80 research outputs found
Penentuan Sisi Aktif Selulase Aspergillus Niger Dengan Docking Ligan
No full textLetak dari sisi aktif selulase Aspergillus Niger, yang akan menentukan aktivitas katalitiknya, dapat diketahui melalui komputasi. Sebuah ligan selobiosa dimodelkan untuk dapat melakukan simulasi docking pada molekul selulase yang telah diketahui struktur kristalnya. Melalui kalkulasi energi ikatan dan pendekatan optimasi memakai algoritma genetik Lamarckian, dapat dipilih konformasi molekul yang menunjukkan adanya daerah tertentu dengan energi terendah. Struktur yang memiliki daerah semacam ini dianggap mewakili konfigurasi terbaik terikatnya ligan pada sisi aktif yang dicari.Hasil perhitungan memperlihatkan bahwa tekukan protein yang membentuk celah konkaf diantara dua kelompok struktur b-sheet yang saling berlawanan arah pada molekul selulase merupakan sisi aktif dari enzim tersebut. Ligan dapat terikat disana melalui interaksi hidrofilik dengan residu asparagin (Asn20), serin (Ser111), dan glutamin (Gln158). Di salah satu ujung sisi aktif selulase terdapat residu aspartat (Asp99) dan glutamat (Glu116, Glu204) yang akan mempengaruhi aksi katalitik dari enzim selulase apabila residu-residu ini terikat oleh ion-ion divalen.Sisi aktif selulase ini merupakan gabungan dari domain pengikat substrat dan domain katalitik. Penambahan ion logam yang tepat pada sisi aktif enzim selulase Aspergillus Niger dapat meningkatkan aktivitas spesifiknya.Kata kunci:docking, ligan, selulase, sisi ikatan, substrat The active site of cellulase from Aspergillus Niger that affects the enzyme activity can be searched by computational methods. A ligand of cellobiose is modelled to perform docking simulation to cellulase with known crystal structure. By calculating the binding free energy and optimization approach using Lamarckian's genetic algorithm, a molecular conformation that has a region with the lowest energy value can be selected. The molecule structure with such region represents the best configuration of ligand bound to the active site.The calculation results that the concave cleft formed by protein folding of two anti-parallel b-sheet structures is the active site of the enzyme. A ligand would bind to the site through hydrophilic interactions with asparagine (Asn20), serine (Ser111), and glutamine (Gln158) residues. The aspartic acid (Asp99) and glutamic acid (Glu116, Glu204) residues that reside in one end of the active site determine the catalytic actions of the enzyme when they are binding with some metal ions.It is shown that the active site of this cellulase has substrate-binding domain and catalytic domain together. The introduction of specific metal ions to the active site of Asperillus Niger cellulase will increase its specific activity
Carbonization of Palm Oil Empty Fruit Bunch (EFB) in Hydrothermal Processes to Produce Biochar
No full textABSTRACT Empty fruit bunch (EFB) of palm oil is a waste from the palm oil industries which in a large amount, those waste is not properly utilized yet. EFB is a lignocelluloses waste as a polymer with big molecule such as cellulose, lignin, and hemicelluloses that can be degraded into smaller molecules in hydrothermal carbonization (HTC) process. The HTC process of EFB will result three fractions such as gas, organic water soluble and biochar as solid residue or bio-char-water-slurry. EFB degradation is influenced by the operation conditions such as temperature, pressure, catalysts, reaction time, stirring and ratio liquid and solid. The HTC process involved many routes of reaction such as liquefaction, hydrolysis, dehydration, decarboxylation, condensation, aromatization, and polymerization. In this experiment 60 ml closed vessel was used as the HTC reactor to degrade of EFB. EFB concentration of 6.44% resulted 62% of conversion. Reaction time of 6 hours resulted 62 % of conversion. Increasing the reaction time and temperature increase the conversion of EFB. Liquid products of organic water soluble has cleared yellow color, after several hours the color become darkness that is further reaction still occurs in that solution. Solid products is biochar as brown coal, that can be easily separated and processed into powder, pellet or briquette form with outstanding storage and transport characteristics. For further economic development, biochar with excellent transport characteristics, the possibility of exporting this commodity to the worlds energy market is possible. Key words: EFB, hydrothermal, carbonization, conversion, biocha
Evaluation of Uncertainty in the Determination of Pesticide Residues in Tea using GC-ECD
No full textKey indicator of quality in test results is the uncertainty value, which could be evaluated using several common approach. Uncertainty evaluation in a-endosulfan and bifenthrin in Oolong tea, and cypermethrin in green tea using bottom-up approach showed that uncertainty component arising from GC-ECD instrument calibration, method performance i.e. repeatability and recovery were the main contributors to total uncertainty. Uncertainty component arising from weighing, dilution factor, stock standard solution, calibration solution, and moisture correction had no significant effect to total uncertainty, hence they could be neglected. Relative standard uncertainty obtained for all of pesticides residue were 18.23, 10.44, dan 14.98% for a-endosulfan, bifenthrin, and cypermethrin, respectively. Comparison with 2/3 CV Horwitz of 17.33, 10.62, and 12.44% respectively for all pesticide residues indicated that the evaluation of uncertainties were realisti
PENGARUH ELEKTROLISIS TERHADAP RENDEMEN MINYAK JARAK YANG DIHASILKAN PADA PROSES PEMBUATAN BIODIESEL
No full textThe use of jatropha oil as a source of raw material for making biodiesel is needed in order to decrease the production cost of biodiesel, since jatropha oil is categorized as non edible fat. In this research, the biodiesel production process by using an electrochemical reactor has been done. At the beginning of treatment, carried out the hydrolysis of oil by using HrS04 with acid and oil volume ratio is 1: 20. At follow-up treatment, carried out the decarboxylation via electrolysis. This process is done by varying the voltage of 0 V, 10 V,20 V,30 V,the variation of the concentration of 0.5 M acetic acid. 1 M, 1.5 M, as well as the distance between the electrodes in the reactor 5em and 10 em. From the experiments shown that electrolysis with voltage parameters, acidic electrolyte solution. and electrode spacing affects the yield of decarboxylation process. Electrolysiswith 1.5 M acetic acid concentration and voltage of 30 volts per cent obtained the highest biodiesel yield of compound that is 70.432% in the reactor with inter-electrode distance of 5cm. While in the reactor with inter-electrode distance of 10 cm. thehighest yield was 53.372% by reacting the oil with 1.5 M acetic acid and voltage 30 Volt.Keywords : voltage, decarboxylation, electrolysis, acidconcentration, electrode distance, biodiesel
Isolasi Senyawa Antioksidan Dalam Ekstrak Heksana Kulit Batang Manggis Hutan (Garcinia Bancana Miq.)
No full textAntioksidan adalah suatu senyawa yang dapat menangkap radikal bebas. Salah satu sumber anti oksidan alami adalah dari tumbuh-tumbuhan. Dalam USAha pencarian antioksidan baru, telah dilakukan identifikasi senyawa antioksidan dari ekstrak n-heksana kulit batang Garcinia bancana Miq dengan metode 1,1-difenil-2-pikrilhidrazil (DPPH). Metode isolasi dilakukan dengan cara kombinasi kromatografi (Kromatografi kolom vacum, kromatografi kolom gravitasi, kromatografi lapis tipis sentrifugal dan kromatografi lempeng tipis) Penentuan struktur molekul berdasarkan analisis data spektroskopi UV-VIS, IR, LC-MS, NMR proton dan karbon. Dari hasil isolasi didapatkan suatu senyawa isoprenil bezofenon dengan bobot molekul 466,22 dan  rumus molekul C28H34O6 dengan nama IUPAC 3-(3,4-dihidroksibenzoil)-4-hidroksi-8-8-dimetil-1,7-bis(3-metilbut-2enil) bisiklo (3.3.1) non-3-ene-2,9-dione atau disebut bacanone yang diduga senyawa baru. Dari proses isolasi juga ditemukan senyawa atsiri b- caryophyllene, α-humulene dan b-cadinene serta stigmasterol. Hasil uji aktivitas antioksidan ekstrak n-heksana dan hasil isolat murni menunjukkan IC50 berturut-turut 17,78 ppm dan 12,79 ppm dimana pembanding kuersetin adalah 9,90 ppm.Kata kunci: Garcinia bancana, antioksidan, DPPH, 3-(3,4-dihidroksibenzoil)-4-hidroksi-8-8-dimetil-1,7-bis(3-metilbut-2enil)bisiklo(3.3.1)no-3-ene-2,9-dione, bacanone. Antioxidants are compounds that can capture free radicals. One source of natural antioxidant is from plants. On searching for new antioxidant, identification of antioxidant compound of the n-hexane extract of the stem bark of Garciniabancana Miq was done by 1.1-diphenyl-2-pikrilhidrazil (DPPH) method. Isolation active compound were done by combination of chromatographic methods (Flash column chromatography, gravitation column chromatography, cetrifugal thin layer chromatography and thin layer chromatography) .Determination of molecular structure by analysis spectroscopic data of UV-VIS, IR, LC-MS, NMR proton and carbon.Isolation results were     isophrenyl bezophenon with molecular weight 466.22 and the molecular formula is C28H34O6 IUPAC name 3 - (3,4-dihydroxybenzoil)-4-hydroxy-8-8-dimethyl-1,7-bis (3-methylbut-2enyl) bicyclo (3.3.1) non-3-ene-2,9-dione or named bacanone wich is suspected as a new compound. From the isolation were also found of known volatile compounds b - caryophyllene, α-humulene and b-cadinene and stigmasterol. The test results of antioxidant activity of n-hexane extract and pure compound showed IC50 respectively 17.78 ppm and 12.79 ppm which comparison with quercetin is 9.90 ppm
Pemekatan Protein Dalam Susu Dan Kecap Menggunakan Membran Serat Berongga
No full textConcentration of protein which found in freshmilk, sweet ketchup and salt ketchup have been done byusing hollow fiber polysulfone membrane with differentmolecular weight cut - off (MWCO). Membranes usedin these experiments have MWCO 66,000, 87,000 and 149,000 Dalton. Experimental were conducted bycontinues flow system and parameters observed in these experimental were protein, sugar and salt, respectively.Protein infresh milk rejected by membrane above 98 %,but all of sugar pass through to the permeate side. Forsweet ketchup feed sample, rejection coefficient towardsprotein was smaller than feed fresh milk. The higherrejection coefficientfor sweet ketchup was 48 % for themembrane with MWCO 66.000 Dalton. Rejectioncoefficient of membrane towards protein for salt ketchup sample was smaller than sweet ketchup sample. For saltketchup, the higher rejection coefficient towards proteinwas 27 % for the membrane with MWCO 66,000Dalton. Rejection coefficient of membrane towardsNaCl for feeding solution sweet ketchup and saltketchup were in the rlJ.1Jgefrom 8.74 to 23.96 %
FERMENTABILITAS EKSTRAK CINCAU HIJAU (Premna oblongifolia Merr) OLEH TIGA JENIS BAKTERI ASAM LAKTAT
No full textPenelitian ini bertujuan untuk menentukan konsentrasi ekstrak cincau yang tepat dan jenis bakteri asam laktat yangdapat tumbuh pada ekstrak cincau tersebut sehingga diperoleh minuman sinbiotik ekstrak cincau dengan karakteristik terbaik.Penelitian dilakukan terhadap 9 perlakuan yang berbeda dimana perlakuan disusun secara faktorial (3 x 3) dalam rancanganacak kelompok lengkap (RAKL) dengan 3 ulangan. Faktor pertama adalah konsentrasi ekstrak cincau hijau yang terdiri daritiga taraf, yaitu 0%, 0.5%, dan 1%. Faktor kedua adalah jenis bakteri asam laktat, yaitu Lactobacilus casei, Lactobacillusacidophilus dan Lactobacillus plantarum. Data dianalisis sidik ragam untuk mengetahui ada tidaknya perbedaan antarperlakuan dan dianalisis lanjut dengan uji Beda Nyata Terkecil (BNT) pada taraf nyata 5%. Hasil penelitian menunjukkanminuman sinbiotik ekstrak cincau terbaik adalah minuman yang difermentasi oleh Lactobacillus casei pada konsentrasiekstrak cincau 0,5% yang menghasilkan nilai log total BAL sebesar 9,07 atau setara 2,3 x 109koloni/ml, nilai total asamsebesar 0,96% dan nilai pH sebesar 3,58. Namun demikian pada semua konsentrasi ekstrak cincau yang ditambahkan dandifermentasi oleh Lactobacillus casei, Lactobacillus acidophillus maupun Lactobacillus plantarum tidak menunjukkanadanya aktivitas antibakteri terhadap Bacillus cereus dan Eschericia coli yang diuji dengan metode difusi agar.Kata Kunci: Ekstrak cincau, bakteri asam laktat, minuman sinbioti
PENGARUH PENINGKATAN LIPOFILISITAS PADA SENYAWA ANALOG UK-3A DALAM MENGHAMBAT PERTUMBUHAN SEL KANKER P-388
No full textAntibiotic UK-3A contains a 9-membered dilactone ring. It had been isolated as a minor component from the mycelium of 5trepyomyces sp. 51701.The antibiotic was hypothesized to be potential to inhibit the growth of leukemia cancer cell line of P388 and KB with ICso 38 and 20 Dg/mL, respectively. To understand the effect of lipophilicity increase of the analogues on their anticancer activities based on QSAR parameter (Log P) and binding energy to BcL-xL protein. To produce analogues of UK-3A, 3hydroxypicolinyl serine methyl ester (A) was synthesized from 3-hydroxypicolinic acid and L-serine methyl ester. The product was then esterified by pentanoic (1), hexanoic (2), heptanoic (3), and octanoic (4). The final products were confirmed with IHand 13C FT-NMR and FTIR spectra, and also MS spectra. Then they were tested against P388 Murine Leukemia cells. The result of bioassay showed lipophilicity increase of3hydroxypicolinyl serine methyl octhyl ester (PSMOE) correlated positively with their anticancer activity increase, withICso 15.4mg/mL against P388 cell lines.Keywords: Anticancer, Streptomyces sp 517-02, UK-3A, Analog UK-3A and P38
Uji Potensi Aktivitas Anti Kanker Ekstrak Daun Pandan Wangi (Pandanus Amaryllifolius Roxb.) Dengan Metode Brine Shrimp Lethality Test (Bslt)
No full textHas been done research to know anticancerpotencial activity from fragrant screw pine leaf extractapplies method Brine Shrimp Lethality Test ( BSLT).Extract is made by the way of macerate to apply threekinds of solvent, that is butanol, ethyl acetate, and etherpetroleum. Toxicity test is done by using prawn larvaArtemia salina Leach which age 48 hours. Toxic effecteach extract is identified with presentase death of prawnlarva applies probit analysis (LC50). Active extract thenis tested its the phytochemistry content and compoundbioa1(fi! suggested applies GC-MS. Result of his (itsshowing ethyl acetate extract to have the character oftoxic ( LC50 : 288,4 ppm). The toxic compounds whichpredietion.implied in ethyl acetate extract is terpenoidsand steroid
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