Acta Chimica Asiana

Aqueous phase synthesis of 2-D copper nanosheets stabilized by organic moieties with enhanced photocatalytic and biological activity.

2024-07-25T11:27:37+08:00

Copper nanosheets supported by organic ligands are significant for biological, electrical, and catalytic applications. The discovery that the coronavirus has a significantly reduced maximum survival period on copper surfaces has elevated the utility of copper nanomaterials. Here, we report a non-hazardous and inexpensive biological technique for forming copper nanosheets (Cu Nsts); synthesis of Cu Nsts has always been a challenge for researchers due to the significant problem of oxidation; in this research, we have successfully synthesized stable Cu Nsts by using Saussurea lappa root extract for the first time, the obtained Cu Nsts has a shiny black color with self-standing ability, the crystal structure of Cu nanosheets was determined using Powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM) revealed that copper nanoparticles grow and aggregates to form Cu Nsts. The surface morphology of Cu Nsts is clear evidence of their synthesis. These nanosheets were very proficient in the deduction of harmful dye (methylene blue); within 105 minutes, the degradation capacity of Cu nanosheets for methylene blue reached 93.493%. This remarkable property of Cu Nsts as a photocatalyst gives potential application for removing dyes from industrial wastewater. Cu Nsts showed excellent antioxidant and antibacterial activity. The Cu Nsts demonstrated potent inhibitory zones against E. coli, with inhibition zones measuring 39 mm. This research lays the foundations for purifying wastewater from harmful dyes and bacteria.

Utilization of Pili (Canarium ovatum) sawdust in bio-crude oil production and the identification of potential by-products through thermochemical conversion

2024-02-01T17:02:12+08:00

This study aimed to utilize Pili sawdust in the production of bio-crude oil and identify its potential by-products through thermochemical conversion. To obtain all the essential data, this research sought to answer the questions: (1) How much bio-crude oil can be produced at constant factors such as temperature and amount of Pili (Canarium ovatum) sawdust? (2) What are the physical characteristics of the generated bio-crude oil after conducting thermochemical conversion? (a) Color, (b) Appearance, and (c) Viscosity (3) What other potential by-product can be generated out of Pili (Canarium ovatum) sawdust after conducting thermochemical conversion. (4) What are the physical characteristics of the generated by-products after conducting thermochemical conversion? (a) Color and (b) Appearance. Experimental-descriptive method was used in perceiving the physical properties of the by-products and its bio-crude oil production, presented in milliliters (mL) and to be expressed in percentage respectively. Based on the gathered observation record results, data revealed that 1000 g of Pili sawdust in 340 ^oC temperature, yields 30% or 300mL of brownish bio-crude oil in color, with a high degree of viscosity. Consequently, the generated by-products are biochar and synthesized biogas. The 242.2g of biochar which yields 24.52%, resulted being porous and coarse-grained in texture. While the synthesized biogas generated 433.4g of net weight yields 43.34%, resulted in having a high flammability. For the betterment of similar study, future researchers are encouraged to evaluate the agricultural potential of the generated biochar and to distillate bio-crude oil for possible commercial use.

Molecular docking study of modified isoniazid compounds on mycolic acid synthase in the cell wall of mycobacterium tuberculosis

2024-02-01T16:36:06+08:00

Using the isoniazid in antituberculosis therapy can lead to mutations in the KatG and inhA genes of Mycobacterium tuberculosis, resulting in the development of resistance and necessitating modifications to the isoniazid compound. This study aims to assess the potential and level of toxicity of modified compounds, namely 4-pyridine carboxylic acid, pyridine aldehyde, and methyl pyridine, on the mycolic acid receptor through a molecular docking approach. PyRx was employed for the docking process using a protocol with an exhaustiveness of 106 and a center grid box at X=42.424, Y=22.4321, and Z=46.6391. Additionally, the ProTox-II website was used to determine the toxicity level of the test compounds. The results obtained from this research consist of the respective affinity values of the test compounds: -6, -5.4, and -5.2 kcal/mol. The toxicity levels of the test compounds are as follows: class 5, class 4, and class 4. All test compounds interact with amino acids on the target protein, specifically with residue numbers Histidine (HIS A:8), Phenylalanine (PHE A:142) through hydrogen bonding, Leucine (LEU A:95) through pi-Sigma (π) bonding, and Valine (VAL A:12) through pi-Alkyl (π) bonding. In conclusion, the 4-pyridine carboxylic acid compound exhibits potential as a promising drug candidate but comes with a high level of toxicity

Synthesis and characterization of bacterial cellulose composite with graphite and TiO2-ZnO: structural and functional analysis

2024-06-04T11:47:06+08:00

This research aims to synthesize and characterize a bacterial cellulose (BC)-based composite with graphite and TiO₂-ZnO as reinforcement materials using ex-situ synthesis with CTAB as a surfactant. FTIR and SEM-EDS analysis revealed interactions between the matrix and the reinforcement materials, as well as irregular particle distribution in the BC/G-TiO₂-ZnO composite. The addition of graphite to BC significantly increased the conductivity of the composite, while the addition of TiO₂-ZnO had the opposite effect. The mechanical properties of the composite exhibited an inverse relationship with the conductivity parameter. Swelling tests indicated that pH and the addition of CTAB influenced the swelling behavior of the BC-based composite. The results of this study provide a strong foundation for the development of potential applications in the fields of electronics and pollutant filtration. The synthesis of this composite aims to harness the unique properties of BC, graphite, and TiO2-ZnO, creating a multifunctional material with potential uses in flexible electronics, sensors, biocompatible conductive materials, and advanced filtration systems.

Effect of solvent in the solvothermal synthesis of nickel(II)-terephthalate complex

2024-08-27T10:12:28+08:00

This research aims to replace the use of dimethylformamide (DMF) with a greener solvent in the solvothermal synthesis of nickel(II)-terephthalate complex. Effect of solvent on the crystallinity degree, thermal stability, and band gap energy of the synthesized complex are also studied. The synthesis was carried out using solvothermal method at 150 ⁰C for 10 hours with a Ni(II) : terephthalate acid mol ratio of 1:1 in several H₂O:DMF solvent compositions (1:0; 1:1; and 0:1). The precipitated products underwent characterization using ATR-IR, P-XRD, SEM, TGA, Surface Area Analyzer, and UV-DRS. Findings revealed the successful formation of the Ni(II)-terephthalate complex using three different solvent compositions (H₂O/DMF = 1:0, 1:1, and 0:1). This suggests that the complex can be synthesized using more environmentally friendly solvents, potentially reducing or substituting the use of DMF solvent. However, the solvent affects the characteristics of the synthesized complex, in which green block microcrystalline solid was obtained when using water as the solvent, meanwhile green aggregates with lower crystallinity degree was precipitated out when using DMF or H₂O-DMF. The Ni(II)-terephthalate complexes obtained from the H₂O and H₂O-DMF solvents are different to that of from the DMF solvent, but they both has identical powder diffraction pattern with previously reported compound of [Ni₃(OH)₂(C₈H₄O₄)₂(H₂O)₄].2H₂O. Furthermore, the use of water as the solvent increase the crystallinity degree and thermal stability of the complex but the band gap energy of the synthesized Ni(II)-terephthalate complex compared to that of obtained from the DMF solvents.

Investigating Pt/Pumice catalyst for efficient 3-methyl-1-butanol conversion

2023-05-24T14:33:31+08:00

The objective of this study was to obtain a modified Pt/pumice catalyst to support the conversion reaction of 3-methyl-1-butanol under specific reaction conditions. To achieve this objective, the first step involved preparing modified pumice catalyst pellets by impregnating them with Pt metal followed by activation at a temperature of 500 °C. The second step involved characterizing the Pt/pumice catalyst, including the surface distribution of Pt metal using SEM. The third step involved conducting the catalyst activity test against 3-methyl-1-butanol in a reactor (furnace) at temperatures ranging from 400 to 500°C with a flow system for the feed. The fourth step involved analyzing the conversion results using GC-MS chromatograms. The research results showed that the Si/Al ratio in the modified Pt/Pumice catalyst using a PtCl₄ solution with a concentration of 0.0321 M for impregnation was 4:1, compared to 4.8:1 for Pt/Zeolite and 3.2:1 for Pt/ABP. The modified catalyst activity test for 3-methyl-1-butanol showed the following conversion results: Pt/Pumice 27.63%, Pt/Zeolite 23.85%, Pt/Black Pumice 14.81%, and for platinum catalyst, the conversion was 22.35%. These results indicated that the highest conversion was observed in the treated sample A-3 under the reaction condition of 450°C. The conversion products analyzed using GC-MS showed the presence of three molecules: 3-methylbutanal, 2-methylbutanal, and anhydrous isobutanoate.

Determination of total flavonoid content from extract and fractions of mangrove (Rhizopora mucronata) leaves

2024-04-19T13:51:25+08:00

Indonesia, an archipelagic country, includes Lombok Island, known for its extensive mangrove forests, where Rhizopora mucronata is the dominant species. Rhizopora mucronata, from the Rhizoporaceae family, is known for its antibacterial, antifungal, and antioxidant properties due to its secondary metabolites, including flavonoids. However, research on the flavonoid content of its leaves remains unexplored. This study aimed to determine the total flavonoid content in extracts and fractions of R. mucronata leaves using the UV-Vis spectrophotometric method. Leaves were extracted with 96% ethanol using sonication and fractionated with n-hexane, ethyl acetate, and water. The extract and fractions yielded 42.33%, 43.15%, 40.49%, 9.74%, and 32.49%, respectively. TLC tests indicated the presence of flavonoids marked by blue spots. The flavonoid contents in the extract and fractions were 12,980; 14,160; 23,880; and 25,350 mg Quercetin equivalent/gram sample (mg QE/g). The total flavonoid content was analyzed using One-way ANOVA, showing higher levels in the n-hexane and ethyl acetate fractions than in the ethanol extract and water fraction. The high flavonoid content contributes to the biological activities of R. mucronata leaves.

Binding studies of ruthenium complexes with antithyroid drug

2024-09-02T08:38:24+08:00

Medicinal substances are essential to our daily existence. A prudent approach to metal complexation with already available medications may result in more stylish, intelligent, and effective drug compositions. Thus, the binding of [Ru(NN)₃]²⁺(NN = 2,2ˈ-bipyridine, 1,10-phenanthroline) with the antithyroid medication thyronorm has been studied in the current attempt. The use of absorption and emission spectrum techniques allowed researchers to examine the complexes' interactions with antithyroid medications. Studies of absorption and emission spectra show that the complex and medication interact through coordinated ligand hydrophobic and hydrogen bonding interactions.Analysis has also been done on the binding of the antithyroid medication Thyronorm to ruthenium complexes. The Benesi-Hildebrand plot was used to determine the binding constants of the drug complexes. Current research indicates that the Thyronorm pill has good affinity with [Ru(phen)₃]²⁺complex.

Physical test and irritation test of water guava leaf extract (Syzygium aqueum) as a natural spray hand sanitizer

2024-09-01T10:10:43+08:00

This study explores the manufacture of water guava (Syzygium aqueum) leaf extract-based hand sanitizers as an effective and safe natural alternative for maintaining hand hygiene. Given the importance of hand hygiene in preventing the spread of disease, especially amid the COVID-19 pandemic, the use of hand sanitizers has increased significantly. However, alcohol-based products are often irritating to the skin. Therefore, this study aims to evaluate the potential of water guava leaf extract to improve the effectiveness and convenience of hand sanitizers. Water guava leaves contain active compounds such as flavonoids, tannins, and phenolics with antibacterial and anti-inflammatory properties. The research method includes extracting water guava leaves, hand sanitizer formulation, and organoleptic, pH, homogeneity, and irritation testing. The tests carried out were physical tests, including organoleptic tests (shape, smell, and colour), pH, homogeneity, spreadability, adhesiveness, and product irritation tests. The research was designed with a posttest-only control group design with true experimental by analyzing the test object after being given treatment. This research is expected to produce products that are useful for the community. The results showed that all hand sanitizer formulas tested had a pH within the safe range of pH 5 for the skin without irritating the skin of the test animals. Formulas with added guava extract showed improved aroma and anti-irritation, with formulas F1 and F2 gaining the highest preference in aroma and colour. This study concludes that water guava leaf extract can be effectively used in the manufacture of hand sanitizers, providing a gentler and skin-friendly alternative to alcohol-based synthetic products.

Synthesis of nanochitosan from oyster pearl shell (Pinctada maxima) as renewable energy candidate

2024-09-01T10:13:13+08:00

The increase in energy needs must be balanced by environmentally friendly technological innovations. Chitosan polymer is one of the technological innovations of energy materials that are being developed by many developed countries. This research aimed to identify the potential of oyster pearl shell waste as a source of electrolyte polymers. The study was conducted experimentally by synthesizing chitosan nanoparticles from chitosan using the ionic gelation method. Chitosan is obtained through the isolation method from Pinctada maxima oyster pearl shell waste. The isolation method is carried out by three processes: deproteination, demineralization, and deacetylation. Several characterizations were carried out to analyze the material from the synthesis, including a proximate test, FTIR analysis, and PSA analysis. Isolated chitosan was identified to have a deacetylation degree that reached 88.63% with the formation of OH and NH2 functional groups. In general, the proximate tets data has shown that the obtained chitosan already meets the Indonesian standard SNI 7949:2013. PSA analysis resulted in differences in size distribution, PDI, and zeta potential between chitosan and chitosan nanoparticles. The results were obtained by the average distribution of chitosan particle size of 52.043 μm and chitosan nanoparticle size of 2.3365 μm—the analysis of the potential zeta of chitosan -3.9 mV and chitosan nanoparticle -21,6 mV. Thus, changes in the size of the chitosan material affect its potential PDI and zeta values. The change of these two values is a good indicator of the initial data and the potential of the material as an energy material. Therefore, chitosan polymer is an electrolyte material that can be used as a candidate for environmentally friendly renewable energy materials