Synthesis of Dihydroartemisinin using Ni/TiO2 catalyst Prepared by Sol Gel Method.

Artemisinin is a δ-sesquiterpene lactone that incorporates an endoperoxide moiety. This compound was isolated as the active compound of Artemisia annua L. Dihydroartemisinin is the simplest semisynthetic derivative of artemisinin and is more potent than artemisinin. Combined with piperaquine, curently this compound is the drug of choice to treat malaria. The objective of this research is to modify the structure of artemisinin into dihydroartemisinin. A new way to modify the structure of artemisinin into dihydroartemisinin, had been successfully conducted using hydrogenation process with Ni/TiO2 catalyst. The yield of the reaction was 16.58%. LC-MS analysis showed that the compound had mainly a peak with retention time tR 2.2 minutes and mass spectrum showed that the molecular weight of the compound was 284.29 which was the molecular formula of dihydroartemisinin, C15H24O5. The IR spectrum showed that there was a spectrum from C-O in a wave number of 1034.14 cm-1. Hydrogenation reaction did not destroy the endoperoxide group. This was proven by the existing of C-O-O-C in a frequency of 1091.71; 875.68; 844.82 cm-1. 1H- and 13C-NMR data and comparison to the authentic sample, showed that the compound was a racemic mixture of /dihydroartemisinin. The dihydroartemisinin resulted from this process was also proven for its antimalarial activity, in vitro assay using cultured Plasmodium falciparum clone 3D7 with its IC50= 2x10-7M.

Determination of total arsenic in Indonesian tuna fish sample.

Indonesia contributed about 4 percent of total global fresh and frozen tuna exports, exporting about 65.5 tones in 2007, valued at US$ 150 million. The determination of total arsenic fish and fish product has not been standardized in Indonesia. To get an accurate result of total arsenic measurement in tuna fish is very difficult, it is due to the relatively low concentration of total arsenic in the sample and the characteristic of organic arsenic species (arsenobetain). Arsenobetaine in particular, are not decomposed to arsenate, which can lead to serious error in quantification when a hydride generator step is additionally used in the analysis scheme. This research covers the performance evaluation of three methods of sample preparation. Determination of total arsenic concentration is done by using hydride generator quartz furnace atomic absorption spectrophotometry (HG-QFAAS) and ICP-MS, and being validated using CRM DORM-2 and DORM-3. The sample preparation and measurement method obtained were expected to be used as an alternative method for determination of total arsenic in tuna fish sample. Abbreviations: HG-QF-AAS: hydride generator quartz cell flame atomic absorption spectrophotometer, ICPMS: inductively coupled plasma mass spectrophotometer.

Scopoletin, a coumarin derivative compound isolated from Macaranga gigantifolia Merr.

Scopoletin (1), a coumarin derivative compound has been isolated from methanol extract of Macaranga gigantifolia Merr. leaves using chromatography methods. Chemical structure determination carried out based on spectroscopic data and compared with a reference. Scopoletin cytotoxicity test using MTT assay method against P-388 murine leukemia cells showed strong cytotoxic activity with IC50 17.42 μg/mL.

Isolation and Elucidation of Pyrrolizidine alkaloids from tuber of Gynura pseudo-china (L.) DC.

Pyrrolizidine alkaloids (PAs) are produced by numerous plant species throughout the world. Numerous intoxications in animals and humans caused by the consumption of certain plants were attributed from the middle of this century to compounds of vegetable origin, the pyrrolizidine alkaloids. Daun dewa (Gynura pseudo-china (L.) DC.) is one of Indonesian medicinal plant which also a native plant of India, Thailand and China. The tuber of this plant is commonly used in Indonesian traditional medicine such as for treatments of uterine hemorrhages, dysentery, and inflamed wounds. Although its medicinal value, it is reported that leaves of this plant and other Gynura species content pyrrolizidine alkaloids (PAs). There are concern about the present of PAs in medicinal plants because of the toxicity of this compounds to human and animal. It is reported that PAs are hepatotoxic, pneumotoxic, genotoxic, neurotoxic, and cytotoxic. The purpose of this study is to study the PAs content of G. pseudochina tuber. The structures-were elucidated using spectral data of Infra Red, Liquid Chromatography-Mass Spectroscopy and a combination of one- and two dimensional 1H and 13C- Nuclear Magnetic Resonance spectroscopy. In this study, two pyrrolizidine alkaloids, senecionine (Compound 1) and senkirkine (Compound 2) were isolated from the tuber of G. pseudo-china. This results suggest that it should be a safety consideration in consuming this plant for traditional medicine because it is also contains PAs which are toxic compounds.

Cytotoxic assay of endophytic fungus 1.2.11 secondary metabolites from Brucea javanica (L) Merr towards cancer cell in vitro.

Cytotoxic assay of secondary metabolite endophytic fungus 1.2.11 from Brucea javanica (L) Merr has been carried out. Brucea javanica fruit collected from Cianjur was used in this experiment. Cytotoxic assay was done on Raji, NS-1, HeLa and Vero cells. The observation was done for 24 hours and also for 48 hours. IC50 was calculated using the Rich and Muench theory. To observe the working mechanism of cytotoxic process, DNA staining with etidium bromide and acridine orange was conducted. The cytotoxic assay of endophytic fungi 1.2.11 showed an IC50 of 58.35 μg/ml, 88.39 μg/ml on Raji cell,; 162.09 μg/ml, 66.24 μg/ml on NS cell; 361.21 μg/ml, 219.97 μg/ml on HeLa cell; and lastly 1075.18 μg/ml, 656.82 μg/ml on Vero cell after 24 and 48 hour incubation respectively. The results of this study showed that secondary metabolite of endophytic fungus 1.2.11 has selective cytotoxic effect towards cancer cell and also showed that it might cause apoptosis in NS-1cell.