Judul: Identifikasi Senyawa Inhibitor -Glukosidase Dari Metabolit Ekstraseluler Bakteri Endofit Streptomyces Sp. Ipbcc.B.15.1539 Brotowali (Tinospora Crispa).
Abstrak: Senyawa bioaktif dari isolat bakteri endofit Streptomyces sp. IPBCC.b.15.1539 tanaman brotowali memiliki aktivitas yang berpotensi digunakan sebagai obat diabetes melitus. Bakteri tersebut ditumbuhkan di media cair ISP-2. Metabolit dihasilkan dari ekstraksi menggunakan etil asetat dan difraksionasi dengan heksana:etil asetat (1:4). Teknik fraksionasi dan isolasi dipandu oleh teknik bioasai, serta senyawa bioaktif diidentifikasi menggunakan kromatografi gas spektrometri massa (GC-MS). Ekstrak etil asetat bakteri diduga mengandung senyawa golongan alkaloid dan flavonoid hasil uji fitokimia. Aktivitas inhibisi α- glukosidase supernatan dan ekstrak etil asetat 500 ppm sebesar 25.57% dan 51.60%, sedangkan akarbosa 500 ppm sebagai kontrol positif sebesar 93.49%. Fraksionasi menghasilkan 8 fraksi dengan pola kromatografi lapis tipis berbeda. Fraksi 1 memiliki aktivitas inhibisi tertinggi, yaitu 29.70% dan memiliki 3 spot pada sinar ultraviolet 254 nm. Spot 1 memiliki aktivitas inhibisi tertinggi, yaitu 12.28%. Kromatogram GC-MS pada fraksi 1 menghasilkan 3 puncak pada kromatogram, yakni bis(2-etilheksil)ester, 9-en-dekanamida, dan griseofulvin.
Keyword: GC-MS, α-glukosidase, kromatografi kolom, Streptomyces sp.

Judul: Karakterisasi ekstrak asal Streptomyces sp. IPBCC.B.15.1539 yang berfungsi sebagai inhibitor alfa-glukosidase
Abstrak: Penderita diabetes melitus (DM) di Indonesia pada tahun 2013 diperkirakan mencapai 6.9% atau sekitar 12 juta jiwa. Lebih dari 95% penderita diabetes merupakan penderita DM tipe 2 dan salah satu metode pengobatannya adalah dengan cara menghambat aktivitas enzim α-glukosidase. Streptomyces sp. IPBCC.B.15.1539 asal brotowali merupakan isolat yang menghasilkan inhibitor α-glukosidase. Besarnya potensi Streptomyces sp. IPBCC.B.15.1539 dalam menghasilkan senyawa inhibitor α-glukosidase, menjadikan karakterisasi ekstrak asal Streptomyces sp. IPBCC.B.15.1539 dinilai penting. Tujuan penelitian ini adalah mengkaji karakter ekstrak Streptomyces sp. IPBCC.B.15.1539 dengan metode kromatografi lapis tipis (KLT), mengukur nilai penghambatan terhadap enzim α-glukosidase (IC50) secara in vitro, dan nilai LC50 menggunakan metode brine shrimp letality test (BSLT). Streptomyces sp. IPBCC.B.15.1539 yang ditumbuhkan pada media ISP-2 selama 10 hari pada suhu 20-25 oC dengan kecepatan 100 rpm menghasilkan biomassa sebesar 2.22 ± 0.03 mg mL-1 dan menghasilkan 28.38% ekstrak etil asetat. Ekstrak ini mengandung 7 komponen utama penyusun ekstrak yang diduga mengandung kelompok senyawa flavonoid dan antosianidin. Ekstrak etil asetat Streptomyces sp. IPBCC.B.15.1539 memiliki nilai IC50 terhadap enzim α-glukosidase sebesar 145.51 μg mL-1 dan nilai LC50 terhadap larva Artemia salina sebesar 517.23 μg mL-1. Nilai LC50 ini dinyatakan toksik terhadap larva A. salina. Karakter ekstrak IPBCC.B.15.1539 tersebut dapat menjadi dasar identifikasi senyawa aktif inhibitor α-glukosidase.
Keyword: characterization, diabetes mellitus, ethyl acetate extract, inhibitor of α- glucosidase, Streptomyces sp

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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