Judul: Sintesis 6-Bromopiperonal dan 2,4,5-Trihidroksibenzaldehida.
Abstrak: Senyawa 6-bromopiperonal memiliki aktivitas sinergis dengan karbaril pada lalat Musca domestica dan juga digunakan sebagai senyawa antara pada pembuatan G protein-coupled receptor 30-selective (GPR30-selektif) agonis G-1. Pada penelitian ini, 6-bromopiperonal disintesis dari vanilin sebagai bahan awalnya. Tahapan reaksi sintesis meliputi demetilasi, metilenasi, lalu brominasi, dengan rendemen keseluruhan mencapai 14%. Senyawa lain yang disintesis ialah 2,4,5-trihidroksibenzaldehida. Senyawa ini memiliki beberapa bioaktivitas seperti antioksidan, antiradang, dan mampu menghambat pertumbuhan tumor. Sintesis 2,4,5-trihidroksibenzaldehida menggunakan p-benzokuinon sebagai bahan awalnya. Tahapan reaksi sintesis meliputi reaksi penataan-ulang Thiele-Winter dan formilasi Gattermann dengan rendemen keseluruhan sebesar 21% berupa produk kasar yang masih perlu dimurnikan lebih lanjut.
Keyword: aktivitas sinergis, antioksidan, 6-bromopiperonal, 2,4,5-trihidroksibenzaldehida

Judul: Modifikasi Sintesis Difenil Eter Terpolibrominasi menggunakan Reksi Metilasi: Hubungan StrukturAktivitas Antibiotik
Abstrak: Penelitian ini bertujuan mendapatkan produk modifikasi sintesis senyawa mayor 2,3,4,5-tetrabromo-6-(3,5-dibromo-2-hidroksifenoksi)fenol 3 dan 2,3,5-tribromo-6-(3,5-dibromo-2-metoksifenoksi)fenol 4 dari spons Indonesia Lamellodysidea herbacea melalui reaksi metilasi parsial dan total dengan trimetilsilildiazometana. Berdasarkan gabungan data elusidasi struktur menggunakan UV-Vis, FTIR, LC-MS, NMR, dan kristalografi sinar-X dapat diidentifikasi senyawa 57 merupakan 2,3,4,5-tetrabromo-6-(3,5-dibromo-2-hidroksifenoksi)anisola (5A), 2,3,4,5-tetrabromo-6-(3,5-dibromo-2-metoksifenoksi)fenol (5B), 2,3,4,5-tetra-bromo-6-(3,5-dibromo-2-metoksifenoksi)anisola (6), dan 2,3,5-tribromo-6-(3,5-dibromo-2-metoksifenoksi)anisola (7). Struktur PBDE yang diperoleh selanjutnya dievaluasi dengan bakteri Gram-positif S. aureus ATCC 6538 pada konsentrasi 0.311.25 μg/disk, dan memberikan aktivitas terbaik pada senyawa 3, yaitu 12.5 ± 0.714.0 ± 0.0 mm. Dapat disimpulkan bahwa kehadiran 2 gugus fenol pada senyawa PBDE berperan penting untuk aktivitas antibakteri.
Keyword: antibacterial, structure elucidation, X-ray crystallography, PBDE

Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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