with three different solvents: n-hexane, ethyl acetate, and 96% ethanol. The extraction yielded varying percentages depending on the solvent used, with the ethyl acetate extract having the highest yield at 16.26%. Phytochemical screening identified the presence of alkaloids, phenolics, and flavonoids in all extracts, with the ethanol and ethyl acetate extracts showing a broader range of compounds. The highest total flavonoid content was found in the ethanol extract, followed by ethyl acetate and n-hexane, indicating ethanol's superior ability to extract flavonoids. These findings demonstrate the influence of solvent polarity on extraction efficiency and compound diversity, highlighting ethanol as the most effective solvent for extracting flavonoids from Lempuyang Wangi. The measurement of total flavonoid content showed that the ethanol extract had the highest concentration, at 24.273 mg QE/g. These results provide a foundation for further research and potential applications in utilizing Lempuyang Wangi extracts for health benefits.
Computational Study of Household Plants as Immunomodulators on Human Metapneumovirus
Human metapneumovirus (HMPV) is a causative agent of acute lower respiratory tract infections, especially in children. Until now, there are not many natural-based immunomodulatory therapies available. This study aims to explore the potential of household plants from the Syzygiumand zingiber Genus as immunomodulators against HMPV using computational studies. The target receptor used is RNA-dependent RNA polymerase (RdRp), a vital enzyme in HMPV genome replication. The methods used include molecular docking, validation of biological activity through Way2Drug and evaluation of pharmacokinetic feasibility using Lipinski’s Rule of Five. Based on the docking results, the compounds with the strongest binding affinity are myricetin (-8.3 kcal/mol) from the Syzygiumgenus and 10-gingerdione (-7.2 kcal/mol) from the Zingiber genus. Based on the Way2Drug assay results, myricetin compounds from the Syzygiumgenus showed the strongest antioxidant potential (Pa 0.924). In the Zingiber Genus, the compound 10- gingerdione showed the highest antiviral value (Pa 0.434). Based on the Lipinski’s Rule of Five analysis, quercetin from the Syzygiumgenus and 10-gingerol from the Zingiber genus fulfilled all five criteria. Both showed high potential as natural immunomodulatory agents against HMPV, confirming that secondary metabolites from household plants deserve further research as natural immunomodulators.
Influence of Polyvinyl Alcohol Content on Starch-Based Bioplastic Reinforced with Chitosan and Microcrystalline Cellulose
Starch-based bioplastics are promising sustainable alternatives to petroleum-based plastics; however, their limited mechanical strength and stability restrict broader packaging applications. This study investigates the influence of polyvinyl alcohol (PVA) content on the structural and functional properties of starch-based bioplastic films reinforced with chitosan and microcrystalline cellulose (MCC). Films prepared by solution casting with varying PVA compositions were characterized in terms of density, mechanical properties, thermal stability, biodegradation behavior, antibacterial activity, and structural features. Increasing PVA content produced denser film structures with improved tensile strength and thermal stability, while elongation at break reached its maximum at the intermediate formulation, indicating a strength–ductility trade-off. The control film exhibited antibacterial inhibition zones of 12.6 mm against Staphylococcus aureus and 8.8 mm against Escherichia coli, with activity decreasing at higher PVA content. These findings demonstrate that adjusting PVA composition effectively tailors the multifunctional performance of starch-based bioplastic films for sustainable packaging applications.