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The dinitroaniline herbicide trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-N, N-dipropyl-p-toluidine), at micromolar concentrations, selectively inhibited both proliferation and differentiation of the parasitic protozoan Leishmania mexicana amazonensis. In vitro, radioactive trifluralin showed specific binding to leishmania tubulin but not to mammalian tubulin. Because herbicides such as trifluralin are economical and are considered safe for man and domesticated animals, they may serve as useful sources of potential antiparasitic agents.

The blue-green alga Agmenellum quadruplicatum (strain PR6) was very sensitive to aniline and p-toluidine (potential environmental toxicants) in an algal lawn assay (the growth of the algal lawn was inhibited with as little as 1 microgram of p-toluidine per disk). Assays with seven other species of blue-green algae showed that they had varying sensitivities ranging from 1 to 100 micrograms of p-toluidine. Under comparable conditions, 0.5 milligram or more of p-toluidine was needed to inhibit a green alga, a diatom, or two species of bacteria. p-Toluidine had no immediate effect on the photosynthesis or respiration of A. quadruplicatum, although growth was arrested and viability declined.