Jurnal Kimia Riset

SYNTHESIS AND CHARACTERIZATION OF SILICA GEL/CHITOSAN COMPOSITE DERIVED FROM TIN TAILING FOR REMOVAL OF Fe(III) IN POST-TIN MINING WATER

Rima Pilani, Shagita Nabila, Vega, Verry Andre Fabiani — Mon, 09 Dec 2024 00:00:00 +0700

A study on the synthesis and characterization of silica gel/chitosan composite derived from tin tailings for removal of Fe(III) in post-tin mining water has been carried out. The silica source used for the synthesis of silica gel is tin tailings. It is produced by the sol-gel method. The characteristics of silica gel from tin tailings sand are white powder with a silica content of 73.58% after compositing with 30 mL and 45 mL chitosan solution, showing that the chitosan phase was successfully formed together with the silica phase. Functional group analysis showed the presence of typical chitosan functional groups (-NH₂) at 1629 cm^-1and 1635 cm^-1 and typical silica functional groups (-Si-O-Si) at 1000 cm^-1 to 1020 cm^-1. These functional groups appeared in addition to all variations of the chitosan solution. Morphological analysis shows that in the addition of 45 mL chitosan solution, the silica gel/chitosan composite has a morphology in the form of small round particles with uneven surfaces and more dominant pores. Adsorption study of silica gel/chitosan composite on Fe(III) in post-tin mining water showed 95.5% adsorption efficiency in the addition of 45 mL chitosan solution. The adsorption condition observed is the adsorption time as a fixed variable in this study, which is for 17 hours.

OPTIMIZATION OF CURCUMIN ENCAPSULATION FORMULA WITH CHITOSAN AND ALGINATE USING SIMPLEX LATTICE DESIGN AND ITS EFFECT ON ANTIOXIDANT ACTIVITY

Mon, 09 Dec 2024 00:00:00 +0700

Curcumin is known to enhance the performance of antioxidant serums, such as superoxide dismutase (SOD). However, curcumin is prone to degradation when exposed to sunlight, necessitating the use of encapsulation technology to protect it from chemical degradation and improve its dispersibility. Biopolymers like chitosan and alginate are commonly used as encapsulation materials. This study aimed to determine the ideal concentrations of chitosan and alginate for curcumin encapsulation and evaluate its antioxidant activity. The optimal formulation was identified using Design Expert software version 13 with a Simplex Lattice Design. Encapsulation was carried out through the ionic gelation method, and the curcumin encapsulates were evaluated for encapsulation efficiency, particle size, zeta potential, and antioxidant activity. The optimal formulation was found to be 1.35% chitosan and 2.145% alginate, achieving an encapsulation efficiency of 71.85%, a particle size of 551.1 nm, a zeta potential of -46 mV, and strong antioxidant activity with an IC50 value of 36.32 ppm. In conclusion, the Simplex Lattice Design method successfully optimized the formulation. Chitosan increased particle size, while alginate enhanced encapsulation efficiency. The antioxidant activity was minimally affected by encapsulation, as most curcumin was retained in the droplets. The zeta potential value confirmed the stability of the encapsulate.

THE EFFECT OF SULFURIC ACID AND Averrhoa bilimbi EXTRACT AS CATALYSTS ON FURFURAL YIELD FROM CORN COBS IN THE HYDROLYSIS PROCESS USING MICROWAVE

Ayu Chandra Kartika Fitri, Fikka Kartika Widyastuti — Mon, 09 Dec 2024 00:00:00 +0700

Furfural is a selective solvent for petroleum that can produce high-quality diesel fuel. Generally, furfural research uses raw materials from corn cobs, but most still use inorganic acid catalysts. Therefore, researchers are trying to find alternative catalysts using environmentally friendly organic acids from Averrhoa bilimbi extract. This research aims to determine the effect of the concentration of sulfuric acid catalyst and Averrhoa bilimbi extract in the hydrolysis process on the quality and yield of furfural and the impact of using microwave heating on the quality and yield of furfural produced. The method used to make furfural is hydrolyzing corn cobs using a microwave heater (400 Watt power) with various sulfuric acid catalyst concentrations (10%, 15%, and 20%) and Averrhoa bilimbi. Observe the number of yields at each time interval of 60, 75, and 90 minutes. The resulting furfural is then analyzed to calculate the yield of each sample and identify furfural compounds using Gas Chromatography-Mass Spectrometry (GCMS). The research results showed that the best furfural yield at a catalyst concentration of 10% H₂SO₄ with a time of 90 minutes was 14.9632%. In GCMS analysis, the compound peaked on gas chromatography at a retention time of 2.208 with a relative molecular mass of 83.

EXPLORATION OF BIOACTIVE COMPOUNDS OF RAMBUSA (Passiflora foetida L.) ROOT EXTRACT FROM EAST KALIMANTAN COAL RECLAMATION LAND AS ANTIOXIDANT

Nishia Waya Meray, Indah Woro Utami, Nurazizah — Mon, 09 Dec 2024 00:00:00 +0700

The rambusa plant (Passiflora foetida L.) is a species utilized as a cover crop due to its capacity to undergo a natural regeneration process in the context of former coal mining operations in East Kalimantan. Rambusa plants have many phytochemical properties, one of which is as an antioxidant. Nevertheless, there is currently a paucity of scientific data regarding the potential antioxidant properties of bioactive compounds in Rambusa roots utilized as cover crop plants. The objective of this study is to investigate the composition of bioactive compounds in the root extract of Rambusa plants that are cultivated on land previously utilized for coal mining in East Kalimantan, with a particular focus on their antioxidant properties. In this study, the exploration was carried out by conducting phytochemical tests using three types of solvents, namely ethanol, ethyl acetate and n-hexane and antioxidant activity tests using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method on the extracted samples. Phytochemical screening results showed the presence of alkaloid, phenolic, flavonoid, terpenoid and saponin bioactive compounds in ethanol extract; alkaloid, phenolic and steroid bioactive compounds in ethyl acetate extract. At the same time, alkaloids and steroids are contained in the n-hexane extract. The DPPH test carried out on the three extracts showed very strong antioxidant activity with IC₅₀ values respectively for ethanol, ethyl acetate and n-hexane extracts are 6.55 ppm, 3.51 ppm and 28.71 ppm. Based on previously reported antioxidant activity data, the antioxidant activity of Rambusa (Passiflora foetida L.) roots growing on coal reclamation land is proven to have much higher activity compared to Rambusa plants growing on fertile land. Thus, the root of the Rambusa plant (Passiflora foetida L.) has enormous potential as an antioxidant and natural medicinal raw material.

SYNTHESIS OF NANO-BENTONITE MODIFIED GRAPHENE OXIDE ELECTRODE FOR FORMALDEHYDE ANALYSIS BY CYCLIC VOLTAMMETRY

Pirim Setiarso, Aisyah Rahmatul Fajrin — Mon, 09 Dec 2024 00:00:00 +0700

In this research, each graphene oxide and nano-bentonite was synthesized using the Improved Hummers method and the Sonochemical method for formaldehyde detection by cyclic voltammetry. Formaldehyde detection by cyclic voltammetry has several factors to accurately detect formaldehyde, such as electrode composition, the pH of the solution, the deposition time, and the scan rate. In this study, formaldehyde detection using nano-bentonite modified graphene oxide electrode has the optimum electrode composition in the ratio of graphene oxide: paraffin: nano-bentonite 3:2:5, pH of the optimum solution for detection of formaldehyde 4, 10-second deposition time and scan rate 100 mV/sec. Nano-bentonite modified graphene oxide electrode has a detection limit of up to 0.16856 ppm (0.005613 mM) with a recovery of 99.414%. This sensor was successfully applied for formaldehyde measurement in the actual sample and showed good selectivity, sensitivity, reproducibility, and precision.

BIOACTIVE COMPOUNDS OF Moringa oleifera AS KRASG12C INHIBITORS IN COLORECTAL CANCER: IN SILICO STUDY

Mon, 09 Dec 2024 00:00:00 +0700

KRAS is a GTPase enzyme that regulates cell growth and division. Mutations in KRAS can lead to its permanent activation, resulting in uncontrolled cell growth and cancer progression. Approximately 30–44% of colorectal cancer cases harbor KRAS mutations, with 1–3% involving the KRAS^G12C variant. Historically considered "undruggable," recent advancements, such as Sotorasib, have demonstrated the potential to target KRAS^G12C effectively, making it a promising focus for drug discovery. Moringa oleifera, a plant rich in phytochemicals, is a potential source of bioactive compounds with therapeutic applications. In this study, 218 compounds derived from M. oleifera were screened using molecular docking, targeting KRAS^G12C. Quercetin (3) exhibited the lowest binding affinity (-9.37 kcal/mol) and showed interactions with key residues, including GLN100A, VAL104A, LYS17A, and TYR97A, suggesting a binding mechanism similar to that of Sotorasib as native ligand. The physicochemical analysis further revealed high gastrointestinal absorption, good lipophilicity, and favorable bioavailability scores for Quercetin (3), supporting its potential as a drug candidate. These findings highlight the potential of M. oleifera compounds, particularly quercetin (3), as inhibitors of KRAS^G12C in colorectal cancer.

CELLULOSE NANOCRYSTALS BASED ON PINEAPPLE LEAF FIBERS IN HEMOPERFUSION APPLICATIONS FOR CREATININE REMOVAL: BATCH METHOD ADSORPTION STUDY

Mon, 09 Dec 2024 00:00:00 +0700

Kidney failure is a major global cause of mortality, often resulting from the buildup of uremic toxins like creatinine. Creatinine serves as an indicator for assessing treatment needs in kidney failure patients. Hemoperfusion, a treatment based on the adsorption of toxins, has shown promise when using cellulose nanocrystals (CNCs) as adsorbents. CNCs derived from pineapple leaf fibers offer unique advantages due to their abundance of active sites, high adsorption capacity, and strong binding affinity. This study investigates the efficiency of CNCs in reducing creatinine levels, with the reduction attributed to the binding of creatinine to CNC hydroxyl groups. Characterization of CNCs was performed using PSA, XRD, FTIR, and SEM-EDX techniques, while the residual creatinine was quantified via UV-Vis spectrophotometry, utilizing a picric acid complex under alkaline conditions and measured at 485 nm. Optimal conditions were found with a stirring speed of 210 rpm, 120-minute contact time, and 10 mg/L creatinine concentration, resulting in an adsorption capacity (Q_ads) of 2.572 mg/g. The CNC adsorbent demonstrated hemocompatibility, with an APTT blood coagulation time of 31.3 seconds. These findings suggest that CNCs could be highly effective in developing safer, efficient hemoperfusion systems for managing kidney failure.

PHYTOCHEMICAL PROFILES, ANTIOXIDANT, AND ANTICANCER ACTIVITIES FROM LEAVES AND SEEDS EXTRACT OF Myristica fragrans

Mon, 09 Dec 2024 00:00:00 +0700

Nutmeg (Myristica fragrans) is a plant that grows naturally in Indonesia and widely used in the food and industrial sectors. Nutmeg seeds have been widely studied because they have a variety of compounds with good activities, but research on the leaves still needs to be completed. Therefore, this research compared nutmeg leaves and seed extracts' secondary metabolite content and bioactivity. This study aims to determine the phytochemical contents of nutmeg leaves and seed extracts by phytochemical screening and GC-MS analysis, as well as its potential as an antioxidant and anticancer. The antioxidant activity test uses the DPPH (1,1-diphenyl-2-picrylhydrazyl) method measured at a wavelength of 517 nm. Meanwhile, the anticancer activity test uses MCF-7 cells with the MTT assay method. Nine compounds (lipid, phenylpropanoid, lignan, terpenoid, and quinone groups) were identified by GC-MS analysis in the leaf extracts. Meanwhile, seed extract has 23 compounds from the lipid, fatty acid, phenylpropanoid, lignan, and terpenoid groups. The antioxidant activity of nutmeg leaves and seed extracts was carried out using the DPPH method, while the cytotoxic activity against MCF-7 cells used the MTT method. Nutmeg leaves have more potent antioxidant activity than nutmeg seeds, with IC₅₀ values of 17.80 µg/mL and 53.01 µg/mL, respectively. The cytotoxic activity test on MCF-7 cells also showed that the inhibition value of nutmeg extract (26%) was higher than that of nutmeg seeds (22.73%). This research shows that nutmeg leaf extract has the potential to carry out further research regarding the bioactivity of its compounds.

THE EFFECT OF COPAL RESIN AND TURPENTINE OIL AS TACKIFIER ON THE ADHESIVES QUALITY BASED OF LIQUID RUBBER COMPOUND

Tri Widayanti, Teja Dwi Sutanto, Irfan Gustian — Mon, 09 Dec 2024 00:00:00 +0700

This research aims to develop adhesives from liquid rubber compounds with a variety of tackifiers, a combination of copal resin, and turpentine oil. It also aims to characterize the adhesives to determine the quality of the adhesives produced. The research comprised several stages, including the preparation of rubber additive dispersions and solutions, formulation of liquid rubber compounds and adhesives, fabrication of test pieces, and subsequent characterization. The liquid rubber compound is made by mixing concentrated latex with rubber additives, which include KOH as a stabilizer, stearic acid and ZnO as an activator, BHT as an antioxidant, CaCO₃ as a filler, MBTS and TMTD as an accelerator, and sulfur as a vulcanizer. The adhesives are made by mixing liquid rubber compound with tackifier material with various combinations of copal resin/turpentine oil, namely F1 (0 gram/4 gram); F2 (1 gram/3 grams); F3 (2 grams/2 grams), F4 (3 grams/1 gram), and F5 (4 grams/0 grams). Adhesives characterization was carried out by testing pH, viscosity, adhesives strength, FTIR, XRD, and thermal analysis. The research results showed that the best conditions were obtained on F4 adhesives with an adhesives strength value of 1.7452 N/mm, viscosity of 1100 cP, and pH 4.6. In this condition, the resulting adhesives meet the requirements for adhesives in accordance with SNI 06-6049-1999 and SNI 12-7195-2006.

ENVIRONMENTALLY FRIENDLY BIFUNCTIONAL MATERIALS BASED ON ZnO/NATURAL ZEOLITE FOR METHYLENE BLUE DYE REMOVAL IN WATER

Mon, 09 Dec 2024 00:00:00 +0700

The treatment of dye wastewater, particularly from the batik industry, poses significant environmental challenges. This study explores the potential of ZnO-coated clinoptilolite natural zeolite as a dual-functional material for efficient and eco-friendly wastewater treatment through adsorption and photocatalysis. This study employed various solvents, i.e., aquadest and ethylene glycol and different treatments of heating and sintering to ensure the ZnO-coated natural zeolite. The ZnO/zeolite composite achieved a dye degradation efficiency of up to 98.68% under UV irradiation within 90 minutes. Characterization through SEM, FTIR, and XRD analyses confirmed the successful synthesis and structural integrity of the ZnO/zeolite composite. We also conducted an analysis of operational costs and energy consumption associated with the use of these bifunctional materials. The results indicate that the potential for utilizing these materials as a treatment method is promising, given their ease of use and low energy consumption, and warrants further investigation.