Judul: a-Glucosidase Inhibitory Activity of Purified Gandarusa by Column Chromatography
Abstrak: Gandarusa (Justicia gendarussa Burm. f.) merupakan herbal sumber daya lokal Indonesia yang berpotensi sebagai obat herbal antidiabetes. Penelitian ini bertujuan menentukan aktivitas inhibisi a-glukosidase dari senyawa yang terkandung pada fraksi hasil purifikasi ekstrak metanol gandarusa menggunakan kromatografi kolom. Simplisia gandarusa dimaserasi bertingkat dengan n-heksana, etil asetat, dan metanol. Ekstrak gandarusa difraksinasi dengan kromatografi kolom menggunakan pelarut optimal (etil asetat:n-heksana 4:6 v/v). Ekstrak kasar dan 8 fraksi hasil purifikasi dipekatkan kemudian ditentukan aktivitas antioksidannya dengan menggunakan KLT bioautografi dan aktivitas inhibisi a-glukosidasenya secara in vitro. Hasil penelitian menunjukkan bahwa purifikasi gandarusa menghasilkan fraksi kolom yang memiliki aktivitas antioksidan dan dapat menghambat a-glukosidase lebih baik dibandingkan ekstrak kasar tanamannya. Aktivitas inhibisi a-glukosidase tertinggi dimiliki oleh F2 (IC50 99,34 ppm), lebih tinggi dibandingkan dengan obat komersial akarbosa. Secara keseluruhan, fraksi gandarusa berpotensi untuk dikembangkan lebih lanjut sebagai obat herbal antidiabetes., Gandarusa (Justicia gendarussa Burm. f.) is a local Indonesian herbal resource with potential as an herbal antidiabetic remedy. This study aimed to determine the inhibitory activity of a-glucosidase from compounds present in the purified fractions of methanolic extract of gandarusa using column chromatography. Simplified gandarusa was extracted in stages with n-hexane, ethyl acetate, and methanol. The gandarusa extract was fractionated using column chromatography with an optimal solvent (ethyl acetate:n-hexane 4:6 v/v). The crude extract and eight purified fractions were then concentrated and evaluated for antioxidant activity using bioautographic thin-layer chromatography and in vitro a-glucosidase inhibitory activity. The results showed that the purification of gandarusa yielded a column fraction with antioxidant activity and better a-glucosidase inhibition compared to the crude extract of the plant. The highest inhibitory activity of a-glucosidase was found in F2 (IC50 99,34 ppm), which was higher than that of the commercial drug acarbose. Overall, the gandarusa fraction has potential for further development as an herbal antidiabetic remedy.
Keyword: a-glucosidase, antidiabetic, column chromatography, Justicia gendarussa

Judul: Aktivitas Inhibisi α-Glukosidase Hasil Purifikasi Gandarusa dengan Kromatografi Kolom
Abstrak: Gandarusa (Justicia gendarussa Burm. f.) merupakan herbal sumber daya lokal Indonesia yang berpotensi sebagai obat herbal antidiabetes. Penelitian ini bertujuan menentukan aktivitas inhibisi α-glukosidase dari senyawa yang terkandung pada fraksi hasil purifikasi ekstrak metanol gandarusa menggunakan kromatografi kolom. Simplisia gandarusa dimaserasi bertingkat dengan n-heksana, etil asetat, dan metanol. Ekstrak gandarusa difraksinasi dengan kromatografi kolom menggunakan pelarut optimal (etil asetat:n-heksana 4:6 v/v). Ekstrak kasar dan 8 fraksi hasil purifikasi dipekatkan kemudian ditentukan aktivitas antioksidannya dengan menggunakan KLT bioautografi dan aktivitas inhibisi α-glukosidasenya secara in vitro. Hasil penelitian menunjukkan bahwa purifikasi gandarusa menghasilkan fraksi kolom yang memiliki aktivitas antioksidan dan dapat menghambat α-glukosidase lebih baik dibandingkan ekstrak kasar tanamannya. Aktivitas inhibisi α-glukosidase tertinggi dimiliki oleh F2 (IC50 99,34 ppm), lebih tinggi dibandingkan dengan obat komersial akarbosa. Secara keseluruhan, fraksi gandarusa berpotensi untuk dikembangkan lebih lanjut sebagai obat herbal antidiabetes.
Keyword: α-glucosidase, antidiabetic, column chromatography, Justicia gendarussa

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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