Judul: Optimization of Extraction of Antimicrobial Peptide from Gandarusa Leaves Using the Box-Behnken Design
Abstrak: Antimicrobial Peptide (AMP) memiliki aktivitas spektrum luas dan dapat membunuh bakteri yang resistan terhadap berbagai obat. Daun gandarusa (Justicia gendarussa Burm. F.) memiliki aktivitas antibakteri namun kajian terkait antimicrobial peptide pada tanaman tersebut belum dilakukan. Penelitian ini bertujuan menentukan kondisi optimum ekstraksi serta mengidentifikasi AMP daun gandarusa yang berpotensi memiliki aktivitas antibakteri. Rancangan optimasi ekstraksi dibuat menggunakan Box-Behnken Design. Kadar total protein diukur dengan metode Bradford, identifikasi AMP dilakukan dengan metode SDS-PAGE, dan pengujian aktivitas antibakteri dilakukan dengan metode difusi sumuran. Hasil penelitian menunjukkan kondisi optimum ekstraksi diperoleh dari kombinasi konsentrasi pelarut 14,997%, waktu ekstraksi 2,998 jam, dan rasio antara sampel dengan pelarut yaitu 1:3. Identifikasi dengan SDS-PAGE menunjukkan AMP terduga dari daun gandarusa memiliki berat molekul sebesar 11 kDa, pengujian aktivitas antibakteri ekstrak kasar terhadap Escherichia coli dan Staphylococcus aureus tidak menunjukkan adanya daya hambat., Antimicrobial Peptide (AMP) has broad-spectrum activity and can kill multidrug-resistant bacteria. Gandarusa leaves (Justicia gendarussa Burm. F.) have antibacterial activity, but studies regarding antimicrobial peptides in this plant have not been carried out. This study aimed to determine the optimum conditions of extraction and identify AMPs of gandarusa leaves that have potential antibacterial activity. Extraction optimization design was made using Box-Behnken Design. Total protein levels were measured by the Bradford method, AMP identification was carried out by the SDS-PAGE method, and antibacterial activity testing was carried out by the well diffusion method. The results showed that the optimum extraction conditions were obtained from a combination of 14,997% solvent concentration, 2,998 hours extraction time, and the ratio between sample and solvent of 1:3. Identification with SDS-PAGE showed that AMP from gandarusa leaves has a molecular weight of 11 kDa, testing the antibacterial activity of crude extracts against Escherichia coli and Staphylococcus aureus showed no inhibition.
Keyword: antimicrobial peptide, Box-Behnken design, Gandarusa leaves, optimization

Judul: Optimization of Extraction for Total Phenolics and Highest  Antioxidant Capacity in Gandarusa Using Two-Level Half Factorial Design
Abstrak: Gandarusa (Justicia gendarussa Burm. f.) telah digunakan sebagai obat tradisional dan dilaporkan memiliki senyawa fitokimia dan aktivitas antioksidan yang tinggi. Penelitian ini bertujuan untuk mengukur pengaruh perbedaan kondisi ekstraksi berdasarkan rasio cairan terhadap padatan, suhu, konsentrasi pelarut, waktu, dan pH tanaman gandarusa dengan two level half factorial design terhadap produksi metabolit sekunder dan kapasitas antioksidannya. Sampel diekstraksi sesuai dengan desain two level half factorial. Kandungan fenolik, kapasitas antioksidan DPPH dan FRAP tertinggi didapat oleh run-13 berturut-turut sebesar 28,15 mg GAE/g, 54,19 μmol TE/g, dan 218,73 μmol TE/g. Desain two level factorial digunakan untuk menentukan faktor yang signifikan terhadap ekstraksi kadar fenolik total, serta kapasitas antioksidan DPPH dan FRAP. Faktor suhu berperan signifikan (< 0,05) terhadap kadar fenolik total. Sedangkan pada kapasitas antioksidan DPPH didapatkan bahwa faktor cairan terhadap padatan dan pH berperan signifikan (< 0,05). Pada FRAP didapatkan bahwa faktor cairan terhadap padatan menjadi faktor yang berperan signifikan (< 0,05). Kata kunci: antioksidan, factorial, gandarusa, cairan terhadap padatan, suhu, Gandarusa (Justicia gendarussa Burm. f.) is often used as a traditional medicine and is reported to contain high levels of phytochemical compounds and antioxidant activity. This study aimed to measure the influence of different extraction conditions based on liquid to solid ratio, temperature, solvent concentration, time, and pH of gandarusa plant on the production of secondary metabolites and antioxidant capacity using a two-level half factorial design. Samples were extracted according to the two-level half factorial design. The highest phenolic content, DPPH and FRAP antioxidant capacity were obtained from run 13, with values of 22.75 mg GAE/g, 43.36 μmol TE/g, and 166.72 μmol TE/g, respectively. A two-level factorial design was used to determine the significant factors affecting the extraction of total phenolic content, DPPH antioxidant capacity, and FRAP antioxidant capacity. Temperature was found to have a significant effect (<0.05) on the total phenolic content. Meanwhile, for DPPH antioxidant capacity, the liquid to solid ratio and pH was found to be the significant factor (<0.05). In FRAP, it was found that the liquid to solid factor was a significant factor (<0.05). Keyword: antioxidant, factorial, gandarusa, liquid to solid, temperature
Keyword: antioxidant, factorial, gandarusa, liquid to solid, temperature

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology