Flavonoids from the Roots of Amomum compactum Soland Ex Maton (Zingiberaceae)

Amomum compactum Soland Ex Maton is one of the Zingiberaceae family plants which is the endemic plants from West Java, Indonesia. This study was aimed to determine the chemical structure of flavonoid compounds from n-hexane extract of A.compactum Sol. Ex Maton roots. Dried powder of the roots was extracted consecutively with n-hexane, ethyl acetate, and methanol solvents. Three flavonoids, 5-hydroxy-3,7,4`-trimethoxy kaempferol (1), 5-hydroxy-3,7,3',4'-tetra methoxy kaempferol (2) and 4'-hydroxy-3,5,7-trimethoxy kaempferol (3), have been isolated from the roots of A. compactum Sol. Ex Maton. The chemical structures of compounds 1-3 were identified by spectroscopy data including infrared 1D-NMR, 2D-NMR and HRTOF-MS as well as by comparison with previously reported spectral data. Compounds 1-3 were isolated from this plant for the first time and showed free radical DPPH scavenging activity.

Synthesis of Adsorbent from Bagasse for Methylene Blue Adsorption

The ability of bagasse adsorbents to adsorb methylene blue without activation using 0.5 M H2SO4 solution was examined. Methylene blue is widely used in the textile industry because it produces bright colors, and the dyeing process is fast and easy. This research aims to determine the optimum adsorption conditions, namely the variations in contact time, dye concentration, adsorbent mass, and pH effect on methylene blue, which were carried out using the batch method. Furthermore, the adsorbents were characterized by FT-IR and SEM. The optimum state of the bagasse adsorbent to adsorb methylene blue dye has a mass of 0.5 grams, a contact time of 30 minutes, a concentration of 50 ppm, and a pH of 5. The character of the adsorbent after activation with H2SO4 was better than without activation. The highest adsorption efficiency of methylene blue dye in the batch method was 99.67%. The FTIR spectrum of the bagasse adsorbent showed OH, C-H, C=O, C=C, and C-O functional groups. The adsorption isotherm model for methylene blue dye follows the Langmuir isotherm since the graph obtained is linear with the correlation coefficient (R2) = 1, where the adsorbent has a homogeneous surface.

Extraction and Characterization of Urease from Durio zibethinus L

Urease is a biocatalyst that serves to hydrolyze urea into ammonia and carbon dioxide. Since it is an imported product, the price of urea is still high. Urease can be found in grains. One of the grains that has not been explored for its urease content is durian (Durio zibethinus L.) seeds. This study aims to determine the effect of germination time on the activity of urease from durian seeds and its characteristics including the effect of pH, incubation temperature, enzymatic reaction time, addition of EDTA and metals, and storage time on the activity of urease from durian seeds. The first step of this study was seed germination which was carried out in the dark for 0, 3, 5, 7, and 9 days. Durian seed sprouts were extracted by mashing them using a mortar and pestle. They were then homogenized using a stirrer and centrifuged in a cold state. The crude urease extract obtained was then tested for its activity using the Nessler method. The acquired data was tested statistically using ANOVA. The results showed that the activity of urease from durian seeds was optimum at 3-day germination time, pH 7, incubation temperature at 30 °C, and 15-minute enzymatic reaction time with an activity of 163.6 U/mL. Urease is a metalloenzyme with its inhibitor being the Cu2+ and Na+ metal ions and its activator being Ba2+ metal ion. Tukey's test analysis showed that the effect of urease storage time at 4 °C resulted in a stable urease activity for 8 days while at room temperature it decreased its activity significantly to 72.8%.

Application of Fourier Transform Infrared Spectrophotometry Method for Analysis of Metformin Hydrochloride in Marketed Tablet Dosage Form

The first line drug given for monotherapy for diabetes mellitus type 2 is metformin hydrochloride, which is a biguanide antihyperglycemic drug. The aim of this research was to develop, validate, and apply the Fourier Transform Infrared spectrophotometry method to identify and determine metformin hydrochloride in marketed tablet dosage form. This research included preparation of standard, analysis of samples, and validation of method. The specific wavenumber obtained for qualitative analysis was 1645.68 cm–1 and 1574.8 cm–1. The specific area obtained for quantitative analysis with a single baseline ranged from 1701.53 cm–1 to 1535.66 cm–1. All metformin hydrochloride marketed tablet dosage forms were analyzed and met all of the qualitative and quantitative requirements. The methods met the requirements of method validation for accuracy with a percentage of recovery of 100.22 %, precision with relative standard deviation of 0.48 %, linearity with a correlation coefficient of 0.9992, limit of detection of 11.17 mg per mL, limit of quantitation of 33.84 mg per mL, and good specificity results. In this study, the Fourier Transform Infrared spectrophotometry method was successfully developed and validated for application in identification and determination of metformin hydrochloride in marketed tablet dosage form.

Degradation of Imidacloprid Residue on Red Tomatoes (Solanum lycopersicum) by Advanced Oxidation Processes and Analysis using Spectrophotometer and HPLC

The insecticide imidacloprid (C9H10ClN5O2) common used by farmers to control pests on red tomato plants, is a dangerous substance classified as a Class II toxic. The imidacloprid residue in red tomatoes enters the body, it will lead to health problems. The purpose of this study was to determine the percentage of imidacloprid residue that can be degraded using the Advanced Oxidation Processes (AOPs) method, which includes sonolysis, sonozolysis, ozonolysis, ozone water, and the effect of various parameters. Processing time, water volume, and red tomato mass were the test parameters studied. The change in imidacloprid residue concentration during the degradation process was measured using a UV/Vis spectrophotometer (double beam) with a wavelength of 200-400 nm and HPLC with mobile phase composition used was acetonitrile/water (65:35 v/v). With a processing time of 10 minutes, the imidacloprid residue in red tomatoes can be degraded 57.38% by sonozonolysis, 63.51 % by sonolysis, 85.17 % by ozonolysis, and 88.76 % by ozone water. The imidacloprid residue in 75 g of red tomatoes could be removed as much as 91.65% by treating with ozone water for 15 minutes. HPLC analysis showed that no intermediate compounds were detected in the imidacloprid residue degradation process in red tomatoes.

Molecular Dynamics Simulation of Bioactive Compounds Against Six Protein Target of Sars-Cov-2 As Covid-19 Antivirus Candidates

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the virus that causes Coronavirus 2019 (COVID-19). To date, there has been no proven effective drug for the treatment or prevention of COVID-19. A study on developing inhibitors for this virus was performed using molecular dynamics simulation. 3CL-Pro, PL-Pro, Helicase, N, E, and M protein were used as protein targets. This study aimed to determine the stability of the selected protein-ligand complex through molecular dynamics simulation by Amber20 to propose bioactive compounds from natural products that have potential as a drug for COVID-19. Based on our previous study, the best value of free binding energy and protein-ligand interactions of the candidate compounds are obtained for each target protein through molecular docking. Corilagin (-14.42 kcal/mol), Scutellarein 7-rutinoside (-13.2 kcal/mol), Genistein 7-O-glucuronide (-10.52 kcal/mol), Biflavonoid-flavone base + 3O (-11.88 and -9.61 kcal/mol), and Enoxolone (-6.96 kcal/mol) has the best free energy value at each protein target. In molecular dynamics simulation, the 3CL-Pro-Corilagin complex was the most stable compared to other complexes, so that it was the most recommended compound. Further research is needed to test the selected ligand activity, which has the lowest free energy value of the six target proteins.

Optimization of Ultrasonic Assisted Extraction Process on Antioxidant Activity of Honje Fruit Extract (Etlingera elatior) Using Surface Response Method

Honje fruit (Etlingera elatior) contains bioactive compounds as antioxidants. An antioxidant can be obtained by extraction. This research aimed to determine the best combination of solvent amount and extraction time to produce the optimal yield and antioxidant activity. The extraction method was UAE (Ultrasound Assisted Extraction) using ethanol 96% solvent amount 125 mL to 250 mL and time level of 30 to 60 minutes. The RSM (Response Surface Methodology) in the Design Expert 11 application was used to arrange the extraction combination treatment, which resulted in 13 runs. Parameters analyzed were total yield, antioxidant activity, pH, specific gravity, and color. The results showed that total yield was revealed quadratic, Y1 = 19.05 – 1.76A + 0.32B – 0.002AB + 0.023A2 – 0.0005B2 and the antioxidant activity was revealed linear, Y2 = 408.147 – 6.424A + 0.326B. The optimum treatment was achieved in the amount of solvent 174.815 ml and extraction time of 60 minutes resulted in a total yield of 17.125% and antioxidant activity of 77.55 ppm that could be classified as strong.

Photocatalytic Degradation of Methylene Blue and Methyl Orange by Y-PTC Metal-Organic Framework

The yttrium based metal-organic framework (MOF) Y-PTC was synthesized by the solvothermal method using perylene as the linker and yttrium as metal ion. This study aims to assess the photocatalytic activity of yttrium-perylenetetracarboxylate (Y-PTC) metal-organic framework (MOF) toward methylene blue and methyl orange under visible light irradiation. The results of the FTIR analysis showed that Y-PTC MOF had a different structure and composition from its precursor (Na4PTC). The Y-PTC MOF has a bandgap energy value of 2.20 eV with a surface area of 47.7487 m2/g. The SEM-EDS analysis showed an elemental composition of yttrium, carbon, and oxygen, were 6.9%, 72.1% and 20.7%, respectively. Furthermore, Y-PTC MOF was able to adsorb dyes at the optimum by 78.10% and 35.57% toward methylene blue (MB) and methyl orange (MO) at the dispersion period of 60 mins. Y-PTC MOF exhibited photocatalytic activity towards the degradation of methylene blue and methyl orange under visible light irradiation. The addition of H2O2 inhibited Y-PTC photocatalytic activity towards MO degradation from 50.89% to 26.38%. In contrast to MO, the addition of H2O2 had a positive effect on MB, which increased the degradation from 87.56% to 91.65%. Therefore, Y-PTC MOF possessed the potential of a photocatalyst material in dyes degradation under visible light irradiation.

Biosynthesis of ZnO Nanoparticles Using Pumpkin Peel Extract (Cucurbita moschata) and its Applications as Semiconductor in Dye Sensitized Solar Cell (DSSC)

ZnO nanoparticles are semiconductor materials that can be used in Dye Sensitized Solar Cells (DSSC). ZnO nanoparticles can be synthesized using pumpkin peel extract (Cucurbita moschata) which functions as a reducing agent, stabilizer, and capping agent. Zn(CH3COO)2.2H2O precursor was used with a concentration of 0.15 M at various pH 7, 8, and 9 reacted with pumpkin peel extract. The functional groups of pumpkin peel extract were characterized using Fourier Transform Infrared Spectroscopy (FTIR), the samples were analyzed by TEM and XRD. The resulting ZnO nanoparticles were used as semiconductors in Dye Sensitized Solar Cell (DSSC) using dyes from mangosteen peel.The FTIR results showed the presence of functional groups O-H hydroxy, CH2, secondary amides (R-CO-NR2, C-H and phosphate (PO43-). XRD results showed that ZnO produced wurzhite crystals with a hexagonal system and the smallest crystal size was 18.99 nm. TEM results showed that ZnO synthesized at a concentration of 0.15 M and pH 8 had a spherical particle shape with a size of 24.90 nm, while the DSSC test results had an efficiency of 9.06 x 10-4%.

Photocataytic Degradation of Phenol Using TiO2-Fe Under H2O2 Presence by Visible and Sunlight Irradiation

Phenol is one of the essential organic pollutants released into the environment because of its high stability and toxicity. It is harmful to organisms, environment, and posing a serious threat to human health at low concentration. This research investigated the photocatalytic degradation process of phenol using a TiO2-Fe catalyst under visible light irradiation and additional H2O2. The effect of various conditions process was applied, including different catalyst doses (0.2, 0.4, 0.6, and 0.8 g/L), pH (3, 6, 8, and 11), irradiation times (60, 90, 120, 150, and 210 minutes) and the presence of H2O2. The degradation process was studied at an initial concentration of phenol 5 mg/L. This study has been decreasing phenol content (90.51%) with catalyst doses 0.6 g/ L sample solution, pH solution 11, reaction time 210 minutes and H2O2 concentration 30%. This final phenol concentration after photodegradation under halogen light was 0.18 mg/L, while sunlight irradiation was 0.11 mg/L. This result is below government regulation as per Permen LH RI No. 5/2014 i.e. 0.5 mg/L. Therefore, this process possible to remove phenol in aqueous such as industrial wastewater or other resources.