Judul: Pencirian Ekstrak Aktif Sitotoksik dari Daun Sirsak Gundul (Annona glabra) Indonesia
Abstrak: Pond apple (Annona glabra) is a member of Annonaceae. It has been reported that plants from Annonaceae family contains alkaloid, flavonoid, and acetogenin having good anticancer potency. The objectives of this research were to fractionate A. glabra leaves assisted with brine-shrimp lethality test (BSLT), to characterize the active extract, and to identify the phytochemical constituents. Fractionation of 95% ethanol extract using liquid-liquid extraction gave 7 fractions, namely yellow, orange, and dark water, chloroform, residue, hexane, and methanol fractions. Based on the BSLT results, chloroform fraction showed the highest activity with LC50 of 98 ppm. Phytochemical test of the most active fraction showed alkaloid, flavonoid, steroid, triterpenoid, and tanin components. Subsequent fractionation of the chloroform fraction by using hexane-CH2Cl2-methanol (90:40:5) eluent produced 16 spots. The infrared spectrum of the best separated spot was analyzed and showed functional groups with -OH, aromatic C=C, C-H sp2, and C-H sp3 bonds.
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Judul: Isolasi dan Identifikasi Senyawa Alkaloid dalam Ekstrak Daun Sirsak Hutan (Annona glabra)
Abstrak: Sirsak hutan (Annona glabra), is a plant that has been traditionally used as medicine. In previous studies, ethanol extract of A. glabra leaves has been reported to be toxic against brine shrimp and zebrafish embryo. The result of phytochemical test showed dominant presence of alkaloids in the chloroform fraction, which was the most active fraction of the extract. This study was intended to isolate alkaloids from the chloroform fraction. The total alkaloid extract was obtained as much as 0.95 g (0.1%). Fractionation using column chromatography showed the presence of alkaloids in D fraction obtained by CHCl3-MeOH (90:10) as the eluent. This fraction exhibited 6 spots that were detected as alkaloids based on thin layer chromatography analysis with CHCl3- MeOH (85:15) eluent. Following separation of these spots on preparative thin layer chromatography, there were only 3 spots (D3; 1.1%, D4; 2.1%, and D5; 1.5%) with good separation based on ultraviolet spectrum at 254 nm. Based on spectra of liquid chromatography-mass spectrometer, Fourier transformed infrared, and ultraviolet, the D3 spot was predicted to be similar with armepavine.
Keyword: Bogor Agricultural University (IPB), isoquinoline, Annona glabra, alkaloids

Judul: Penerapan Vector Error Correction Model pada Peramalan Nilai Tukar Rupiah terhadap Dollar Amerika
Abstrak: Nilai tukar rupiah (kurs) menjadi salah satu indikator kestabilan ekonomi. Namun demikian, kurs selalu mengalami fluktuasi dari waktu ke waktu yang disebabkan oleh beberapa faktor diantaranya adalah tingkat inflasi, ekspor, impor, cadangan devisa dan BI rate. Dalam teori ekonomi keenam peubah tersebut memiliki pengaruh satu sama lain. Jika kurs melemah maka akan berdampak besar pada perekonomian dan sosial, dimana pertumbuhan ekonomi akan melambat sehingga kemiskinan akan meningkat. Dengan demikian, fluktuasi kurs harus tetap terkendali dengan baik. Peramalan kurs bisa dilakukan dengan berbagai metode, diantaranya adalah metode VECM. VECM termasuk dalam analisis deret waktu peubah ganda. VECM di berbagai penelitian memberikan indikasi dapat memberikan angka ramalan lebih baik daripada ARIMA. Metode VECM secara umum memberikan informasi bermakna baik dalam jangka pendek maupun jangka panjang. Peubah yang digunakan dalam penelitian ini adalah kurs terhadap dollar Amerika, ekspor, impor, inflasi, cadangan devisa, dan BI rate dari bulan Januari 2012 hingga Desember 2019. Model yang didapatkan adalah VECM(2) dengan 5 rank kointegrasi. Dalam jangka pendek maupun jangka panjang, peubah kurs, ekspor, dan BI rate berpengaruh nyata pada perubahan nilai kurs.
Keyword: Kurs, VECM