Judul: Isolasi senyawa sinamaldehida dari minyak kulit kayu manis sedagai antioksidan
Abstrak: Cinnamaldehyde is a major essential oil component of cinnamon bark. Cinnamon oil was isolated by using water distillation method that yielded 0.93% (w/w) or 0.95% (v/w). Gas chromatography mass spectrometry (GCMS) of cinnamon oil showed that the main component of the oil is a trans-cinnamaldehyde 32.8% and 3-phenyl-2-propenal 22.9%. The oil was further isolated for cinnamaldehyde by using preparative thin layer chromatography method at Rf of 0.62. GCMS analysis showed that cinnamaldehyde content was 89.1%. Furthermore, the cinnamaldehyde was tested for its antioxidant activity. The isolated product has antioxidant activity with IC50 of 5.06 mg/L as compared with positive control using butylated hydroxytoluene, which has the activity of 10.4 mg/L.
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Judul: Antioxidant Activity and Total Phenolic Content of Cinnamon Bark (Cinnamomum burmannii) from Jambi based on Simplisia's Particle size
Abstrak: Kulit kayu manis mengandung senyawa polifenol yang berpotensi sebagai antioksidan dan dapat ditingkatkan dengan memperkecil ukuran partikel simplisia. Penelitian ini bertujuan menentukan pengaruh ukuran partikel simplisia terhadap rendemen ekstrak, nilai kadar total fenolik, dan aktivitas antioksidan kulit kayu manis asal Jambi. Kayu manis diekstraksi menggunakan pelarut etanol 70%, pengujian aktivitas antioksidan dilakukan menggunakan uji DPPH dengan nilai IC50. Hasil rendemen simplisia nanopartikel lebih tinggi yakni sebesar 38,36% dari kedua sampel lainnya. Hasil uji aktivitas antioksidan sampel simplisia nanopartikel lebih kuat yakni sebesar 34,56 ± 0,72 μg/ml daripada kedua sampel lainnya. Kadar total fenolik sampel simplisia nanopartikel lebih tinggi daripada sampel lainnya yakni sebesar 60,14 ± 3,66 mg GAE/g bobot kering. Hasil pengujian menunjukkan hasil yang berbeda nyata (p<0,05). Korelasi diantara nilai total fenolik dengan nilai IC50 DPPH sangat kuat dan bernilai negatif. Semakin tinggi kadar total fenolik maka semakin kecil nilai IC50, sehingga semakin baik aktivitas antioksidan yang dimiliki pada sampel. Ukuran simplisia terbukti secara positif mempengaruhi hasil rendemen ekstrak, nilai kadar total fenolik dan aktivitas antioksidan kulit kayu manis., Cinnamon bark is known contains polyphenol compounds which have potential as antioxidants and can be increased by reducing the size of the simplisia particles. This research was aimed to determine the effects of simplisia’s particle size on extract yield, total phenolic levels, and antioxidant activity of cinnamon bark from Jambi. Cinnamon was extracted using 70% ethanol solvent, antioxidant activity testing was performed using DPPH test with IC50 value. The yield of simplisia nanoparticles was higher at 38.36%. The antioxidant activity test results of the nanoparticle simplisia samples were stronger, 34.56 ± 0.72 μg/ml than the. The TPC of the nanoparticle simplisia samples was higher than the other samples, 60.14 ± 3.66 mg GAE/g dry weight. The test results showed significantly different results (p<0.05). The correlation between the total phenolic value and the IC50 DPPH value is very strong and negative. The higher the total phenolic content, the lower the IC50 value, so the better the antioxidant activity in the sample. The simplisia size was proven to positively affect the total phenolic content and antioxidant activity of cinnamon bark.
Keyword: antioksidan, fenolik, kulit kayu manis, nanopartikel

Judul: Dynamics Model for Rural and Urban Economic Growth
Abstrak: Lewis theory of structural change has focused on mechanisms that allow countries to transform their domestic economic structure to a more modern economy. The proposed model deals with the mechanism of interaction between rural and urban Economic. This model is concerned with the process of labor transfer from rural to urban areas. This study aims to model the dynamics of economic growth in rural and urban areas, including determining the equilibrium solution and to carry out simulation of the model. The simulation results show that the transfer of labor from rural to urban areas will increase the rate of change of capital so that structural changes can be realized. In addition, increased propensity to save in rural areas will also accelerate structural change
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