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1

The effect of manganese on the structural and surface properties of nanocrystalline cobalt catalyst for ammonia synthesis

100%

Lendzion-Bieluń Z.

Open Chemistry

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2012

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vol. 10

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issue 2

327-331

EN

Based on the active surface model of the iron catalyst for ammonia synthesis, the assumptions which led to obtaining the cobalt catalyst for ammonia synthesis were described. The incorporation into the system small amounts of manganese, an element which binds oxygen stronger than cobalt, has influence the development of the catalyst’s specific surface area. The activity of manganese modified catalysts is higher than that of cobalt catalyst without manganese addition. The obtained catalysts were characterized with the following methods: ICP-OES, XRD, BET [...]

2

Paclitaxel as an anticancer agent: isolation, activity, synthesis and stability

88%

Nikolic V., Savic I., Savic I., Nikolic L., Stankovic M., Marinkovic V.

Open Medicine

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2011

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vol. 6

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issue 5

527-536

EN

Paclitaxel is isolated from the Pacific yew. It can be obtained from the European yew, but only after chemical modification of the isolated compound by a semi-synthesis procedure. The procedure for total synthesis of paclitaxel is very complicated, involving multiple steps, and the yields of paclitaxel are meagre. This substance is also a metabolite of certain kinds of fungus. The microbiological pathway for producing paclitaxel compared with isolation from plant material involves shorter procuction times but a small yield. Cyclodextrins are usually used for improving the solubility of paclitaxel in aqueous media, with polymeric and other substances added. Paclitaxel has anticancer activity and use for preparing the formulations intravenously administrated to patients with tumors. The paclitaxel concentration in these formulations is determined using validated HPLC methods.

3

Catalytic reduction of sulfuric acid to sulfur dioxide

88%

Balla A., Marcu C., Axente D., Borodi G., Lazăr D.

Open Chemistry

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2012

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vol. 10

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issue 6

1817-1823

EN

The reduction of H2SO4 to SO2 occurs with a relatively good efficiency only at high temperatures, in the presence of catalysts. Some experimental results, regarding conversion of sulfuric acid (96 wt.%) to sulfur dioxide and oxygen, are reported. The reduction has been performed at 800 – 900°C and atmospheric pressure, in a tubular quartz reactor. The following commercial catalysts were tested: Pd/Al2O3 (5 wt.% and 0.5 wt.% Pd), Pt/Al2O3 (0.1 wt.% Pt) and α-Fe2O3. The fresh and spent catalysts were characterized by X-Ray diffraction and BET method. The highest catalytic activity was determined for 5 wt.% Pd/Al2O3, a conversion of 80% being obtained for 5 hours time on stream, at 9 mL h−1 flow rate of 96 wt.% H2SO4. A conversion of 64% was determined for 0.5 wt.% Pd/Al2O3 and 0.1 wt.% Pt/Al2O3. For α-Fe2O3, a less expensive catalyst, a conversion of 61% for about 60 hours was obtained. [...]

4

Phytochemical Screening and Antimicrobial Activity of Ethanol and Methanol Extracts of Lantana camara Leaf

75%

Ezebo R. O., Okonkwo C. C., Ozoh C. N., Nwankwo C. A., Nwafor E. C., Esimai B. G., Achonye C. C., Obienyem J. N.

World News of Natural Sciences

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2021

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vol. 37

151-163

EN

This study investigated the phytochemical composition and antimicrobial activities of ethanol and methanol leaf extracts of Lantana camara Linn against some clinical pathogens. The ethanol and methanol extracts were obtained by soaking each of the powdered leaf in each solvent. The soaked powdered leaf was allowed to stand for four days at room temperature and later filtered using Whatman filter paper. The filtrate was further concentrated using rotary evaporator and then freeze-dried. The minimum inhibitory concentration (MIC) of the ethanol and methanol leaf extracts was carried out using agar well diffusion method. The phytochemical analysis was done using standard techniques. Data were analysed using Analysis of Variance (ANOVA) to test for significance. Means were separated using Duncan’s Multiple Range Test (DMRT). The results of the antimicrobial activity revealed that V. cholerae was the most susceptible while E. coli was the most resistant to plant extracts. The phytochemicals present in the plant leaf had antimicrobial properties and may serve as a good substitute for resistant human pathogens.

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2 Open Chemistry

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1 World News of Natural Sciences

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1 Achonye C. C.

1 Axente D.

1 Balla A.

1 Borodi G.

1 Esimai B. G.

1 Ezebo R. O.

1 Lazăr D.

1 Lendzion-Bieluń Z.

1 Marcu C.

1 Marinkovic V.

1 Nikolic L.

1 Nikolic V.

1 Nwafor E. C.

1 Nwankwo C. A.

1 Obienyem J. N.

1 Okonkwo C. C.

1 Ozoh C. N.

1 Savic I.

1 Stankovic M.

The effect of manganese on the structural and surface properties of nanocrystalline cobalt catalyst for ammonia synthesis

Paclitaxel as an anticancer agent: isolation, activity, synthesis and stability

Catalytic reduction of sulfuric acid to sulfur dioxide

Phytochemical Screening and Antimicrobial Activity of Ethanol and Methanol Extracts of Lantana camara Leaf