Dimethomorph is a morpholine fungicide that inhibits fungal cell wall formation.1 It inhibits mycelial growth of the oomycete fungi P. citrophthora, P. parasitica, P. capsici, and P. infestans (EC50s = 0.14, 0.38, <0.1, and 0.16-0.3 µg/ml, respectively) but is less active against the green algae species C. vulgaris or S. obliquus in vitro (EC50s = 47.46 and 44.87 µg/ml, respectively).2,3,4 It inhibits androgen receptor (AR) activity in a reporter assay in MDA-kb2 human breast cancer cells but not in a yeast antiandrogen screen (IC20s = 0.263 and 38.5 µM, respectively).5 It is not toxic to rats (LD50 = 3,900 mg/kg) or goldfish (C. auratus; LC50 = >32 µg/ml).4,1
1.Authority, E.F.S.Conclusion regarding the peer review of the pesticide risk assessment of the active substance dimethoateEFSA J.4(7)(2006) 2.Matheron, M.E., and Porchas, M.Impact of azoxystrobin, dimethomorph, fluazinam, fosetyl-al, and metalaxyl on growth, sporulation, and zoospore cyst germination of Three phytophthora sppPlant Dis.84(4)454-458(2000) 3.Rekanovi?, E., Poto?nik, I., Milijaševi?-Mar?i?, S., et al.Toxicity of metalaxyl, azoxystrobin, dimethomorph, cymoxanil, zoxamide and mancozeb to Phytophthora infestans isolates from SerbiaJ. Environ. Sci. Health B.47(5)403-409(2012) 4.Yu, X.-B., Hao, K., Ling, F., et al.Aquatic environmental safety assessment and inhibition mechanism of chemicals for targeting Microcystis aeruginosaEcotoxicology23(9)1638-1647(2014) 5.Orton, F., Rosivatz, E., Scholze, M., et al.Widely used pesticides with previously unknown endocrine activity revealed as in vitro antiandrogensEnviron. Health Perspect.119(6)794-800(2011)