Growth Inhibition Effects of Loreclezole on the Various Microalgae and Plant Species

Jin-Seog Kim 1,*   Bo Gwan  Kim1   Yun Gyeong  Hwang1   Ji Hye  Choi1   Byoung-Seok  Lee2   Ill Young  Lee1   

1Research Center for Eco-Friendly New Materials, Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
2Department of Advanced Toxicology Research, Korea Institute of Toxicology, Daejeon 34114, Korea


This study was conducted to investigate the biological activities of loreclezole on the various microalgae and plant species. Loreclezole roughly showed a broad algicidal spectrum with a active rate of 2.0-35 μM. Among the tested green algae, there was sensitive response in the order of Scenedesmus spp.>Raphidocelis subcapitata>Chlorella sorokiniana>C. vulgaris (KCTC)>C. vulgaris (FBCC). In the tested cyanobacteria (blue-green algae), Microcystis aeruginosa exhibited higher response to loreclezole than that of Dolichospermum circinale. In the case of Lemnaceae (duckweeds), Lemna paucicostata showed higher herbicidal activity (IC50=10.5 μM) to loreclezole than that of Spirodella polyrhiza (SPIPO). Loreclezole seemed to have a novel action mechanism different with the those of commercial herbicides when it was gathered through symptoms of SPIPO treated with loreclezole. In the mixture experiment to evaluate a chemical interaction in SPIPO control, loreclezole showed a mild synergistic effect with bentazon, photosynthesis inhibitor. In herbicidal activities against the various weeds at a foliar application, loreclezole primarily induced burning symptoms (leaf desiccation, discoloration and necrosis), had about 50% control at the rate of 1.0 kg ha-1 and a short efficacy duration within about 5 days. Taken together, our results suggested that loreclezole had a potential as an algicide in water ecological system, but an optimization of chemical structure was likely to be required for the use of herbicide.

Figures & Tables

Fig. 1. Algicidal activities of loreclezole on the various microalgae according to the increase of incubation time after chemical treatment. Abbreviation of microalgae species used in this experiment was designated in Table 1.