Thioureides of 2-(phenoxymethyl)benzoic acid 4-R substituted: a novel class of anti-parasitic compounds.
Fifty members of a novel class of antimicrobial compounds, 2-(4-R-phenoxymethyl)benzoic acid thioureides, were synthesized and characterized with respect to their activities against three parasites of human relevance, namely the protozoa Giardia lamblia and Toxoplasma gondii, and the larval (metacestode) stage of the tapeworm Echinococcus multilocularis. To determine the selective toxicity of these compounds, the human colon cancer cell line Caco2 and primary cultures of human foreskin fibroblasts (HFF) were also investigated. The new thioureides were obtained in a three-step-reaction process and subsequently characterized by their physical constants (melting point, solubility). The chemical structures were elucidated by (1)H NMR, (13)C NMR, IR spectral methods and elemental analysis. The analyses confirmed the final and intermediate compound structures and the synthesis. The compounds were then tested on the parasites in vitro. All thioureides, except two compounds with a nitro group, were totally ineffective against Giardia lamblia. 23 compounds inhibited the proliferation of T. gondii, three of them with an IC(50) of approximately 1 microM. The structural integrity of E. multilocularis metacestodes was affected by 22 compounds. In contrast, HFF were not susceptible to any of these thioureides, while Caco2 cells were affected by 17 compounds, two of them inhibiting proliferation with an IC(50) in the micromolar range. Thioureides may thus present a promising class of anti-infective agents.
Müller
Joachim
J
Institute of Parasitology, University of Berne, Länggass-Strasse 122, CH-3012 Berne, Switzerland. joachim.mueller@ipa.unibe.ch
Limban
Carmen
C
Stadelmann
Britta
B
Missir
Alexandru Vasile
AV
Chirita
Ileana Cornelia
IC
Chifiriuc
Mariana Carmen
MC
Nitulescu
George Mihai
GM
Hemphill
Andrew
A
D000818:Animals; D000977:Antiparasitic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D001565:Benzoates / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D018938:Caco-2 Cells / Q000187:drug effects; D048210:Echinococcus multilocularis / Q000187:drug effects* / Q000254:growth & development; D005347:Fibroblasts / Q000187:drug effects; D016829:Giardia lamblia / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D007814:Larva / Q000187:drug effects; D021261:Parasitic Sensitivity Tests; D013890:Thiourea / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D014122:Toxoplasma / Q000187:drug effects* / Q000254:growth & development
D000977:Antiparasitic Agents; D001565:Benzoates; D013890:Thiourea