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INDONESIA
Indonesian Journal of Chemistry
Published by Universitas Gadjah Mada
ISSN : 14119420     EISSN : 24601578     DOI : -
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
Indonesian Journal of Chemistry is an International, peer-reviewed, open access journal that publishes original research articles, review articles, as well as short communication in all areas of chemistry including applied chemistry. The journal is accredited by The Ministry of Research, Technology and Higher Education (RISTEKDIKTI) No : 21/E/KPT/2018 (in First Rank) and indexed in Scopus since 2012. Since 2018 (Volume 18), Indonesian Journal of Chemistry publish four issues (numbers) annually (February, May, August and November).
Arjuna Subject : -
Articles 1,956 Documents
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Ability of Ectoine to Stabilize Lipase against Elevated Temperatures and Methanol Concentrations I Putu Parwata; Deana Wahyuningrum; Sony Suhandono; Rukman Hertadi
Indonesian Journal of Chemistry Vol 21, No 2 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.54931

Abstract

Ectoine is one of the compatible organic molecules that can protect the protein from heating, freezing, and chemicals contact. This study aims to investigate the ability of ectoine to stabilize lipase on heating and in methanol treatments as an effort to provide a stable biocatalyst for the production of biodiesel. Various ectoine concentrations were added to lipase solutions, then the mixture was heated, and the residual activity of the lipase was determined. Similar steps were also conducted for methanol treatment. The results showed that ectoine maintained and even improved the catalytic activity of lipase after treatment with either heat or methanol. The addition of ectoine to a final concentration of 110 to 150 mM could maintain lipase activity up to 80% when heating to approximately 95 °C. Additionally, more than 20% of lipase activity increased on heating to temperatures below 75 °C in the presence of ectoine at a final concentration of 25 to 120 mM. Meanwhile, after incubation in methanol at a level of around 84% (v/v), the activity of lipase containing 40–90 mM ectoine was maintained. These results demonstrated that ectoine was highly effective in protecting lipase from heat and methanol.
Analysis of Dissolution of Salicylamide from Carrageenan Based Hard-Shell Capsules: A Study of the Drug-Matrix Interaction Muhammad Al Rizqi Dharma Fauzi; Esti Hendradi; Pratiwi Pudjiastuti; Riyanto Teguh Widodo
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55047

Abstract

In drug release kinetics, the drug-matrix interaction is one of the important mechanisms to be dictated. Unfortunately, there is still minimum information discussing the effect of interaction between a drug and its matrix to the release profile of the drug. Therefore, there is an urgent need to conduct research related to the study of drug-matrix interaction. This paper reports the preparation of a drug delivery system (DDS) in the form of hard-shell capsules containing salicylamide (SCA) and analyses its drug-matrix interaction via dissolution test at different pH media and various release kinetics models. The matrix of hard-shell capsules was prepared from κ-carrageenan (CRG), crosslinked with maltodextrin (MD), and plasticized by sorbitol (SOR). The chemical properties of SCA were compared with paracetamol (PCT) using computational analysis to help to depict its drug-matrix interaction. The statistical analyses showed that SCA and PCT at pH 1.2, 4.5, and 6.8 had all different release profiles. Based on the goodness of fit evaluation, the diffusion mechanism of SCA at pH 1.2 and 4.5 could be best described by the Peppas-Sahlin model while the zeroth-order model fitted the dissolution profile at pH 6.8. In summary, it was proven that a different drug-matrix interaction produced a different dissolution profile.
Development of Voltammetry Analysis Method of Copper Metal Ions by Solid-State Membrane with Carbon Nanotube Suyanta Suyanta; Sunarto Sunarto; Regina Tutik Padmaningrum; Karlinda Karlinda; Illyas Md. Isa; Rahadian Rahadian
Indonesian Journal of Chemistry Vol 21, No 2 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55056

Abstract

This study was aimed to develop a method for metal analysis in continuous integration using voltammetry techniques. The research subject was copper(II) ions. The objects of research were linearity, scan rate, repeatability of readings, and the presence of Cu(II) levels in well water samples. In this study, a selective electrode was developed with a solid membrane voltammetry system using differential pulse voltammetry measurement. The results showed the regression line of voltammetry method, y = 10.265 ln (x) + 330.47, with a correlation value of 0.9654, the optimum scan rate was 10 mV/s, and within five repetitions of each measurement for one electrode, it showed good repeatability. Meanwhile, the result of regression with the UV-Vis spectrophotometric method for Cu(II) was y = 0.12386x + 0.00879 with a correlation value of 0.9943. The voltammetry method was found to be much better than the UV-Vis method because it was able to be used for analysis up to a concentration of 6.35 × 10–4 ppm (or 1.00 × 10–11 M), while the UV-Vis method was only able to analyze up to 1.5 ppm (or 2.36 × 10–5 M).
Controlled Release Fertilizer Encapsulated by Glutaraldehyde-Crosslinked Chitosan Using Freeze-Drying Method Adhitasari Suratman; Dwi Ratih Purwaningsih; Eko Sri Kunarti; Agus Kuncaka
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55133

Abstract

A new encapsulation of NPK fertilizer hydrogel granules made from glutaraldehyde crosslinked chitosan has been successfully fabricated. This designed fertilizer was aimed to maximize the fertilizing process in the soil, as the environmental pollution affected by the excess release of the nutrients can be prevented. The granule was prepared from biodegradable chitosan crosslinked with glutaraldehyde by applying a method of air and freeze-drying. The release test proved that this designed fertilizer showed a good performance as a Controlled Release Fertilizer (CRF) in which the hydrogel granules could absorb and deposit large amounts of NPK. Later on, they could also release large amounts of NPK as well, unlike several types of CRFs. The release percentage of NPK out of the granules tended to decrease with an increase of pH at a range close to the average pH of the soil, which is neutral to base. Comparing two methods, the freeze-drying technique, which yields a bigger pore size, showed a higher release percentage than air-drying. The release kinetics of the granules followed the Korsmeyer-Peppas model.
Conformational Analysis of Diterpene Lactone Andrographolide towards Reestablishment of Its Absolute Configuration via Theoretical and Experimental ECD and VCD Methods Muhamad Faid A Kadir; Agustono Wibowo; Fatimah Salim; El Hassane Anouar; Khalijah Awang; Moses Kiprotich Langat; Rohaya Ahmad
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55206

Abstract

Andrographolide, the major constituent from the terrestrial plant Andrographis paniculata is a much-studied bioactive ent-labdane diterpene lactone and has become an important medicinal intermediate. Its structure as determined by X-ray crystallography has been applied in molecular docking studies to explain biological activities. Nevertheless, recently there has been a number of conflicting reports concerning the stereochemistry at the C-14 and C-10 positions affecting the absolute configuration (AC) of the compound. Since a lack of information on the molecular flexibility of the molecule can lead to misleading conclusions on biological activity, a conformational analysis of the molecule in the solution state was necessary. The conformational analysis was performed by the Spartan14 package using the Merck Molecular Force Field (MMFF). The exciton chirality method in electronic circular dichroism spectroscopy (ECM-ECD) and vibrational circular dichroism (VCD) techniques were then jointly employed to re-establish the AC of andrographolide. Theoretical calculations were performed using TD-DFT methods by using the hybrid functionals B3LYP and CAM-B3LYP combined with 6-31G(d,p) basis set. Long-range exciton coupling of 2-naphthoyl chromophores at C-14 and C-19 led to the establishment of the AC to be 3R, 4R, 5S, 9R, 10R and 14S. Comparison between the theoretical VCD data of 14-S and 14-R stereoisomer confirmed a configuration of S at C-14 position instead of R.
Synthesis, Characterization, and Study of Proton Exchange Polymer Membrane Properties of Sulfonated Copolymer Eugenol-diallyl Phthalate Ngadiwiyana Ngadiwiyana; Nor Basid Adiwibawa Prasetya; Gunawan Gunawan; Tutuk Djoko Kusworo; Heru Susanto
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55353

Abstract

Synthesis biopolymer of sulfonated copolymer eugenol-diallyl phthalate (PEGDAF), its characterization, and study of proton exchange polymer membrane properties had been done. This synthesis was conducted by eugenol and diallyl phthalate reaction to form PEGDAF, which is sulfonated using sulfuric acid. In addition, the functional groups of the PEGDAF and its sulfonated form were analyzed using FT-IR. Furthermore, the polymer properties were determined by measuring values of sulfonation degree, cation exchange capacity, proton conductivity, and water uptake. FT-IR spectra showed that the vinyl group had been added to the process of PEGDAF formation, while spectra deconvolution was used to confirm the occurrence of sulfonation reaction. The sulfonation of PEGDAF in 2 h optimum reaction time produces a black solid with a melting point of 133 °C in 16.55% yield. The highest proton conductivity, cation exchange capacity (CEC), and water uptake were 8.334 × 10–6 S cm–1, 0.44 meq/g, and 73.0%, respectively.
Identification of the Chemical Constituents of the Selected Fraction of the Dichloromethane Extract of Syzygium samarangense Stem Bark Using LC-ESI-MS and Evaluation Its Potential as Antifungal Agent Tukiran Tukiran; Suyatno Suyatno; Frisca Nadya Safitri
Indonesian Journal of Chemistry Vol 21, No 2 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55366

Abstract

Several extracts of Syzygium species have been shown to inhibit the growth of some fungal microorganisms implicated in skin diseases, such as Candida albicans included S. samarangense. However, an antifungal test of C. Albicans on this plant's stem bark had not been reported. This study aimed to identify chemical constituents of the selected fraction from dichloromethane extracts of the stem bark of S. samarangense and determine the antifungal activity of the selected fraction at various concentrations on C. Albicans. The identification of the chemical constituent of the selected fraction has been performed by the LC-ESI-MS technique. An antifungal test of the selected fraction was carried out using the disk diffusion method. The samples used included the selected fraction with 5 variations of concentration (2.5; 2.0; 1.5; 1.0; and 0.5%), positive control (ketoconazole 1%), and negative control (DMSO). The results showed that the selected fraction has antifungal activity on C. Albicans. The results showed that the selected fraction contains four flavonoids: pinocembrin, uvangoletin, stercurensin, and aurentiacin. Due to antifungal activity on C. Albicans, it has moderate activity at a concentration of 2.5%, while concentrations of 2.0, 1.5, 1.0, and 0.5% have weak activity.
Computer-Aided Discovery of Pentapeptide AEYTR as a Potent Acetylcholinesterase Inhibitor Enade Perdana Istyastono; Vivitri Dewi Prasasty
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55447

Abstract

One of the key targets in the drug development for potential Alzheimer’s disease (AD) therapeutics is the search for acetylcholinesterase enzyme (AChE) inhibitors. Very recently, a pentapeptide AEYTR was reported as a potential inhibitor for AChE. The peptide was identified in a retrospectively validated virtual screening campaign, which was subsequently followed by 10 ns molecular dynamics (MD) simulations. The study aimed to characterize the structure and identify in vitro of AEYTR peptide as a potent acetylcholinesterase inhibitor. This article presents the structure characterization and the in vitro examination of the peptide as an AChE inhibitor, followed by MD simulations for 100 ns. The results show that the pentapeptide is a potent AChE inhibitor with an IC50 value in the picomolar range and stabilizes the enzyme during MD simulations.
Polyvinyl Alcohol Food Packaging System Comprising Green Synthesized Silver Nanoparticles Ahmed Elsayed Abdelhamid; Eman AboBakr Ali Yousif; Manal Mohamed Talaat El-Saidi; Ahmed Ali El-Sayed
Indonesian Journal of Chemistry Vol 21, No 2 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55483

Abstract

Green synthesis of silver nanoparticles (AgNPs) using aqueous Moringa extract and their incorporation in polyvinyl alcohol (PVA) as food packaging materials have been performed. The prepared nanoparticles were characterized via Ultraviolet-visible spectra and transmission electron microscope, and the results revealed the formation of silver nanoparticles in a semi-spherical shape with an average size ranged from 2 to 5 nm. The addition of different ratios of the nanoparticles onto the PVA matrix and their crosslinking via citric acid to obtain nanocomposite sheets were performed. The nanocomposite sheets were characterized using FT-IR, UV-Vis, and TGA. In addition, their mechanical properties were evaluated. Water vapor permeability rate and water content were also determined. The composite sheets showed good thermal and optical performance. Antibacterial activities of the prepared nanocomposite sheets were evaluated, and the results exhibited good resistance to bacterial growth.
Hydrocracking of Coconut Oil on the NiO/Silica-Rich Zeolite Synthesized Using a Quaternary Ammonium Surfactant Sriatun Sriatun; Heru Susanto; Widayat Widayat; Adi Darmawan
Indonesian Journal of Chemistry Vol 21, No 2 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55522

Abstract

NiO/silica-rich zeolite catalysts were used for coconut oil hydrocracking. The catalyst was prepared with a mixture of Na2SiO3, Al(OH)3, NaOH, and quaternary ammonium surfactants. The surfactant was varied of types like as tetrapropylammonium bromide (TPAB) and cetyltrimethylammonium bromide (CTAB). The acidity of the silica-rich sodalite zeolites enhances with the increase in nickel oxide added through a wet impregnation. The hydrocracking process was carried out by a semi-batch method. Liquid products were analyzed using GC-MS. The results showed that the addition of surfactants increased the catalyst surface area and acidity. Meanwhile, the presence of nickel oxide increases the acidity of the catalyst. The hydrocracking results showed an increase in gas products when the surface area was high, i.e., 23.781% in silica-rich sodalite zeolite without template (Z), 32.68% in silica-rich sodalite zeolite with tetrapropylammonium (ZTPA), and 39.673% in silica-rich sodalite zeolite with cetyltrimethylammonium (ZCTA). The presence of NiO increased the liquid product and the selectivity of the bioavtur fraction (C10-C15), where the highest percentage of liquid product was 60.07% at NiO/ZTPA.

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