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INDONESIA
KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 325 Documents
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Isolasi dan Identifikasi Steroid dari Ekstrak N-Heksana Daun Afrika (Vernonia amygdalina Del.): Isolation and Identification of Steroid from N-Hexane Extract of Vernonia amygdalina Del. Evi Mashunah; Erwin; Saibun Sitorus
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 1 (2020): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i1.15032

Abstract

Isolation and identification of steroids from the n-hexane fraction of Vernonia amygdalina Del. was carried out. Separation and purification were performed using flash chromatographic and gravity chromatography. Based on the results of phytochemical tests supported by UV and FT-IR data analysis, the isolate obtained was a steroid (sterol type). Toxicity test results using the Brine Shrimp Lethality Test (BSLT) were known that the steroid has moderate toxicity with an LC50 value of 48.39 ppm. Keywords: Vernonia amygdalina Del., Toxicity, BSLT, Sterol, Steroid
Penyerapan Ion Logam Merkuri Menggunakan Arang Aktif Limbah Kulit Pisang Kepok (Musa paradisiaca Formatypica): The Adsorption of Mercury Metal Ion Using Kepok Banana’s Peel Waste (Musa paradisiaca Formatypica) Charcoal Musafira; Dzulkifli; Fadrinah; Laila Qadrini
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 1 (2020): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i1.15043

Abstract

This research aimed to determine the percentage of mercury metal ion adsorbed in kapok banana peel’s activated carbon. It was done by applying Completely Randomized Design (CRD) with 6 variations of contact time, pH, and mercury concentration (i.e 10, 20, 30, 40, 50, 60 minutes; pH of 1, 2, 3, 4, 5, 6; and concentration of 10, 20, 30, 40, 50, 60 ppm, accordingly). The result showed that the equilibrium time was reached at 30 minutes, the maximum pH was reached at pH 5 and the maximum of adsorbed mercury ion at 40 ppm of mercury ion concentration. The adsorption percentages of those parameters were 61%, 98%, and 99%, respectively. Keywords: Kepok banana’s peel, charcoal, mercury metal ion.
Analisis Kualitatif dan Kuantitatif Metabolit Sekunder Ekstrak Etanol Buah Okra (Abelmoschus esculentus L. Moench) dengan Metode Spektrofotometri UV-Vis: Qualitative and Quantitative Analysis of Secondary Metabolites in Ethanol Extract of Okra (Abelmoschus esculentus L. Moench) Fruit with UV-Vis Spectrophotometry Method Joni Tandi; Bella Melinda; Anita Purwantari; Agustinus Widodo
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 1 (2020): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i1.15044

Abstract

This study aims to determine the content of secondary metabolites and the levels of total secondary metabolites in ethanol extract of Okra (Abelmoschus esculentus L. Moench) fruit with UV-Vis Spectrophotometry method. Okra (Abelmoschus esculentus L. Moench) fruit extract was prepared by maceration method with 96% ethanol. The extract was concentrated using a rotary evaporator that followed by a qualitative test for alkaloids, flavonoids, saponins, and tannins using suitable reagents with the test parameters, while for the qualitative assay using a UV-Vis Spectrophotometry. Qualitative analysis of alkaloids using test parameters of total alkaloids equivalent to quinine, flavonoid using parameter of total flavonoids equivalent to quercetin, saponin using parameters of standard saponins total from the Quillaja Bark, and tannin using test parameters of total tannins equivalent to tannic acid. Qualitative test results indicated that the ethanol extract of Okra fruit tested positive for alkaloids content wich characterized by the orange deposition, flavonoids characterized by the formation of an orange-yellow color, a stable foam for saponins and tannins marked in black. The quantitative analysis resulted alkaloids of 2228.06 mg/gram, flavonoids of 2.79 mg/gram, saponins of 10.03 mg/gram, and tannins of 1973.27 mg/gram. Keywords: Okra fruit, secondary metabolites, UV- Vis spectrophotometry, qualitative, quantitative.
Skrining Fitokimia, Uji Toksisitas dan Uji Peredaman Radikal DPPH Ekstrak Daun Gelinggang (Cassia alata L): Phytochemical Screening, Toxicity Test and DPPH Radical Scavenging Test of Cassia alata L (Gelinggang) Leaves Extract Izkia Mawaddah; Erwin E; Chairul Saleh
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 1 (2020): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i1.15045

Abstract

Cassia alata L. (Gelinggang) one of the plants known as medicinal plants, especially for the treatment of skin diseases. The purpose of this study was to determine the type of secondary metabolites using phytochemical tests, toxicity with the BSLT method and antioxidant properties against DPPH radicals from the extract of the Gelinggang leaves. The results of the study showed extracts of Gelinggang leaves containing alkaloids, triterpenoids, steroids, and quinones. Based on the results of toxicity and antioxidant tests showed that Gelinggang leaves extract was very toxic to Artemia salina shrimp and it was a strong antioxidant against DPPH radicals with LC50 and IC50 were 28.84 ppm and 73.57 ppm, respectively. Keywords: Gelinggang, Cassia alata L., toxicity, antioxidants, DPPH
Isolasi dan Identifikasi Metabolit Sekunder dari Ekstrak Etil Asetat Batang Nangka (Artocarpus heterophyllus Lmk.) dan Aktivitasnya Sebagai Antibakteri: Isolation and Identification of Secondary Metabolite from Ethyl Acetate Extract of Jackfruit Stem (Artocarpus heterophyllus Lmk.) and Its Antibacterial Activity Indriani; Iswan
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 1 (2020): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i1.15047

Abstract

Isolation and identification of secondary metabolite of ethyl acetate extract of jackfruit stem (Artocarpus heterophyllus Lmk.) as well as its activity as antibacterial have been carried out. The purpose of this study was to know the characterization and antibacterial activity of secondary metabolites from ethyl acetate extract of the Jackfruit stem. Ethyl acetate extract was fractionated and purified using several chromatographic techniques. The identification of the isolated compound was elucidated by spectroscopic UV-Vis, IR, and NMR. Based on data analysis of UV, IR, and NMR spectra showed that the isolated compound was a flavonoid derivative. Antibacterial activity test of the isolated compound to Escherichia coli and Staphylococcus aureus was done by a well diffusion method. The inhibitory zone values of flavonoid compound in concentration series of 1000 µg/ml, 3000 µg/ml, and 5000 µg/ml against E. coli were 9.65 mm, 10.25 mm, and 11.00 mm, respectively. While, the inhibitory zone values in the same concentration series against S. aureus were 9.00 mm, 10.75 mm, and 11.38 mm. Keywords: Jackfruit, Artocarpus heterophyllus Lmk., flavonoid, antibacterial activity.
Mikroenkapsulasi Ekstrak Kulit Buah Naga Super Merah (Hylocereus costaricensis) pada Berbagai Massa Maltodekstrin dan Aplikasinya Sebagai Antioksidan: Microencapsulation of Super Red Dragon Fruit (Hylocereus costaricensis) in Various of Maltodextrin Mass and its Application as an Antioxidant Sucianti; Nurhaeni; Jaya Hardi
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.9889

Abstract

Red super dragon fruit peel (Hylocereus costaricensis) extract has capability to scavenge DPPH and the activity could be maintained by using maltodextrin as coating. The aims of the research are to determine ratio of red super dragon fruit peel ethanol extract toward maltodextrin producing microcapsule with the highest coating efficiency and DPPH scavenging content by microcapsule of red super dragon fruit peel extract. Microencapsulation was carried out using freeze drying technique. Comparison of red super dragon fruit peel extract and maltodextrin were 1: 8, 1: 10, 1: 12, and 1:14 (w / w). The results show that the highest efficiency ratio of coating extract of red super dragon fruit peel with maltodextrin was 1: 8 with percentage of 90,77%. Level of DPPH scavenging content of red super dragon fruit peel extract microcapsule with ratio of 1:8 on 5 minutes and 60 minutes each is 27.36% and 46.62%. Keywords: Hylocereus costaricensis, freeze drying, maltodextrin, microencapsulation
Studi Perbandingan Aktivitas Antioksidan Xantofil dan Karoten Kapang Oncm Merah pada Berbagai Waktu Inkubasi: Comparison Study of Antioxidant Activity of Xanthophyll and Carotene from Red Oncom Mold In Various Incubation Times Sriwulan Indriani Pea; Khairuddin; Prismawiryanti
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 2 (2020): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i2.11547

Abstract

Research on a comparative study of antioxidant activity of xanthophyll and carotenoids from red oncom, mold in various incubation times has been studied. This study aims to determine the antioxidant activity of xanthophyll and carotene at various incubation times of red oncom cultured in corn cob medium. This study used a Completely Randomized Design (CRD) at variations in incubation time: 2, 3, 4, 5, 6, and 7 days. The results showed that the best antioxidant activity of xanthophyll and carotene was on the second day with antioxidant activity of 82.27% and 65.80%, respectively. Keywords: antioxidant activity, xanthophyll, carotene, carotenoids, red oncom
Analisis Kadar Glukomanan Dari Biji Durian (Durio zeibethinus Murr) dengan Metode Spektrofotometri pada Berbagai Waktu dan Suhu Hidrolisis: Analysis of Glucomannan Content From Durian Seeds (Durio zeibethinus Murr) Using Spectrophotometry Methods in Several Hydrolysis Times and Temperatures Darmawati Darmawati; Syaiful Bahri; Husain Sosidi
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 2 (2020): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i2.11582

Abstract

Durian seeds are one type of seed that contains glucomannan. The aim is to determine glucomannan levels in the durian seed. The study was designed using a completely randomized design (CRD). The extracted glucomannan was determined by the spectrophotometry method at various temperature and hydrolysis time. The crude extract of glucomannan was hydrolyzed using 3 M HCl for 70, 80, 90, 100, and 110 minutes at 70, 80, 90, 100, and 110°C. The highest glucomannan concentration of 39.60% was obtained at a hydrolysis temperature of 100°C for 100 minutes. The analysis of the FTIR spectrophotometer shown that the vibration of the C-O-C functional group (glycoside bond) was obtained at the wavelength number of 1020.34 cm-1 which is a characteristic of glucomannan. Keywords: glucomannan, durian seed, hydrolysis, spectrophotometry
Ekstraksi Glukomanan dari Umbi Gembili (Dioscorea esculenta L.): Extraction of Glucomannan from Gembili Bulbs (Dioscorea esculenta L.) Pratiwi Listyana Sareu; Nurhaeni; Ahmad Ridhay; Moh. Mirzan; Syamsuddin
KOVALEN: Jurnal Riset Kimia Vol. 7 No. 1 (2021): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2021.v7.i1.12008

Abstract

Gembili bulbs (Dioscorea esculenta L.) have a fairly high carbohydrate content, so they can potentially be a new source of glucomannan compounds. This study aims to determine the yield and glucomannan characteristics of Gembili bulbs at different extraction times and temperatures. Glucomannan was obtained by extraction with water at temperatures of 45, 60, 75, 90, and 105oC for 45, 60, 75, 90, and 105 minutes, and precipitated with isopropyl alcohol. The results showed that the highest yield was obtained at the extraction time of 90 minutes and a temperature of 105oC of 53.09%. The glucomannan of Gembili bulb has a molecular weight of 1,865 x 104 g/mol with ash and water content values of 0.866% and 10.45%, respectively. The results of identification of functional groups with an FTIR spectrophotometer showed that there was a functional group stretching vibration of glucomannan compounds, including the –OH group at a wavenumber of 3431 cm-1 and -C-O-C (glycosidic bond) at a wavenumber of 1020.34 cm-1 and bending vibration of -CH functional groups on wavenumber of 850.61 cm-1.
Retensi Ekstrak Karoten pada Olahan Mie Wortel (Daucus carrota L.): Retention of Carotene Extract on Carrot (Daucus carrota L.) Noodles Putri Wahyuni; Ni Ketut Sumarni; Prismawiryanti; Jaya Hardi
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 2 (2020): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i2.12794

Abstract

Carotene extract from carrots (Daucus carrota L.) can improve the quality of processed noodles. Determining of carotene retention in processed carrot noodles during the storage period that has been done aims to know the reaction kinetics and shelf life of the noodles. Carrot noodles were stored for 8 weeks at room temperature and analyzed its carotene content by using a UV-Vis spectrophotometer every 7 days. The result showed that the retention of carrot noodles during storage of 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks was 53.64%, 53.19%, 52.49%, 51.68%, 51.07%, 46.30%, 45.96, 45.88, and 44.93%, respectively. The retention kinetics of carrot noodles during storage followed a zero-order reaction and had a shelf life of up to 30 weeks, 4 days, 4 hours. Keywords: carrot noodles, retention, self life

Page 15 of 33 | Total Record : 325

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