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Indonesian Journal of Chemistry

ijc
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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

108 109 110 111 112

THE STABILIZING OF ANATASE AEROGEL AT HIGH TEMPERATURE Silvester Tursiloadi; Hiroshi Hirashima
Indonesian Journal of Chemistry Vol 4, No 2 (2004)
Publisher : Universitas Gadjah Mada

Stable anatase is attractive to its notable functions for photo catalysis and photon-electron transfer. Stable anatase TiO2 containing amorphous SiO2 aerogel was prepared by hydrolysis of Ti (OC3H7)4 and Si (OC3H7)4 in a 2-propanol solution with acid catalyst. The solvent in wet gels was supercritically extracted in CO2 at 60 oC and 22 Mpa. Thermal evolutions of the microstructure of the gels were evaluated by TGA-DTA, N2 adsorption and XRD. A stable anatase TiO2 containing amorphous SiO2 aerogel with a BET specific surface area of 365 m2/g and a total pore volume of 0.20 cm3/g was obtained as prepared condition. The anatase phase was stable after calcination up to 1000 oC, and BET specific surface area, total pore volume and average pore diameter did not change significantly after calcination up to 900 oC.

MULTIPLE REGRESSION ANALYSIS OF THE INFLUENCE OF CATALYST CHARACTERS SUPPORTED ON γ-Al2O3 TOWARDS THEIR HYDROCRACKING CONVERSION OF ASPHALTENE Wega Trisunaryanti; Triyono Triyono; Mudasir Mudasir; Akhmad Syoufian
Indonesian Journal of Chemistry Vol 4, No 1 (2004)
Publisher : Universitas Gadjah Mada

Multiple regression study of the influence of catalyst's characters with γ-Al2O3 as a support, including acidity, specific area, average pore volume, average pore radius, Ni content, and Mo content the hydrocracking conversion of asphaltene has been conducted.A multivariable regression analysis method, including regression analysis and correlation analysis, was applied on this study. Using multivariable regression, the characters of catalyst was correlated together with the data of the asphaltene conversions. Furthermore, using this method, the characters of catalyst, which have the greatest influence on conversion, may be evaluated. The results showed that there was a high correlation between catalyst characters and hydrocracking conversion of asphalten (r = 0.983). It means that the conversion was 98.3% correlated with the catalyst characters. The value of the multivariable determination coefficient was 0.966, indicating that at least 96.6% variation on the conversions was determined by combination of catalyst characters on this research. From the parameter value of regression equation, it could also be known that average pore radius and specific surface area were the two characters that have the greatest influence on the hydrocracking conversion of asphalten.

ISOLATION OF AN ANTIFEEDANT TRITERPENOID FROM THE SEED OF Barringtonia asiatica Emma J Pongoh; Rymond J Rumampuk; Ponis Tarigan; Anthony J Herlt; Lewis N Mander
Indonesian Journal of Chemistry Vol 4, No 1 (2004)
Publisher : Universitas Gadjah Mada

An antifeedant triterpenoid saponin has been isolated from the seed of Barringtonia asiatica and its structure elucidated mainly by two dimensional NMR spectroscopy is identified as 3-O-{[β-D-galactopyranosyl(1→3)-β-D-glucopyranosyl (1→2)]-β-D-glucuronopyranosyloxy}-22-O-[2-(E)-methyl-2-butenyloyloxy]-15, 16,28-trihydroxy-(3β,15α,16α,22α)-olean-12-ene. This compound showed antifeedant activity towards Epilachna sp larvae

THE USE OF GRIGNARD REAGENT IN PHEROMONE SYNTHESIS FOR PALM WEEVIL (Rhynchorus, Sp) Warsito Warsito; Edi Priyo Utomo; Achmad Ashadi; Satriyo Santosa
Indonesian Journal of Chemistry Vol 3, No 3 (2003)
Publisher : Universitas Gadjah Mada

In an integrated controlling system of palm weevil, using of synthetic feromoid is strickly needed. The research is aimed to synthesize pheromone which secreted by the weevil, e.g. 4-methyl-5-nonanol (R. ferrugineus) and 3-methyl-4-octanol (R. schach) through Grignard reagent which formed in situ.The synthesis was proceded by retrosynthesis to determine the precursor, valeraldehyde. The precursor was reacted with Grignard reagent of sec-amyl magnesium bromide (R. ferrugenieus) and sec-butyl magnesium bromide (R. shach) which made in situ. Characterization of the synthetic molecular pheromone was performed by Gas Chromatography-mass spectroscopy and Fourier Transformed Infra Red. The bioassay of the molecule was carried out by olfactometer.The result showed that the conversion of the reactions were 51.28% (4-methyl-5-nonanol) and 85.90% (3-methyl-4-octanol). The character of physico-chemical and bioactivity of the synthetic pheromone are identic with natural pheromones.

SUSCEPTIBILY OF Aeromonar hydrophylla BACTERIA ISOLATED FROM UNHEALTHY BAUNG FISH (Mystus nemurus) TOWARDS ANTIMICROBIAL AGENTS Pipik Taufik; Dayat Bastiawan
Indonesian Journal of Chemistry Vol 3, No 3 (2003)
Publisher : Universitas Gadjah Mada

The susceptibility of Aeromonas hydrophila isolated from ikan baung (Mystus nemurus) to antimicrobial agents was carried out. The objective of study is to know the kind of antimicrobial agents for the control aeromonasis of Mystus nemurus. Tryptic soy agar (TSA) plate consisted 106 cells/plate of A. hydrophila on its surface was kept paper disk consisted antimicrobial agent, than incubated on 30 0C for 24 hours. The results showed that from 10 isolates to be tested, 5 isolates were resistant, 2 isolates were intermediate and 3 isolates were sensitive to tetracycline and chloramphenicol respectively; one isolate was resistant, 6 isolates were intermediate and 2 isolates were sensitive to nalidixic acid. Minimal in hibitory concentration (MIC) of tetracycline and chlorampenicol to the sensitive isolates were 0.5 ppm respectively.

STRUCTURAL STUDY OF BIS(2,6-BIS(PYRAZOL-3-YL)PYRIDINE)NICKEL(II) BY CALORIMETRY AND EXAFS SPECTROMETRY Kristian H Sugiyarto
Indonesian Journal of Chemistry Vol 3, No 2 (2003)
Publisher : Universitas Gadjah Mada

The main aim of this work is to reveal the complex formation of 2,6-bis(pyrazol-3-yl)pyridine, bpp, with nickel(II) perchlorate in DMF by calorimetric stepwise complex formation and then followed by EXAFS spectrometry. It was found that the complex formation follows two stepwise pathways namely the formation of mono pyrazolyl-pyridine, [Ni(DMF)3 bpp]2+, and bis pyrazolyl-pyridine, [Ni(bpp)2]2+; the formation constants being log β1 = 6.57, and log β2 = 5.02, and the total value of log β = 11.58. The final formation of six-coordinated compound was confirmed by EXAFS analysis with the mean Ni-Nbpp bond length of 2.0646(0.0014) Å.

THEORETICAL STUDY OF THE EFFECT OF WATER MOLECULE ADDITION ON THE CONFORMATION OF SUBSTITUTED DIBENZO-18-CROWN-6 ETHER IN ITS COMPLEXATION WITH Na+ CATION USING SEMI EMPIRICAL METHOD MNDO/d Harno Dwi Pranowo; Tuti Hartati Siregar; Mudasir Mudasir
Indonesian Journal of Chemistry Vol 3, No 2 (2003)
Publisher : Universitas Gadjah Mada

The effect of water molecule addition into modeling structure of complex of substituted dibenzo-18-crown-6 ether with metal ion Na+ was studied. The aim of this research is to find information about geometrical conformation of substituted DB18C6 and its selectivity to complex/coordinate metal ion Na+ in the presence of water molecule. In this research semi empirical method was used for calculation. To find the best conformation, trial and error experiments were conducted using semi empirical method available in HyperChem 6.0, finally MNDO/d method was selected. The result of geometry optimization showed that addition of water molecule improve the stability of the conformation of substituted DB18C6 and increase the selectivity of this compound to complex metal ion Na+. The presence of electron-withdrawing substituents decreased the binding energy while that of electron-donating one increase the binding energy (value of DE more negative). Cavity radii of DB18C6 in the presence of water molecule extended from 2.3 Å to 2.6 Å. This figure is almost similar to that of experimental data.

A PRELIMINARY QUALITATIVE STUDY OF AN ALKALOID IN THE FRUIT OF TERONG BELANDA (Cyphomandra betacea, Cav) Fredryk Mandey; Mikael Dominggus; Tjodi Harlim
Indonesian Journal of Chemistry Vol 3, No 1 (2003)
Publisher : Universitas Gadjah Mada

Preliminary studies on Terong Belanda (C. betacea ) have been carried out in this investigation with an aim to examine the presence of an alkaloid in the fruit of Terong Belanda. Several protocols had been done including maceration, extraction, evaporation, separation under column chromatography, crystallization and recrystallization, and testing with series of alkaloid reagent test. Finally one fraction, fraction D, obtaining in white sharp crystals, 96 mg, m.p 117.5 ºC gave positive results to an alkaloid especially from the group of atropine.

SIMULTANEOUS DETERMINATION OF PARACETAMOL AND IBUPROFENE MIXTURES BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY Sophi Damayanti; Slamet Ibrahim; Kurnia Firman; Daryono H Tjahjono
Indonesian Journal of Chemistry Vol 3, No 1 (2003)
Publisher : Universitas Gadjah Mada

Analytical method for the determination of paracetamol and ibuprofene mixtures has been developed by High Performance Liquid Chromatography using C-18 column and acetinitrile - phosphate buffer pH = 4.5 (75:25) containing 0.075% sodium hexanesulfunate as a mobile phase. The detector was set at 215 nm. Using such conditions, retention time for paracetamol and ibuprofen was 4.89 and 7.11 min, respectively. The recovery for paracetamol and ibuprofen was found to be 101.07± 0.73% and 102.02 ± 1.58%, respectively. The detector limits of the method was 1.30 and 1.60 μg/mL with the relative standard deviation (RSD) 0.74 and 1.52% for paracetamol and ibuprofen, respectively.

SYNTHESIS OF 6-NITRO VERATRYL ALCOHOL AND 6-NITRO VERATRALDOXIM FROM VANILIN AS INTERMEDIATES FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERVATIVES Jumina Jumina; Undri Rastuti; Sabirin Matsjeh
Indonesian Journal of Chemistry Vol 3, No 1 (2003)
Publisher : Universitas Gadjah Mada

The synthesis of 6-nitro veratryl alcohol and 6-nitro veratraldoxim from vanilin which was required as intermediates for the preparation of C-9154 antibiotic derivatives was carried out. C-9154 antibiotic is a sufficiently potent antibiotic, but so far this is produced only in low yields through microbiological processes. The reaction steps performed were (1) methylation of vanilin, (2) nitration of the methylation product, (3) reduction of the corresponding nitro compound and (4) reaction of the nitration product with HO-NH2.HCl. Methylation of vanilin was conducted using dimethylsulfate and NaOH at 60 oC for 2 hours. Nitration of the methylation product was performed in 2 methods, i.e. using neat HNO3 and using a mixture of HNO3 and H2SO4 both at 5 oC for 2 hours. Reduction of the nitration product was conducted using NaBH4 either at room temperature and at reflux. Reaction of the nitration product with HO-NH2.HCl was carried out in ethanol 95% at 50 oC for 2 hours. The products were analyzed by means of TLC, GC, IR, 1H NMR and GC-MS spectrometers. The methylation of vanilin gave 87.7% yield of veratraldehyde which was found as a white crystal (m.p 43 oC). The nitration of veratraldehyde produced 6-nitro veratraldehyde observed as a yellow crystal having of m.p. 130 oC. Nitration using neat HNO3 gave a smaller yield (50.35%) of 6-nitro veratraldehyde than nitration with a mixture of HNO3 and H2SO4 (93.63%). Reduction of 6-nitro veratraldehyde using NaBH4 at room temperature and at reflux afforded 6-nitro veratryl alcohol which was found as brown crystal (m.p 123-127 oC) respectively in 13.47% and 56.61%. This reduction also produced 6-amino veratryl alcohol and 3,4-dimethoxy benzoic zcid as by products. 6-Nitro veratraldehyde reacts with HO-NH2.HCl to give 6-nitro veratraldoxim in 48.27% yield.

Page 110 of 196 | Total Record : 1956

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