Judul: Fractionation of Antimicrobial Peptide Candidates from Gandarusa  (Justicia gendarussa) Leaves
Abstrak: Peptida antimikroba adalah senyawa yang ditemukan pada organisme hidup dan berfungsi sebagai komponen penting dalam sistem pertahanan tubuh. Keunggulan peptida antimikroba adalah memiliki sprektum luas membunuh bakteri patogen dan bakteri yang resistan. Daun gandarusa (Justicia gendarussa Burm. F.) memiliki aktivitas antibakteri namun kajian terkait peptida antimikroba pada tanaman tersebut masih terbatas. Penelitian ini bertujuan untuk memfraksinasi peptida antimikroba dari daun gandarusa serta menguji aktivitas antimikrobanya. Ekstraksi peptida daun gandarusa menggunakan pelarut asam asetat 10% dan waktu ekstraksi 2 jam. Kadar total protein diukur dengan metode Bradford, identifikasi kandidat peptida antimikroba dilakukan dengan metode SDS-PAGE, dan pengujian aktivitas antibakteri dilakukan dengan metode difusi sumuran. Hasil penelitian menunjukkan sampel optimum ekstraksi terhadap bobot molekul dan kadar protein daun gandarusa adalah sampel 100 mesh dengan sonikasi. Identifikasidengan SDS-PAGE menunjukkan peptida antimikroba dari daun gandarusa memiliki berat molekul berkisar 10-12 kDa. Uji aktivitas antibakteri Fraksi peptida daun gandarusa terhadap Escherichia coli dan Propionibacterium acnes tidak menunjukkan adanya daya hambat., Antimicrobial peptides are compounds found in living organisms that function as crucial components of the body's defense system. The advantage of antimicrobial peptides lies in their broad spectrum of activity, capable of killing pathogenic bacteria and antibiotic-resistant bacteria. Justicia gendarussa Burm. F. leaves are known to have antibacterial activity; however, research on antimicrobial peptides from this plant is still limited. This study aims to isolate and fractionate antimicrobial peptides from Justicia gendarussa leaves and evaluate their antimicrobial activity. The extraction of peptides from Justicia gendarussa leaves was performed using 10% acetic acid solvent with an extraction time of 2 hours. The total protein content was measured using the Bradford method, antimicrobial peptide candidates were identified using SDS-PAGE, and antibacterial activity was tested using the well diffusion method. The results showed that the optimal sample for extraction, in terms of molecular weight and protein content, was 100 mesh with sonication. Identification with SDS-PAGE indicated that the antimicrobial peptides from Justicia gendarussa leaves have a molecular weight ranging from 10-12 kDa. However, the antibacterial activity test of the peptites fraction of Justicia gendarussa leaves against Escherichia coli and Propionibacterium acnes did not show any inhibitory effect.
Keyword: antibakteri, Justicia gendarussa, peptida antimikroba, dialisis, SDS-PAGE

Judul: Purification of Gendarusa Antioxidant  Compound (Justicia gendarussa Burm. f.) by Column Chromatography Method
Abstrak: Gandarusa (Justicia gendarussa Burm. f.) merupakan salah satu tanaman yang berpotensi sebagai sumber antioksidan karena kandungan metabolit sekundernya. Gandarusa termasuk ke dalam tanaman liar dan sudah lama dimanfaatkan sebagai tanaman obat. Penelitian ini bertujuan menentukan aktivitas antioksidan dengan metode DPPH hasil purifikasi ekstrak gandarusa menggunakan kromatografi kolom. Metode penelitian ini terdiri atas ekstraksi dengan maserasi bertingkat, optimasi pelarut dengan Kromatografi Lapis Tipis (KLT), purifikasi dengan kromatografi kolom, dan analisis antioksidan kualitatif dengan metode KLT bioautografi dan kuantitatif dengan metode DPPH. Pelarut n-heksana:etil asetat (6:4) dapat memisahkan ekstrak gandarusa dengan baik. Hasil purifikasi dengan kromatografi kolom menghasilkan 8 fraksi. Fraksi 3.2 memiliki aktivitas antioksidan tertinggi dengan nilai IC50 sebesar 617,34 µg/mL, sedangkan ekstrak kasarnya sebesar 2551,30 µg/mL. Purifikasi gandarusa dengan kromatografi kolom menghasilkan fraksi dengan aktivitas antioksidan lebih kuat dibandingkan dengan kondisi campurannya (ekstrak kasar)., Gandarusa (Justicia gendarussa Burm. f.) is a plant with potential as an antioxidant source due to its secondary metabolite content. Gandarusa is considered a wild plant and has long been used as a medicinal plant. This research aimed to determine the antioxidant activity using the DPPH method of purified gandarusa extract obtained through column chromatography. The research methods include extraction through stepwise maceration, solvent optimization using Thin Layer Chromatography (TLC), purification with column chromatography, and qualitative antioxidant analysis using TLC bioautography and quantitative analysis using the DPPH method. The n-hexane:acetate (6:4) solvent can effectively separate gandarusa extract. The purification results from column chromatography produced 8 fractions. Fraction 3.2 exhibited the highest antioxidant activity with an IC50 value of 617.34 µg/mL, while the crude extract had an IC50 value of 2551.30 µg/mL. Purification of gandarusa using column chromatography yielded fractions with stronger antioxidant activity compared to the mixed state (crude extract).
Keyword: antioxidant, column chromatography, gendarussa, purification, TLC

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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