Invasive fungal infections have been gaining notoriety due to several factors, mainly their increasing incidence in immunocompromised patients. The aim of the present study was to evaluate the antifungal activity and ...Invasive fungal infections have been gaining notoriety due to several factors, mainly their increasing incidence in immunocompromised patients. The aim of the present study was to evaluate the antifungal activity and toxicity of the 3,4,5-trihydroxybenzoic acid (3,4,5-THB) and of its derivative, the 3,4,5-tris(acetyloxy)benzoic acid (3,4,5-TAB). The 3,4,5-THB was purchased and its derivative was obtained by purifying and characterizing performed using semisynthesis reactions (esterification), recrystallization, column chromatography and infrared analytical techniques and nuclear magnetic resonance. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined in order to evaluate the antifungal activity of the compounds against four clinical isolates and four standard strains of Candida sp. and five clinical isolates of dermatophytes, following the Clinical and Laboratory Standards Institute protocols. The toxicity of the compounds was evaluated by determining the lethal dosis (LD50) using lethality assay of Artemia salina. The most sensitive yeasts to the 3,4,5-THB were C. albicans ATCC 10231 and C. krusei ATCC 6258, both presenting a MIC of 128 μg·mL-1. For Trichophyton sp. and Epidermophyton floccosum, the MIC was 32 μg·mL-1. The 3,4,5-TAB showed a lower inhibitory activity against Candida and dermatophyte species tested. The LD50 of 3,4,5-THB was 222.60 μg·mL-1 and the 3,4,5-TAB showed 481.69 μg·mL-1 of LD50. In conclusion, the 3,4,5-trihydroxybenzoic acid showed antifungal activity against species of medical importance, mainly dermatophytosis-causing fungi, and the 3,4,5-tris(acetyloxy)benzoic acid showed no increasing antifungal activity and toxicity in relation to the original compound.展开更多
Supramolecular assemblies of 2,2＇-biimidazole with 5-sulfosalicylic acid and 3,4,5-trihydroxybenzoic acid, have been synthesized and characterized by single-crystal X-ray diffraction methods. Both the two proton-tran...Supramolecular assemblies of 2,2＇-biimidazole with 5-sulfosalicylic acid and 3,4,5-trihydroxybenzoic acid, have been synthesized and characterized by single-crystal X-ray diffraction methods. Both the two proton-transfer compounds of 2,2＇-biimidazole with 3-carboxy-4-hydroxybenzenesulfonic acid （5-sulfosalicylic acid, 5-SSA） [namely bis（2-（2-1H-imidazolyl）-1H-imidazolium） 4-hydroxybenzene-3-carboxylate-1-sulfonate monohydrate, 2（C6HTN4）^＋· CTH4068^2-.H2O, （Ⅰ）] and 3,4,5-trihydroxybenzoic acid [namely 2,2＇-bi-1H-imidazolium bis（3,4,5-trihydroxybenzoate） tetrahydrate, C6H8N4^2＋ ·2（C7H5O5）^-·4（H20）, （Ⅱ）] feature extensively hydrogen-bonded three-dimensional network structures having significant interlayer n-n interactions between the cation and anion species. In Ⅰ, a 5-SSA^2- dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, all available O-atom acceptors interact with all cation and water molecule donors by hydrogen bonds. In Ⅱ, the formula unit displays a crystallographic inversion symmetry. The structural information about the two complexes between 2,2＇-biimidazole compound and benzenecarboxylic acids obtained in this work will be particularly important for the rational design of supramolecular organic functional materials.展开更多
文摘Invasive fungal infections have been gaining notoriety due to several factors, mainly their increasing incidence in immunocompromised patients. The aim of the present study was to evaluate the antifungal activity and toxicity of the 3,4,5-trihydroxybenzoic acid (3,4,5-THB) and of its derivative, the 3,4,5-tris(acetyloxy)benzoic acid (3,4,5-TAB). The 3,4,5-THB was purchased and its derivative was obtained by purifying and characterizing performed using semisynthesis reactions (esterification), recrystallization, column chromatography and infrared analytical techniques and nuclear magnetic resonance. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined in order to evaluate the antifungal activity of the compounds against four clinical isolates and four standard strains of Candida sp. and five clinical isolates of dermatophytes, following the Clinical and Laboratory Standards Institute protocols. The toxicity of the compounds was evaluated by determining the lethal dosis (LD50) using lethality assay of Artemia salina. The most sensitive yeasts to the 3,4,5-THB were C. albicans ATCC 10231 and C. krusei ATCC 6258, both presenting a MIC of 128 μg·mL-1. For Trichophyton sp. and Epidermophyton floccosum, the MIC was 32 μg·mL-1. The 3,4,5-TAB showed a lower inhibitory activity against Candida and dermatophyte species tested. The LD50 of 3,4,5-THB was 222.60 μg·mL-1 and the 3,4,5-TAB showed 481.69 μg·mL-1 of LD50. In conclusion, the 3,4,5-trihydroxybenzoic acid showed antifungal activity against species of medical importance, mainly dermatophytosis-causing fungi, and the 3,4,5-tris(acetyloxy)benzoic acid showed no increasing antifungal activity and toxicity in relation to the original compound.
基金Project supported by the National Natural Science Foundation of China （No. 30470408） and the Shanxi Provincial Natural Science Foundation for Youth （No. 20041032）.
文摘Supramolecular assemblies of 2,2＇-biimidazole with 5-sulfosalicylic acid and 3,4,5-trihydroxybenzoic acid, have been synthesized and characterized by single-crystal X-ray diffraction methods. Both the two proton-transfer compounds of 2,2＇-biimidazole with 3-carboxy-4-hydroxybenzenesulfonic acid （5-sulfosalicylic acid, 5-SSA） [namely bis（2-（2-1H-imidazolyl）-1H-imidazolium） 4-hydroxybenzene-3-carboxylate-1-sulfonate monohydrate, 2（C6HTN4）^＋· CTH4068^2-.H2O, （Ⅰ）] and 3,4,5-trihydroxybenzoic acid [namely 2,2＇-bi-1H-imidazolium bis（3,4,5-trihydroxybenzoate） tetrahydrate, C6H8N4^2＋ ·2（C7H5O5）^-·4（H20）, （Ⅱ）] feature extensively hydrogen-bonded three-dimensional network structures having significant interlayer n-n interactions between the cation and anion species. In Ⅰ, a 5-SSA^2- dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, all available O-atom acceptors interact with all cation and water molecule donors by hydrogen bonds. In Ⅱ, the formula unit displays a crystallographic inversion symmetry. The structural information about the two complexes between 2,2＇-biimidazole compound and benzenecarboxylic acids obtained in this work will be particularly important for the rational design of supramolecular organic functional materials.
