Synthesis and Biological Evaluation of Novel Mono Acid Esters Derived from the Constituents of Urtica pilulifera

Abstract: New mono acid esters have been synthesized from the reaction of benzoic acid and mono-hydroxybenzoic acids with 2-phenoxyethanol separated from Urtica pilulifera, characterized, and screened for possible antioxidant, antifungal, antimicrobial and anticancer activities. These phenolic acid esters gave various degrees of free radical scavenging, but the values were lower than that of α-tocopherol. The concentrations of the tested compounds needed to reduce DPPH absorption by 50% at 517 nm were nearly in the range of 900-1100 µg/mL. While for α-tocopherol was 40 µg /mL. The compounds were tested in vitro against six bacterial species which are known to cause dermic and mucosal infections in human. 2-phenoxyethyl benzoate showed significant activity in the range of 30% against P. aeruginosa to 70% against E. coli compared with the activity of Streptomycin. On the other hand 2-phenoxyethyl 2-hydroxybenzoate reveals 70% of gentamicin against K. pneumoniae. The tested compounds also showed complete inhibition at a concentration less than 37.5 µg/mL against M. canis and less than 50µg/mL against T. rubrum. 2-phenoxyethyl 4-hydroxybenzoate showed considerable activity against MCF-7 with IC50 is less than 62.5µg/mL.