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AKTIVITAS EKSTRAK BUAH MAKASAR (Brucea Javanica L. Merr) TERHADAP RADIKAL ANION SUPEROKSIDA SECARA IN VIVO Widiyantoro, Ari; Wardoyo, Elvi R.P.; Sayekti, Endah
Jurnal Penelitian Saintek Vol 15, No 1 (2010): April 2010
Publisher : Jurnal Penelitian Saintek

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Abstract

Activity  of scavengering  radical  anion superoxide  by extract of Makasar fruit  (Brucea javanica   L. Merr)  have  been  research  with  methods  of  inhibition  reduction  nitroblue tetrazolium,  by in vivo on rat  Wistar induction with aflatoxin. Results showed  there are inhihition  reduction  of  nitroblue  tetrazolium  by  methanol  extract,  methanol fraction, ethylacetate fraction,  methylen chloride fraction  and n-hexane fraction. Phytochemical test showed alkaloid, terpenoid, quinone, polyphenol and steroid.
MEKANISME KLORINASI EUGENOL MENGGUNAKAN KLORIN (CL2) DENGAN KATALIS FECL3 DALAM PELARUT DIKLOROMETANA Sayekti, Endah; Silalahi, Imelda H; Awalliah, Emy
Jurnal Sains dan Teknologi Kimia Vol 4, No 1 (2013): Jurnal Sains dan Teknologi Kimia
Publisher : Program Studi Kimia Jurusan Pendidikan Kimia FPMIPA UPI

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 Chlorination of eugenol by chlorine with catalyst of FeCl3 in dichloromethane solvent had been performed. Chlorination was carried out at 2oC for 5 hours. The reaction produced dark brown clot which was soluble in methanol, acetone, ethyl acetate, dichloromethane and chloroform but insoluble in aquadest. An infrared analysis gave the chlorobenzene groups at 1095.57-1072.42 cm-1. The NMR1H showed the CHCl and CH2Cl groups at 3.2884-3.0185 ppm and NMR13C showed carbon as C-Cl at 100-20 ppm. GC-MS spectrum analysis showed there are four dominant products with the time retention at 28.650; 29.300; 32.383 and 37.242. Result of the spectroscopy analysis showed that the main coumpound of eugenol chlorination were 4-(2,3-dichloroprophyl)-2-methoxyphenol (24,67%); 4-(2-chloroprophyl)-6-chloro-2-methoxyphenol(20,57%); 4-(2,3-dichloroprophyl)-6-chloro-2-methoxyphenol (13,65%) and 3,6-dichloro-4-(2,3-dichloropropyl)-2-methoxyphenol or 5,6-dichloro-4-(2,3-dichloropropyl)-2-methoxyphenol  (9,92 %). Therefore, based on all analysis which were done, it can conclude that   chlorination of eugenol using chlorine catalyzed by FeCl3 in dichloromethane cause addition and aromatic electrofilic substitution. Key Word: Eugenol, Chlorination, FeCl3, Dichloromethane
PENGARUH MODEL PEMBELAJARAN INKUIRI SAINS BERBANTUAN MIND MAPPING TERHADAP HASIL BELAJAR BIOLOGI SISWA KELAS X SMA Sayekti, Endah; Suwono, Hadi; Sueb, Sueb
Jurnal Pendidikan: Teori, Penelitian, dan Pengembangan Vol 2, No 4: April, 2017
Publisher : Graduate School of Universitas Negeri Malang

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Abstract

This research aims to determine the differences of biology learning outcomes between students taught by science inquiry model assisted by mind mapping and students taught by confirmatory model with adjusting early biology learning outcomes. This research was quasy experiment by nonrandomized control group pretest-posttest design. The population was all grade ten students of SMAN 1 Bungkal Kabupaten Ponorogo which samples were class X3 as experiment groups and class X4 as control groups. The result shows that the mean scores and the enhancement of biology learning outcomes of students taught by science inquiry model assisted by mind mapping was higher than students taught by confirmatory model. The result of ancova test shows that there were differences of biology learning outcomes between students taught by science inquiry model assisted by mind mapping and students taught by confirmatory model and covariate influence biology learning outcomes (p<0,05).Penelitian ini bertujuan untuk mengetahui perbedaan hasil belajar Biologi siswa yang dibelajarkan dengan model inkuiri sains berbantuan mind mapping dengan siswa yang dibelajarkan menggunakan model konfirmatori dengan menyesuaikan hasil belajar Biologi awal. Penelitian ini merupakan eksperimen semu dengan desain non randomized control group pretest-posttest. Populasi penelitian ini yaitu seluruh siswa kelas X SMAN 1 Bungkal Kabupaten Ponorogo dengan dua sampel yaitu kelas X3 sebagai kelompok eksperimen dan kelas X4 sebagai kelompok kontrol. Hasil penelitian menunjukkan nilai rerata dan peningkatan nilai rerata hasil belajar biologi siswa yang dibelajarkan dengan model inkuiri sains berbantuan mind mapping lebih tinggi dibandingkan dengan siswa yang dibelajarkan dengan model konfirmatori. Hasil uji anakova menunjukkan bahwa terdapat perbedaan hasil belajar Biologi siswa yang dibelajarkan dengan model inkuiri sains berbantuan mind mapping dan siswa yang dibelajarkan menggunakan model konfirmatori dan kovariat berpengaruh terhadap hasil belajar Biologi (p<0,05).
SUBSTITUTION REACTION OF HYDROXY OF CITRONELLOL WITH CHLORIDE USING A MIXTURE OF AMMONIUM CHLORIDE AND SULPHURIC ACID Sayekti, Endah; Silalahi, Imelda H; Zaharah, Titin Anita
ALCHEMY Jurnal Penelitian Kimia Vol 11, No 2 (2015): Alchemy Jurnal Penelitian Kimia
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

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Abstract

Substitution reaction of hydroxy of citronellol with chloride using a mixture of ammonium chloride (NH4Cl) and sulphuric acid (H2SO4) has been conducted. The citronellol was obtained from the reduction of citronellal using sodium borohydride (NaBH4) at room temperature for 30 minutes. Substitution of hydroxy of citronellol with chloride ion was carried out at 80 oC and molarity ratio of citronellol and NH4Cl 1:1, 1:2; 1:3; and 1:4 respectively. Identification of the product by gas chromatography-mass spectrometry (GC-MS) showed that the substitution reaction produced 2-isopropyl-5-methyl-1-chlorocyclohexane compound with rendemen 64,49 % in mol ratio of 1:4. The infra red (IR) analysis showed that there was a vibration at wave number 763 cm-1 which is a typical C-Cl vibrations.
CHARACTERISTICS OF Chlorella sp BIOMASS IMMOBILIZED ON CHITOSAN (Chlo-Kit) FOR ADSORPTION OF CHROMIUM(III) SOLUTION Zaharah, Titin Anita; Shofiyani, Anis; Sayekti, Endah
ALCHEMY Jurnal Penelitian Kimia Vol 11, No 1 (2015): Alchemy jurnal penelitian kimia
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

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Abstract

Properties of biosorbent prepared from biomass of Chlorella sp immobilized on chitosan (Chlo-Kit) have been studied for adsorption of Chromium(III). Chlo-Kit adsorbent prepared by following steps: dissolving chitosan to get hydrogel form, immobilization of biomasson chitosan hydrogel, beads formation and crosslinkingthe adsorbent beads using epichlorohydrin reagent.Characterization using FT-IR spectrophotometry  and SEM showed that mechanism of biomass immobilization on chitosan involves electrostatic interactions between the functional groups of such both materials. Biomass immobilized on chitosan (Chlo-Kit) showed the higher stability in acid medium than un-immobilized biomass. Adsorption of Cr(III) metal ion on Chlo-Kit occured at optimum pH of 4-5 and followed well the Langmuir adsorption isotherm model. The adsorption capacity of Cr(III) on Chlo-Kit was 68.965 mg/g, about 91% higher than that on Chlorella biomass
Cadmium Adsorption on Chitosan/Chlorella Biomass Sorbent Prepared by Ionic-Imprinting Technique Shofiyani, Anis; Narsito, Narsito; Santosa, Sri Juari; Noegrohati, Sri; Zahara, Titin Anita; Sayekti, Endah
Indonesian Journal of Chemistry Vol 15, No 2 (2015)
Publisher : Universitas Gadjah Mada

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Abstract

Ionic-Imprinted Chitosan/Chlorella biomass sorbent (IICCb) has been synthesized for selective adsorption of Cd(II) adsorption. IICCb was prepared by coating Cd(II)-complexed-chitosan hydrogel on the biomass surface followed by cross-linking procedure. Cd(II)-imprinting ions were then eluted using Na2EDTA solution to provide a specific template for binding sites of Cd(II). Batch adsorption was carried out as function of initial pH, contact time, and initial concentration of the Cd(II) solution. Result showed that the optimum adsorption of Cd(II) was found at pH 4-6. Study of pseudo-second order kinetic showed that the adsorption of Cd(II) on IICCb went faster than that on Ionic-Imprinted Chitosan (IIC) or Non-Imprinted Ionic Chitosan/Chlorella sorbent (NIICCb). The maximum Cd(II) adsorption capacity as obtained from Langmuir adsorption isotherm was found to be 53.76 mg/g on IICCb, that was comparatively higher than that on IIC (44.44 mg/g) or on NIICCb (51.02 mg/g) adsorbent.
Pengaruh Variasi Garam Ammonium Terhadap Keasaman Zeolit Alam Pada Reaksi Perengkahan Minyak Jelantah Fabiani, Verry A.; Silalahi, Imelda H.; Sayekti, Endah
Indo. J. Chem. Res. Vol 5 No 1 (2017): Edisi Bulan Juli (Edition For July)
Publisher : Jurusan Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Pattimura

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Abstract

Natural zeolite modification with the addition of ammonium salt variations was conducted. The modification was conducted by demineralization method, dealumination and followed by activation of ammonium salt. The types of activators were ammonium chloride, ammonium nitrate and ammonium fluoride. The effect of ammonium salt was assessed through acidity parameter with Si/Al ratio variable and applied catalyst for catalytic cracking of waste cooking oil. The results showed that the activation of natural zeolite by using ammonium chloride salt could increase the acidity of natural zeolite with the highest Si/Al ratio about 15.56. Based on the XRF analysis showed that the reduced amount of Na metal in zeolite about 92.8%. The effect of ammonium salt variation on the acidity of natural zeolites was observed by applying a catalyst in the catalytic cracking of waste cooking oil. Physical characteristic of catalytic cracking products from waste cooking oil indicated all products fulfill the solar standards requirement. The results concluded that ammonium chloride salt was the best activator in natural zeolite modification and generally all ammonium salts gave high acidity effect to natural zeolite in catalytic cracking of waste cooking oil.