Display omitted
•Synthesized gemini compounds display effective tensioactive properties.•Their antifungal activities are comparable to commercial products.•New gemini succeeded in turning wood highly ...resistant against fungal degradation.•Ecotoxicity assays show less environmental impact using this new preservative.
Three gemini compounds were synthesized and characterized in the search of an alternative eco-friendly wood preservative. Synthesis was carried out from N,N-dimethylamines and 2-O-acetyl-1,3- dichloropropane as linker molecule. All the synthesized molecules were adequately purified and characterized by TLC, GC, FT-IR and NMR. Their tensioactive properties were determined. All three efficiently lowered the surface tension in aqueous solutions with critical micelle concentrations ranging from 0.53 to 1.34mM. Their antifungal activities were evaluated from a broth dilution test against four yeasts and two filamentous fungi and were compared to commercially available references: Fluconazole and TCMTB (2-thiocyanomethylthiobenzothiazole). All gemini compounds displayed good antifungal activity; particularly, the gemini derived from N,N-dimethyldodecylamine, with even better performance than Fluconazole against Saccharomyces cerevisiae, Aspergillus niger and Alternaria sp., and than TCMTB against the last one. The environmental impact of the gemini compound that showed the highest antifungal activity was analyzed through ecotoxicity tests, using Chlorella vulgaris and Daphnia magna as model organisms. It was several orders of magnitude less toxic than TCMTB. Finally, wood preservation efficacy studies were carried out on pine (Pinus ponderosa) samples. Results demonstrated accomplished resistance against brown rot fungi, comparable to a widespread commercial hydrosoluble preservative.
A novel series of quaternary ammonium gemini compounds having a butynylene spacer and different hydrocarbon chain lengths (CGBu8‐16) were prepared. Carbonate group inserted between the hydrocarbon ...chains and the polar heads make these compounds hydrolyzable. The degradation under hydrolysis of these novel series will lead to the generation of fatty alcohols and readily degradable compounds. The reagents used are biodegradable, renewable, or reusable. The surface activities and foamability in aqueous solution of the cleavable gemini compounds containing n‐octyl, n‐decyl, and n‐dodecyl chains meet the criteria for being good surfactants and showed stable foams even at low concentrations.
Display omitted
•We have found a regio-specific condensation of tert-butyl hydrazine with certain dicarbonilic compounds.•We have developed a high yield acylation reaction for poorly nucleophilic ...aryl amines.•The present work reports a wide library of new compounds with similar structures to commercial bioactives.
Regio-specific and non-regiospecific condensation reactions on 1,3-dicarbonyl compounds rendered 1,3,5-trisubstituted pyrazoles. Herein, the control of regio-specificity was a significant improvement in pyrazole research. A high yield acylation of poorly nucleophilic aryl amines, which resulted in mono- or diacylated products depending on the reaction conditions, is described. As a result, a library of potentially bioactive compounds was obtained.
A novel series of cleavable alkyltrimethylammonium surfactants with different hydrocarbon chain lengths (C8–16) were synthesized. A carbonate break site inserted between the polar head and the ...hydrocarbon chain makes these compounds hydrolyzable. The reagents used are renewable, (bio)degradable, or reusable. The hydrolysis of these cleavable surfactants will lead to the generation of fatty alcohols and choline, which is an essential biological nutrient. The surface activities in aqueous solution of the synthesized carbonates fulfill the requirement of being good surfactants. In addition, the cleavable compounds containing n‐decyl and n‐dodecyl chains showed similar or higher antimicrobial activities when compared to a non‐cleavable analog.
In this study, novel biosorbents were obtained from peanut shells modified with gemini-type surfactants. Peanut shells, an agro-industrial residue, were successfully modified to enhance their ...naturally low biosorption capacity towards anionic contaminants. An anionic dye (tartrazine) was employed to test their performance. Three gemini were synthesized from N,N-dimethylamines with different chain length and 1,3-dichloro-2-propanol as a linker. They were purified and characterized and their surfactant properties were determined. The successful modification of the peanut shells was confirmed through a retention study based on a two-phase titration method. This method has not been reported before for modified biosorbents and should be considered to prevent risky lixiviation. Retention was found to be high (98.0–99.7%) and to be chain length-dependent. Biosorption followed the pseudo-second order kinetic model and equilibrium isotherms of the gemini-modified biosorbents were best fitted by the Langmuir model. Their maximum biosorption capacities (0.126–0.141 mmol g−1) proved to be more than threefold higher than that of the unmodified peanut shells. The retention capacity of the gemini was also tested after biosorption studies.
Display omitted
•Peanut shells modified by synthesized gemini surfactants were tested as biosorbents.•Retention of the three surfactants onto the matrix was studied for the first time.•A two-phase titration method successfully quantified the lixiviation of the gemini.•Reduction of peanut shells residues and efficient dye-contaminated water treatment.
Tomato cultivation is an important agricultural activity in northeast of Argentina, and disease control is indispensable for its production. The purpose of the current study was to identify two fungi ...isolated from tomato plants cultivated in greenhouses, with symptoms of leaf mould disease and a strain of the genus Cladosporium from a culture collection, and evaluate their in vitro susceptibility to four commercial fungicides. Macro and microscopic examination, molecular characterisation and sequence analysis were applied for identification. Broth dilution and spread plate methods were used to determine the minimal inhibitory concentration (MIC) and minimal fungicide concentration (MFC). The active ingredients of the products were azoxystrobin+difenoconazole, trifloxystrobin+tebuconazole, chlorothalonil and metalaxyl-M+mancozeb. The results were processed using the Kruskal-Wallis method. The isolates were identified as Cladosporium cladosporioidesa-c; consequently, lesions found on tomato plants did not corrspond to Cladosporium fulvum. There was a significant statistical difference between the obtained values. Qualitatively, the three strains had a similar behaviour for chlorothalonil (MIC values: 0.25 - 0.5 μg/ml, MFC values: 4 μg/ml). In all cases, tests with metalaxyl-M+mancozeb yielded higher values than those achieved for chlorothalonil (MIC values: 8 μg/ml, MFC values: 8- 32 μg/ml). trobilurin-formulated fungicides were less effective against C. cladosporioidesa-b (MIC values: 16-256 μg/ml, MFC values: >64 μg/ml). C. cladosporioidesc was the most sensitive isolate. The information about the presence of a non-frequent fungus and its fungicide susceptibility, would be useful for establishing control strategies and enhance production.
