Results in Journal Jurnal Kimia Sains dan Aplikasi: 490
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Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 290-294; doi:10.14710/jksa.23.8.290-294
Moringa ( Moringa oleifera Lam) is a medicinal plant that is a source of nutrients. It is rich in protein, fatty acids, minerals, relatively high polyphenol compounds, and has antioxidant activity. This study aims to obtain information about secondary metabolites, total phenol content, total flavonoids, and antioxidant activity of the ethanol extract of Moringa leaves. Total phenol was determined by the Folin–Ciocâlteu method, while total flavonoids were determined by the AlCl 3 colorimetric method. Whilst the antioxidant activity was determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method at a wavelength of 517 nm. The results showed that the ethanol extract of Moringa leaves contained flavonoids, phenols, tannins, saponins, alkaloids, and steroids. The total phenol content in the ethanol leaf extract was 63.16 mg GAE/g extract, and the total flavonoid content was 10.477 mg QE/g extract. Moringa leaf ethanol extract has antioxidant activity with an IC 50 of 118.6145 mg/L, classified as having moderate antioxidant activity. Moringa ( Moringa oleifera Lam) is a medicinal plant that is a source of nutrients. It is rich in protein, fatty acids, minerals, relatively high polyphenol compounds, and has antioxidant activity. This study aims to obtain information about secondary metabolites, total phenol content, total flavonoids, and antioxidant activity of the ethanol extract of Moringa leaves. Total phenol was determined by the Folin–Ciocâlteu method, while total flavonoids were determined by the AlCl 3 colorimetric method. Whilst the antioxidant activity was determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method at a wavelength of 517 nm. The results showed that the ethanol extract of Moringa leaves contained flavonoids, phenols, tannins, saponins, alkaloids, and steroids. The total phenol content in the ethanol leaf extract was 63.16 mg GAE/g extract, and the total flavonoid content was 10.477 mg QE/g extract. Moringa leaf ethanol extract has antioxidant activity with an IC 50 of 118.6145 mg/L, classified as having moderate antioxidant activity.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 267-275; doi:10.14710/jksa.23.8.267-275
Honey has natural bacteriostatic and bactericide activities; thus, it could be active compounds as an antibacterial against Propionibacterium acnes, the main bacteria in acne forming state. Our study aims to determine phenolic and flavonoid contents (qualitative and quantitative), antioxidants, along with antibacterial activity against P. acnes of selected Indonesian honey. Honey used in this study, including honeybees and stingless bees, were collected from Sumbawa, Riau, Belitung, Sukabumi, Banyuwangi, Bogor, and South Sulawesi. In the method, the quantitative content of phenols and flavonoid were measured using a spectrophotometer. Further, DPPH (2, 2’-diphenylpicryl hydrazyl) and ABTS (2’-azino-bis (3- ethylbenzothiazoline-6-sulfonic acid) assays were used to measure the antioxidant activities, and subsequently microdilution method was applied to determine antibacterial activity. The results showed that Indonesian honey contains phenolics and flavonoids in the range of 49.5-67.3 μg Gallic Acid Equivalent (GAE)/g and 766.5-1509.5 μg Quercetin Equivalent (QE)/g, respectively. All honey samples also show antioxidant and antibacterial activities. Of note, Apis cerana honey from Banyuwangi has the highest antioxidant and antibacterial activity compared to others. It has the Inhibition Concentration (IC50), Trolox Equivalent Antioxidant Capacity, Minimum Inhibitory Concentration (MIC) and Minimum Bactericide Concentration (MBC) values of 59.85 mg/L, 122 μg Trolox/g, 125 mg/mL, and 500 mg/mL respectively. Our study reveals that Indonesian honey can inhibit and kill P. acnes as well. Nonetheless, the phenolic content of honey is not always linear with antioxidant and antibacterial activities.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 283-289; doi:10.14710/jksa.23.8.283-289
High concentrations of creatinine and urea in the blood can be removed by dialysis using semipermeable membranes that are selective for certain species and hold other species through diffusion processes. This ability requires a membrane that has an active side, which functions as a targeted species identifier. The membrane must be biocompatible because the membrane will be in direct contact with the body’s biological systems. The membrane material that is made must be acceptable to the blood system so that there is no rejection from the body and have a large contact area to obtain an effective diffusion process. For this reason, a hollow fiber membrane (HFM) is needed. One of the synthetic polymers used as the base material for HFM is PSf. PSf has mechanical strength, heat resistance, and is easily formed into HFM. However, PSf has disadvantages such as lack of active side and less compatible with blood due to its hydrophobic properties. Modification using PEG and chitosan will reduce the hydrophobicity of the PSf. Membrane results were analyzed the physical, chemical, and transportability for urea and creatinine. The results of functional group characterization by FTIR show that the modification reaction was successfully carried out on polysulfone to produce PEG-PSf/CS. The modification succeeded in making the PSf membrane more hydrophilic, as evidenced by a decrease in the contact angle from 69.4° (PSf) to 53° (PEG-PSf/CS). Water uptake capability increases to 609%, and membrane porosity increases porosity increased from 72 to 83%. The water flux is also increased. Creatinine clearance ability increases from 0.09 mg/dl to 0.25 mg/dL. Urea clearance ability increases from 2.3 mg/dL to 3.07 mg/dL. The SEM image showed that the modification makes the membranes more porous.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 295-304; doi:10.14710/jksa.23.8.295-304
Polylactic acid (PLA) is a biopolymer that can replace thermoplastic polymers such as polypropylene (PP) in various applications due to strength, young modulus, biocompatibility, biodegradability, good clarity, oil resistance, and oxygen barrier ability. However, PLA has some drawbacks, including brittle, high glass transition temperature (Tg), and low degradation and crystallization rates. Therefore, modification is needed with the addition of nucleating agents and plasticizers to overcome these limitations of PLA. This research aims to study the effect of plasticizers and microfibril cellulose of oil palm frond (OPF) on thermal stability and to review the crystallization kinetics of PLA biocomposites. Polyethylene glycol and triacetin were used as plasticizers. Thermal analysis was performed using Thermal Gravimetry analysis (TGA) and Differential Scanning Calorimetry (DSC). The crystallization kinetics study was analyzed using a modified Avrami model under non-isothermal conditions. PLAP4000 has better thermal stability than PLAP200 and PLAG with Tonset and Tmax values reaching 349.17°C and 374.68°C, respectively, which are close to pure PLA. All types of plasticizers influenced decreasing the Tg value in the range of 27–42%, whereas OPF microfiber addition contributes to a Tg reduction of 37-55 %. Crystallization kinetic study was informed for heterogeneous and simultaneous nucleation mechanisms with an n value range of about 2-3 for PLAP4000 and PLAOP4000. The crystallization rate was multiplied 4-9-fold for PLAOP200 and 2-3-fold for PLAOP4000.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 276-282; doi:10.14710/jksa.23.8.276-282
Functional drinks based on red betel leaf extract have antioxidant activity, but they still have a bitter taste. This study aims to determine the effect of microencapsulation on phenol content, antioxidant activity, and sensory quality of functional drinks based on betel leaf extract. Microencapsulation of functional drinks was made using maltodextrin coatings with concentrations of 10% and 20%. Antioxidant activity was tested by the CUPRAC method. The ready to drink (RTD) functional drink has a total phenolic content and antioxidant activity of 782.30 ± 2.54 mg GAE/g and 1660.19 ± 31.67 µmol Tr/g, respectively. These values are higher than microencapsulated functional drinks with maltodextrin (MM). The microencapsulated functional drink with 10% maltodextrin coating (MM10) is the chosen formulation since it has the smallest particle size (1.283 µm), total phenolic content of 12.90 ± 0.01 mg GAE/g and antioxidant activity of 189.41 ± 1.88 µmol Tr/g. Microencapsulated functional drinks provide sensory quality that is not significantly different (p
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 261-266; doi:10.14710/jksa.23.7.261-266
Two potential compounds as an n-Type organic thin-film transistor (OTFT) from benzodithiophene (BDT) derivatives have been synthesized and characterized. BDT was chosen as the core because it has π-conjugated bonds, rigid structures, and planar. Quinoid structure with end-cap (terminal group) in the form of dicyanomethylene is used because it can lower the LUMO value of the compound, and side chains are selected in the form of alkoxy so that two BDT derivatives are obtained namely BDTQ-6 (hexyloxy) and BDTQ-10 (decyloxy). Based on the results of TGA, BDTQ-6 and BDTQ-10 have decomposition points of 183°C and 203°C, which indicate the compound has excellent thermal stability. From the UV-Vis measurement, the λmax value of the two compounds is 599 nm with optical gap energy (Eg°pt) of 1.7 eV. From the DPV measurement, the LUMO value for the two compounds is -4.3 eV, with an energy gap (Eg) of 1.69 eV (BDTQ-6) and 1.70 eV (BDTQ-10). Based on observations of the crystal structure through x-ray diffraction, it was found that the BDTQ-10 crystal has a "brick type" layer arrangement with a distance between layers of 3.55 Å. With excellent thermal stability and suitable LUMO values and energy gaps, it is expected that BDTQ-6 and BDTQ-10 compounds have the potential to be n-Type OTFT materials.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 255-260; doi:10.14710/jksa.23.7.255-260
The Centrifugal liquid Membrane (CLM) method, which provides an ultra-thin two-phase liquid membrane system in a rotating glass cell, was successfully applied to Green Synthesis from Polyscias scutellaria (PS) capped gold nanoparticles (AuNPs-PS) using a Mangkokan leaf (Polyscias scutellaria) extract as a reducing agent and stabilizer in the hexane-water system. PS extract in hexane fraction as the organic phase has a UV absorption spectrum at the maximum wavelength, λmax of 220 nm, while the precursor of HAuCl4 solution as an aqueous phase has an λmax of 214 nm. Investigation of AuNPs-PS formation was carried out at various concentrations of Mangkokan leaf extract concentration; i.e., 0.001 0.003; 0.005; 0.007 and 0.009%, while the reaction was carried out at various rotational speeds of 5,000-9,000 rpm. The formation and stability of AuNPs-PS were observed from the phenomenon of surface plasmon resonance (SPR) and absorbance changes as measured by a UV-Vis spectrophotometer. The results of measurements using CLM-Spectrophotometry shows the formation of AuNPs-PS in the hexane-water system at λmax of 534 nm.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 244-248; doi:10.14710/jksa.23.7.244-248
The rapid development of the batik industry can pollute water resources and become an increasingly severe problem. This research studies the adsorption-desorption of naphthol blue-black (one of the dyes in batik liquid waste) by magnetite modified humic acid (HA-Fe 3 O 4 ). The adsorption isotherm was studied using the Langmuir and Freundlich isotherm models. Meanwhile, desorption agents used in this study were distilled water and hydrochloric acid. The results show that the adsorption isotherm followed the Langmuir adsorption model with a maximum adsorption capacity of 2.41 mmol/g. Desorption studies show that the desorption efficiency of naphthol blue-black on HA-Fe 3 O 4 is 0.058% and 5.86% in the desorption agent of distilled water and HCl (1 M)
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 238-243; doi:10.14710/jksa.23.7.238-243
Indonesia has a diversity of hot spring as a habitat of bacteria. One of the hot springs is Natar hot spring, Lampung. This study is to report the characteristics of a bacterium called Nat1 isolate that produces amylase to degrade raw starch from Natar hot spring. Water samples were taken from hot springs with a temperature of 45°C and a pH of 7.0. Nat1 was isolated by screening on the medium of Starch-Luria Bertani at 37°C. Its amylase-producing bacteria showed an optimum amylolytic activity of a crude enzyme of Nat1 isolate in soluble starch was 267.2774 U/mL at 60°C. Genotypic identification results using the 16S rRNA gene showed that the Nat1 isolate is identified as Panninobacter phragmatetus. A crude enzyme of Nat1 isolate showed a novel amylase ability and could degrade the raw starch substrates, such as corn and sago, with the amount of reducing sugar for each raw starch, 37.0688 µmol/mg, and 24.2697 µmol/mg. In conclusion, Nat1 amylase is potentially used in industry for its ability to degrade raw starch directly.
Jurnal Kimia Sains dan Aplikasi, Volume 23, pp 234-237; doi:10.14710/jksa.23.7.234-237
Ethyl acetate fraction from Swietenia macrophylla was reported to have toxicity against the larvae of Artemia salina shrimp larvae. However, there areno reports aboutS. macrophylla, which can inhibit human breast cancer cells MCF-7. Therefore, this study aims to evaluate S. macrophyllaextract's cytotoxicity using human breast cancer MCF-7 cells assay, followed by confirmation of its toxicity using brine shrimp lethality assay. The most active fraction obtained from the ethyl acetate extract of S. macrophylla showed 76.49% inhibition at 50 µg/mL (IC50=34.11 µg/mL). At the same time, the most active fraction may contain a mixture of limonoid compounds after LCMS analysis. The most active fraction obtained from ethyl acetate extract of S. macrophylla showed 76.49%