Kinetic Study of Gas Formation in Styrofoam Pyrolysis Process

This research aims to study the reaction kinetics of gas formation in the pyrolysis of styrofoam waste. Pyrolysis of styrofoam waste without a catalyst takes place at a constant temperature of 180°C. In contrast, the pyrolysis of styrofoam waste by adding a zeolite catalyst took place at a constant temperature of 170°C. The amount of styrofoam waste used in this research sample is 200 grams, and the natural zeolite catalyst is 5 grams. Pyrolysis of styrofoam waste without using a catalyst form a gas at a constant temperature of 180°C, the kinetics of the reaction takes place on the zero-order. This result follows the Arrhenius equation K = Ae10617/RT with an activation energy value (Ea) of 1.27x103 kJ.mol-1. Pyrolysis of styrofoam waste by adding a zeolite catalyst to gas formation at a constant temperature of 170°C also takes place on the zero-order. The equation follows Arrhenius K= Ae4711,5/RT and the activation energy value (Ea) is 5.66x102 kJ.mol-1.

Molecular Study of Antiviral Compound of Indonesian Herbal Medicine as 3CLpro and PLpro Inhibitor in SARS-COV-2

Rapid transmission of COVID-19 disease and the fatal effects of the disease lead researchers to use various way to find potential anti-COVID-19 compounds, including using modern approaches. Molecular docking is one of the methods that can be used to analyse antiviral compounds and its molecular target from Indonesian herbs that are believed to have properties as anti-COVID-19. This study aims to analyse antiviral compounds from 5 herbs that have the potential as inhibitors of PLpro and 3CLpro, which both are a non-structural protein in SARS-CoV-2 by molecular docking approach using PLANTS. Remdesivir triphosphate, the active metabolite of remdesivir, was used as the comparison compound in studies. The results showed docking scores obtained from interactions between natural ligands, remdesivir trifospat, curcumin, demetoksikurkumin, bisdemetoksikurkumin, luteolin, apigenin, kuersetin, kaempferol, formononrtin-7-O-glucoronide, androgafolide, and neoandrogafolide with PLpro are as follows -111,441, -103,827, -103,609, -102,363, -100,27,-79,6655, -78.6901, -80.9337, -79.4686, -82.1124, -79.1789, and -97.2452.Combination between quercetin, neoandrographolide, bisdemethoxycurcumin, demetoxycurcumin, and curcumin showed a synergy effect by reduce its docking score. Meanwhile its interaction with the protein 3CLpro showed docking score for those compounds as follows 64.0074, -86.1811, -81.428, -87.1625, -78.2899, -73.4345,-70,3368, -71.5539, -68.4321, -72.0154, -75.9777 and -93.7746.Combination between andrographolide, neoandrographolide, bisdemethoxycurcumin, demetoxycurcumin and curcumin, also shows synegy effect in 3CLpro allow them to reduce the docking score.This study concludes that curcumin was known as the most potent compound that act as a PLpro inhibitor based on a docking score of -103,609, while in 3CLpro all the compound have a potential to inhibit 3CLpro with demethosxycurcumin and neoandrogafolide as the most potent compound with a docking score -87,126 and -93.7746.

Microemulsion Stability of Virgin Coconut Oil Based on Tradition of Melala Sumbawa's Society

The Melala is a tradition of the Sumbawa people who use coconut milk to obtain Sumbawa oil for traditional medicine. Coconut milk is a colloidal system of stable oil in water (O/W) microemulsion. Within a particular time, the emulsion will split to produce oil (VCO), protein, and water due to the colloid equilibrium on the stability of the coconut milk emulsion. The purpose of this study was to compare the microemulsion stability of the coconut milk colloid system. The VCO was isolated by heating, enzymatically, acidifying, and adding whiting methods for comparison. The physical stability of the O/W microemulsion was measured by the volume of VCO produced from various isolation methods in simple laboratory experiments. The results showed that the physical stability of the O/W microemulsion on VCO isolation by enzymatic method using papain enzyme was the least.

Physical Characteristics, Total Phenolic, and Flavonoid Content of Coccinia grandis (L.) Voigt Leaves Extract

Coccinia grandis (L.) Voigt is an herbal plant that has been widely used for the treatment of various types of diseases. The phenolic and flavonoid content of plant extracts largely determine their pharmacological activity. The aim of this study was to determine the total phenolic and flavonoid contents of the ethanol extract of C. grandis leaves. Leaf samples in this study were obtained in the area of ​​Dalung, North Kuta, Badung, Bali. The powdered C. grandis leaf was extracted by maceration method using 70% ethanol followed by evaporation using an oven at 45oC to obtain a thick extract. The non-specific parameters of the extract were then determined, such as moisture content, ash content, and acid insoluble ash. Total phenolic content was determined using the follin-ciocalteu method and total flavonoid content was determined using the aluminum chloride method. Based on the research results, the yield of C. grandis leaf extract was 19.36%. C. grandis leaf extract has a description of a thick and sticky extract, blackish brown color, distinctive aroma, and a bitter sour taste. The water content of the ethanolic extract of C. grandis leaves was 9.93±0.03% (g/g). The total ash value of the simplicia and ethanolic extract of C. grandis leaves were 20.76±0.15% (g/g) and 27.38±0.19% (g/g), respectively. The acid insoluble ash content of the extract was 4.05±0.30% (g/g). The total phenolic and total flavonoid contents of the extract were 111.92±0.49 µg GAE/mg dry extract and 73.60±3.53 µg QE/mg dry extract, respectively.

Isolation and Identification of Andrographolide Compounds from the Leaves of Sambiloto Plant (Andrographis paniculata Ness)

Sambiloto plant (Andrographis paniculata Ness) is a plant that has been used as medicine from generation to generation. Bioactive compounds in Sambiloto have pharmacological effects such as immunostimulants (increase immunity), antibiotic diuretics (facilitate urine), antipyretics, anti-inflammatory (anti-inflammatory), hepatoprotective, hypotensive, hypoglycemic, antibacterial, anti-inflammatory, respiratory tract, and heart and lung meridians - lungs. The bioactive compound in Sambiloto which is mostly found in the leaves is Andrographolide. In this study, the isolation of Andrographolide from the leaves of the sambiloto plant (Andrographis paniculata Ness) was carried out using purification and crystallization methods aimed at obtaining pure Andrographolide isolates more efficiently and identifying the results of Andrographolide isolates. The results showed that the isolates obtained using the purification and crystallization methods obtained a yield of 0.47%. In the qualitative test of Andrographolide isolates using eluent and acetate: n-hexane (3: 2), the Rf value was 0.38. The results obtained from Andrographolide isolates using infrared spectroscopy (FT-IR) were identical to the literature on Andrographolide. The absorption peaks at the wavenumbers obtained includes 3400,41 cm-1, 1979,68 cm-1, 1959,46 cm-1, 2928,22 cm-1, 1727,56 cm-1, 1646,98 cm-1, and 907,53 cm-1.

Lead Metal in Water and Sediment: A Case Study of Rumbia River

The purpose of this study was to determine and analyze the levels of leadcontained in the water and sediments of the Rumbia River. This research was conducted in a quantitative manner. Lead levels were measured using Atomic Absorption Spectrophotometer (SSA) of Simatzu AA 500. The results showed that the leadcontent in Rumbia River water for point A1 was undetectable whereas point 2 and 3 were 0.001 mg/kg. In sediments, at point A1 is 1.8 mg/kg and at points 2 and 3 were 0.9 mg/kg. The level of Pb in Rumbia River water is still below the water quality standard limit for marine biota determined by the Ministry of Environment No. 51 of 2004. Similarly, lead levels in sediments are below the threshold standard for sediment quality based on sediment quality guidelines for metals and associated levels of concern to be used in doing assessments of sediment quality. In general, it can be said that the concentration of lead in the Rumbia River is still at a harmless level. However, socio-economic conditions that continue to change over time can cause changes in the level of water pollution. So there needs to be an effort and public awareness in maintaining the occurrence of increased levels of pollutants in the Rumbia River.

The Effect of Stirring Speeds to the Entrapment Efficiency in a Nanoparticles Formulation of Java Plum’s seed Ethanol Extract (Syzygium cumini)

Java Plum’s (Syzygium cumini) seed contains flavonoids in the form of quercetin. Quercetin plays an essential role in stimulating insulin production from pancreatic beta cells. However, it could be easily degraded by gastric acid or the digestive system. Thus, in this research, a good delivery system for quercetin will be established, namely nanoparticles. The study objectives are determining the entrapment efficiency’s percentage of nanoparticle preparations from ethanol extracts of Java Plum’s seeds as well as observing the effect of stirring speed on the percentage of entrapment efficiency. Java Plum’s seed extract was obtained by maceration method using ethanol 70% with the ratio between the simplicial powder and solvent is 1 : 4 respectively. Meanwhile, the solvent evaporation process was undergone by using a water bath with temperature not exceeding 70°C. The nanoparticle formulation of Java Plum’s seed extract was made by adding polymers in the form of chitosan and sodium tripolyphosphate cross-linker with three variations of stirring speed (500, 1000, and 1500 rpm) using a magnetic stirrer. The percentage of entrapment efficiency was obtained by subtracting the flavonoids levels of Java Plum’s seeds extract and flavonoids levels of Java Plum’s seeds extract in nanoparticles. Then, the value was divided by flavonoids levels of Java Plum’s seeds extract and multiplied by 100%. Quercetin levels obtained by absorbance readings using spectrophotometry UV-Visible, then absorbance value added into variable X on equation quercetin’s standard curve y = 0,0229x + 0,0644. The results show that the percentage of entrapment efficiency at speed variations of 500, 1000, and 1500 rpm are 48.8459%, 49.1064%, and 56.0413% respectively. According to the t-test two independent samples statistical test, the data has a 0.961 probability value (500 rpm vs 1000 rpm), 0.324 probability value (1000 rpm vs 1500 rpm), 0.25 (500 rpm vs 1500 rpm). Probability value > 0.05, which means the stirring speed does not significantly influence the percentage of entrapment efficiency.

Synthesis of 5-nitrovanillin in low temperature as cyanide anion sensor

In the synthesis of the organic sensor, the molecular structure will affect the ability of a compound to be used as a colorimetric chemosensor. Here, we present a simple synthesis technique for 5-nitrovanillin. It has been successfully synthesized using nitric acid as a source of nitro groups. Dichloromethane DCM was used as a solvent, and the synthesis was carried out at low temperatures (under 5°C). The method produces a good yield. The nitro group attached to the structure of the chemosensor plays a role in prolonging the electron delocalization. Its effect is in the process of anion recognition by the chemosensor. The formation of a sensor-analyte complex between the chemosensor and anion produces a color change in the solution.

QSAR and Ab Initio studies of quinolon-4(1H)-imine derivatives as antimalarial agents

Study on antimalarial activity of 22 quinolon-4(1H)-imine derivatives by using Quantitative Structure-Activity Relationships (QSAR) has been performed. Electronic and molecular descriptors were used in Quantitative Structure-Activity Relationships (QSAR) model and it was obtained from Hartree-Fock (HF) molecular orbital calculation with 6-31G basis set. QSAR analysis has been performed by multiple linear regression (MLR) method. The best equation of QSAR model on this study is: pEC50 = -4,177 + (37,902 x qC3) + (171,282 x qC8) + (9,061 x qC10) + (125,818 x qC11) + (-149,125 x qC17) + (191,623 x qC18), with statistical parameters, n = 22; r2 = 0,910; SEE = 0,171; Fcal/Ftab = 4,510 and PRESS = 0,697. The best equation can applied to design and predict new compounds with higher antimalarial activity.

Effect of Storage Duration on Physicochemical and Antibacterial Activities of Sweet Corn-based Synbiotic Yogurt with Honey

Synbiotic yogurt is fermented milk containing probiotics and prebiotics. The quality of symbiotic yogurt products during cold storage must meet the SNI quality requirements (2981-2009). This study aimed to find the effect of yogurt storage duration on physicochemical properties and antibacterial activity for the best yogurt storage time. In this study, synbiotic yogurt was made from sweet corn, honey, and full cream milk as prebiotics and Lactobacillus acidophilus and Bifidobacterium bifidum as probiotics. The tests carried out include testing total coliform, total lactic acid bacteria, degree of acidity (pH), total titrated acid, organoleptic quality, and antibacterial activity. The tests were carried out on days 0, 5, 10, 15, and 20. The results showed that storage duration affected product quality and antibacterial activity. The best storage duration for yogurt was found to be ten days, where the yogurt stored for ten days found to have a total coliform of 0 APM/g, total lactic acid bacteria of 2.81 x 1012, total lactic acid of 1.684%, pH value of 3.5 and was still preferred and could be accepted by the panelists, based on the organoleptic assessments. The yogurt stored for ten days also gave the largest average inhibition diameter of 21.78 mm with the category 'very strong' against Escherichia coli and 22.13 mm with the classification 'very strong' against Salmonella typhi. The yogurt stored for up to 10 days still met the SNI yogurt quality standard requirements (2981: 2009).