Judul: Aktivitas antioksidan ekstrak selaginella
Abstrak: Selaginella (Selaginellaceae) is a pteridophyte plant, having a lot of potential and benefits as food material and pharmaceutical. As a medicinal plant, Selaginella has been used as anti-cancer, anti-tumor, and antioxidant. The objective of the study was to analyze the potential of S. ornata, S. plana, and S. willdenovii extract as antioxidant by measuring lipid peroxidation (MDA level) and Superoxide Dismutase (SOD) activity. This experiment was started with LD50 test of three kinds of Selaginella extract as preliminary experiment. The experiment was designed as complete randomize design with two factors. The first factor was three species of Selaginella and the second factor was four doses of Selaginella extracts, which were 0, 0.3, 0.6, and 1.2 g extract/kg bw. The result showed that at the dose of 0.6 g extract/kg bw, Selaginella extract could decrease the MDA level to the lowest level. The dose of 0.3 g extract/kg bw could increase the SOD activity. Among the three species of Selaginella extract, S. ornata showed the best antioxidant activity.
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Judul: Metabolomic Analysis of Selaginella spp. (Selaginellaceae) and its Potential as Medicinal Plants
Abstrak: Selaginella merupakan salah satu marga tumbuhan paku dari suku Selaginellaceae yang memiliki keragaman spesies yang tinggi di daerah tropis dan subtropis. Selaginella memiliki potensi dan manfaat yang cukup besar terutama dalam bidang kesehatan, khususnya dapat dimanfaatkan sebagai tumbuhan obat. Namun, informasi metabolit pada Selaginella spp. masih terbatas. Penelitian ini bertujuan menganalisis metabolit pada Selaginella spp. yang dapat dimanfaatkan sebagai obat dan dapat digunakan sebagai pembeda antar spesies. Metode penelitian yang dilakukan meliputi preparasi sampel, ekstraksi sampel, analisis kandungan metabolit dengan LC-MS/MS, dan analisis data. Analisis metabolomik meliputi identifikasi metabolit menggunakan perangkat lunak MZmine 3.1.0 beta, analisis profil metabolit, klaster heatmap, dan analisis gugus menggunakan MetaboAnalyst 5.0. Hasil analisis menunjukkan sebanyak 113 metabolit terdeteksi pada tiga spesies Selaginella yang diamati. Analisis gugus berdasarkan ciri metabolit mengelompokan seluruh individu menjadi 3 kelompok sesuai dengan spesiesnya. Metabolit Selaginella willdenowii lebih mirip Selaginella ornata dibandingkan dengan Selaginella plana. Beberapa senyawa yang terdeteksi memiliki manfaat penting dalam bidang pangan, kesehatan, dan kecantikan. Senyawa aloeresin a, naringin, rhoifolin, isoschaftoside, isovitexin 2''-oarabinoside, 4-vinylphenol, dan isofraxidin merupakan kandidat penanda kimia pada Selaginella plana. Senyawa velutin, aspalathin, 2-hydroxybenzaldehyde, gardenin a, catechol, dan n-(1,1-dimethyl-3-oxobutyl)acrylamide merupakan kandidat penanda kimia pada Selaginella ornata. Senyawa kapakahine b, dihydrojasmonic acid, linoleic acid, alantoic acid, menaquinone, dan nandrolone merupakan kandidat penanda kimia pada Selaginella willdenowii., Selaginella is a genus of Pteridophyta from the Selaginellaceae which has high diversity in tropical and subtropical areas. Selaginella has considerable potential and benefits, particularly it can be used as a medicinal plant. However, information on metabolites in Selaginella spp. is still limited. This study aimed to analyze the metabolite compounds in Selaginella spp. which can be used as medicine and as a biomarker to differentiate among species. The research methods included sample preparation, sample extraction, analysis of metabolite content by LC-MS/MS, and data analysis. The metabolomic analysis included the identification of metabolites using MZmine 3.1.0 beta software, analysis of metabolite profiles, and cluster analysis using MetaboAnalyst 5.0. The results of the analysis showed that as many as 113 different metabolites were detected in the three Selaginella species. Metabolite based cluster analysis grouped all individuals into 3 groups according to the species. Selaginella willdenowii metabolites are more similar to Selaginella ornata than Selaginella plana. Some of the metabolites detected have important benefits for food, health, and beauty. Aloeresin a, naringin, rhoifolin, isoschaftoside, isovitexin 2''-o-arabinoside, 4- vinylphenol, and isofraxidin compound are candidate chemical markers in Selaginella plana. Velutin, aspalathin, 2-hydroxybenzaldehyde, gardenin a, catechol and n-(1,1-dimethyl-3-oxobutyl)acrylamide compound are candidate chemical markers in Selaginella ornata. Kapakahine b, dihydrojasmonic acid, linoleic acid, alantoic acid, menaquinone, and nandrolone compound are candidate chemical markers in Selaginella willdenowii.
Keyword: cluster analysis, heatmap, LC-MS/MS, metabolite

Judul: Bifurkasi Hopf pada siklus bisnis IS-LM tanpa dan dengan waktu tunda
Abstrak: One of business cycle models in dynamical economics is the IS-LM business cycle model with time delay, where the time delay lies in stock capital variables. It is a time delay between the existence of stock capital and the time to get ready to invest. In a model without time delay, changing the parameter of investment rate on income could affect the system stability. On the other hand, in a model with time delay, there exists critical time delay changing the system stability. This shows limit cycle, which can be concluded that Hopf bifurcation occurs
Keyword: Bogor Agricultural University (IPB), time delay, Hopf bifurcation, business cycle model