TITLE:
Antifungal Activity and Toxicity of the 3,4,5-Trihydroxybenzoic and 3,4,5-Tris(Acetyloxy)Benzoic Acids
AUTHORS:
Jéssica Pinto, Diego Silva, João Honorato, Antônio Menezes, Eugénia Pinto, Plínio Naves
KEYWORDS:
Antifungal, Toxicity, Candida, Dermatophytes, 3, 4, 5-Trihydroxybenzoic Acid, 3, 4, 5-Tris(Acetyloxy)Benzoic Acid
JOURNAL NAME:
Advances in Microbiology,
Vol.5 No.7,
July
8,
2015
ABSTRACT: 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.