Judul: Aktivitas Fraksi Kloroform Buah Makasar (Brucea javanica [L.] Merr.) sebagai Inhibitor Enzim α-Glukosidase
Abstrak: Brucea fruit (Brucea javanica (L.) Merr) is a plant used in traditional medicine and proven pre-clinically for antimalaria, antipyretic, anticancer and homeostatic effects. However, the antidiabetic mechanism of this plant has not been elucidated. This research was done to determine the potential of chloroform fraction of brucea fruit at 1, 1.5, 2% as α-glucosidase inhibitor and compared their activities with acarbose 1% as a positive control. Brucea fruits were extracted with ethanol solution of 95% using maceration dan fractination solution method. Chloroform fraction of brucea fruits were used for phytochemical assay and used for α-glucosidase inhibition method. The α-glucosidase activity was determined by measuring the p-nitrophenol release from the reaction of the enzyme and substrate p-nitrophenyl-α-D-glukopiranosida (p-NPG) at wavelength 400 nm. The phytochemical analysis indicates that the chloroform fraction of brucea fruit contain alkaloid, saponin, and tannin. The fraction at concentration 1, 1.5, and 2% (b/v) and acarbose 1% can inhibit α-glucosidase enzyme activity respectively 16.48%, 17.96%, 19.68%, and 81.16%.
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Judul: Potensi Buah Makasar (Brucea javanica (L.) Merr) sebagai Inhibitor Enzim α-Glukosidae
Abstrak: Brucea fruit is one Indonesian medicine plants which rich in advantages. Empirically, brucea fruit can decrease blood glucose concentration for patient of diabetes mellitus. Water fraction of brucea fruit extract have been observed to determine its ability as antidiabetic would be compared with acarbose as positive control in same concentration (1%). Antidiabetic test in water and hexane fraction of brucea fruit extract use α-glucosidase inhibition method. Antidiabetic activity has been measured by formation of p-nitrophenol from enzymatic reaction of nitrophenil--D-glucopyranose (p-NPG) which is catalyze by α-glucosidase enzyme. The formation of p-nitrophenol was measured by spectrophotometer at λ=400 nm. Phytochemistry test showed that water fraction contains alkaloid and flavonoid, whereas hexane fraction only contain alkaloid. The result of this research is water fraction and hexane of brucea fruit (Brucea javanica (L.) Merr) at concentration 1% (b/v) can inhibit α-glucosidase enzyme activity 14.32% and 12.76%, whereas Acarbose as positive control can inhibit α-glucosidase enzyme activity 81.15%.
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Judul: Simulasi persamaan keadaan bintang dengan pendekatan klasik dan relativistik
Abstrak: Komposisi bintang yang selalu berubah akanmempengaruhi massa dan radius bintang itu sendiri. Dimana semakin tua sebuah bintang, maka bintang akan didominasi oleh unsur-unsur berat. Dengan persamaan politrop dan metode Runge-Kutta orde 4 didapatkan radius dan massa bintang semakin berkurang seiring berkurangnya nilai Ye, sedangkan kerapatan semakin meningkat. Pendekatan terbaik terdapat pada nilai Ye sebesar 0.5 dimana didapatkan bahwa massa bintang katai putih sebesar 1.4Mo sesuai dengan massa Chandrasekhar dengan radius bintang 5000 km dan nilai kerapatan bintang sebesar 5.31x 106 g cm-3. Untuk massa bintang neutron diperoleh nilai 0.05Modan radius bintang sebesar 2300 km, sedangkan kerapatannya bintang neutron diperoleh sebesar 1.84 x 107 g cm-3 dengan menggunakan pendekatan relativistic. Pendekatan relativistic terbukti lebih baik untuk menentukan radius dan massa bintang, dengan pendekatan terbaik pada nilai Ye sebesar 0.5 yaitu pada bintang katai putih
Keyword: Composition of the stars, density of the stars, mass of the stars, radii of the stars