Judul: Isolasi dan Elusidasi Struktur Molekul Aktif dari Spons Laut Lamellodysidea herbacea asal Ujung Kulon
Abstrak: Penelitian bertujuan mengisolasi dan mengelusidasi struktur molekul aktif spons laut Lamellodysidea herbacea asal Ujung Kulon. Lapisan CH2Cl2 (4.05 g) memiliki aktivitas antibakteri terhadap bakteri S. aureus (20 mm) dan P. aeruginosa (12 mm) pada konsentrasi 100 g/cakram menggunakan metode difusi plat-agar. Lapisan CH2Cl2 direkristalisasi dengan CHCl3−Me2CO−MeCN menghasilkan senyawa 3 (C12H6O4Br6) dalam kelompok ruang monoklinik P21/n (Z = 4) yang diidentifikasi sebagai 2,3,4,5-tetrabromo-6-(3',5'-dibromo-2'-hidroksi fenoksi) fenol setelah dielusidasi dengan 1H NMR, UV-Vis, FTIR, dan kristal tunggal difraksi sinar-X. Senyawa 3 mempunyai konformasi seperti twist dengan sudut torsi 1 = 27.7 (6) ; 2 = 86.5 (5) dan sudut ikatan eter 117.5. Senyawa 3 menunjukkan aktivitas antibakteri Gram-positif S. aureus ATCC 6535 dan Gram-negatif K. pneumoniae. Senyawa 3 tidak menunjukkan aktivitas terhadap bakteri patogen Gram-negatif E.coli (resisten ampicillin) hingga konsentrasi 50 g/cakram. Toksisitas senyawa 3 terhadap embrio D. rerio adalah LC50 > 10 g/mL.
Keyword: antibakteri, Danio rerio, elusidasi struktur, kristalografi sinar-X, Lamellodysidea herbacea

Judul: Isolasi dan Elusidasi Struktur Molekul Bioaktif dari Spons Laut Neopetrosia chaliniformis.
Abstrak: Penelitian ini bertujuan mengisolasi dan menentukan suatu struktur molekul bioaktif spons laut Neopetrosia chaliniformis asal perairan Lampung. Lapisan BuOH (4.0278 g) ditemukan memiliki toksisitas (LC50) paling ampuh terhadap embrio ikan zebra, yaitu 61 μg/mL. Fraksionasi lapisan BuOH menghasilkan 6 fraksi A–F dengan fraksi teraktif F (LC50 12 μg/mL) diperoleh sebanyak 1.4482 g. Fraksi F menyebabkan matinya sel pada embrio ikan zebra dengan persentase malformasi 76%. Molekul 3 (0.5 mg) diisolasi dari sejumlah tertentu fraksi F (15.4 mg) menggunakan KCKT. Struktur planar dan stereostruktur molekul 3 dielusidasi menggunakan data gabungan rotasi spesifik [α]D, bobot molekul, data NMR 1D (1H dan 13C) dan 2D, analisis energi minimum konformasi dengan Spartan ‘14, serta perbandingan dengan data pustaka. Berdasarkan semua data tersebut, molekul 3 adalah (+)-araguspongin C, suatu molekul simetri C2 alkaloid bis-1-oksakuinolizidina dengan konfigurasi relatif 2R*, 9R*, 10S*, 2'R*, 9'R*, 10'S*.
Keyword: alkaloid, elusidasi struktur, embrio ikan zebra, Neopetrosia chaliniformis, NMR

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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