Judul: Eksplorasi dan Identifikasi Kulit Mimba (Azadirachtaindica A.Juss) sebagai Larvisida terhadap Nyamuk Aedes aegypti
Abstrak: Synthetic pesticide causes many negative side-effects. For insects, it causes physiological resistances and can kill non-target insects. Resistant insects will need more insecticide dose than before. To avoid the negative effect, World Health Organization (WHO) recomends to use natural insecticide. Resistant mechanism is combination of many factors which are biochemistry, physiology, andbehaviour. The more specific insecticide is used, the easier it causes the resistant effect.Neem is one of plants that has been extensively used to study its insecticidal and medicinal activity. It has opportunity to become strong natural insectides to many insects. Aims of this research were to analysis of extractivecontens of neem bark, toxicity test of bioactive against Aedesegyptilarvae, and isolate and identify bioactive compounds of neems bark in against Ae.aegypti larvae. Neem bark powder was extracted using methanol as a solvent. Obtained extract of this process was separated by different polar solvent. Separation process obtains three fractions that are ethyl acetatesoluble fraction, buthanolsolublefraction, and unsoluble fraction. Each fraction was evaporated to get condensed extract. Effectiveness of each fraction to Ae.aegypti larvae were tested with several concentrations that are 50, 100, 250, 500, and 1000 ppm. This experiment showed that ethyl acetatesolublefraction was the most effective fraction. Phytochemical analysis also confirmed that it contained many compound such as; alkaloid, flavonoid, saponin, and triterpenoid. Then, ethyl acetatesolublefraction was separated using chromatography column and yield 9 fractions. Second fraction (Ef-2) was the best larvicidal efficacy, and it also had higher efficacy than ethyl acetate fraction before it was isolated. Furthermore, magnetic resonance analysis (1H and 13C NMR) of Ef-2 was performed, and the molecul structure of bioactive compound was identifiedas Glycerol 1,2-di-(9Z-octadecenoate) 3-tetradecanoate.
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Judul: Aktivitas Larvasida Ekstrak Bintaro (Cerbera manghas) Terhadap Larva Nyamuk Aedes aegypti (Diptera: Culicidae)
Abstrak: Dengue is a very dangerous disease and contagious because it causes deadth at short time on the patient. This desease was caused by dengue virus which was infected by Aedes aegypti. Plants have potency to develop as larvacide because itself containts chemical compound which have bioactive. Bintaro (Cerbera manghas) have been known as poisonous tree. The aim of this research is to know the activity of bintaro extract to larvae Ae. aegypti. First, we extracted a leaf, steam bark, kernel and rind of bintaro. Then the best extract was fracinated, after that it was done chromatography colom step. Futhermore, we did bioassay to larvae Ae. aegypti for every step. The result showed that kernel of bintaro have highest activity to mortality of larvae Ae. aegypti than steam bark, rind, and leaf; with LC50 517,3 ppm dan LC90 964,8 ppm. Ethyl acetate fraction have great activity to mortality of Ae. aegypti than n-hexane dan nonsoluble fraction with LC50 34,6 ppm dan LC90 95,1 ppm. We had 10 sub fractions in this research and the sub fraction 1, 7 and 10 had most toxic compound to Ae. aegypti than the others. The kernel extract contains saponim, alkaloid, flavonoid, triterfenoid glikosida and steroid.
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Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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