... Nornicotine causes aberrant protein glycation and catalyzes the covalent modification of certain prescription drugs such as the commonly used steroid, prednisone. ...
/CASE REPORTS/ Umbilical cord tissue was studied as a means of detecting prenatal exposure to nicotine. ... Between June and September 2009, 19 women with a tobacco exposure history (either first- or second-hand tobacco smoke exposure during pregnancy) were consented for the study. A questionnaire was completed to document nicotine exposure during each trimester of pregnancy. All infants were delivered at term (38 weeks or greater) and paired umbilical cord tissue (10-cm segment or greater) and meconium were obtained. ... Nornicotine was detected only in meconium, at very low concentrations. ... All analyte concentrations were lowest when the mother stated she quit smoking early in pregnancy or had only second-hand exposure, and detection was poor if exposure was limited to the first or second trimesters. ...
/LABORATORY ANIMALS: Neurotoxicity/ The present study demonstrates that S(-)-nornicotine evoked a concentration-dependent increase in dopamine (DA) release from superfused rat striatal slices. The increase in DA release was indicated by an S(-)-nornicotine-induced overflow of endogenous 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatal superfusate and by an S(-)-nornicotine-induced increase in tritium overflow from striatal slices preloaded with [3H]DA. Low concentrations (0.01-1.0 microM) of S(-)-nornicotine, which did not evoke endogenous DOPAC overflow, also were unable to modulate electrically evoked DOPAC overflow. The increase in DOPAC overflow induced by S(-)-nornicotine was compared with that produced by S(-)-nicotine. Comparing equimolar concentrations (0.1-100 microM) of S(-)-nornicotine and S(-)-nicotine, superfusion with S(-)-nornicotine resulted in a significantly greater DOPAC overflow. In contrast to the effect of S(-)-nicotine, S(-)-nornicotine evoked a sustained increase in DOPAC overflow for the entire period of S(-)-nornicotine exposure. Furthermore, DOPAC overflow evoked by S(-)-nornicotine in control Krebs buffer was inhibited by superfusion with a low-calcium buffer. Moreover, in the low-calcium buffer, DOPAC overflow induced by 30 and 100 microM S(-)-nornicotine was not different from that with no S(-)-nicotine, tobacco products and a known metabolite of S(-)-nicotine, increases DA release in a calcium-dependent manner in superfused rat striatal slices. It is interesting that unlike S(-)-nicotine, there does not appear to be desensitization to this effect of S(-)-nornicotine.
/GENOTOXICITY/ Of five tobacco alkaloids tested, only anatabine led to a dose-dependent enhancement of the number of sister-chromatid exchanges (SCE) in Chinese hamster ovary cells (CHO). Nicotine and nornicotine at high concentrations increased the baseline frequency of SCEs moderately. Anabasine and myosmine had no influence on the spontaneous frequency of SCEs.
/OTHER TOXICITY INFORMATION/ ... Nornicotine was found to covalently alter amyloid beta-peptide, leading to reduced peptide aggregation. Potential consequences of this reaction cascade include reduced plaque formation and/or altered clearance of the peptide, as well as attenuated toxicity of soluble amyloid beta-peptide aggregates. The findings described provide an alternative mechanism for nicotine neuroprotection in AD and a means for the alteration of amyloid folding based on a covalent chemical event.
Compounds of formula I
wherein the substituents are as defined in claim 1, and the agrochemically acceptable salts and all stereoisomers and tautomeric forms of the compounds of formula I can be used as insecticides and can be prepared in a manner known per se.
Molecules having pesticidal utility, and intermediates, compositions, and processes, related thereto
申请人:Dow AgroSciences LLC
公开号:US20180279612A1
公开(公告)日:2018-10-04
This disclosure relates to the field of molecules having pesticidal utility against pests in Phyla Arthropoda, Mollusca, and Nematoda, processes to produce such molecules, intermediates used in such processes, pesticidal compositions containing such molecules, and processes of using such pesticidal compositions against such pests. These pesticidal compositions may be used, for example, as acaricides, insecticides, miticides, molluscicides, and nematicides. This document discloses molecules having the following formula (“Formula One”).
(R,S)-Nicotine was resolved through diastereomeric salt formation using dibenzoyl-d-tartaric acid and dibenzoyl-l-tartaric acid to obtain enantiomerically pure (S)-nicotine and (R)-nicotine.