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All Journal JURNAL KIMIA SAINS DAN APLIKASI
Ngadiwiyana Ngadiwiyana
Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto, SH., Tembalang, Semarang|Diponegoro University|Indonesia
Chemical Engineering, Chemistry & Bioengineering Chemistry Engineering

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Antioxidant Activity of Flavonoids from Cassava Leaves (Manihot esculenta Crantz) Enny Fachriyah; Ifan Bagus Haryanto; Dewi Kusrini; Purbowatiningrum Ria Sarjono; Ngadiwiyana Ngadiwiyana
Jurnal Kimia Sains dan Aplikasi Vol 26, No 1 (2023): Volume 26 Issue 1 Year 2023
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.26.1.10-18

Abstract

The community uses cassava leaves for cooking because of their high protein content, β-carotene, Fe, Mg, Zn, S, Ca, Zn, Ni, and K. Cassava leaves contain various secondary metabolites, including flavonoids, saponins, tannins, phenolics, steroids, anthocyanins, and anthraquinones. The antioxidant activity of flavonoid compounds in cassava leaves (Manihot esculenta Crantz) has been successfully investigated. This study consisted of six stages: the preparation of ethanol extract of cassava leaves, phytochemical screening, determination of total flavonoid content in the extract, isolation of flavonoids, and purity testing of flavonoid isolates using the chromatographic method, identification of the structure of pure flavonoid isolates using a UV-Vis spectrophotometer with the addition of a shear reagent, FTIR, and LC-MS/MS. As well as test the antioxidant activity using the DPPH method. The yield of ethanol extract from cassava leaf in this study was 14.67%. The results of the phytochemical screening showed that the cassava leaves and the ethanol extract of cassava leaves contained alkaloids, flavonoids, saponins, tannins, quinones, steroids, phenolics, and triterpenoids. The total content of flavonoids in the ethanol extract was 35.71 mg EQ/g extract. UV-Vis, FTIR, and LC-MS/MS analysis revealed that the flavonoid isolate was quercetin. The results of the antioxidant activity of the ethanol extract and BC isolate showed IC50 of 81.76 ± 0.505 mg/L and 77.85 ± 4.708 mg/L.
Encapsulation of Cinnamaldehyde using Chitosan: Stability, Mucoadhesive and Cinnamaldehyde Release Purbowatiningrum Ria Sarjono; Ngadiwiyana Ngadiwiyana; Enny Fachriyah; Ismiyarto Ismiyarto; Nor Basid Adiwibawa Prasetya; Khikmah Khikmah
Jurnal Kimia Sains dan Aplikasi Vol 21, No 4 (2018): volume 21 Issue 4 Year 2018
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2829.242 KB) | DOI: 10.14710/jksa.21.4.175-181

Abstract

Cinnamaldehyde contained in cinnamon oil is useful as an antidiabetic; however, it has very low oral bioavailability. One effort to increase oral bioavailability of cinnamaldehyde is by encapsulation using chitosan. Encapsulation of cinnamaldehyde in chitosan has been successfully made in the form of powder. The aim of this study was to obtain data of stability, mucoadhesive and cinnamaldehyde release from cinnamaldehyde encapsulated chitosan. Stability tests were performed physically and chemically. Mucoadhesive tests were carried out in vitro in two steps, which were granule fabrication and then mucoadhesive test. The results showed that the levels of cinnamaldehyde decreased within 4 weeks, from the first to the fourth week 100%; 99.87%; 98.85%; 97.33%, respectively. Cinnamaldehyde powder did not change significantly in specific gravity, pH, centrifugation and organoleptic after a month. The release precentage of cinnamaldehyde in acidic media pH 1.2 for 180 minutes was 83.4%, whereas in alkaline media pH 7.4 for 360 minutes was 61%. The cinnamaldehyde encapsulated chitosan nanoparticle powder performed mucoadhesive capacity in the gastric mucosa and in the intestinal mucosa of 91.5% and 84.61%, respectively.
Sulfonation of Eugenol-Diallyl Phthalate Copolymer as Base Material of Supercapacitor Electrode Material Ngadiwiyana Ngadiwiyana; Cinta Nur Nabila; Ismiyarto Ismiyarto; Marcelinus Christwardana
Jurnal Kimia Sains dan Aplikasi Vol 27, No 11 (2024): Volume 27 Issue 11 Year 2024
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.27.11.523-530

Abstract

Polyeugenol is a polymer synthesized from renewable natural resources and has potential as a supercapacitor electrode material. Polyeugenol was modified by the addition of diallyl phthalate to increase structural density and thermal stability and the addition of sulfonate groups to increase ion exchange capacity and electrical conductivity. This research begins with the synthesis of eugenol-diallyl phthalate copolymer (PEGDAF) carried out by cationic polymerization using BF3O(C2H5)2 catalyst and sulfonation of eugenol-diallyl phthalate copolymer (SPEGDAF) using sulfuric acid. The synthesis of PEGDAF in the form of pink solids with a yield of 68.44%, a molecular weight of 6739.99 Daltons, and a melting point of 85°C, FTIR analysis showed that the formation of PEGDAF was characterized by the loss of vinyl groups with the absence of C=C alkene wavenumber absorption which is the wavenumber absorption of eugenol and diallyl phthalate, respectively 1640 cm-1 and 1647 cm-1 and TGA with a mass loss of 5% and 10% at 176°C and 219°C. SPEGDAF results in dark purple solids with a sulfonation degree of 17.18% and a cation exchange capacity of 0.4186 meq/g, molecular weight 8342.25 Daltons, melting point 114°C. Analysis using FTIR showed the presence of sulfonate groups with the resulting absorption peaks of 1218 cm-1 (S=O), 1065 cm-1 (S-O), and 578 cm-1 (C-S) and TGA with a mass decrease of 5% and 10% at temperatures of 169°C and 215°C. Potential test of supercapacitor electrode material with Cyclic Voltammetry and Electrochemical Impedance Spectroscopy obtained a specific capacitance value of 3.23 × 10-3 F/g and ion conductivity of 7.58 × 10-6 S/cm.
Synthesis of Sulfonated Chitosan as An Active Agent of Antibacterial Packaging for Fish Fillets Dwi Susilo; Syahnindita Dyah Ajeng Wartari; Ngadiwiyana Ngadiwiyana; Purbowatiningrum Ria Sarjono; Ismiyarto Ismiyarto
Jurnal Kimia Sains dan Aplikasi Vol 27, No 9 (2024): Volume 27 Issue 9 Year 2024
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.27.9.409-418

Abstract

Modifying chitosan by increasing its hydrophilic properties through sulfonation reactions will increase its solubility in water and antibacterial activity and expand the application of chitosan. This study aims to determine the antibacterial activity of sulfonated chitosan film applied as fish fillet packaging using the total plate count method. Sulfonated chitosan in this study was successfully synthesized by reacting chitosan with 1,3-propane sultone. Sulfonated chitosan products were characterized using FTIR and UV-Vis spectrophotometers, while antibacterial activity was measured using the disc diffusion method. The optimum temperature for sulfonated chitosan synthesis was 60°C (SCS60). The resulting SCS 60 was a yellowish-white solid soluble in water with a yield of 61.46% and a degree of substitution of 33%. The diameters of the SCS 60 inhibition zone against E. coli and S. aureus isolates were 7 and 10 mm, respectively. SCS60-gelatin film is elastic (elongation 272%) and more hydrophobic with a contact angle of 90.12° compared to chitosan-gelatin film (62.8°). SCC60-gelatin film was able to suppress bacterial growth in fish fillets by up to 0.3 × 104 cfu/g compared to unpackaged fish (30 × 104 cfu/g). Sulfonated chitosan has the potential to be an antibacterial food packaging material.
Synthesis of Polyethylene Glycol-Modified Salicylaldehyde–Chitosan Schiff Base and Its Antibacterial Assay Umi Shofiyatun Ni’mah; Kamilia Hijriani Zain; Ngadiwiyana Ngadiwiyana; Purbowatiningrum Ria Sarjono; Ismiyarto Ismiyarto
Jurnal Kimia Sains dan Aplikasi Vol 29, No 4 (2026): Volume 29 Issue 4 Year 2026
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.29.4.252-264

Abstract

Antibacterial materials are essential for inhibiting the growth of pathogenic microorganisms, and chitosan has received considerable attention due to its intrinsic antibacterial properties, biocompatibility, and biodegradability. However, the limited hydrophilicity and moderate mechanical strength of pristine chitosan restrict its broader application. In this study, chitosan was chemically modified through Schiff base formation with salicylaldehyde, followed by modification with polyethylene glycol (PEG), to enhance its physicochemical properties while maintaining detectable antibacterial performance. The objectives of this research were to synthesize Salicylaldehyde–chitosan Schiff base and PEG-modified Salicylaldehyde–chitosan Schiff base, to characterize their structural and physical properties, and to evaluate their antibacterial performance. The molecular weight of chitosan was determined by viscometry, and the degree of deacetylation was evaluated by Fourier transform infrared (FTIR) spectroscopy. The chitosan used exhibited a molecular weight of 147,926 g/mol and a degree of deacetylation of 67%. Schiff base formation was carried out by refluxing chitosan with salicylaldehyde at 60°C for 3 hours, using various molar ratios. The highest degree of substitution (68.75%) and yield (41.08%) were obtained, with the moderate yield attributed to incomplete conversion and material loss during purification steps. Structural confirmation was achieved through FTIR and UV–Vis spectroscopy by the appearance of characteristic imine (C=N) absorption bands. Subsequent modification with PEG at room temperature for 24 hours yielded 40.49%. The PEG-modified material exhibited significantly enhanced hydrophilicity, as indicated by a swelling ratio of 333.33% and a reduced contact angle of 63.04°. Antibacterial activity evaluated by the disc diffusion method showed inhibition zones of 9 mm against Escherichia coli and 10 mm against Staphylococcus aureus, which are modestly higher than those of the solvent control under the tested conditions. These results suggest that PEG modification improves the hydrophilicity of the chitosan-based Schiff base material while maintaining measurable antibacterial activity, indicating potential for further development in antimicrobial and biomedical materials.
The Release of Curcumin from β-TCP/SiO₂/Curcumin Composites in a Ringer’s Lactate Solution Tri Windarti; Ngadiwiyana Ngadiwiyana; Fadila Fibriani
Jurnal Kimia Sains dan Aplikasi Vol 29, No 5 (2026): Volume 29 Issue 5 Year 2026
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.29.5.373-378

Abstract

Osteoporosis is characterized by bone deterioration caused by high levels of reactive oxygen species (ROS), which inhibit osteoblast activity and lead to a decrease in bone density. Adding curcumin, a natural antioxidant, to calcium phosphate cement (CPC) enhances its function beyond simply increasing bone density. In this study, CPC was prepared from a β-tricalcium phosphate (β-TCP, β-Ca3(PO4)2) composite with curcumin. To enhance the interaction between β- TCP and curcumin, silicon dioxide (SiO2) was added. β-TCP was synthesized by the sol-gel method, with SiO2 content ranging from 1.6 to 8.3%. CPC preparation was carried out using a 2.5% Na2HPO4 solution. The release of curcumin in a Ringer’s lactate solution was studied in relation to the role of SiO2. The UV-Vis spectral intensity of the remaining Ringer’s lactate solution after soaking decreased as the SiO2 content increased. Results from a five-day soaking period showed that β-TCP did not transform into hydroxyapatite, but rather experienced a decrease in crystallinity and average crystal size from 96.175% to 25.524% and from 58.335 nm to 39.474 nm, respectively. Therefore, it can be predicted that CPC can maintain the presence of curcumin in a physiological environment.
Improved Thermal Stability of Silica Nanofluids Using Anionic Surfactants for Enhanced Oil Recovery Applications Khasan Rowi; Ngadiwiyana Ngadiwiyana; Agus Subagio
Jurnal Kimia Sains dan Aplikasi Vol 28, No 5 (2025): Volume 28 Issue 5 Year 2025
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.28.5.244-251

Abstract

Silica nanoparticles have shown great potential in the oil and gas industry sector, especially in applications for enhanced oil recovery. Silica nanofluids are widely used in EOR applications because they are inexpensive, easy to synthesize, environmentally friendly, can be surface modified, and provide high oil recovery rates. However, silica nanofluids have drawbacks in thermal stability and salinity at high temperatures, adversely affecting their application in oil reservoirs. In this paper, the effects of a surfactant sulfonate compound (SPU11) and a co-surfactant sulfosuccinate compound (SPU22) on the thermal stability of silica nanofluids at temperatures ranging from 60 to 100°C were investigated. Next, the silica nanofluids were analyzed for particle size using a particle size analyzer (PSA), wettability using a sessile drop contact angle, and oil recovery capacity using a core flooding test. The results showed that the silica nanofluid with 0.3% SPU11 and 0.3% SPU22 surfactant showed good thermal stability below 80°C for 3 months in 3 wt% brine; PSA analysis showed that the aggregate diameter was 52.86 nm; wettability analysis showed that the silica nanofluid had a contact angle of 60.8° to 36.6° and the core flooding results of silica nanofluid showed an oil in place recovery (OOIP) of 9.7%.
Co-Authors Agus Subagio Cinta Nur Nabila Dewi Kusrini Dwi Susilo Enny Fachriyah Fadila Fibriani Ifan Bagus Haryanto Ismiyarto Ismiyarto Kamilia Hijriani Zain Khasan Rowi Khikmah Khikmah Marcelinus Christwardana Nor Basid Adiwibawa Prasetya Purbowatiningrum Ria Sarjono Syahnindita Dyah Ajeng Wartari Tri Windarti Umi Shofiyatun Ni’mah