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: 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: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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