(E)-Tetrachlorovinphos is an (E)- isomer of Tetrachlorovinphos. Tetrachlorovinphos is an organophosphate cholinesterase inhibitor that is used as an insecticide. Tetrachlorvinphos was introduced and first used commercially in 1966 in the USA. Tetrachlorvinphos was originally registered for use on various food crops, livestock, pet animals. Tetrachlorvinphos is applied dermally to livestock to control flies and mites. It is used as an oral larvicide in cattle, hog, goats and horses; in cattle ear tags to control flies; in cattle feedlots; in poultry dust boxes to control poultry mites; and in poultry houses. Tetrachlorvinphos also is used in pet sleeping areas and pet flea collars and to control flies around refuse sites, recreational areas, and for general outdoor treatment. Tetrachlorvinphos can cause cholinesterase inhibition in humans; that is, it can overstimulate the nervous system causing nausea, dizziness, confusion, and at very high exposures (e.g., accidents or major spills), respiratory paralysis and death. In 2014, the Natural Resources Defense Council (NRDC) filed a lawsuit against the United States Environmental Protection Agency (EPA) seeking EPA to respond to NRDC’s 2009 petition to ban tetrachlorvinphos in common pet flea treatment products. Tetrachlorvinphos is reportedly registered for use in Canada, South Africa, and Australia.

Nornicotine is a natural alkaloid produced by plants in the genus Nicotiana and is structurally related to nicotine. Nornicotine is the direct precursor of tobacco-specific nitrosamine N'-nitrosonornicotine, which is a highly potent human carcinogen. Nornicotine is an active nicotine metabolite, which accumulates in brain to pharmacologically relevant concentrations following repeated nicotine administration to rats. Nornicotine stimulated DA release from nucleus accumbens in a nicotinic receptor-mediated manner, further supporting the hypothesis that nornicotine contributes to tobacco dependence. Nornicotine is present in Nicotiana tobaccum in both S(-) and R(+) enantiomeric forms. Nornicotine enantiomeric forms appear to differ in analgesic potency and side effects. Exposure to nornicotine results in additional activation of α7-type receptors, which may be important for effects on cognition and attention. Likewise, the effects of nornicotine on α6-containing receptors may contribute to the reinforcing effects of nicotine, and therefore, is relevant to dependence on tobacco. In contrast to nicotine, nornicotine had relatively low activity on receptors other than those containing α7 or α6 subunits. Yaupon Therapeutics was developing Nornicotine as a once a day oral drug for smoking cessation. However this development was discontinued.