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: 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: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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