Thermoanalytical studies of cimetidine and complexes with Mn(II) Co(II) and Ni(II)

Cimetidine is an important hydrogen histamine receptor and can coordinate metal ions in blood plasma. The stability of cimetidine and its complexes with Mn(II), Co(II) and Ni(II) was evaluated by studies of thermogravimetry (TG) and differential thermal analysis (DTA). Cimetidine was thermally stable up to near 190 °C and above this temperature the thermal decomposition occurred in two stages. Complexes of [Mn(HCm)2]Cl2, [Co(Cm)2]Cl2 and [Ni(Cm)2]Cl2 showed a similar behavior. The pyrolytic decomposition occurred in two stages at temperatures above 250 oC. A residue for each complex was detected at the end of the decomposition process. This probably corresponds to the respective metal oxide

Jabuticaba (myrciaria Cauliflora) Seeds: Chemical Characterization And Extraction Of Antioxidant And Antimicrobial Compounds

This study was aimed to assess the effect of time and temperature on the extraction of antioxidant compounds from jabuticaba seeds (Myrciaria cauliflora cv. Sabara), to optimize the solvent proportion (water, ethyl alcohol, and propanone), and to characterize the extract according to the chemical composition, antioxidant, and antimicrobial properties. Proximal composition, total phenolic content (TPC), antioxidant, and antimicrobial activities were analyzed. The optimized solvent ratio of 60% water and 40% propanone provided a mean TPC of 8.65 g GAE/100 g seeds and the antioxidant activity toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 82.79% 0.50%. Time and temperature parameters did not influence the yield of TPC. The gross seed extract was partially purified and both exhibited a high antioxidant activity and antimicrobial potential toward Gram-positive and Gram-negative bacteria. The purified jabuticaba seed lyophilized extract contained a higher (P < 0.05) TPC, o-diphenols, flavonols, and antioxidant activity measured by the DPPH assay and total reducing capacity as compared to the gross lyophilized extract. Electrospray ionization coupled with tandem mass spectrometry (ESI-MS/MS) data showed the presence of ellagitannins and ellagic acid in the extracts, which are probably the responsible for the antimicrobial and antioxidant activities. Practical Application Jabuticaba seeds are not used in industrial applications and, therefore, are considered as wastes. In this work, we studied 3 different solvents in mixtures aiming to optimize the extraction of bioactive compounds. A proportion of propanone and water was established using multiresponse statistical optimization and the gross and purified extract were demonstrated to present antioxidant and antimicrobial activities. These results are clear evidences that jabuticaba seeds should be used in food and pharmaceutical applications as a source of bioactive compounds.819C2206C221

Jabuticaba (myrciaria cauliflora) seeds: chemical characterization and extraction of antioxidant and antimicrobial compounds

This study was aimed to assess the effect of time and temperature on the extraction of antioxidant compounds from jabuticaba seeds (Myrciaria cauliflora cv. Sabará), to optimize the solvent proportion (water, ethyl alcohol, and propanone), and to characterize the extract according to the chemical composition, antioxidant, and antimicrobial properties. Proximal composition, total phenolic content (TPC), antioxidant, and antimicrobial activities were analyzed. The optimized solvent ratio of 60% water and 40% propanone provided a mean TPC of 8.65 g GAE/100 g seeds and the antioxidant activity toward 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) was 82.79% ± 0.50%. Time and temperature parameters did not influence the yield of TPC. The gross seed extract was partially purified and both exhibited a high antioxidant activity and antimicrobial potential toward Gram‐positive and Gram‐negative bacteria. The purified jabuticaba seed lyophilized extract contained a higher (P < 0.05) TPC, o‐diphenols, flavonols, and antioxidant activity measured by the DPPH assay and total reducing capacity as compared to the gross lyophilized extract. Electrospray ionization coupled with tandem mass spectrometry (ESI‐MS/MS) data showed the presence of ellagitannins and ellagic acid in the extracts, which are probably the responsible for the antimicrobial and antioxidant activities819C2206C221