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PERBANDINGAN PEMBELAJARAN KOPERASI TIPE TWO STAY TWO STRAY (TSTS) DAN GROUP INVESTIGATION (GI) TERHADAP HASIL BELAJAR KIMIA Apria Haja Krisma; Dewi Handayani; Nurhamidah Nurhamidah
ALOTROP Vol 5, No 1 (2021)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v5i1.16482

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SKRINING FITOKIMIA DAN AKTIVITAS ANTIOKSIDAN BEBERAPA FRAKSI DARI KULIT BATANG JARAK (Ricinus communis L.) Wulan Agustina; Nurhamidah Nurhamidah; Dewi Handayani
ALOTROP Vol 1, No 2 (2017)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v1i2.3529

Abstract

[PHYTOCHEMICAL SCREENING AND ANTIOXIDANT ACTIVITY OF SOME FRACTIONS FROM BARK OF CASTOR (Ricinus communis L.)]. The Phytochemical screening was conducted to determine secondary metabolites found in the bark of castor (Ricinus communis L.).The test results of phytochemical screening that has been done presence of  phenolic, flavonoids, alkaloids, saponins, and terpenoids. Extraction is done by maceration using ethanol 96%. Tests performed on the fraction of the antioxidant activity of ethanol, ethyl acetate, n-hexane, and ascorbic acid as compared to using DPPH. The results of measuring the antioxidant activity using Uv-Vis Spectrophotometer IC50 values obtained succession namely fraction of ethanol, ethyl acetate, n-hexane, and ascorbic acid, 33,38, 24,38, 289, 05 and 12, 48 ppm. Fraction of ethanol and ethyl acetate has a very strong antioxidant activity due IC50<50 ppm while the n-hexane fraction very weak antioxidant activity. Phenolic and flavonoids the bark of castor that can be potentially as antioxidants
POTENSI SITOTOKSIK DAN ANTIBAKTERI EKSTRAK DAUN Laportea interrupta (L.) Chew (JELATANG AYAM) TERHADAP Staphylococcus aureus Okti Mindi Safitri; Nurhamidah Nurhamidah; Hermansyah Amir
ALOTROP Vol 2, No 2 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i2.7492

Abstract

This research aims to determine the profile of phytochemicals, determine the level of cytotoxic extract toward the larva of Artemia salina Leach by using Brine Shrimp Lethality Test (BSLT) method, and to measure how much the activity of  antibacteria leaf ekstract of Laportea Interrupta (L.) Chew  (Jelatang Ayam )  toward the Staphylococcus aureus bacteria. The leaf of L. interrupta  (L.) Chew are dried and grinded well. The half of grinded sample are tested by phytochemical  profile and another one are ekstracted by using etanol liquid for three days then they are evaporated. The result of fitokimia leaf L. interrupta  (L.) Chew test contains secondary metabolite alkaloid,  tanin, terpenoid,  and saponin. The result of cytotoxic extract of leaf L. interrupta  (L.) Chew toward the A. salina Leach is obtained LC50 for 93,33 ppm, so, the L. interrupta  (L.) Chew is toxic because it is in the range of 31 ppm to 1000 ppm and it can be potentially as a anticancer agents. The eksract of Jelatang Ayam leaf can obstruct the growth of S. aureus, on 5 x 104 clear zone concentration that formed 9 mm being medium categorized. The more concentration of the Jelatang leaf ekstract then more its obstruction energy.
PERBANDINGAN HASIL BELAJAR KIMIA SISWA ANTARA MODEL PEMBELAJARAN KOOPERATIF TIPE STAD DAN CORE DI SMAN 2 KOTA BENGKULU TAHUN PELAJARAN 2018/2019 Citra Utari; Salastri Rohiat; Nurhamidah Nurhamidah
ALOTROP Vol 4, No 2 (2020)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v4i2.13862

Abstract

This study aims to see whether or not there are differences in student chemistry learning outcomes between classes that apply STAD and CORE type cooperative learning models to buffer solution material in class XI MIPA Bengkulu City 2 High School 2018/2019. The study was conducted in March-April 2019. This type of research is Quasi research experiments. The population of this study was students of class XI MIPA with a population of 243 students. Sampling was carried out after the homogeneity and normality test, so the class XI MIPA A and XI MIPA B was selected as the research sample with random sampling technique with a sample of 60 students. The first experimental class uses the STAD learning model and the experimental class II uses the CORE learning model. Student learning outcomes data obtained from the value of the pretest and posttest. The two treatments given can improve learning outcomes with the average value of the pretest of experimental class I and experiment II namely 27.83 and 33.83 then the average value of the posttest of experimental class I and experiment II is 80 and 80.2 which means the posttest value has reached KKM which is 75. Hypothesis testing is done using a significant level (? = 0.05), the value obtained for t count> t table is 2,286> 1,672. These results can be concluded that there are significant differences in learning outcomes between the experimental class I and experiment II on the buffer solution material
UJI SITOTOKSIK DAN AKTIVITAS ANTIBAKTERI EKSTRAK DAUN PANDAN LAUT (Pandanus Odorifer) TERHADAP BAKTERI Staphylococcus aureus Shinta Puspasari; Nurhamidah Nurhamidah; Hermansyah Amir
ALOTROP Vol 4, No 1 (2020)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v4i1.13708

Abstract

This study aims to determine the activity of marine pandanus extract(Pandanus odorifer) as cytotoxic and antibacterial to Staphylococcus aureus bacteria. This research begins with phytochemical test conducted to find out the secondary metabolite compounds contained in the leaves of P. odorifer. Cytotoxic testing was performed using BSLT method. An antibacterial test was performed against the activity in inhibiting the growth of S. aureus bacteria using a modified disc diffusion method. The results of phytochemical tests showed that ethanol extract of pandanus leaves contain saponin, flavonoids, tannin and terpenoid compounds. The results of cytotoxic test of sea pandan have a very strong toxic level with LC50 value of 4.3557 ppm.The result of measurement of the highest inhibiting zone diameter was obtained at the concentration of 5x104 ppm is 6 mm with the power of inhibitory that is medium. Based on the results of this study can be concluded that the leaves of sea pandan are cytotoxic and have activity as antibacterial
PEMANFAATAN EKSTRAK BUAH Morus alba L. (Murbei) SEBAGAI PENGAWET ALAMI IKAN Selaroides leptolepis (Selar) Diah Sari Nastiti; Nurhamidah Nurhamidah; I Nyoman Chandra
ALOTROP Vol 3, No 1 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i1.9019

Abstract

The purpose of this study is to measure the influence of concentration and time of soaking of fruit extracts Morus alba l. (Mulberry) is effective as a preservative Selaroides leptolepis fish (Trevally). Samples taken of coral in the fruit of the Holy City of Argamakmur, North Bengkulu and trevally fish samples taken directly from the beach, the village Plow Jakat, province of Bengkulu. Fruit samples grinded using a blender and aqueous extracts are obtained through maceration method using aquades and filtered so that retrieved the mulberry and subsequent solution diluted with aquades be a concentration of 20, 40, 60 and 80% (v/v). Phytochemicals profile test to determination of secondary metabolites in extracts. The test is done through the methods of preserving this soaking on a several concentrations variation and soaking time with without soaking as control. The variation of the concentrations is done at a concentration of 10, 20, 30 and 40%, with soaking time variation 1, 2 and 3 hours. Variation of time observations were at 12, 18 and 24 hours and test the chemical content in the form of a test of water content, levels of Total Volatile Bases (TVB), and pH values. Phytochemical test results obtained the presence of saponins, alkaloids, terpenoids, phenolic and flavonoid compounds and do not contain steroids. The results showed that the extract of Mulberry fruits proved capable of lowering the pH and the levels of TVB but does not affect the water content of the fish. Soaking time variations do not affect the water content, pH and the levels of TVB. From the results obtained that the use of the mulberry fruit extract at concentrations of 30% with long submergence 1 hour most optimal for use as a preservative natural for S. leptolepis up to 18 hours at room temperature to the value pH 6.7 and TVB at 27.2 mg N%.
STUDI PERBANDINGAN HASIL BELAJAR KIMIA SISWA MENGGUNAKAN MODEL PEMBELAJARAN PROBLEM BASED LEARNING (PBL) DAN DISCOVERY LEARNING PADA MATERI LARUTAN PENYANGGA Rina Anjelina; Elvinawati Elvinawati; Nurhamidah Nurhamidah
ALOTROP Vol 5, No 1 (2021)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v5i1.16483

Abstract

PENERAPAN MODEL PEMBELAJARAN PROBLEM BASED INSTRUCTION (PBI)DENGAN MENGGUNAKAN MEDIA AUDIO-VISUAL UNTUK MENINGKATKAN AKTIVITAS BELAJARDAN HASIL BELAJAR SISWA DI SMA N09 KOTA BENGKULU Isna Mutaqwiyati; Nurhamidah Nurhamidah; Hermansyah Amir
ALOTROP Vol 2, No 2 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i2.7558

Abstract

This research was aimed to find out the student’s improvement of  learning activity and learning outcome as the implementation of  Problem Based Instruction (PBI) by using audio-visual media. The subject of this research was the students at grade X MIPA 3 of SMA N 09 Bengkulu Ciyty academic year of 2017/2018 which consisted of 27 students, on the subject of of chemistry’s basic laws and stoichiometry. This research was conducted by the researcher by using three cycles which consisted of four steps; planning, action, observation and reflection. The data collections were tests and non tests which consisted of post test and student’s learning activity observation sheets. The data of this research was analyzed by using simple quantitative data analysis;   the student’s average score, the percentage of classical absorption and the percentage of classical learning mastery.   Based on the result of this research can be concluded that the implementation of   PBI by using audio-visual media improved student’s learning activity and learning outcomes in each cycle and achieved the clasical learning outcomes in cycle III. The improvements of student’s average score was; score 23 (Fair) of cycle I; score 26,33 (good) of cycle II; and score 28,66 (good) cycle III. The average score of teacher observation sheets of each cycles were; 25,66 fpr the first cycle (good), 28 for the second cycle (good), and 29,66 in the last cycle (good). There  was also  improvements of the students’ percentage of classical learning mastery from in cycle I 51,85%, to 66,66% in cycle II and 85,15% in cycle III.
AKTIVITAS ANTIOKSIDAN METABOLIT SEKUNDER BAKTERI ENDOFIT AKAR TANAMAN Moringa oleifera L (Kelor) Zeta Kuntari; Sumpono Sumpono; Nurhamidah Nurhamidah
ALOTROP Vol 1, No 2 (2017)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v1i2.3483

Abstract

[ANTIOXIDANT ACTIVITY OF SECONDARY METABOLITE FROM ENDOFIT BACTERIA OF  Moringa oleifera L (KELOR) ROOTS]  The purpose of this research was aims to isolate and measure the ability of antioxidant activity from secondary metabolites produced by endophytic bacteria that grow in the live tissue root  of Moringa oleifera L. (kelor). Endophytic bacteria were purified and cultured using a solid  Murashige-skoog (MS)  medium for 3 days at room temperature. Secondary metabolites were obtained by centrifugation process at a rate of 3000 rpm for 20 minutes. The bacterial fermentation process  using  Nutrient Broth  (NB) medium for 72 hours with a shaker speed at 170 rpm . The suspension supernatant was extracted with a maceration method using 86% ethyl acetate, followed by vacuum rotary evaporator concentration at 40 ° C. The extract antioxidant activity test  was performed using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method using a UV-Vis spectrophotometer at 517 nm wavelength and ascorbic acid as standard. The result of DPPH test showed that the antioxidant activity of ethyl acetate extract of endophytic bacterial from root of M. oleifera L root has IC50 value at  315, 396 ppm.  Based on these results, it can be concluded that the secondary metabolite extract of endophytic bacterial from M. oleifera L root classified as weak antioxidant (IC50> 250 ppm).
POTENSI EKSTRAK TUMBUHAN ANDALIMAN (Zanthoxylum acanthopodium DC.) SEBAGAI ANTIBAKTERI Staphylococcus aureus Oma Sepriani; Nurhamidah Nirhamidah; Dewi Handayani
ALOTROP Vol 4, No 2 (2020)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v4i2.13864

Abstract

The aims of this study is to determine the secondary metabolite compounds in Roots, stem bark, leaves and fruit of Andaliman (Zanthoxylum acanthopodium DC), and determine the most potent part of Andaliman plant extract in inhibiting the growth of Staphylococcus aureus bacteria. Andaliman plant taken in Simarpingan, Sipaholon village sub district of North Sumatra. Part of the Andaliman plantar are cleaned, cut into small pieces and then dried and mashed, samples that have been finely phytochemically tested and extracted. Testing of secondary metabolite compound by doing phytochemical screening of roots, stem bark, leaves and fruit of Andaliman, alkaloid test using meyers reagent, terpenoid test and steroid using TLC plate with eluent n-hexana : ethyl acetate with ratio 6:4, flavonoid test using soluton HCl and Mg band, saponin test using soap test, tannin test using ferro (III) chloride solution. Test of antibacterial activity using disc diffusion method. Phytochemical results showed that all parts of the plant andaliman contain secondary metabolite compounds namely alkaloids, flavonoids, terpenoids, tannins and also saponins. The result of antibacterial activity test of leaf extract of leaf and leaf which has the most potential as antibacterial of S.aureus is bark. Because it able to inhibit S.aureus growth with 11 mm inhibition zone at concentration 5x104 ppm, which is included in the strong category. In addition to skin of andaliman leaf stem is also potential as an antibacterial with a 10 mm inhibition zone at concentration 5x104 ppm, which is included in the medium category.