No abstract

In this work, we synthesized a series of metal-substituted potassium heteropolyacid salts and investigated its catalytic activity on oxidation of benzyl alcohol with H 2 O 2 under homogeneous (CH 3 CN) and biphasic (toluene/water) conditions. The Keggin heteropolyacids were converted to lacunar salts (i. e., K 7 PW 11 O 39 ; K 7 PMo 11 O 39 and K 8 SiW 11 O 39 ), which had their vacancies filled with metal cations (i. e., Al 3 + , Fe 3 + , Co 2 + , Cu 2 + , and Ni 2 + ), generating the metal-substituted salts. The K 5 PW 11 NiO 39 proved to be the most efficient catalyst. The synergic effect raised between the PW 11 O 39 7À anion and Ni 2 + cation improved the redox properties and the activity of the catalyst. The K 5 PW 11 NiO 39 catalyst was able to promote the benzyl alcohol oxidation with hydrogen peroxide in biphasic conditions in the absence of phase transfer catalyst. Benzaldehyde and benzoic acid were the main products. The effects of main reaction parameters were assessed. The K 5 PW 11 NiO 39 catalyst was successfully recovered and reused without losing activity.

No abstract

Approximately 55% of the Rubus glaucus Benth (Andean blackberry) produced in Colombia is sold fresh and 10% is used in agroindustry. There are two types of cultivars for this species: Andean blackberries with prickles and ones without prickles. The investigations carried out in the Department of Risaralda are focused on finding the best genetic materials; however, studies on the bioprospecting that can generate an added value to these fruits are lacking. Therefore, soil fertility analysis, physicochemical characterization, and evaluation of the total phenolic content and antioxidant activity of Andean blackberries with and without prickles were carried out. The parameters evaluated for soil analysis were pH, organic matter, minor elements, phosphorus, nitrogen, aluminum, and texture, and the parameters evaluated for physicochemical characterization were titratable acidity, ash, dietary fiber, fat, moisture, maturity index, protein, and soluble solids. The total phenolic content and antioxidant activity were evaluated with the Folin–Ciocalteu and DPPH methods, respectively. Statistical analysis showed significant differences in the content of fat, proteins, total soluble solids, titratable acidity, acidity index, and ash between the materials with and without prickles. The ash content and soluble solids are highlighted: they presented differences by study municipality, The ash content and soluble solids are highlighted; in addition, a high content of phenolic compounds was observed in fruits from plants without prickles. The diagnosis of blackberry crops by the materials planted and place of cultivation in the Department of Risaralda showed that the materials without prickles are more widely distributed in the department due to their ease of handling. According to the results of the soil analysis, most Castilla blackberry crops in the Santa Rosa, Santuario, and Pereira municipalities are within the recommended parameters for blackberry production at the national level.