bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE INFLUENCE OF STRONG AND WEAK ACID UPON AGGREGATION AND PHEOPHYTINIZATION OF CHLOROPHYLL A AND B
Authors: Kusmita Lia , Limantara Leenawaty 
Published: January 2019

Chlorophyll is green pigment that can be found in plant chloroplast. Higher plants usually have two kinds of chlorophylls, chlorophyll a and b. These green pigments are easily degraded by temperature, light intensity, oxygen, acid, and water. Water causes aggregation of chlorophyll, while acid causes pheophytinization of chlorophyll. Aggregation and pheophytinization process of chlorophyll are influenced by solvents. This study was conducted to observe the spectral difference of aggregated chlorophyll in acetone and methanol upon pheophytinization by strong (HCl) and weak acid (CH3COOH), in comparison to the non-aggregated chlorophyll. Observation of spectral pattern was carried out using double beam spectrophotometer CARY 50 at 350-1100 nm. The result shows that pheophytinization of chlorophyll a and b causes hypsochromic shift, particularly at Soret band. There are new peak formations in Qx region, specifically at 506 and 535 nm for pheophytinized-chlorophyll a, and at 371, 435, 526 and 599 nm for pheophytinized-chlorophyll b. Keywords: aggregation, chlorophyll a and b, pheophytinization
BENZOPHENONE GLUCOSIDE ISOLATED FROM THE ETHYL ACETATE EXTRACT OF THE BARK OF MAHKOTA DEWA [Phaleria macrocarpa (Scheff.) Boerl.] AND ITS INHIBITORY ACTIVITY ON LEUKEMIA L1210 CELL LINE
Authors: Winarno Hendig , Katrin W Ermin 
Published: January 2019

Isolation and elucidation of benzophenone glucoside from ethyl acetate extract of Phaleria macrocarpa bark and its inhibitory activity test against leukemia L1210 cell line have been done. The Phaleria macrocarpa bark were macerated using n-hexane, ethyl acetate, and ethanol, respectively. The ethyl acetate extract was then chromatographed on silica gel column and gradiently eluted by n-hexane - ethyl acetate - ethanol with the composition from 20:1:0 until 0:0:1, gave eight fractions. Separation of fraction 6 using semipreparative HPLC on reverse phase column (Capcell Pak C-18 SG120, 15 mm I.D. x 250 mm) using methanol - water (40:60, 5 mL/min) gave a brown powder, with the melting point of 182.3 ºC. Spectroscopic analysis and comparison of its physico-chemical data, this compound was clarified as 2,4'-dihydroxy-4-methoxy-benzophenone-6-O-b-D-glucopyranoside (3). Inhibitory activity of its compound against leukemia L1210 cell line showed that this compound exhibited inhibitory activity with IC50 was 5.1mg/mL. Keywords: Phaleria macrocarpa, 2,4'-dihydroxy-4-methoxybenzophenone-6-O-b-D-glucopyranoside, cytotoxic activity, leukemia L1210
HOPEAPHENOL-O-GLYCOSIDE, A COMPOUND ISOLATED FROM STEM BARK Anisoptera marginata (Dipterocarpaceae)
Authors: Atun Sri 
Published: January 2019

Isolation and structure elucidation of some compounds from stem bark of Anisoptera marginata had been done. The isolation of those compounds was carried out by chromatographyc method and structure elucidation was performed by interpretation of spectroscopic data, including UV, IR, 1H and 13C NMR 1D and 2D, and FABMS. From acetone extract stem bark A. marginata we isolated five known compounds namely bergenin (1), (-)-ε-vinipherin (2), (-)-ampelopsin A (3), vaticanol B (4), (-)-hopeaphenol (5), and a glycoside compound namely hopeaphenol-O- glycoside (6). Keywords: Dipterocarpaceae; Anisoptera marginata; hopeaphenol-O-glucoside
SYNTHESIS OF HYDROTALCITE Zn-Al-SO<sub>4</sub> AS ANION EXCHANGER AND ITS APPLICATION TO TREAT OF POLLLUTANT CONTAINED HEXACYANOFERRAT(II)
Authors: Roto Roto , Tahir Iqmal , Sholikhah Umi Nur 
Published: January 2019

Synthesis of Zn-Al-SO4 hydrotalcite and its application as anion exchanger for hexacyanoferrat (II) have been studied. Synthesis of Zn-Al-SO4 hydrotalcite was carried out by stoichiometric method and hydrothermal treatment. Sulphate in hydrotalcite interlayer was exchanged by hexacyanoferrat (II) that was assumed as pollutant. Kinetics of ion exchange was also investigated. The product of ion exchange was characterized by XRD, IR spectrophotometry and atomic absorption spectrometry. Zn-Al-SO4 hydrotalcite can be obtained by stoichiometric method at pH 8 and followed by hydrothermal treatment. The chemical formula of the hydrotalcite was Zn0.74Al0.26(OH)1.74(SO4)0.13.0.52H2O. The hexacyanoferrat (II) anion could exchange sulphate in hydrotalcite interlayer as showed by IR spectra and XRD patterns. The anion exchange capacity was 645.35 meq/100 g, and the kinetics of ion exchange reaction was first order with k = 5 x 10-5 s-1. It showed that Zn-Al-Fe(CN)6 could be regenerated easily, so it has been regenerate frequently. Keywords: hydrotalcite, anion exchanger, hexacyanoferrat
ADSORPTION MODEL OF Mn<sup>2+</sup>, Cd<sup>2+</sup> and Hg<sup>2+</sup> IN THE WATER - SEDIMENT SYSTEMS ALONG CODE RIVER, YOGYAKARTA
Authors: Muzakky Muzakky 
Published: January 2019

Prediction of adsorption model of Mn2+, Cd2+ and Hg2+ in water-sediment systems along Code River, Yogyakarta has been experimentally investigated. The aim of this investigation is to predict the transfer models based on isotherm adsorption of Mn2+, Cd2+ and Hg2+ metal ions from water into sediment. In addition, this investigation is expected to be able to inform the initial condition of Code River, dynamics, and the fate of Mn2+, Cd2+ and Hg2+ ions from upstream to downstream. Based on the investigation the transfer of Mn2+, and Cd2+ ions into sediment follows Langmuir adsorption model, with the coefficient determination (R2) of 0,9916 and 0,9799, while the value of the adsorption energy are 20,95 kJ/mol and 16,85 kJ/mol. The transfer of Hg2+ ion tend to follow Freundlich adsorption model. From the adsorption energies, it is proven that Mn2+ ion was chemically sorpted into the sediment, while Cd2+ ion will tend to be physically sorpted into the sediment. The binding strength of which ise in the order of Mn2+ > Cd2+ and the adsorption energy of Hg2+ ion could not be determined. Keywords: adsorption model, chemically sorpted, physically sorpted
DETERMINATION OF REACTION KINETICS USING ONLINE X-RAY DIFFRACTION
Authors: Purba Elida 
Published: January 2019

X-ray diffraction (XRD) is a powerful technique for the study of polymorphism and polymorphic phase transformations. Monitoring of phase transformation directly has been very limited to-date. The XRD system used in this study was used to determine the rate of transformation of pure glutamic acid a form to b form in a solution mediated phase. On every run starting from the pure a form, the transformation process was monitored continuously at fixed temperature, and separate experiments were performed as a function of temperature. The operating temperature was varied from 36 to 57 °C with 10% w/w solid concentration. Data were taken every 200 seconds until the transformation was completed. This paper is concerned with a study of the transformation of the alpha (a) form of L-glutamic acid (L-GA) to the beta (b) form in order to determine the kinetic reaction. The rate constant (k), activation energy (Ea) and pre-exponential factor (A) were obtained. Sensitivity tests were also carried out to examine minimum detection limit when both a and b present in the mixture. In addition, effect of particle size on XRD patterns was also determined. The results show that XRD gives useful information to observe polymorphism for pharmaceutical industry. Keywords: XRD, polymorphism, glutamic acid, reaction kinetics
QUANTITATIVE ELECTRONIC STRUCTURE - ACTIVITY RELATIONSHIP OF ANTIMALARIAL COMPOUND OF ARTEMISININ DERIVATIVES USING PRINCIPAL COMPONENT REGRESSION APPROACH
Authors: Werfette Paul Robert Martin , Armunanto Ria , Tahir Iqmal 
Published: January 2019

Analysis of quantitative structure - activity relationship (QSAR) for a series of antimalarial compound artemisinin derivatives has been done using principal component regression. The descriptors for QSAR study were representation of electronic structure i.e. atomic net charges of the artemisinin skeleton calculated by AM1 semi-empirical method. The antimalarial activity of the compound was expressed in log 1/IC50 which is an experimental data. The main purpose of the principal component analysis approach is to transform a large data set of atomic net charges to simplify into a data set which known as latent variables. The best QSAR equation to analyze of log 1/IC50 can be obtained from the regression method as a linear function of several latent variables i.e. x1, x2, x3, x4 and x5. The best QSAR model is expressed in the following equation, (;;) Keywords: QSAR, antimalarial, artemisinin, principal component regression
THE ANTIBACTERIAL COMPOUND COLLISMICIN A DERIVED FROM MARINE <i>Streptomyces</i> sp Q-629K
Authors: Murniasih Tutik , Adachi Kyoko 
Published: January 2019

In our course of screening for secondary metabolite derived from marine bacterial, we isolate the antimicrobial compound collysmicin A from the ethyl acetate extract of Streptomyces sp Q-629K. Separation of this compound was carried out by silica gel open column chromatography. Purification of an active compound was done using HPLC C18 with acetonitril-water system. Determination of chemical structure was done by 1H, 13C NMR and LC-MS analysis. Collysmicin A was contained in fraction 3, fraction 7.2 and fraction 8.7. The antimicrobial assayed from purified compound Fr.8.7 gave diameter inhibition approximately 13 mm against S. aureus and 12 mm against B. subtilis . Keywords: antimicrobial, collismycin A and marine Streptomyces sp
DETERMINATION AND VALIDATION OF MEBHYDROLINE NAPADISYLATE IN TABLETS BY HPLC
Authors: Wulandari Lestyo 
Published: January 2019

An accurate and sensitive HPLC method has been developed for the determination of mebhydroline napadisylate in the tablet. The Chromatography was performed on a reversed phase C-18 column, using a mobile phase of acetonitrile : ammonia 25% (80 : 20 v/v) at ambient temperature 25±5 °C and UV detection operates at 320 nm in an overall analysis time of about 15 min, based on peak area. This HPLC method is selective, precise, and accurate and can be used for routine analysis of pharmaceutical preparation in industrial quality-control laboratories. Keywords : HPLC, mebhydroline napadisylate, validation
PRE-CONCENTRATION AND DETERMINATION OF HEAVY METALS ON MODIFIED ACTIVATED CARBON IN REAL SAMPLES
Authors: Ahmadi F. , Niknam K. , Khanmohammadi A. , Adibmehr Z. 
Published: January 2019

A sensitive and simple method for the simultaneous pre-concentration of nutritionally important minerals in real samples has been reported. The method is based on the formation of metal complexes by N, N'-diacetyl-4-bromo-2, 6-di (aminomethyl) phenol (DBDP) loaded on activated carbon. The metals content on the complexes are then eluted using 6mL 4M HNO3, which are detected by AAS at resonance line. In this procedure, minerals such as Ni, Cu, Co, Pb Zn and Cd can be analyzed in one run by caring out the simultaneous separation and quantification of them. At optimum condition the response are linear over concentration range of for 0.03-1.1 µg mL-1 for Ni2+ , 0.03-1.0 µg mL-1 for Cu2+, 0.02-1.0 µg mL-1 for Pb2+ , 0.02-1.0 µg mL-1 for Co2+,0.02-1.1 µg mL-1 Zn2+ and 0.05-1.3 µg mL-1for Cd2+. The detection limits of each element are expressed as the amount of analytes in µg mL-1 giving a signal to noise ratio of 3 are equal to 2.5, 2.4, 1.6, 2.4, 1.9 and 2.1 for Ni2+ , Cu2+, Pb2+ , Co2+,Zn2+ and Cd2+. The ability of method for repeatable recovery of trace ion are 99.9, 98.7, 99.2 , 98.7, 98.5and 95.6 with R.S.D of 1.3, 1.4, 1.2, 1.4, 1.7 and 1.4 for Ni2+ , Cu2+, Pb2+ , Co2+,Zn2+ and Cd2+. The method has been successfully applied for these metals content evaluation in some real samples including natural water and vegetable. Keywords: Heavy Metals, N, N'-diacetyl-4-bromo-2,6-di(aminomethyl) phenol (DBDP), Activated Carbon
ISOLATION AND CHARACTERIZATION OF CHITIN AND CHITOSAN PREPARED UNDER VARIOUS PROCESSING TIMES
Authors: Poeloengasih Crescentiana Dewi , Hernawan Hernawan , Angwar M. 
Published: January 2019

Generally production of chitosan from crustacean shells consists of 4 steps, i.e. deproteinization, demineralization, decolorization and deacetylation. Simplification of chitosan production by elimination of deproteinization and/or demineralization, or reducing of reaction time would give many advantages, e.g. reduction of processing time and cost production due to reduction of chemical and power usage. The objectives of this research were to prepare chitosan under various processing times and to characterize the obtained chitin and chitosan. Chitin was prepared under various deproteinization times (0, 15, 30 min at 90 ºC using NaOH 2N) and demineralization times (0, 15, 30 min at ambient temperature using HCl 2N). Chitin was then bleached using aceton/etanol (1:1) for an hour. Deacetylation was achieved by treatment of chitin under condition at 120 ºC for 5 hr using NaOH 50%. Ash and nitrogen content, and degree of deacetylation of chitosan were evaluated. Demineralization and/or deproteinization times influenced the quality of chitin. Chitin and chitosan prepared without demineralization had white and chalky appearance, whereas the other chitosan were off-white in color. Ash and nitrogen contents of the chitosan products were 0.18 - 32.40% and 3.56 - 7.59%, respectively. Chitosan prepared under various processing times, except chitosan without demineralization treatment, had degree of deacetylation ≥ 70%. Keywords: chitosan, deproteinization, demineralization, deacetylation, processing times
PHYTOCHEMICAL STUDY ON THE ETHYLACETATE EXTRACT OF THE LEAVES OF <i>Mesua ferrea</i> LINN
Authors: Rahman S. M. Mizanur , Shabnom Swati , Quader M. Abdul , Hossain M. Amzad 
Published: January 2019

Furano-napthyl-hydroxy cyclohexyl type of compound was isolated first times in plant from the ethyl extracts of the leaves of Mesua ferrea. The structure of the compound has been established by the modern spectroscopic techniques such as UV, IR, 1H-NMR, 13C-NMR and mass spectroscopy and identified as 12, 13-furano-8-hydroxy napthyl-6-0-b-2',3',4',6' tetrahydroxy-5',5' dimethyl cyclohexyl ether. Keywords: Mesua ferrea Linn; Euphorbiaceae; Medicinal plant; new compound; spectral analysis
RbNb<sub>6</sub>Cl<sub>12</sub>O<sub>2</sub>: CRYSTAL STRUCTURE AND MAGNETIC PROPERTIES
Authors: Gulo Fakhili 
Published: January 2019

A novel niobium oxychloride cluster compound, RbNb6Cl12O2 was obtained by solid state synthesis from stoichiometric mixture of RbCl, Nb2O5, NbCl5 and Nb powder, heated at 675 °C. Its structure was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic system (a = 6.8097(4) Å, b = 11.6700(9) Å, c = 12.5090(9) Å, ß = 101.337(4) °, V = 974.68(12) Å3, and Z = 2) with the space group of P21/c. The cluster framework of this compound is based on units connected via oxide ligands in the a-direction with two Nb-O linkages between adjacent clusters, which resembles intercluster bonding in Chevrel-Sergent phases. In the other two directions, the linkages occur through single Cla-a bridges. The framework generates channels where the cations Rb+ are located. This compound contains valence electron concentration (VEC) of 15 per cluster unit and therefore exhibits the paramagnetic behavior. Keywords: niobium oxychloride cluster, solid state, VEC, paramagnetic
CHARACTERISTIC OF ACRYLIC ACID GRAFTED POLYETHYLENE FILM PREPARED BY GAMMA IRRADIATION METHOD
Authors: Hendri John , Suka Irwan Ginting , Simanjuntak Wasinton , Annisa Annisa , Gatot Gatot 
Published: January 2019

In this study, high density polyethylene (PE) film (thickness 80 μm) was modified by grafting of acrylic acid (AA) onto the film using 15 kGy of g irradiation as initiator, applied at different exposure times. In addition to irradiation dose, other variables investigated are concentration of AA, the type of solvent, and polymerization time carried out at 60 oC. The success of the graft copolymerization processes was confirmed by analysing the grafted film using FTIR spectroscopy, which revealed the existence of absorption band at wave number of 1721 cm-1 (assigned to C=O), and that at 3385 cm-1 (assigned to -OH), and the physical endurance of the sample was evaluated by carrying out tensile strength measurement. The percent of grafting was determined according to the gravimetric method. The results indicated that the highest percent of grafting was obtained by application of 2-hour irradiation time, with monomer concentration of 30 % in water as a solvent, grafting temperature of 60 oC. Activity of grafted was evaluated by measurement of the absorption capacity toward water and Cu2+ ion, and revealed the increase of the absorption capacity with increased percent of grafting. Keywords: Graft copolymerization, acrylic acid, low density polyethylene, gamma irradiation, water absorbency, absorption of cupric ion
CHARACTERISTICS OF RICE HUSK SILICA GRAFTED 4-VINYL PYRIDINE
Authors: Suka Irwan Ginting , Simanjuntak Wasinton 
Published: January 2019

This study was carried out to investigate the grafting of4-Vinyl Pyridine (4-VP) on silica prepared from rice husk, with the main aim to study wether the 4-VP grafted retains its characteristics. For this purpose, the grafted silica was analysed using FTIR spectroscopic method, followed by testing of the sample for solvent adsorption, Cu2+ adsorption from solution, and bacterial inhibitions, since 4-VP has been known to possess such properties. The FTIR analysis revealed that under the experimental conditions applied, the 4-PV was well grafted onto silica surface. The success of grafting was also supported by the results of solvent adsorption, which indicate the increase in adsorption capacity with increased percent of grafting and higher adsorption capacity toward polar solvent. The same supports are also provided by the ability of the sample to adsorp results of Cu2+ adsorption from solution, and the ability of the sample to inhibit the microorganism growth. Keywords: Graft copolymerization, rice husk silica, 3-methacryloxypropyl trimethoxysilane, 4-vinyl pyridine, microorganism growth inhibition
PHOTO-REDUCTION KINETICS OF MnO<sub>2</sub> IN AQUATIC ENVIRONMENTS CONTAINING HUMIC ACIDS
Authors: Narsito Narsito , Santosa Sri Juari , Lastuti Setya 
Published: January 2019

The kinetics of photo-reduction of manganese(IV) oxide, MnO2 in aqueous medium, in the presence of humic acid has been investigated, including the possibility for the involvement of such radicals in the reduction. Results showed that in aqueous medium, the efficiency of the photo-reduction of MnO2 producing a soluble ionic Mn(II) was governed strongly by an internal electron transfer within an intermediate of HA-MnO2 anion complex, resulted in the chemical adsorption of humic acid on MnO2 surface. It was observed that under solar radiation and atmosphere containing oxygen, the rate of MnO2 reduction increased considerably, by factors of about 46 and 2 respectively. Moreover, there was evidence that some radicals certainly played a role in the photo-reduction of MnO2, since radical scavenger addition significantly decreased the reduction efficiency of MnO2. In the present of an excess of propanol-2, however, which was expected to remove all OH radicals present, only about 60 % decrease in reduction efficiency were observed, suggesting that radicals other than OH radical are involved in the reduction of MnO2. It was observed further that the presence of iron(III) in MnO2 up to 1 % (w/w) did not alter the reduction efficiency of MnO2. Keywords: MnO2 kinetics, photo-reduction, aquatic, humic acids
THEORETICAL STUDY OF SOLVENT EFFECTS AND NMR SHIELDING TENSORS OF DLPC
Authors: Monajjemi M. , Afsharnezhad S. , Jaafari M.R. , Mirdamadi S. , Monajemi H. , Mollaamin S. 
Published: January 2019

The effect of the polarity of the environment on the conformation zwitterionic membrane dilauroyl phosphatidylcholine (DLPC) has been investigated with calculation at the Hatree-Fock level using the 6-31G* basis set with Onsager continuum solvation model. The ‘Gauge Including Atomic Orbital' (GIAO) approach is used to investigate Ab initio GIAO calculations of NMR chemical shielding tensors carried out within SCF-Hartree-Fock approximation are described. In order to compare the calculated chemical shifts with experimental ones, it is important to use consistent nuclear shielding for NMR reference compounds like TMS. Conformation of DLPC was evaluated with four different solvents with different dielectric constant (Water (ε = 78.39), Dimethyl Sulfoxide (ε = 46.7), Acetone (ε = 20.7) and Heptane (ε = 1.92). In concern with conformational energy, Water could be the most suitable solvent for DLPC. Moreover, as the polarity of the medium increase, the conformational stability of this molecule increases faster than that of DLPC in the gas phase. Consequently, the relative energy of DLPC also depends on the polarity of the environment. This subject was considered as well as the most variable in some dihedral angles degree and NMR isotropic shift were in the less dielectric constant (ε = 1.92). It could be in polar medium DLPC conformer becomes additionally stabilized by intermolecular ionic and hydrogen bond interactions with polar neighboring molecules. On the basis of this work it can be concluded that the effect of the polarity of the environment clearly are influenced on the isotropic values by geometry variation due to intermolecular motion in molecule. Keywords: Onsager continuum model, DLPC ,NMR shielding, isotropic, solvent models, anisotropic
TRANSPORT OF Cr(III), Cd(II), Pb(II), AND Ag(I) IONS THROUGH BULK LIQUID MEMBRANE CONTAINING <i>p-tert</i>-BUTYLCALIX[4]ARENE –TETRAETHYLESTER AS ION CARRIER
Authors: Maming Maming , Jumina Jumina , Siswanta Dwi , Firdaus Firdaus , Sastrohamidjojo Hardjono 
Published: January 2019

The study on transport of Cr(III), Cd(II), Pb(II), and Ag(I) through bulk liquid membrane using p-tert-butylcalix[4]arene-tetraethylester as ions carrier has been conducted. The aims of this work are to determine the optimum condition, efficiency, and selectivity of transport of the carriers for those ions. Both optimum condition and efficiency of transport were obtained by determination of the concentration of transported ions with variation of source phase pH, ion carrier concentration, the nature of stripping agent in the target phase, and transport time. The ion transport selectivity of ion carrier was obtained from the ions transport competition experiments using equimolar mixtures. The amount of Cr(III), Pb(II), Cd(II), and Ag(I that was transported across liquid membrane was about 0, 10, 10 and 50 % respectively after 24 hours, except for Pb(II) (32 hours). The ion carrier is selective for Ag(I) where separation factor to Cd(II) was 16.0, that to Pb(II) was 42.8, and that to Cr(III) was infinite. Keywords: transport, calix[4]arene, efficiency, selectivity, bulk liquid membrane, heavy metals
OXIDATION OF BENZYLIC SECONDARY ALCOHOL WITH PYRIDINIUM CHLOROCHROMATE-ALUMINA (PCC-Al<sub>2</sub>O<sub>3</sub>)
Authors: Sohilait Hanoch J. 
Published: January 2019

In these studies, Pyridinium chlorochromate-Alumina was used for oxidation of secondary alcohols (safryl alcohol and methyleugenyl alcohol) to ketone. The oxidation of safryl alcohol with PCC-Al2O3 followed by purification by potassium bisulfite yields safryl ketone (62,92%). The oxidation of methyleugenyl alcohol with PCC-Al2O3, followed by purification by potassium bisulfite yields methyleugenyl ketone (68,04%). The elucidation of these products was analyzed by FTIR, 1H-NMR and MS. Keywords : PCC-alumina, secondary alcohols, ketone