Judul: Detection of antibacterial compound from kesum leaves (Polygonum minus Huds) by TLC-bioautography method and the effect to escherichia coli and staphylococcus aureus membrane.
Abstrak: Kesum (Polygonum minus Huds) is the one of biodiversities from West Borneo and commonly used as flavouring ingredient for local culinary. Kesum leaves contain some bioactive compounds i.e high phenolic compounds, flavonoids, alkaloids, tannins and terpenoids which are potential as natural antibacterial agent. Detection of antimicrobial fractions of compounds from natural extracts could be done by TLC-bioautography. It is a combining method of chemical (thin layer cromatography/TLC) and microbology technique (antimicrobial activity assay) which allowed the localization of active compound. Generally, the kesum leaves extracts have been obtained by conventional maceration technique. This technique is often time consuming and requires relatively large amounts of solvent and sometimes diminishes the active compounds. Ultrasound assisted extraction (UAE) is one of the emerging technologies being developed in order to minimize the length of the extraction time, to reduce the cost, and to maximize the extract quality. The aims of this study are: 1) comparing extraction of kesum leaves maceration technique and UAE using some solvent with different polarity by multilevel extraction, 2) screening of extract based on antibacterial activity of kesum leaves extracts against E. coli and S. aureus, 3) fractination of kesum leaves extracts with the highest antibacterial activity by TLC, 4) to detect the active fraction of kesum leaves extracts with TLC-bioautography, and 5) to find out the mechanism inhibition of kesum leaves extracts against E. coli and S. aureus cell membrane. The experiment was conducted in four stages. The first stage covers extraction was done by steam distillation to obtain essential oils, followed multilevel extraction by maceration and UAE to obtain different extracts, i.e. polar, semipolar and nonpolar. The second stage covers qualitative analysis of phytochemical extracts, preparation of bacterial test and test the bacterial activity of extracts using disc – diffusion method and Minimum Inhibitory Concentration (MIC) using macrodilution method. The third stage was fractionation of extract with the highest antibacterial activity by TLC method. The fourth stage was detection the active fraction of kesum leaves extracts with TLC-bioautography, followed by TLC-bioautography. The last stage was study of mechanism inhibition of kesum leaves extracts against cell membrane by DNA probe staining using fluorescen microscopy and detection leakage of the cytoplasmic membrane has been analysed by spectrophotometer UV – Vis. This study exhibited that UAE provided higher extraction yields and shortened the extraction time, in comparison to the conventional maceration technique. Phytochemical analysis showed kesum leaves extract contain phenolics, alkaloids, flavonoids, triterpenoids, tannins and saponins. The ethanolic extract of kesum leaves were potential as source of antibacterial agent. The MIC of the ethanolic extract, was 25 mg/ml for E. coli and 30 mg/ml for S. aureus. Fractination by TLC showed six spots under UV light at λ 254 nm. TLC-bioautography with agar overlay technique effectively detected that fractions of ethanolic extract of kesum leaves with Rf4 = 0.30 and Rf5 = 0.37 demonstrated the most noticeable antibacterial activity for both E. coli and S. aureus. Inhibitory mechanism of kesum leaves extract against E. coli and S. aureus is the disruption cytoplasmic membrane permeability that causes leakage of cell materials.
Keyword: antibacterial, kesum, membrane permeability, TLC-bioautography, UAE

Judul: Antibacterial Testing and Metabolomic Analysis of Ethanol Extract from Basil Leaves from Three Regions
Abstrak: Kemangi merupakan tumbuhan obat yang banyak dijumpai di Indonesia dan dilaporkan memiliki aktivitas antibakteri. Penelitian mengenai antibakteri perlu terus dilakukan seiring meningkatnya kasus resistensi antibiotik. Uji antibakteri dan analisis metabolomik pada ekstrak etanol daun kemangi yang dibudidayakan di tiga daerah asal (Banyuwangi, Cibungbulang, dan Dramaga) belum pernah dilakukan sebelumnya. Penelitian ini bertujuan menguji aktivitas antibakteri, mengidentifikasi senyawa, serta mendeskripsikan aktivitas biologis dari senyawa yang terkandung dalam ekstrak etanol daun kemangi asal Banyuwangi, Cibungbulang, dan Dramaga. Ektraksi daun kemangi dilakukan menggunakan teknik maserasi dengan pelarut etanol 96%. Ekstrak diencerkan menggunakan DMSO 10% menghasilkan konsentrasi 10%, 20%, 40%, dan 60%. Setiap konsentrasi diuji aktivitas antibakteri menggunakan metode difusi cakram. Pengujian antibakteri dilakukan terhadap bakteri Bacillus subtilis ATCC 19659, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 15442. Analisis metabolomik dilakukan menggunakan GC-MS. Ekstrak etanol kemangi konsentrasi 40% dan 60% asal Banyuwangi, Cibungbulang, dan Dramaga dapat menghambat pertumbuhan Bacillus subtilis, tetapi tidak menghambat tiga jenis bakteri lainnya. Hasil analisis metabolomik menunjukkan bahwa ketiga sampel kemangi memiliki 12 senyawa yang sama. Senyawa mayor yang terdeteksi adalah salvigenin (Banyuwangi), salvigenin dan phytol (Cibungbulang), serta salvigenin dan linalool (Dramaga). Ketiga jenis senyawa mayor tersebut dilaporkan memiliki aktivitas antibakteri., Basil is a medicinal plant in Indonesia and reported to have antibacterial activity. Research on antibacterials needs to be continuously conducted due to the increasing cases of antibiotic resistance. Antibacterial testing and metabolomic analysis on ethanol extracts of basil leaves from Banyuwangi, Cibungbulang, and Dramaga have not been previously conducted. Therefore, this study aims to test the antibacterial activity, identify compounds, and describe the biological activities of the compounds. The maceration of basil leaves was performed with 96% ethanol as the solvent. The extracts were diluted using 10% DMSO to obtain concentrations of 10%, 20%, 40%, and 60%. Each concentration was tested for antibacterial activity using the disc diffusion method against Bacillus subtilis ATCC 19659, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, and Pseudomonas aeruginosa ATCC 15442. Metabolomic analysis was carried out using GC-MS. The 40% and 60% ethanol extracts of basil from three regions were able to inhibit te growth of Bacillus subtilis, but did not inhibit the other three bacterial strains. All three samples of basil have 12 identical compounds. The major coupounds detected are salvigenin (Banyuwangi), salvigenin and phytol (Cibungbulang), salvigenin and linalool (Dramaga). All these major compounds have been reported to have antibacterial activity.
Keyword: maceration technique, metabolomics, disc diffusion method

Judul: Pemanenan Energi Listrik dari Kincir Angin Vertikal
Abstrak: Usaha pemanenan energi angin di Indonesia masih sedikit. Sampai Tahun 2016 hanya 3.54 MW alat pemanenan energi angin yang sudah terpasang. Kendala utamanya ialah dibutuhkan investasi yang besar untuk membuatnya. Pembuatan kincir angin dengan ukuran yang lebih kecil dengan bahan yang dapat dibeli di pasar lokal menjadi solusi agar pembuatan kincir angin lebih ekonomis. Pembuatan kincir vertikal tipe Savonius dapat menjadi solusinya. Kincir vertikal Savonius dapat beroperasi pada kecepatan < 3 m/s dan ketinggian < 50 m. Kincir angin ini terdiri dari tiga sistem, yaitu generator, rotor kincir dan transmisi pulley-belt. Generator dibuat dari modifikasi motor AC dan magnet neodymium. Rotor kincir dibuat dari pipa PVC 4”, pipa alumunium ¾”, dan papan polikarbonat. Transmisi pulley-belt dibuat dari plastik dan karet. Kincir ini membutuhkan gaya minimal 3 N untuk dapat berputar atau torsi minimalnya 0.75 Nm. Kecepatan angin yang dibutuhkan untuk merotasikannya sebesar 1.9 m/s. Daya maksimal yang dapat dihasilkan ialah 5.76 watt berupa tegangan sebesar 36 volt dan arus 160 mA.
Keyword: energi terbarukan, generator, motor AC, sudu Savonius