Tuesday, June 4, 2019
Optimization of Solvent Extractions
Optimization of Solvent ExtractionsCHAPTER 3METHODOLOGY3.1IntroductionIn this study, the leaves of A. Malanccensis, formulated gaharu teatime bags from Gaharu tea Valley, Gopeng and Kebun Rimau, Tawau were extracted by using solvent ancestry method. The optimization of solvent extractions were determined in this study as well. Chemical physical composition of the lowbred extracts were analyzed by using GC-MS and HPLC. Besides, the obtained c uncouth extracts were evaluated for their antioxidant property.3.2Chemicals and utensilThrough emerge this study, several of chemical and apparatus were used as listed in hold over 3.1 and table 3.2.Table 3.1 Chemical and reagent usedChemical and reagentsBrandManufacturer1,1-diphenyl-2-pycrylhydrazyl (DPPH)Sigma regular army2,4,6-tripyridyl-striazineSigmaUSASodium acetateAcetic erosiveMBGermanyAluminum chloride hexahydrateAscorbic acidSystermMalaysiaEthanolSystermMalaysiaFolin-Ciocalteus reagentSigmaUSAGallic acidHydrochloric acidIron (II ) sulphateSigmaUSAIron (III) ChlorideSystermMalaysiaMethanolMerckGermanyPotassium bromideQuercetinSodium changeSodium carbonate anhydrousSodium hydroxideMerckGermanySodium nitrateHelium gasNovalandMalaysiaNitrogen gasNovalandMalaysiaTable 3.2 Apparatus usedApparatusBrandManufacturerAluminium foilDiamond brandMalaysiaAnalytical balanceMettler-ToledoSwiterlandBeaker c mLSchoot DuranGermanyBeaker 250 mLSchoot DuranGermanyBeaker euchre mLIwakiJapan cone-shaped flask 250 mLIsolabGermanyFilter funnelFrontier Transform Infra-red mass spectrometerPerkin ElmerGermany attack Chromatography-Mass spectrometerPerkin-ElmerGermanyMeasuring cylinderIwakiJapanMicropipetteEppendrofEnglandOvenMemmetUSAParafilm MPechineyUSARotatory evaporatorBuchi LabortechincSwitzerlandRound bottle flask 250 mLFavoritMalaysiaTest tube 15 mLUV-Vis spectrometerPerkin ElmerGermanyVolumetric flaskExeloMalaysiaWater bathCifton NE 5-289EnglandWhatman No. 1 Filter paperBuchi ReiiiSwitzerlandGrinderKikaGermany3.3 Extracti on of the Gaharu Leaves and Formulated Gaharu Tea3.3.1 Raw MaterialThe samples of gaharu leaves and formulated gaharu tea bag were used in this research were obtained from the Kebun Rimau Sdn Bhd, Tawau and Gaharu Tea Valley, Gopeng. Gaharu leaves were dried in the shade for 7 days at roomtemperature (28 2C). After ironicaling, leaves were cut into small pieces. The pieces of dried gaharu leaves and the formulated gaharu tea bag are used for the aqueous extraction and ethanolic extraction.3.3.2Aqueous Extraction of Gaharu Leaves and Formulated Gaharu Tea50g of dried leaves grind and contents of formulated gaharu tea bag were weighed and regularise into ergocalciferolmL beaker, respectively. 250 mL of distilled piss was added into both beaker and boil for 30 minutes. Beakers were wrapped with aluminium foil (Diamond brand) to prevent spilling of mixture and put down exposure.The pooled extracts were filtered by using Whatman No. 1 filterpaper (Buchi Reiii) with 0.45m membrane. The remains were re-extracted under same condition and filtered. The obtained uncut extracts were concentrated at 50C using a rotary evaporator under number one pressure. The concentrated crude extracts from gaharu leaves and formulated gaharu tea bag were collected in air-tight containers and covered by the aluminum foil to prevent the active components in the extracts from decomposing by light. They were stored in refrigerator at 4 C to prevent fungal attacking. every last(predicate) the extractions were carried out in replicates.3.3.3 Ethanolic Extraction of the Gaharu Leaves and FormulatedGaharu Tea10g of dried leaves powder and 6g of the formulated gaharu tea bag were weighed and put into 100 mL beaker, respectively. 50mL ethanol was poured into both beaker. Beakers were sealed with parafilm (Pechiney) and wrapped with aluminum foil (Diamond brand) to prevent spilling of mixture and light exposure, respectively. The pooled extracts were filtered by using Whatman No. 1 filte r paper (Whatman International, England). The remains were re-extracted under same condition and filtered. The obtained crude extracts were concentrated at 40C using a rotary evaporator under low pressure. The concentrated crude extracts from gaharu leaves and formulated gaharu tea bag were collected in air-tight containers and covered by the aluminum foil to prevent the light decomposition of bioactive components in the crude extracts. They were stored in refrigerator at 4 C to avoid fungal attacking. All the extractions were carried out in replicates.3.4 Optimization of the Gaharu Leaves and Formulated Gaharu Tea Extraction3.4.1Ethanol ConcentrationWith the constants 180 minutes and temperature 25OC, samples were extracted with six different concentrations of ethanol starting from 0% to 100% (v/v). The extraction procedures were described in section 3.2.3. The best ethanol concentration which related to the values of bestow phenolic contain (TPC) (mg gallic acid equivalent, GAE /g dry weight, DW) and total flavonoid contain (TFC) (mg quercetin equivalent, QE/g DW) were selected.3.4.2Extraction timeThe samples were extracted with the optimal ethanol concentration which was determined in the section 3.3.1 for 60, 120, 180, 240, 300 minutes by restore the extraction temperature constant at 25oC. The best extraction time which related to the values of total phenolic contain (TPC) (mg gallic acid equivalent, GAE/g dry weight, DW) and total flavonoid contain (TFC) (mg quercetin equivalent, QE/g DW) eres selected.3.4.3TemperatureThe samples were extracted at different temperatures, which were 25, 35, 45, 55, and 65oC with the optimal temperature and extraction time as determined in section 3.3.1 and section 3.3.2. The best extraction temperature which related to the values of total phenolic contain (TPC) (mg gallic acid equivalent, GAE/g dry weight, DW) and total flavonoid contain (TFC) (mg quercetin equivalent, QE/g DW) weres selected.3.5Chemical Characterizati on of Gaharu Leaves and Formulated Gaharu Tea3.5.1Characterization using FT-IR18.104.22.168 Sample PreparationThe method of FT-IR analysis by Khalil et al. (2013) was used with minor qualifyings (Khalil et al., 2013). The formation of transparent pellet (Thin disc) was done by mixing 2mg of crude extract powder with 40mg of potassium bromide (120), a mold was used to compress the mixture under a pressure of 7 tons. The analysis was carried out with the wavelength starting from 4000 to 400 cm-1. About 3 minutes were taken by the spectrum recording. FT-IR software Spectrum version 6.35 (Perkin Elmer) was used to perform the acquisition of the spectra and peak assignment.3.5.2Characterization Using Gas Liquid Chromatography- Mass Spectroscopy (GC-MS)22.214.171.124 Sample PreparationThe method of GC-MS analysis by Khalil et al. (2013) and Soetardjo et al., (2007) were used with the passing of experimental conditions. The crude extract powder was fade out in 60% (v/v) methanol result and filter ed by using membrane filter with 0.45 m pore size. The 0.5 L of samples were injected into a gas chromatograph equipped with Perkin Elmer Clarus 500 mass spectrometer and Elite-5MS column 30m (length) x 0.25 mm (diameter), film thickness 0.25 m. The column temperature was programmed to 50oC for 6 min, with 5oC increase per min to 250oC. The temperature of detector and injector were both maintained at 250 oC. Hellium was used as the carrier gas with a linear velocity of 1 ml/min and the splitting ratio was 101. The mass spectrometer was operated in the electron impact ionization (EI) mode at 70 eV. The constituents of gaharu crude extract powder were identified by comparing their mass spectra with those of NIST02 library data of the GC-MS system. The condition of GC-MS are summarized in Table 3.4.Table 3.4 Condition used for GC-MS analysis.ParametersConditionsGas chromatographyPerkin Elmer Clarus 500 gas chromatographyMass selective detectorPerkin Elmer Clarus 500 mass spectrometerC apillary columnsElite-5MS (30 m (length) x 0.25 mm (diameter) film thickness 0.25 m)Injection people0.5 LCarrier gasHeliuminitial oven temperature50 oCFinal oven temperature260-300 oCInlet temperature250 oCInjectionSplitInjector pressure8.00-9.43 psiInjector temperature80 oCFlow rate1 mL min -1Electron capability70 eVSource temperature180 oCSolvent delay2 minutesData libraryNIST 023.5.2.2 Kovats Retention IndexKovats retention powerfulness is an thinker used in the gas chromatography to convert retention times into system-independent constant. The collected data of GC-MS were processed by using the Kovats retention index (Equation 3.1). The calculated Kovats index was compared with the retention time of n-alkane which were given by the GC-MS manufacture company (Perkin Elmer) based on the same type of column with higher ramp temperature (10oC instead of 5 oC, Appendix A). (Equation 3.1)Where,I = Kovats retention index,n = the number of carbon atoms in the smaller n-alkane,N = t he number of carbon atoms in the larger n-alkane,tr = the retention time.3.6Determination of measure Phenolic Compounds and keep down Flavonoid Compounds in Crude Extracts3.6.1Evaluation of Total Phenolic Compounds in Gaharu Leaves and Formulated Tea Crude ExtractsTotal phenolic content (TPC) of concentrated rude extract of three samples with the different extraction condition were determined by using the Folin-Ciocalten (F-C) assay according to the method described by Tay et al. with a modification (Tay et al., 2014). Concentrated crude extractwas diluted 30 times before use. 15 mL campaign tube was wrapped with aluminum foil and 1 mL of diluted sample was placed into it. Then, 5 mL of Folin-Ciocalten reagent was added into the test tube. After 5 minutes, 4 mL of 7.5% (w/v) sodium carbonate was added. The test tube was jolted to mix the diluted sample and reagents for 5 seconds. Thus, the test tube was allowed to stand in the dark room at room temperature for 30 minutes. The bl ank solution was prepared by replacing 1 mL of samples with 1 mL of deionized water. Absorbance was measured against the blank at 765 nm by using UV-Vis spectrometer (Perkin Elmer).Besides, 1 mM gallic acid stock solution was prepared. 17.012 mg of gallic acid was weighed ad transferred into 100 mL conelike flask. Thus, deionized water was added in until the volume of 100 mL was achieved. The 1 mM gallic acid stock solution was further diluted into 0.1, 0.2, 0.4, 0.6, 0.8 mM gallic acid standard solutions. Total phenolic content was determined and calculated based on gallic acid calibration curve and verbalized as gallic acid equivalents (GAEs) in milligram per g dry weight (mg GAE/ g DW). The TPC test was repeated with the concentrated crude extract with different solvent extraction conditions.3.6.2Evaluation of Total Flavonoid Compounds in Gaharu Leaves and Formulated Tea Crude ExtractsThe total flavonoid content (TFC) of the concentrated crude extract of three samples with dif ferent extraction conditions were determined according to the procedures described by Thoo et al. with slight modifications (Thoo et al., 2010). Concentrated crude extract was diluted for 15 times. Thus, 1 mL of diluted crude extract was mixed with 5 mL of deionized water and 0.3 mL 5% sodium nitrite in a 15 mL aluminum foil-wrapped test tube. After 12 minutes, 0.6 mL 10% aluminum chloride hexahydrate was added into the test tube. In the next 10 minutes, 2 mL of 1M sodium hydroxide solution and 1.1 mL were added to the mixture. Thus, test tube was shaken to mix the diluted sample with the reagents for 10 seconds. A blank was prepared by replacing diluted crude extract with 1 mL of deionized water. The absorbance was measured immediately at 510 nm by using UV-Vis light spectrometer (Perkin Elmer). Besides, the 1 mM quercetin stock solution was prepared as well. 30.22 mg of quercetin was accurately weighed and transferred into 100 mL conical flask. Thus, the deionized water was added into the conical flask until the volume of 100 mL was reached. The 1 mM quercetin stock solution was further diluted to 0.1, 0.2, 0.4, 0.6, 0.8 mM quercetin standard solutions. The total flavonoid content of diluted crude extract was determined and calculated based on quercetin calibration curve and expressed as quecertin equivalents (QEs) in milligram per g dry weight (mg QE/ g DW).). The TFC test was repeated with the concentrated crude extract with different solvent extraction conditions.3.7Determination of Antioxidant Activity3.7.12,2-diphenyl-1-picrylhydrazyl (DPPH) Free RadicalScavenging substantiationThe antioxidant capacity of crude extracts were measured by the DPPH assay based on the method which were carried out by Asadujjamanet al. and Tay et al. with slight modification (Asadujjamanet al., 2013 Tay et al., 2014). The 0.1 mL concentrated crude extract was added with 3.9 mL 0.004% ethanolic DPPH solution in an aluminium-wrapped test tube. A parafilm was immediately used to cover the opening of test tube. Thus, the test tube was allowed to stand in dark room at room temperature for 30 minutes. The absorbance of DPPH solution was determined against a deionized water blank a 517 nm by using the UV-Vis spectrometer (Perkin Elmer Lambda 25). 0.1 mL of the crude extract was replaced by extract solvent in the preparing of negative control. Absorbance measurements of the crude extracts and negative control was carried out in triplicate. The result was expressed as a percentage of DPPH radical scavenging activity.The following formula (Equation 3.2) was used to calculate the DPPH radical scavenging activity of crude extract.1 100%= DPPH radical scavenging activityEquation 3.2Where,As= absorbance of crude extractAc = Absorbance of control3.7.2Ferric Reducing Antioxidant Power (FRAP) AssayThe FRAP assay was carried out according to procedures described by Kamonwannasitet al. with slight modification (Kamonwannasitet al., 2013).The FRAP reagent was made of 0 .01 M TPTZ (2,4,6-tripyridyl-striazine) in 0.04 M HCl, 0.02 M FeCl3, and 0.03M acetate buffer (pH 3.6) in a ratio of 1110(v/v/v). 0.03M acetate buffer (pH3.6) was prepared by mixing 46.3 mL of 0.2M acetic acid and 3.7 mL 0.2 M sodium acetate 0.5 mL together. Thus, the deionized water was added into mixture to chafe up the volume to 100mL. Then, 0.5g of the sample was added to 15 ml of FRAP reagent which was prepared in situ and warmed until 37C before it was being used. The absorbance was measured at 593 nm by using an UV-Vis spectrophotometer (Perkin Elmer) after the solution was incubated for 5 minutes. Besides, 1 mM FeSO4stock solution was prepared as well. 0.278g of FeSO4 were dissolved into 1 L of deionized water. Thus, 1 mM FeSO4stock solution was diluted into 0.1, 0.2, 0.4, 0.6, 0.8 mM FeSO4 standard solution. A standard calibration curve was constructed by using different concentration of FeSO4 solution. The results were expressed as mol Fe2+/mg dry weight of plant material . All measurements were carried out in triplicate and the mean values were calculated.3.8Statistical analysisThe experimental results in this study were calculated and analyzed by using the IBM software (SPSS Statistics version 21). All values were expressed as the mean standard deviation (SD) of triplicate measurements of replicate extraction. Simple correlation was used to determine the relationship between total amount of flavonoids in the crude extracts and their antioxidant capacities.