Indonesian Chimica Letters

Synthesis and Characterisation of Bentonite/Poly(Acrylic Acid) Hybrid Material for Its Application as A Catalyst in Esterification of Glycerol with Acetic Acid

Thu, 20 Jun 2024 00:00:00 +0700

Bentonite/poly(acrylic acid) (BTAA) hybrid material commonly applied as superabsorbent was prepared via intercalation method coupled with in situ polymerisation of partially neutralised acrylic acid monomers. The structural characteristics of various BTAA ratios and their constituents were scrutinised using XRF, XRD, and FTIR. Basal spacing of BTAA hybrid materials decreased as a result of intercalation with polyacrylic acid. Interaction between bentonite and polyacrylic acid was also observed in the shifting and reduced intensity of O–H, C=O, and Si–O–Al absorption bands. Catalytic activity of BTAA was investigated through its ability to facilitate the esterification reaction of glycerol with acetic acid. The result suggests that catalytic activity is present in BTAA hybrid materials, as evidenced by the production of monoacetin and triacetin.

Analysis of Flavonoid Contents in Coffee Mistella (Dendrophthoe pentandra (L.) Miq.) Using Thin Layer Chromatography-Densitometry Techniques

Nora Dwi Saputri, I Nyoman Adiwinata, Yeni Maulidah Muflihah — Thu, 20 Jun 2024 00:00:00 +0700

Flavonoids, a class of phenolic compounds widely distributed in plants, are present in the coffee mistletoe Dendrophthoe pentandra (L.) Miq. The extraction of flavonoids from Dendrophthoe pentandra (L.) Miq leaves involve the use of methanol as a solvent in maceration extraction methods. The presence of flavonoids was ascertained through color changes from green to yellow-green, yellow, and yellow-orange when subjected to AlCl₃ 5%, NaOH 10%, and Mg-HCl, respectively. Thin-layer chromatography using aluminum plates coated with silica gel F₂₅₄ as the stationary phase and methanol-chloroform 4:1 (v/v) as the mobile phase was employed to separate the flavonoids. The method validation demonstrated strong linearity in the concentration range of 60-130 ppm for flavonoid standard solutions, with a correlation coefficient (r) of 0.998. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) were determined to be 182.5 ng and 608.3 ng, respectively. Precision, expressed as Relative Standard Deviation (RSD), was found to be 5.1%, 2.8%, and 2.5% for concentrations of 80, 90, and 100 ppm, respectively. These RSD values were also less than 2/3 CV Horwitz, which were 5.5, 5.4, and 5.4. The method's accuracy was assessed through percent recovery values for each concentration (80, 90, and 100 ppm), which were found to be 102.46 ± 1.78%, 86.14 ± 1.74%, and 89.89 ± 1.44%. The flavonoid content in the dried coffee mistletoe powder was determined to be 1.404x10^-2 ± 0.0007 mg per gram, with a water content of 8.7%.

Study of The Effect of Concentration on The Level of Wetness in Chicory Leaves Using The ADSA-Overlay Method

Thu, 20 Jun 2024 00:00:00 +0700

It is challenging to distinguish between farmers and insecticides. Chemicals called pesticides are applied to eliminate pests in order to boost agricultural production for farmers. Using the Axisymmetric Drop Shape Analysis (ADSA)-Overlay approach, this study attempts to investigate the impact of the pesticide fipronil concentration on the degree of wetness in mustard leaves. The size of the contact angle between the mustard leaf surface and the pesticide solution determines the pesticide's wetting action. The cosine of the contact angle (θ) between the liquid insecticide and the solid surface determines the surface tension (γ). Sessile drop is the method used to assess surface tension. Chicory is the surface area that comes into touch with pesticide drops. At 25^oC samples containing 50 ppm were poured onto mustard leaves using a syringe. A digital microscope that was linked to a personal computer was used to capture sessile drop pictures. Three iterations of sessile drop imaging were conducted using samples at temperatures of 27, 29, 31, 33, and 35^oC. Samples of pesticide solution at concentrations of 75, 100, 125, and 150 ppm were photographed again. The reagent 50Sc pesticide's wetting level rises with an increase in fipronil content. As concentration increases, the reagent 50Sc insecticide solution's contact angle tends to get smaller.

Development of Dihydrofolate Reductase Inhibitor Based on QSAR and Molecular Docking

Thu, 20 Jun 2024 00:00:00 +0700

QSAR modeling allows for predicting activity through quantitative relationships between molecular structure and activity. This research uses DEEPScreen, which is a development of QSAR for searching new drugs. This research leverages DEEPScreen-QSAR modeling to optimize the predictive power of machine learning algorithms on a dataset of 645 molecules from previous research. The optimized model achieves an accuracy of 0.7461 and precision of 0.8169, demonstrating its effectiveness in the virtual screening stage. The optimized DEEPscreen-QSAR model is used to screen approximately 1.9 million small molecules in the ChEMBL database, resulting in binary classification predictions of active (1) molecules as 781,213 and inactive (0) molecules as 1,133,325 (molecules with IC50 activity ≤10,000 nM are considered active). The active (1) molecules obtained are screened again to find molecules that can be absorbed by the body (orally) using Lipinski’s RO5 with 0 deviations, resulting in 557,428 active molecules that can be absorbed by the body. These screening results are validated using molecular docking methods by linking protein and ligand to determine Gibbs free energy (∆G) and interactions using PyRx, PyMOL, and Biovia Discovery Studio programs. Based on the results of this research, candidate DHFR inhibitors with codes CHEMBL3302655, CHEMBL1384989, and CHEMBL1729486 are recommended.

The Study Redox Catalytic of KARES@PdNPs Using Formic Acid

Thu, 20 Jun 2024 00:00:00 +0700

This study aims to synthesize Calixresorcine material and KARES@PdNPs nanoparticles as catalysts to support the synthesis of PdNP nanoparticles. The process of interaction of the hydroxy groups with palladium (II) cations led to a significant decrease and increase in the quality of the nanoparticles and could increase the specific quality of KARES@PdNPs nanoparticles and increase the catalytic activity of KARES@PdNPs with a very high number of PdNPs. Thus, the KARES@PdNPs is very suitable and shows a very efficient catalytic ability in the redox reaction process.

Cover and Table of Contents

Thu, 20 Jun 2024 00:00:00 +0700

Editorial Team

Thu, 20 Jun 2024 00:00:00 +0700