A new oligostilbenoid, diptoindonesin C, has been isolated from the tree bark of Shorea pinanga Scheff., along with the two known oligostilbenoids gnetin H and hopeaphenol, and a known coumarin scopoletin. The new oligostilbenoid was moderately active against brine shrimps Artemia salina.
ABSTRAK. Kayu putih (Melaleuca cajuputi) merupakan tumbuhan yang banyak dijumpai di pesisir pantai Kota Singkawang. Tumbuhan ini berpotensi digunakan untuk mengobati diare. Penelitian ini bertujuan untuk mengetahui aktivitas antibakteri daun kayu putih yang berasal dariKota Singkawang terhadap bakteri uji Escherichia coli dan Staphylococcus aureus. Metode yang digunakan untuk isolasi minyak atsiri yaitu distilasi uap, sedangkan uji aktivitas antibakteri menggunakan metode difusi sumuran. Hasil isolasi minyak atsiri daun kayu putih menghasilkan rendemen sebesar 0,55%. Analisis GC-MS menghasilkan 26 puncak senyawa dengan 2 senyawa utama yaitu 1,8 sineol sebesar 71,96% dan alpha-terpineol sebesar 11,44%. Hasil uji aktivitas antibakteri minyak atsiri daun kayu putih terhadap bakteri E. coli dan S. aureus menghasilkan aktivitas yang tergolong lemah. Diameter zona hambat terhadap bakteri E. coli dengan konsentrasi 50µg/µl menghasilkan zona sebesar 4,39 mm, sedangkan pada bakteri S. aureus yaitu sebesar 4,62 mm. Kata kunci: Escherichia coli, Melaleuca cajuputi, minyak atsiri daun kayu putih, Singkawang, Staphylococcus aureus ABSTRACT. Eucalyptus (Melaleuca cajuputi), is a plant which often found on the coast of the city of Singkawang, West Kalimantan. This plant is potentially used to treat diarrhea. This study aimed to determine antibacterial activity of eucalyptus leaf from Singkawang city on bacteria Escherichia coli and Staphylococcus aureus. Isolation of the essential oils was using steam distillation, while the analysis of antibacterial activity with well diffusion method. The isolation resulted 0.55% yield. Analysis using GC-MS yielded 26 peak compounds with 2 main compounds namely 1.8 cineol at 71.96% and alpha-terpineol 11.44%. Furthermore, antibacterial activity test of eucalyptus leaf essential oil against E. coli and S. aureus bacteria belongs to the category of low. The diameter of the inhibition zone on bacteria E. coli at a concentration of 50µg/µl obtained 4.39 mm zone, while on S. aureus was 4.62 mm zone.
KAJIAN KUALITAS AIR LAUT DAN DOSIS CESIUM 137 PADA BIOTA DI PANTAI GOSONG, KALIMANTAN BARAT SEBAGAI CALON TAPAK PLTN. Kondisi awal lingkungan di Pantai Gosong sebagai calon tapak PLTN di Kalimantan Barat sebelum pembangunan dan pengoperasian PLTN penting untuk dilakukan. Salah satu deskripsi lingkungan yang diperlukan namun belum tersedia adalah data radionuklida Cs-137 dan besarnya dosis radiasi Cs-137 terhadap biota laut di perairan laut Pantai Gosong. Penelitian ini bertujuan menentukan kualitas air termasuk konsentrasi radionuklida Cs-137 di perairan Pantai Gosong dan dosis radiasi Cs-137 terhadap biota lautnya. Penentuan lokasi penelitian didasarkan dengan metode purposive sampling. Metode penelitian meliputi pengendapan Cs-137, pemisahan, pengeringan dan pencacahan dengan spectrometer gamma. Selanjutnya dilakukan simulasi dosis radiasi terhadap biota laut menggunakan perangkat lunak Erica Tools. Parameter kualitas air lainnya diukur menggunakan Water Qulity Mater. Hasil pengukuran empat parameter yang diukur seperti pH, suhu, salinitas dan TDS mempunyai nilai yang serupa dengan penelitian lain pada lokasi yang berdekatan dan tidak terjadi perubahan kualitas lingkungan. Dari aspek radioekologi yang diwakili olah nuklida Cs-137, didapatkan bahwa aktivitasnya di perairan Pantai Gosong hampir sama nilainya dengan penelitian serupa di perairan Indonesia yang sumbernya berasal dari fallout. Dosis radiasi Cs-137 pada biota laut yang berada di perairan Pantai Gosong lebih rendah dari tingkat dosis skrining level.
Legundi (Vitex trifolia L.) is a plant that contains essential oils. Legundi leaf essential oil has the potential as a more environmentally friendly rice lice repellent. The process of extracting essential oils from Legundi leaves uses the steam-water distillation method. The yield obtained from distillation is 0.10% with a bright yellow color, has a distinctive smell of Legundi oil with a specific gravity of 0.9065 gram/cm3. GC-MS search results showed that Legundi leaf essential oil contains 5 main components, namely 2-β-Pinene (16.18 %), trans-caryophyllene (13.75 %), β-Ocimene (11.16 %), Cyclohexanol (10.03%), and Eucalyptol (5.45%). Testing of repellent activity was carried out on rice lice with variations in volatile oil concentrations of 1%, 5%, 10%, and 20%. The results of the repellent test showed that the highest percentage occurred at a concentration of 20% (P4), which was 56.7%, with an application time of 120 hours (L5). Based on this, it can be said that the greater the concentration of the essential oil used, the higher the percentage of rejection of the population, this also indicates that Legundi leaf essential oil has lice repellent activity (Sitophilus oryzae).
Three isolates of Actinomycetes namely MA02, MA03, and MA04 were isolated from an unidentified sponge, Lemukutan Island, Indonesia. They were identified as Streptomyces based on Bergey’s Manual of Determinative Bacteriology. In the preliminary screening, all of the isolates showed antimicrobial activities towards 13 microorganism tests. However, the activities were not similar when their extract produced from various medium and incubation time were tested. Their cultivation was conducted on M13 agar with incubation time for 3 days, M13 broth with incubation time for 4 days, M2+ broth with incubation time for 7 days and M2+ broth with incubation time for 9 days. The result of antimicrobial assay showed difference in the ability to inhibit the microorganism tests. The best antimicrobial activity of the extracts based on cultivated condition (medium and incubation time) for Streptomyces MA02, Streptomyces MA03, and Streptomyces MA04 were M2+ broth for 3 days, M2+ broth for 9 days and M2+ broth for 9 days respectively.
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