Judul: Total Phenolic, Flavonoid, and Antioxidant Activity Content of Purslane (Portulaca oleracea L.) Resulting from Streptomycin Mutation
Abstrak: Krokot (Portulaca oleracea L.) merupakan tanaman yang mengandung polifenol, seperti asam fenolik dan flavonoid yang berperan sebagai sumber antioksidan dalam alternatif pengobatan penyakit degeneratif. Penelitian ini bertujuan menentukan konsentrasi dan durasi perendaman streptomycin yang optimum untuk menghasilkan mutan putatif dengan kandungan fitokimia serta aktivitas antioksidan terbaik. Krokot diekstraksi secara basah menggunakan metode MAE dengan pelarut etanol 96%. Uji kadar total fenolik dan flavonoid ditentukan menggunakan metode Folin-Ciocalteu dan AlCl3 serta aktivitas antioksidan menggunakan metode DPPH juga FRAP. Kadar total fenolik dan aktivitas antioksidan DPPH tertinggi terdapat pada sampel A1B1 dan A2B2 (0,4507 ± 0,0115 mg GAE g¯? bb dan 0,0062 ± 0,0002 µmol TE g¯? bb) dengan peningkatan sebesar 3,59 kali dan 1,41 kali dibandingkan kontrol. Kadar total flavonoid dan aktivitas antioksidan FRAP tertinggi terdapat pada sampel A1B4 (2,3383 ± 0,0493 mg QE g¯? bb dan 5,5622 ± 0,0909 µmol TE g¯? bb) dengan peningkatan 4,4 kali dan 5,42 kali dibandingkan kontrol. Hasil karakteristik stomata dengan analisis dendogram menunjukkan bahwa A1B4 terbukti mengalami mutasi ditandai fenomena kimera., Purslane (Portulaca oleracea L.) contains polyphenols like phenolic acids and flavonoids, serving as antioxidants for treating degenerative diseases. This study aimed to determine the optimal concentration and duration of streptomycin soaking to produce mutants with the best phytochemical content and antioxidant activity. Wet extraction was performed using the MAE method with 96% ethanol. Total phenolic and flavonoid contents were measured using the Folin-Ciocalteu and AlCl3 methods, and antioxidant activity using DPPH and FRAP methods. The highest phenolic content and DPPH activity were in samples A1B1 and A2B2 (0,4507 ± 0,0115 mg GAE g¯? bb and 0,0062 ± 0,0002 µmol TE g¯? bb), showing increases of 3,59 and 1,41 times compared to the control. The highest flavonoid content and FRAP activity were in sample A1B4 (2,3383 ± 0,0493 mg QE g¯? bb and 5,5622 ± 0,0909 µmol TE g¯? bb), with increases of 4,4 and 5,42 times compared to the control. The dendrogram analysis of stomatal characteristics indicates that A1B4 has undergone mutation, as evidenced by the presence of chimera phenomena.
Keyword: antioxidant, flavonoid, phenolic, chimera, mutation, streptomycin

Judul: Total Phenolic Content and Antioxidant Capacity of Purslane (Portulaca oleracea L.) as Affected by Different
Abstrak: Krokot (Portulaca oleracea L.) merupakan tanaman yang telah terbukti mengandung berbagai macam senyawa bioaktif. Penelitian ini bertujuan mengukur dan menganalisis pengaruh jenis pelarut ekstraksi terhadap kadar fenolik total serta kapasitas antioksidan pada tanaman krokot. Sampel diekstraksi menggunakan gabungan metode ekstraksi sonikasi-maserasi dengan lima jenis pelarut (etanol p.a, metanol p.a, aseton p.a, etil asetat p.a, air). Hasil penelitian menunjukkan bahwa kadar fenolik total tertinggi dihasilkan oleh ekstrak air (2.78 mg GAE/g BK), sementara kadar terendah dihasilkan oleh ekstrak etil asetat (0.60 mg GAE/g BK). Kapasitas antioksidan pada berbagai metode uji (CUPRAC, FRAP, ABTS, DPPH) memiliki nilai signifikansi berbeda-beda berdasarkan hasil uji One-Way ANOVA (Analysis of Variance) dan uji lanjut Tukey HSD. Hasil korelasi Pearson positif sangat kuat ditunjukkan oleh kadar fenolik total dengan kapasitas antioksidan metode ABTS (r = 0.9145) dan FRAP (r = 0.9452). Penggunaan pelarut yang memiliki tingkat polaritas tinggi (air, metanol, etanol) direkomendasikan untuk mengekstrak senyawa fenolik dari aerial parts tanaman krokot maupun untuk isolasi, karakterisasi, serta pemanfaatan lebih lanjut., Purslane (Portulaca oleracea L.) is a plant that has been proven to contain various bioactive compounds. This study aim to measure and analyze the effect of extraction solvent type on total phenolic content and antioxidant capacity in purslane plants. Samples were extracted using a combined sonication-maseration extraction method with five types of solvents (ethanol p.a, methanol p.a, acetone p.a, ethyl acetate p.a, water). The results showed that the highest total phenolic content was produced by water extract (2.78 mg GAE/g BK), while the lowest level was produced by ethyl acetate extract (0.60 mg GAE/g BK). Antioxidant capacity in various test methods (CUPRAC, FRAP, ABTS, DPPH) has different significance values based on the results of One-Way ANOVA (Analysis of Variance) test and Tukey HSD. Very strong positive Pearson correlation results were shown by total phenolic content with antioxidant capacity of ABTS (r = 0.9145) and FRAP (r = 0.9452). The use of solvents that have a high level of polarity (water, methanol, ethanol) is recommended to extract phenolic compounds from aerial parts of purslane plants as well as for isolation, characterization, and further utilization.
Keyword: antioxidant, phenolic, purslane, solvent

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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