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: Free Radical Reduction Activity of DPPH and Inhibition of α-Glucosidase Aqueous Extract of Cinnamon Bark (Cinnamomum burmannii)
Abstrak: Kayu manis (Cinnamomum burmannii) merupakan tanaman herbal yang mempunyai fungsi salah satunya yaitu menurunkan glukosa dalam darah dan menangkal radikal bebas yang menyebabkan stress oksidatif. Penelitian ini bertujuan menentukan rendemen, total fenolik, peredaman radikal bebas DPPH, dan aktivitas penghambatan enzim α-glukosidase pada ekstrak air kulit kayu manis (Cinnamomum burmannii) yang berulang (residu pertama, residu kedua, dan residu ketiga). Metode ekstraksi menggunakan teknik infundasi dan pengujian lanjutan dilakukan menggunakan spektronanometer. Hasil pengujian kadar total fenolik dan aktivitas antioksidan ekstrak residu pertama, residu kedua, dan residu ketiga mendapatkan hasil yang berbeda nyata (p<0,05). Rendemen dan aktivitias inhibisi enzim α-glukosidase ekstrak residu pertama, residu kedua, dan residu ketiga mendapatkan hasil yang tidak berbeda nyata (p>0,05)., Cinnamon (Cinnamomum burmannii) is an herbal plant with various functions, one of them is lowering glucose in the blood and counteracting free radicals that cause oxidative stress. This research was aimed to determine the yield, total phenolic, scavenging of DPPH free radical, and α-glucosidase enzyme inhibitory activities in the aqueous extract of cinnamon bark (Cinnamomum burmannii) that recurs (first residue, second residue, and third residue). Extraction method used the infundation technique and further testing was carried out using spectronometer. Test results of total phenolic content and antioxidant activity of the first, second, and third residual extract got significantly different results (p<0.05). Yield and activity of α-glucosidase enzyme inhibition of the first, second, and the third residue extracts obtained insignificantly different results (p>0.05).
Keyword: Antioksidan, Diabetes Mellitus, Enzim α-Glukosidase, Kayu Manis

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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