Seniwati Dali
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Hasanuddin University

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Antituberculosis Activity Test of N-p-Methylbenzyl-p-coumaramide (MBC) Against M. tuberculosis H37Rv Nasriadi Dali Wela; Arniah Dali Wela; Seniwati Dali; Hilda Ayu Melvi Amalia
Al-Kimia Vol 8 No 2 (2020): DECEMBER
Publisher : Study Program of Chemistry - Alauddin State Islamic University of Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24252/al-kimia.v8i2.10761

Abstract

An antituberculosis activity test of N-p-Methylbenzyl-p-coumaramide (MBC) against M. tuberculosis H37Rv has been carried out. The purpose of this study was to determine the antituberculosis activity of MBC against M. tuberculosis H37Rv. The study was conducted using agar diffusion method. The test solution was prepared by dissolving MBC in 20 mL Ogawa medium to a final concentration of 0.25; 0.50; 1; and 2 mg/L. PDA media that had been inoculated with M. tuberculosis H37Rv (seeded agar) were poured over the base layer on the petridish surface. Paper disks that have been immersed in the test solution were put symmetrically on the seeded agar. Furthermore, the seeds were incubated at 37 oC for 48 hours. Then the diameter of the inhibition zone was measured to the accuracy of 0.5 mm with a ruler. The results showed that MBC has biological activity as an antituberculosis. MBC can inhibit the growth of M. tuberculosis H37Rv at a concentration of 0.25; 0.50; 1; and 2 mg/L with a diameter of inhibitory zones respectively 8.9; 13.7; 18.5; and 21.3 mm. This showed that the inhibition of MBC on the growth of M. tuberculosis H37Rv increased with increasing concentration of MBC used.
ANALYSIS METALS Fe AND Mn IN SEAGRASS ENHALUS ACOROIDES IN THE WATERS PASARWAJO BUTON Sabaniah Indjar Gama; Nursiah La Nafie; Seniwati Dali
Marina Chimica Acta Vol. 16 No. 2 (2015): Volume 16 No. 2 (2015)
Publisher : Hasanuddin University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (347.15 KB) | DOI: 10.20956/mca.v16i2.7475

Abstract

The research aims to identify ferrous metals and manganese in seagrasses Enhalus acoroides. The sample used was obtained from the water pasarwajo buton. The sample was extracted, then the metal was analyzed using AAS. Metal concentrations (ppm) are Fe (143.667 mg / kg) and Mn (46.67 mg / kg), respectively. Metal content obtained below the maximum limit and seagrass Enhalus acoraides can be used as a bio-indicator of the presence of heavy metals
EFFECT OF Mg (II) METAL ION ON ANTIOXIDANT ACTIVITIES OF ETHANOL EXTRACTS OF RAMBUTAN PEEL (Nephelium lappaceum) Emmi Astuti; Ahyar Ahmad; Seniwati dali
Jurnal Akta Kimia Indonesia (Indonesia Chimica Acta) Volume 11, No.1: June 2018
Publisher : Hasanuddin University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20956/ica.v11i1.6403

Abstract

Anthocyanin is the one of natural dyes that often used in foodstuffe, because anthocyanin can make a more color like red, blue and purple. Anthocyanin storage can make anthocyanin is damage, because the interaction with tempherature, light, and oxygen show that can given effect about the stability anthocyanin color, and decrease the anthocyanin as an antioxidant. That problem can be solved with copigmentation, that is an anthocyanin reaction with metal ion. In this study can showed that ethanol extract from Rambutan peel and we obtained 23.824 gram with total anthocyanin content of 709.3866 mg/L with antioxidant activity of 0.0046 μg/mL, and then the extract of anthocyanin with metal ion Mg2+ in concentration 50; 100 and 150 ppm had IC50 are 0.0061; 0.0048 and 0.0067 μg/mL. This conclution from the added of metal ion Mg2+ showed that has not show much different antioxidant activity. 
Pretreatment of Used Cooking Oil Using Avocado Seed Adsorbent for Biodiesel Production Preparation Nasriadi Dali; Seniwati Dali; Armadi Chairunnas; Hilda Ayu Melvi Amalia; Sri Ayu Andini Puspitasari
METANA Vol 19, No 1 (2023): Juni 2023
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/metana.v19i1.51797

Abstract

Used cooking oil (UCO) can be used as raw material for biodiesel production, but its free fatty acid (FFA) content is still quite high, so it is necessary to do pretreatment in the form of an adsorption process to reduce FFA levels. This study aims to determine the optimum conditions for the adsorption process and determine FFA levels of UCO before and after pretreatment. The adsorbent used is avocado seed activated charcoal, because it has a surface area of 19.62 m2/g. The larger the surface area of the adsorbent material, the greater the adsorption capacity of the adsorbent. Optimization of the UCO adsorption process includes variations in adsorbent mass (6, 8, 10 g), adsorbent particle size (60, 100, 140 mesh), contact time (2, 6, 10 hours), and temperature (60, 80, 100oC). The results showed that the optimum conditions for adsorption of UCO were obtained at mass (10 g), particle size (100 mesh), contact time (6 h), and temperature (80oC). This condition can reduce the FFA content of UCO by 71.64% (w/w), from 5.29% (w/w) to 1.50% (w/w). The FFA content of UCO [1.50% (w/w)] produced after pretreatment was qualified as a raw material for the preparation of biodiesel production through the transesterification stage.
Biosynthesis of Methyl Esters from Used Cooking Oil (UCO) using Lipase Enzyme from Aspergillus oryzae on Moldy Copra Nasriadi Dali; Seniwati Dali; Armadi Chairunnas; Hilda Ayu Melvi Amalia; Ayu Andini Puspitasari
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 8, No 2 (2023): JKPK (Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/jkpk.v8i2.67818

Abstract

The successful production of methyl esters from used cooking oil (UCO) using lipase enzymes from Aspergillus oryzae on moldy copra has been achieved. This method offers an eco-friendly substitute for crude palm oil (CPO) in generating methyl esters or biodiesel, contributing to waste reduction, economic benefits, and lowered greenhouse gas emissions for sustainable development. This study aimed to synthesize methyl esters from UCO using the Aspergillus oryzae lipase enzyme sourced from moldy copra. The enzyme was purified through ammonium sulfate fractionation and gel filtration column chromatography. Electrophoresis validated its purity, and activity was assessed through the Erdmann and Lowry method. Methyl ester synthesis involved transesterification with a UCO (1 mol): methanol (9 mol): lipase enzyme (15% v/v) ratio. The enzyme displayed notable characteristics, including 43.76 units/mg protein activity, a 41.7 kDa molecular weight, optimum pH of 8.2, temperature preference of 35°C, Km of 0.046, and a 1.926 µmol/minute Vmax. This enzyme efficiently catalyzed UCO (triolein) into methyl ester (methyl oleate), yielding 75.65%. Characterization using Fourier Transform Infrared (FTIR) revealed specific functional groups like –OH carboxylic acid, C=C alkenes, C=O esters, methyl (CH3-), and methylene (-CH2-). Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified prominent compounds: methyl palmitate (12.53%), methyl vacsenate (16.44%), and, notably, methyl oleate (41.08%). This underscores the potential of Aspergillus oryzae lipase as an effective biocatalyst for UCO transesterification, yielding valuable methyl esters or biodiesel.