Judul: Potensi Antioksidan dan Antikanker Ekstrak Batang Lelutung Tokak (Tabernaemontana macrocarpa Jack.)
Abstrak: The purpose of this research was to determine the activity of n-hexane, ethylacetate, ethanol and water extracts of Lelutung Tokak (Tabernaemontana macrocarpa Jack.) as antioxidation and anticancer. This research consisted of four steps, the first step was extration and phytochemistry. The second step was Brine Shrimp Lethality Test (BSLT) to determine the toxicity of the extract. The third step was examination of antioxidation activity using DPPH method and the last step was examination of anticancer activity of the extract using L1210 leukimia cell line. The results of this research showed that four extract of stem of T. Macrocarpa Jack. has antioxidation and anticancer activity. The LC50 of BSLT was hexane extract 567,886 ppm; ethyl acetate extract 119,339 ppm; ethanol extract 120,56 ppm and water extract 156,441 ppm. The IC50 of antioxidation activity using DPPH method was hexane 653,540 ppm; ethyl acetate 48,103 ppm; ethanol 53,322 ppm and water 121,019 ppm. Furthermore the most active extract which was tested as anticancer. The IC50 of anticancer test was ethyl acetate extract of 6,039 ppm; ethanol extract of 7,145 ppm. The result of phytochemistry analysis showed four extract of stem of T. macrocarpa Jack. contains alkaloid, flavonoid, saponin and tanin compounds. The conclusion of this experiment wasethylacetate and ethanolextract have a strong anticancer and antioxidation activity.
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Judul: Potensi Pelepah Temulawak (Curcuma xanthorriza) sebagai Antikanker dan Antioksidan
Abstrak: The study aimed to evaluate the potency of temulawak (Curcuma xanthorrhiza) stem as anticancer by brine shrimp lethality test (BSLT) and antioxidant by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The stem of temulawak midrib obtained from Bogor, was extracted by n-hexane, chloroform, ethyl acetate, methanol, and water, and the volatile oil was obtained by water distillation. The chloroform extract and volatile oil showed anticancer potency towards Artemia salina (LC50: 370.69 ± 22.69 μg mL-1 ; 123.05 ± 3.49 μg mL-1, respectively). Ethyl acetate and chloroform extracts had antioxidant activities (IC50: 46.41 ± 15.49 μg mL-1 and 52.72 ± 3.46 μg mL-1) but the activity did not as strong as ascorbic acid (control positive, IC50 1.80 ± 0.33 μg mL-1). The chloroform extract was further fractionated by column chromatography with Silica Gel G60F254-Merck as stationary phase and gradient of n-hexane, chloroform, and methanol as mobile phase. Antioxidant and anticancer potency of fraction which had antioxidant activity qualitatively were tested. The most antioxidant active fraction (F9) had anticancer potency (LC50: 522.95 ± 43.35 μg mL-1) and antioxidant activity (IC50: 79.57 ± 8.96 μg mL-1). In conclusion, F9 is potencial as an anticancer and antioxidant.
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Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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