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All Journal JURNAL KIMIA SAINS DAN APLIKASI Pharmaciana: Jurnal Kefarmasian Bulletin of Chemical Reaction Engineering & Catalysis Indonesian Journal of Chemistry Indonesian Journal of Natural Pigments Jurnal Bakti Untuk Negeri
Leny Yuliati
Universitas Ma Chung
Chemical Engineering, Chemistry & Bioengineering Chemistry Dentistry Engineering Health Professions Medicine & Pharmacology Nursing Public Health Other

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Effects of pH and Storage Time on the Stability of Papaya and Carrot Extracts Juliana, Juliana; Indrawati, Renny; Yuliati, Leny
Indonesian Journal of Natural Pigments Vol 1 No 1 (2019): February 2019
Publisher : Ma Chung Research Center for Photosynthetic Pigments

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33479/ijnp.2019.01.1.25

Abstract

Papaya and carrot are rich in natural pigments, especially b-carotene. Unfortunately, in most cases, natural pigments are less stable than the synthetic ones when they are put in a variety of treatment conditions, such as pH. In this work, the stability of the papaya and carrot extracts were evaluated in various pH, which ranges of 1-10 for 7 days. The extracts were obtained by a slow juicer, followed by encapsulation and drying by a freeze dryer. The extracts were then dispersed in buffer solutions and the chroma and color difference (DE) values were calculated from the obtained lightness (L*), redness (a*), and yellowness (b*). The results showed that carrot extract was better than the papaya extract in terms of chroma values. It was also shown that both extracts were not stable under acidic condition, but more stable in neutral to alkaline condition. The acid condition facilitated the cleavage of the conjugated bonds in the b-carotene, which in turn caused the color degradation in the papaya and carrot extracts.
Selection of Maceration Solvent for Natural Pigment Extraction from Red Fruit (Pandanus conoideus Lam) Purnomo, Tantyo Ardy Bintoro; Kurniawan, Yehezkiel Steven; Kesuma, Ruth Febriana; Yuliati, Leny
Indonesian Journal of Natural Pigments Vol 2 No 1 (2020): February 2020
Publisher : Ma Chung Research Center for Photosynthetic Pigments

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33479/ijnp.2020.02.1.8

Abstract

Red fruit (Pandanus conoideus Lam) is rich with red-orange natural pigments, such as β-carotene. In this work, the solvent selection was investigated to extract the β-carotene from the red fruit via a simple maceration technique. Three types of solvents were used in the maceration, which were distilled water, ethanol, and acetone. The obtained extracts were characterized using spectrophotometer ultraviolet-visible (UV-visible), Fourier transform infrared (FTIR) and spectrofluorometer. The different solvents gave different spectroscopic information, suggesting that the solvent selection influenced the type of the extracted compounds. Among the examined solvents, acetone was found to be the most effective one to extract the β-carotene. The presence of the β-carotene pigment in acetone extract was confirmed by the appearance of the absorption peak at 476 nm on its UV-visible spectrum, while from its FTIR spectrum, the C-H sp3 functional group of β-carotene was found at 2924 and 2854 cm-1. In addition, the emission peak of β-carotene was found at 394 and 561 nm. This study confirmed that acetone performed as a better maceration solvent for β-carotene as compared to the distilled water and ethanol, which would be strongly related to the non-polar property of the acetone.
High Antioxidant Activity of Pucuk Merah (Syzygium oleina) Leaf and Zinnia (Zinnia elegans) Flower Extracts Purnomo, Tantyo Ardy Bintoro; Yuliati, Leny
Indonesian Journal of Natural Pigments Vol 2 No 2 (2020): Agustus 2020
Publisher : Ma Chung Research Center for Photosynthetic Pigments

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33479/ijnp.2020.02.02.54

Abstract

A study on the antioxidant activity of natural sources is very crucial to explore their benefits, especially for food, medicine, as well as cosmetic applications. In this work, the antioxidant activities of pucuk merah (Syzygium oleina) leaves and zinnia (Zinnia elegans) flower were examined. Pucuk merah leaves and zinnia flowers were extracted using an acidic ethanol solvent by a simple maceration method for 24 hours. The color of the obtained pucuk merah leaf extract was red, while the zinnia flower extract was yellowish-brown. UV-visible spectrophotometer showed that the pucuk merah leaf extract has anthocyanin as the main part and chlorophyll as the minor part. On the other hand, zinnia flower extract contained carotenoid as the main part, as well as small parts of anthocyanin and chlorophyll. The antioxidant activity test was carried out by using 2-2-diphenyl-1-picrylhydrazyl (DPPH) as the antioxidant assay. It was revealed that the inhibitory concentration at 50% (IC50) values of the pucuk merah leaf and zinnia flower extracts were 25.83 and 20.16 mg/L, respectively, while the antioxidant activity index (AAI) of the pucuk merah leaf and zinnia flower extracts were 1.55 and 1.98, respectively. These results showed that both pucuk merah leaf and zinnia flower extracts have strong antioxidant activity, and thus very potential to be used as great antioxidants.
Spectroscopy Study of Honey Pineapple Peels Extracted in Different Solvents Kurniawan, Yehezkiel Steven; Setiyono, Edi; Adhiwibawa, Marcelinus Alfasisurya Setya; Priyangga, Krisfian Tata Aneka; Yuliati, Leny
Indonesian Journal of Natural Pigments Vol 3 No 1 (2021): February 2021
Publisher : Ma Chung Research Center for Photosynthetic Pigments

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33479/ijnp.2021.03.1.32-35

Abstract

In the present work, we investigated the extract of honey pineapple peels in distilled water, ethanol, and acetone solvents. The spectroscopy study of each extract was performed using a Fourier transform infrared (FTIR) spectrometer, an ultraviolet-visible (UV-Vis) spectrophotometer, and a spectrofluorometer. The FTIR spectrum of the distilled water extract indicated that the distilled water extract may contain alcohol or carboxylic acid compounds. Meanwhile, the ethanolic extract may contain alcohol or carboxylic acid, or ether compounds. On the other hand, the acetone extract may contain alcohol or ether or aromatic or aliphatic compounds. The UV-Vis spectrum of the honey pineapple peels extracted in the distilled water, ethanol, and acetone showed a broad absorption signal at UV region (< 300 nm), four absorption signals at UV region (232-368 nm), and four absorption signals at UV region (231-368 nm) with a weak absorption signal at the visible region at 559 nm, respectively. The distilled water and acetone extracts gave fluorescence signals, however, the ethanolic extract showed no fluorescence intensity. From the FTIR, UV-Vis, and fluorescence spectra characterization, the extracted natural pigments from the honey pineapple peels in distilled water, ethanol, and acetone solvents were identified. The distilled water extract may contain polar flavonoid or steroid compounds while the ethanolic extract may contain polar carotenoid pigments. On the other hand, the acetone extract may contain carotenoid and chlorophyll pigments as shown by an emission signal at 670 nm.
Validation of TLC densitometry method for the quantitative determination of alkaloid in fermented endophytic fungi extract Phyllantus niruri Linn Rollando rollando; Sandra Dewi Tansil; Eva Monica; Yuyun Yuniati; Leny Yuliati
Pharmaciana Vol 9, No 1 (2019): Pharmaciana
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (392.619 KB) | DOI: 10.12928/pharmaciana.v9i1.11807

Abstract

Endophytic fungi can produce compound that similar with the host, so it can be  used as mass production of compound. The optimal and valid assay method is needed to obtain the proper culture condition, which one using densitometric Thin Layer Chromatography (TLC). This research used 11 samples of endophytic fungi culture extract from Phyllantus niruri within various culture condition. Optimization of mobile phase was done using 3 kinds of mobile phase mixture, chloroform: ethyl acetate: methanol (8:8:4); chloroform: ethyl acetate: methanol: NH4OH (8:8:4:0.005); chloroform:ethyl acetate:NH4OH (8:8:0.005). Validation method measured using some parameters such as linearity, accuracy, and precision. The result of optimization and validation showed that TLC densitometry method can be used for measuring alkaloid level within the endophytic fungi extract of P. niruri using chloroform: ethyl acetate: NH4OH (8:8:0.005), with R value is 0.977, percentage of recovery is between 90–110, and RSD ≤7% on each concentration series. While the proper condition of endophytic fungi culture is using sucrose as carbon source and at pH 6 condition. The content of alkaoid reached 25.9 ± 1.4 mg 100 g-1 fresh weight. 
Activity Enhancement of P25 Titanium Dioxide by Zinc Oxide for Photocatalytic Phenol Degradation Yehezkiel Steven Kurniawan; Leny Yuliati
Bulletin of Chemical Reaction Engineering & Catalysis 2021: BCREC Volume 16 Issue 2 Year 2021 (June 2021)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.16.2.10319.310-319

Abstract

As a benchmark photocatalyst, P25 titanium dioxide (TiO2) nanomaterial has been widely reported for its remarkable photocatalytic activity under ultraviolet (UV) irradiation. However, approaches to further improve the photocatalytic activity of the P25 TiO2 are still required. In the present work, we reported the activity enhancement of the P25 TiO2 up to more than five times higher rate constant for phenol degradation when the P25 TiO2 was coupled with zinc oxide (ZnO). The composites were prepared by a physical mixing method of P25 TiO2 and ZnO with various weight ratios of 1:0.5, 1:1, and 1:2. The composite materials were then characterized using X-ray diffraction (XRD), diffuse-reflectance ultraviolet-visible (DR UV-vis), Fourier transform infrared (FTIR), and fluorescence spectroscopies. All the composites gave better activity than the P25 TiO2, in which the TiO2/ZnO 1:1 composite material exhibited the highest first-order reaction rate constant (0.43 h−1). This remarkable enhanced degradation rate was much higher than that of the unmodified TiO2 (0.08 h−1) and ZnO (0.13 h-1). The fluorescence study revealed that the electron-hole recombination on the P25 TiO2 could be suppressed by the ZnO, which would be the reason for such activity enhancement. A study on the effect of the scavenger showed that the hydroxyl radicals played a crucial role in the photocatalytic phenol degradation. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Effect of Calcination Temperature on the Photocatalytic Activity of Zn2Ti3O8 Materials for Phenol Photodegradation Krisfian Tata Aneka Priyangga; Yehezkiel Steven Kurniawan; Leny Yuliati
Bulletin of Chemical Reaction Engineering & Catalysis 2021: BCREC Volume 16 Issue 1 Year 2021 (March 2021)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.16.1.10322.196-204

Abstract

Zinc titanate (Zn2Ti3O8) is a bimetal oxide material that is especially attractive as a photocatalyst. In the preparation of the Zn2Ti3O8, the calcination temperature is a crucial parameter. Hence, in the present work, we aimed to synthesize the Zn2Ti3O8 materials from zinc(II) nitrate and titanium(IV) isopropoxide as precursors by using a sol-gel method and followed by calcination at 700, 900, and 1100 °C to give ZT-700, ZT-900, and ZT-100 materials, respectively. The ZT materials were characterized using Fourier transform infrared (FTIR), diffuse reflectance ultraviolet-visible (DR UV-vis), and fluorescence spectroscopies. It was confirmed that the ZT materials contained O−Ti−O, Zn−O−Ti, Zn−O, Ti−O−Ti, and Ti−O functional groups as shown from their FTIR spectra. Similar fluorescence properties were only observed on the ZT-700 and ZT-900. From the bandgap energy analysis, ZT-700 and ZT-900 contained spinel and cubic Zn2Ti3O8 (spl-Zn2Ti3O8 and c-Zn2Ti3O8) crystal phases), while ZT-1100 contained c-Zn2TiO4 and TiO2 rutile crystal phases. The kinetic analysis of photocatalytic phenol degradation showed that both ZT-700 and ZT-900 materials exhibited high photocatalytic activity with the reaction rate constants of 0.0353 and 0.0355 h−1, respectively. These values were higher than that of the ZT-1100 (0.0206 h−1). This study demonstrated that calcination at 700 and 900 °C resulted in the formation of the spl-Zn2Ti3O8 and c-Zn2Ti3O8 phases, which were effective as the photocatalyst, but the formation of c-Zn2TiO4 and rutile TiO2 at calcination of 1100 °C deteriorated the photocatalytic activity. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Supramolecular Phosphorescent Trinuclear Copper(I) Pyrazolate Complexes for Vapochromic Chemosensors of Ethanol Hendrik Oktendy Lintang; Nur Fatiha Ghazalli; Leny Yuliati
Indonesian Journal of Chemistry Vol 17, No 2 (2017)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (730.351 KB) | DOI: 10.22146/ijc.22553

Abstract

We highlight that by using supramolecular single crystals of phosphorescent trinuclear copper(I) pyrazolate complexes with different molecular structures (2A-E), vapochromic chemosensors were successfully designed for sensing ethanol with high sensing capability. These complexes 2A-E were synthesized from non-side chain, 3,5-dimethyl, 3,5-bis(trifluoromethyl), 3,5-diphenyl and 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligands (1A-E) in 83, 97, 99, 88 and 85% yields, respectively. All complexes showed emission bands centered at 553, 584, 570 and 616 nm upon an excitation at 280 nm for complexes 2A-C,E, respectively and 642 nm upon an excitation at 321 nm for complex 2D with lifetime in microseconds, indicating a large Stoke shift for phosphorescent compounds. These emission spectra were in good agreement with their colors from green to red upon exposure to a UV lamp with an excitation at 254 nm in dark room. Upon exposure to ethanol in 5 min, quenching, photoinduced energy transfer and shifting of emission intensities were observed for chemosensors 2A-C, 2D and 2E, respectively. Interestingly, chemosensor 2E only showed completely and autonomously recovery of its original emission intensity. Such novel finding in sensing capability might be caused by a weak intermolecular hydrogen bonding interaction of ethanol to oxygen atoms at dimethoxybenzyl side-chains of the pyrazole ring.
Cobalt Oxide-Modified Titanium Dioxide Nanoparticle Photocatalyst for Degradation of 2,4-Dichlorophenoxyacetic Acid Leny Yuliati; Nur Azmina Roslan; Wai Ruu Siah; Hendrik Oktendy Lintang
Indonesian Journal of Chemistry Vol 17, No 2 (2017)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (405.881 KB) | DOI: 10.22146/ijc.22624

Abstract

2,4-dichlorophenoxyacetic acid (2,4-D) has been recognized as a possibly carcinogenic compound to human, therefore, 2,4-D should be treated before it is discharged to the environment. Photocatalytic degradation of 2,4-D has been proposed as one of the best methods that offer environmentally safe process. In the present research, titanium dioxide (TiO2) was modified with cobalt oxide (CoO) and tested for photocatalytic degradation of 2,4-D under UV light irradiation. Different amounts of CoO (0.1, 0.5, 1 and 5 mol%) were added onto TiO2 by an impregnation method. The photocatalytic reaction was monitored and analyzed by measurement of 2,4-D absorbance using UV spectrophotometer. After 1 h photocatalytic reaction, it was confirmed that the sample with low loading of 0.1 mol% gave the highest photocatalytic activity among the bare and modified TiO2 photocatalysts. The photocatalytic activity was decreased with the increase of CoO loading, suggesting that the optimum amount of CoO was an important factor to improve the performance of TiO2. Based on fluorescence spectroscopy, such addition of CoO resulted in the reduced emission intensity, which showed the successful decrease in the electron-hole recombination.
Optimized Synthesis Temperature and Time to Obtain Crystalline Carbon Nitride with Enhanced Photocatalytic Activity for Phenol Degradation Leny Yuliati; Mohd Hayrie Mohd Hatta; Siew Ling Lee; Hendrik Oktendy Lintang
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.52345

Abstract

In this work, the crystalline carbon nitride photocatalysts were synthesized by an ionothermal technique with varied synthesis temperature of 500, 550, and 600 °C, and synthesis time of 2, 4, and 6 h. Fourier transform infrared spectra showed the successful formation of the prepared carbon nitrides from their characteristic vibration peaks. X-ray diffraction patterns suggested that the same phase of poly(triazine imide) and heptazine could be observed, but with different crystallinity. The optical properties showed that different temperatures and synthesis time resulted in the different band gap energy (2.72–3.02 eV) as well as the specific surface area (24–73 m2 g–1). The transmission electron microscopy image revealed that the crystalline carbon nitride has a near-hexagonal prismatic crystallite size of about 50 nm. Analysis by high-performance liquid chromatography showed that the best photocatalytic activity for phenol degradation under solar light simulator was obtained on the crystalline carbon nitride prepared at the 550 °C for 4 h, which would be due to the high crystallinity, suitable low band gap energy (2.82 eV), and large specific surface area (73 m2 g–1). Controlling both the temperature and synthesis time is shown to be important to obtain the best physicochemical properties leading to high activity.
Co-Authors Adhiwibawa, Marcelinus Alfasisurya Setya B. Maharani, Novia Cinta Sari, Yunda Edi Setiyono Hendrik Oktendy Lintang Hendrik Oktendy Lintang Hendrik Oktendy Lintang Hendrik Oktendy Lintang Juliana Juliana Kesuma, Ruth Febriana Krisfian Tata Aneka Priyangga Kurniawan, Yehezkiel Steven Mohd Hayrie Mohd Hatta Monica, Eva Nur Azmina Roslan Nur Fatiha Ghazalli Priyangga, Krisfian Tata Aneka Purnomo, Tantyo Ardy Bintoro Renny Indrawati, Renny Rollando, Rollando S. Alfisyah Nur Aziza Sandra Dewi Tansil Setya Dhini, Ellyvina Siew Ling Lee Tamara, Aulia Wai Ruu Siah Wynona Agatha Nimpoeno Yehezkiel Steven Kurniawan Yehezkiel Steven Kurniawan Yehezkiel Steven Kurniawan Yulinda Cesa, Fibe Yuyun Yuniati