Judul: Toksisitas Akut Ekstrak Daun Sirsak Ratu (Annona muricata) dan Sirsak Hutan (Annona glabra) sebagai Potensi Antikanker
Abstrak: Soursop plants has been known to have pharmacological activities such as anticancer. Soursop species that are widely found in Indonesia are soursop (Annona muricata) and pond apple (A. glabra). This study has determined the toxicity properties of leaf extracts of these species to brine shrimps larvae and zebra fish embryos. Overall, the pond apple extract showed higher toxicity then the soursop. The best LC50 values were obtained from hexane extract of pond apple leaves, namely 197 μg/mL to brine shrimps larvae and 326 μg/mL to zebra fish embryo. These values indicate a significant correlation as anticancer compounds. This extract of pond apple resulted 8 spots in separation by using thin layer chromatography. 1H-NMR measurement towards these 2 well-separated spot did not show acetogenin component, as previously reported as the anticancer components in soursop plants. Further fractionation of the extract is needed to ensure the structure of the anticancer active component it contained.
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Judul: Acute Toxicity Test of Active Fruit Extract from Soursop (Annona muricata) and Pond Apple (Annona glabra) as an Anticancer Potential.
Abstrak: Penelitian khasiat antikanker dari berbagai bagian tumbuhan sirsak telah marak dilakukan, namun penelitian khasiat antikanker dari bagian buah masih jarang dilakukan. Buah sirsak yang cukup banyak terdapat di Indonesia adalah buah sirsak ratu (Annona. muricata) dan buah sirsak hutan (A. glabra). Penelitian toksisitas dari buah sirsak ratu dan buah sirsak hutan dilakukan dengan dua metode, yaitu metode uji letalitas larva udang (BSLT) dan metode lebih terkini dengan menggunakan embrio ikan zebra (Danio rerio). Nilai LC50 terbaik dari ekstrak buah sirsak ratu dan sirsak hutan diberikan oleh ekstrak etil asetat baik dengan menggunakan metode BSLT maupun dengan embrio ikan zebra. Hasil pengamatan embrio ikan zebra melaporkan bahwa ekstrak etil asetat sirsak ratu merupakan ekstrak dengan daya sitotoksik tertinggi. Uji fitokimia dari ekstrak etil asetat masing-masing buah menghasilkan uji positif pada golongan senyawa alkaloid, tanin, dan flavonoid. Ekstrak etil asetat sirsak ratu menghasilkan 6 noda dari hasil pemisahan dengan kromatografi lapis tipis dan ekstrak etil asetat sirsak hutan menghasilkan 8 noda dengan cara yang sama.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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