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•Three new amides together with 30 known compounds were isolated from the fruits of Piper retrofractum.•A plausible biosynthetic pathway leading to the amides isolated in this study ...is discussed.•All isolated compounds were screened for their antifungal and cytotoxic activities.
Three new amides, (2E,14Z)-N-isobutyleicosa-2,14-dienamide (1), dipiperamides F and G (2 and 3), together with 30 known compounds were isolated from the fruits of Piper retrofractum. Their structures were elucidated by extensive spectroscopic analyses including 1D and 2D NMR as well as MS, and by comparison with the literature. A plausible biosynthetic pathway leading to the amides isolated in this study is discussed. All isolated compounds were screened for their antifungal and cytotoxic activities. Piperanine (9) showed growth inhibition against the fungus Cladosporium cladosporioides, while dipiperamides F and G (2 and 3), chabamide (30), nigramide R (31), dehydropipernonaline (24), pipernonaline (25), guineensine (22), brachystamide B (23), retrofractamide C (20), pellitorine (13), and pipericine (14) exhibited considerable cytotoxicity against L5178Y mouse lymphoma cells with IC50 values of 10.0, 13.9, 11.6, 9.3, 8.9, 17.0, 17.0, 16.4, 13.4, 28.3, and 24.2μM, respectively.
Penelitian bertujuan untuk menentukan bahan ajar berbasis android pada material tata nama yang ditentukan. Pengembangan bahan ajar android dapat memudahkan peserta didik mengakses materi secara ...praktis dan membantu pemahaman materi tata nama senyawa yang mungkin terjadi, serta diharapkan peserta didik dapat memanfaatkan teknologi informasi dalam hal belajar. Penelitian menggunakan metode penelitian dan pengembangan dengan model ADDIE. Teknik pengumpulan data menggunakan instrumen validasi dan angket respon. Analisis data secara deskriptif kualitatif.Hasil analisis menunjukan bahwa validasi aspek materi 91,39% dengan kriteria sangat layak, validasi aspek media 90% dengan kriteria sangat layak, validasi aspek bahasa 94,73% dengan kriteria sangat layak, angket respon guru kimia 93,75% dengan kriteria sangat layak . baik, respon peserta didik uji coba skala kecil diperoleh 89.32% dengan kriteria sangat baik serta hasil respon peserta didik uji coba skala meluas sebesar 89.45% dengan kriteria sangat baik. Dapat dikatakan bahwa bahan ajar berbasis android berupa aplikasi dengan kapasitas 42 MB yang dikembangkan dengan respon peserta didik yang baik dan respon guru yang sangat baik, sehingga bahan ajar tersebut sangat layak digunakan sebagai perangkat pembelajaran. Kata kunci: pengembangan; bahan terbuka; android; senyawa berbahaya
Fourteen new natural products, namely, 2-(Z)-styryl-5-geranylresorcin-1-carboxylic acid (1), amorfrutin D (2), 4-O-demethylamorfrutin D (3), 8-geranyl-3,5,7-trihydroxyflavanone (4), ...8-geranyl-5,7,3′-trihydroxy-4′-methoxyisoflavone (5), 6-geranyl-5,7,3′-trihydroxy-4′-methoxyisoflavone (6), 8-geranyl-7,3′-dihydroxy-4′-methoxyisoflavone (7), 3-O-demethyldalbinol (8), 6a,12a-dehydro-3-O-demethylamorphigenin (9), (6aR,12aR,5′R)-amorphigenin (10), amorphispironones B and C (11 and 12), resokaempferol 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside-7-O-α-l-rhamnopyranoside (13), and daidzein 7-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside (14), together with 40 known compounds, were isolated from the fruits of Amorpha fruticosa. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic analysis as well as from the mass spectrometry data. ECD calculations were performed to determine the absolute configurations of 11 and 15. Compounds 1, 4–6, and 16–23 showed potent to moderate antibacterial activities against several Gram-positive bacteria with MIC values ranging from 3.1 to 100 μM. In addition, compounds 11 and 24–33 were significantly cytotoxic against the L5178Y mouse lymphoma cell line and exhibited IC50 values from 0.2 to 10.2 μM.
Penelitian ini bertujuan untuk mengetahui ada tidaknya perbedaan hasil belajar pada model pembelajaran Numbered Heads Together pada mata pelajaran Hukum Kimia Dasar. Bentuk penelitian ini adalah ...rancangan eksperimen sejati. Sampel penelitian adalah kelas X TSM sebagai kelas eksperimen, kelas X TKR sebagai kelas kontrol dengan purposive sampling. Alat pengumpulan data yang digunakan terdiri dari tes hasil belajar, wawancara, dan lembar observasi. Hasil belajar dianalisis menggunakan uji Mann Whitney U. Hasil analisis menunjukkan bahwa terdapat perbedaan hasil belajar antara siswa yang diajar menggunakan LKPD model Numbered Heads Together dengan siswa yang diajar menggunakan metode konvensional. Pembelajaran dengan NHT berbantuan LKPD memiliki pengaruh sebesar 42,51% dengan kategori tinggi (Effect Size = 1,44) terhadap peningkatan hasil belajar siswa kelas X TSM SMK PGRI Pontianak pada materi hukum kimia dasar.
This research was aimed to produce a valid electronic graphic novel on free radical reaction subject and to find out the student’s response to the developed product. This research employed Research ...Development (RD) method by using Thiagarajan’s 4D model with modification, in which applied only three of four steps in 4D model. The developed product was validated by experts. The responses toward developed product were collected from the students of Chemistry Education FKIP Untan who have taken organic chemistry course. Data collection tools used were validation sheets and student’s response questionnaires on the developed product. The validation’s result from the experts showed that the developed product was very proper in terms of content, presentation, linguistic, and graphic aspects with consecutive total scores of 94.0%, 95.0%, 89.0%, and 100,00% respectively. The results of the student’s responses in small group trials and in large group trials were of 82.5% with high category and of 83.2% with very high category, respectively. Thus, this electronic graphic novel on radical reaction has very good potential as a learning media to attract students to learn free radical reaction and its application in daily life.
This study aims to determine and compare antioxidant activity, total phenolics, flavonoids, and the relationship of phenolic and total flavonoids with the antioxidant activity of the three kratom ...variants. The ethanol extract of the third variant of kratom leaves was obtained by maceration. Through the antioxidant activity test using DPPH method, all three extracts showed strong antioxidant activity with IC50 values of 26.39, 30.25, and 30.59 μg/mL. The relationship of total phenolics and flavonoids with antioxidant activity was determined by the Pearson correlation test. Examination of total phenolic content using the Folin-Ciocalteu method with successive results for green, red, and white kratom are 6.11, 8.67, and 9.09 mg GAE/g extract. Examination of total flavonoid content using the colorimetric method for green, red, and white kratom were 0.86, 0.68, and 1.13 mg QE/g extract, respectively. The total phenolic content and antioxidant activity showed a correlation coefficient value of -0.32 (P0.05), and the total flavonoid content to antioxidant activity showed a correlation coefficient value of 0.81 (P0.05). Thus, all three variants of kratom have potency as natural antioxidants, but their total phenolic and flavonoid content does not influence their antioxidant activity.
Dillenia suffruticosa is one of the tropical medicinal plants that has been used traditionally for treating several tropical diseases. However, phytochemical and pharmacological investigations of D. ...suffruticosa wood bark have not been well-investigated. This research aimed to investigate the correlation between antioxidant properties and total phenolic content of phenolics rich extract and fractions from D. suffruticosa wood bark. The phytochemical investigation revealed the existence of phenolics and alkaloids in methanolic crude wood bark extract and all fractions. Meanwhile, the presence of flavonoids was shown in chloroform and methanol fractions. The highest total phenolic content was demonstrated by methanol fraction with 254.34 ± 16.86 mg GAE/g extract. Meanwhile, the highest total flavonoid content was interestingly displayed in chloroform fraction with 15.33 ± 0.26 mg RE/g extract. The crude extract and methanol fraction had a profound antioxidant activity with IC50 values of less than 15.63 ppm and 8.83 ppm, respectively. A strong correlation was shown between the antioxidant activity and total phenolic contents through correlation analysis. Thus, the D. suffruticosa wood bark could be considered a potential natural source of antioxidants.
Penelitian ini dilakukan dengan tujuan menentukan tingkat kelayakan serta respon peserta didik mengenai media video pembelajaran animasi pada materi hidrokarbon. Metode penelitian yang diterapkan ...adalah Research and Development (RD) dengan model ADDIE mencakup tahap Analyze, Design dan Development . Subjek penelitian ini yaitu media pembelajaran video animasi pada materi hidrokarbon. Teknik pengumpulan data yang diterapkan adalah pengukuran dan komunikasi tidak langsung. Alat pengumpul data menggunakan lembar penilaian kelayakan dan angket respon yang diukur menggunakan skala likert. Penilaian kelayakan media pembelajaran video animasi pada materi hidrokarbon memperoleh hasil sangat layak dengan persentase 96,67% pada aspek materi dan 100% pada aspek media. Hasil uji respon peserta didik memperoleh hasil sangat baik dengan persentase pada uji coba perorangan, uji coba kelompok kecil dan uji coba lapangan berturut-turut sebesar 88,33%, 86,14% dan 89,57%. Dengan demikian, media pembelajaran video animasi pada materi hidrokarbon yang dihasilkan dapat diimplementasikan sebagai media pembelajaran tambahan pada materi hidrokarbon.
Cytotoxic activities of extracts of Pycnarrhena cauliflora leaves, stems and roots on some human cancer cells have been known. However, the cytotoxicity of stem of Pycnarrhena cauliflora on human ...breast cancer cell line T47D through an apoptosis induction has not been proven yet. This study was an effort in understanding the cytotoxic activity of stem of Pycnarrhena cauliflora through apoptosis induction. The crude ethanol extract was partitioned between n-hexane and dichloromethane at pH 3, 7 and 9, which was subsequently tested for their cytotoxic activity against human breast cancer cell line T47D by using 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT). Flow cytometric analysis with Annexin V-FLUOS/ propidium iodide (PI) double staining was used for apoptosis analysis. The dichloromethane fraction at pH 7 was considered the most potent with an IC50 value of 59.30 µg/mL and induced apoptosis on the T47D cell line. The result indicated the potential of dichloromethane fraction of the stem of P.cauliflora as a source of bioactive compounds and provided a basis of further studies to isolate a new anticancer compound.
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