Judul: Sifat Antijamur Ekstrak Metanol Kulit Batang Litsea tomentosa Blume
Abstrak: The bark is a waste that produced from harvesting activity and wood processing that have not been utilized efficiently. The bark volume is about 10-20% of whole stem volume depend on stem diameter. The bark utilization also has been grow to extract utilization for medical purpose, anti-fungi, anti-bacteria, and insecticides. The bark powder of L.tomentosa with size 40-60 mesh as much as 170 g was extracted using soxhlet with the methanol solvent. Rough methanol extract was tested to the brown rot fungi Poria placenta and Gloeophyllum trabeum. Meanwhile, Coriolus versicolor was used for white rot fungi. Anti-fungi index of methanol extract are 66.7% for Poria placenta, 54% for Coriolus versicolor and 100.0 % for Gloeophyllum trabeum, respectively. The concentrated methanol extract of L. tomentosa stem bark then separated using column chromatography. The results of LCMS and NMR analysis show that the extract contained alcaloid compound of brucine and 17 oxulapanine
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Judul: Antibacterial Activity of Meranti Bark Ethanol Extract Againts Staphylococcus aureus
Abstrak: Ekstrak kulit kayu meranti diketahui memiliki aktivitas antibakteri. Dalam penelitian ini, berbagai konsentrasi etanol, 50% (E50), 75% (E75), dan 100% (E100) digunakan sebagai pelarut untuk mengekstraksi kulit kayu menggunakan metode ekstraksi soxhlet. Hasil ekstrak ditentukan dan kemudian dilakukan uji aktivitas antibakteri terhadap S. aureus menggunakan metode difusi cakram. Kandungan fitokimia ditentukan secara kualitatif mengacu pada metode Harborne. Komposisi kimia ekstrak dengan aktivitas antibakteri tertinggi dianalisis dengan LC-MS dan dikonfirmasi dengan spektroskopi FTIR. Hasil penelitian menunjukkan bahwa rendemen ekstrak tertinggi diperoleh pada E75 (8,39%), diikuti oleh E50 (7,86%), dan E100 (6,58%). Ekstrak tersebut dapat menghambat pertumbuhan S. aureus pada kisaran sedang sampai kuat. Analisis fitokimia dan spektrum FTIR mengkonfirmasi adanya kandungan flavonoid, fenolhidrokuinon, tanin, saponin, dan triterpenoid dalam ekstrak. Analisis LC-MS menunjukkan adanya (+)-Nootkatone, aurantimide acetate, Vitisin C, Kievitone yang diduga berperan dalam aktivitas antibakteri terhadap S. aureus., Meranti bark extract has been known posses the antibacterial activity. In this study, various concentrations of ethanol, 50% (E50), 75% (E75), and 100% (E100) was used as solvent to extract the bark using soxhlet extraction method. The extract yields were determined and then subjected to the antibacterial activity assay against S. aureus using disc diffusion method. The phytochemicals content was determined qualitatively reffered to Harborne method. The chemical composition of the extract with the highest antibacterial activity was analyzed by LC-MS and confirmed by FTIR spectroscopy. The study showed that the highest extract yield was obtained in E75 (8.39%), followed by E50 (7.86%), and E100 (6.58%). The extract can inhibited the growth of S. aureus in the range of moderate to strong. The phytochemical analysis and FTIR spectrum confirmed flavonoid, phenolhydroquinone, tannin, saponin, and triterpenoid in the extract. LC-MS analysis showed the presence of (+)-Nootkatone, aurantimide acetate, Vitisin C, Kievitone that suggested have a role in the antibacterial activity against S. aureus
Keyword: antibakteri, konsentrasi pelarut, etanol, meranti, rendemen, sokhlet, antibacterial, ethanol solvent concentration, meranti, soxhlet, yield

Judul: Dynamic New Keynesian Model for Unemployment and Inflation Rate.
Abstrak: This paper deals with a scientific analysis of the equilibrium level of hiring, employment and unemployment. The basic model being used is a standard new Keynesian model, which states that utility function depends on consumptions and working hours. Utility maximization refers to a standard labour supply equation, with the marginal cost’s dynamics on new Keynesian model simply reflects movements in real wages and productivity. Furthermore, trade-off between output and inflation stabilization can be considered using the new Keynesian Phillips curve. Dynamic general equilibrium model is a model that can be used to study interactions between market imperfections and nominal rigidities, which is capable of overcoming the main shortcoming of the standard new Keynesian model. In the general equilibrium model there are three groups of the economy agents, namely households, firms and monetary authority. The results of this research science that bargaining processes between firms and workers will yield optimal wage. Increase in labour will cause wages to fall, but the unemployment rate can be reduced. An increase in the firm’s monopoly power will shift the labour demand curve downward, which will reduce the number of workers that firm is willing to hire for any given bargained wage.
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