Judul: Ekstraksi Komponen Antioksidan Dan Antibakteri Biji Lotus (Nelumbium Nelumbo)
Abstrak: Indonesia memiliki tanah rawa yang sangat luas. Menurut Departemen Komunikasi dan Informatika Republik Indonesia (2002), luas rawa di Indonesia sekitar 33,4 juta hektar dari luas lahan 162,4 juta hektar. Luas lahan rawa yang besar tersebut belum dimanfaatkan secara optimal dan sebagian besar masih ditumbuhi oleh semak belukar. Tanaman lotus (Nelumbium Nelumbo) adalah salah satu jenis tanaman ekonomis yang dapat mengoptimalkan penggunaan lahan rawa. Menurut Rahman (2004), biji bunga lotus juga telah banyak dikonsumsi orang sebagai campuran dalam sayuran atau dimakan mentah. Pada kebudayaan Cina tradisional, biji lotus digunakan untuk mengobati berbagai macam penyakit, terutama diare. Biji lotus juga dipercaya dapat menjaga tubuh agar selalu bugar dan awet muda. Selain itu, biji lotus juga diyakini dapat menjaga kesehatan limpa dan memperkuat jantung (Rahman 2004). Oleh karena itu, biji tanaman ini diduga mengandung komponen yang dapat berfungsi sebagai antioksidan dan antibakteri. Hasil pengujian ekstrak biji lotus menunjukkan ekstrak heksana biji lotus mentah mempunyai nilai protection factor 2.61 ± 0.95 %, sedangkan ekstrak heksana biji lotus kukus mempunyai nilai protection factor 1.36 . ± 0.18 %. Ekstrak etilasetat biji lotus mentah mempunyai nilai protection factor 9.45 ± 0.54 % sedangkan ekstrak etilasetat biji lotus kukus mempuayai nilai protection factor 6.12 ± 1.25 %. Ekstrak etanol biji lotus mentah mempunyai nilai protection factor 4.63 ± 1.07 %, sedangkan ekstrak etanol biji lotus kukus mempunyai nilai protection factor 3.56 ± 1.31 %. Hasil terbaik dari uji ransimat, yaitu ekstrak etilasetat biji lotus mentah dilanjutkan dengan uji DPPH. Hasl uji DPPH pada ekstrak etilasetat biji lotus mentah mempunyai aktivitas sebesar AEAC . 0.007606 / berat kering. Hasil pengujian ekstrak biji lotus terhadap aktivitas antibakteri menunjukkan ekstrak etilasetat biji lotus mentah menunjukkan aktivitas penghambatan paling baik terhadap bakteri E.coli, S.aureus, P.aeruginosa, dan B.cereus. Ekstrak heksana biji lotus baik mentah maupun kukus tidak mempunyai aktivitas penghambatan terhadap keempat bakteri uji tersebut. Hasil pengujian fitokimia terhadap ekstrak etilasetat biji lotus mentah menunjukkan terdapat komponen yang bersifat antibakteri seperti alkaloid, saponin, steroid, dan tanin yang cukup kuat. Sedangkan komponen yang bersifat antioksidan seperti fenol hidrokuinon negatif, dan flavonoid positif lemah.
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Judul: Antibacterial Activity and Identification of Bioactive Compounds from Mangkokan Leaf Extract (Polyscias scutellaria)
Abstrak: Tanaman mangkokan (Polyscias scutellaria) merupakan salah satu tanaman obat Indonesia yang biasanya dimanfaatkan sebagai obat tradisional, tanaman hias, tanaman pagar, dan sumber pangan. Ekstrak daun mangkokan mengandung senyawa dengan aktivitas antibakteri. Penelitian ini bertujuan menguji aktivitas antibakteri ekstrak daun mangkokan, serta mengidentifikasi senyawa bioaktif yang terkandung dalam ekstrak. Ekstraksi daun mangkokan dilakukan menggunakan pelarut metanol, etanol, etil asetat, dan n-heksana. Ekstrak diuji aktivitas antibakteri dan diidentifikasi senyawa bioaktifnya menggunakan GC-MS. Hasil uji antibakteri menunjukkan bahwa ekstrak metanol dan etanol memiliki aktivitas antibakteri terhadap Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, dan Bacillus subtilis. Ekstrak n-heksana hanya memiliki aktivitas antibakteri terhadap E. coli, sedangkan ekstrak etil asetat tidak menunjukkan aktivitas antibakteri. Berdasarkan hasil analisis GC-MS, semua ekstrak daun mangkokan mengandung senyawa bioaktif dengan aktivitas antibakteri. Penelitian lebih lanjut diperlukan untuk menampilkan potensi antibakteri ekstrak daun mangkokan secara lebih baik., The mangkokan plant (Polyscias scutellaria) is one of the Indonesian medicinal plants which are usually used as a traditional medicine, ornamental plant, hedge plant, and food source. Mangkokan leaf extract contain antibacterial activity compounds. This study aims to examine the antibacterial activity of mangkokan leaf extract, as well as to identify the bioactive compounds contained in the extract. Mangkokan leaf extraction was carried out using methanol, ethanol, ethyl acetate, and n-hexane solvents. The extracts were tested for antibacterial activity and the bioactive compounds were identified using GC-MS. The results of the antibacterial test showed that the methanol and ethanol extracts had antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis. The n-hexane extract only had antibacterial activity against E. coli, while the ethyl acetate extract did not show antibacterial activity. Based on the results of GC-MS analysis, all mangkokan leaf extracts contained bioactive compounds which have antibacterial activities. Further research is needed to reveal the antibacterial potential of mangkokan leaf extract.
Keyword: Antibacterial, Bioactive compounds, mangkokan leaf extract

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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