Cov luam yeeb muaj nicotine, uas tuaj yeem tua kab. Feem ntau, cov ntawv pov tseg ntawm cov ntawv luam yeeb lossis cov stems yog siv los ua cov khoom siv raw, thiab cov nicotine tau muab rho tawm nrog cov kua qaub, thiab tom qab ntawd tsim cov tshuaj tua kab nicotine.
Nicotine yog lub npe nrov nicotine. Nws yog ib qho organic compound nrog cov tshuaj formula C10H14N2. Nws yog tshuaj lom heev. Nws yog ib qho alkaloid uas muaj nyob hauv cov nroj tsuag Solanaceae (genus Solanum) thiab tseem yog ib qho tseem ceeb ntawm cov luam yeeb. Nicotine tuaj yeem ua rau muaj kev quav yeeb quav tshuaj lossis kev vam khom, thiab rov siv dua kuj ua rau lub plawv dhia thiab ntshav siab thiab txo qis qab los noj mov. Kev noj tshuaj nicotine ntau tuaj yeem ua rau ntuav thiab xeev siab, thiab thaum mob hnyav, tuag. Tau kawg, nicotine hauv luam yeeb yog hom tshuaj thiab muaj cov tshuaj tua kab mob.
Lub npe tshuaj nicotine yog: (S)-3-(1-methylpyrrolidin-2-yl)pyridine los yog 1-methyl-2-(3-pyridyl) pyrrolidine. Cov qauv tseem ceeb ntawm cov tshuaj tua kab neonicotinoid yog raws li nicotine thiab hloov kho nrog cov ntsiab lus halogen.
Hauv cov tsiaj nyeg thiab kab, nicotine feem ntau ua rau nicotinic acetylcholine receptors (nAChRs)
Neonicotinoid insecticides feem ntau ua rau nicotinic acetylcholine receptors (nAChRs) ntawm cov kab mob postsynaptic ntawm kab. Acetylcholine yog ib qho endogenous agonist ntawm kab paj hlwb uas txhawb nqa neurotransmitters.
Neurotransmitters dhau los ntawm synapse ntawm nicotinic choline nyob rau hauv ob kauj ruam: ua ntej, vesicles nyob rau hauv lub presynaptic membrane tso acetylcholine, thiab acetylcholine khi rau receptors ntawm lub postsynaptic membrane; Qhov thib ob, kev hloov pauv hauv kev sib haum xeeb ntawm cov receptor molecules ua rau Txoj kev loj hlob ntawm cov ion channel txhawb cov dej ntws sab hauv ntawm extracellular Na + thiab sab nraud ntws ntawm intracellular K +, yog li rhuav tshem qhov sib npaug ntawm daim nyias nyias. ) Cov tshuaj tua kab neonicotinoid tuaj yeem ua rau cov kab tsis tuaj yeem tswj tau lawv cov kev txav, tshee, ua rau tuag tes tuag taw thiab tuag taus. Ntawm sublethal concentrations, nws muaj peev xwm ua rau noj aphids rau convulse, txo honeydew tawm, thiab thaum kawg tshaib plab tuag.
Cov tshuaj tua kab Neonicotinoid yog ib hom tshuaj tua kab tshiab tsim, tshuaj xyuas thiab ua ke raws li kev tshawb fawb ntawm nicotine (pib xyoo 1904). Ob leeg neonicotinoids thiab nicotinic insecticides ua agonists ntawm postsynaptic nicotinic acetylcholine (nAChRs).
Txawm li cas los xij, muaj qhov sib txawv loj ntawm cov tshuaj lom ntawm neonicotinoids thiab tshuaj tua kab nicotine. Piv nrog rau cov tshuaj tua kab nicotine, neonicotinoids tsis tshua muaj tshuaj lom rau cov tsiaj nyeg thiab muaj txiaj ntsig zoo rau cov kab mob paj hlwb. Kev xaiv. Nws kuj muaj qhov cuam tshuam ntawm kev sib cuag tua, mob plab hnyuv, kev nqus dej, tshuaj tua kab mob thiab tshuaj tua kab mob; Nws yog qhov tshwj xeeb tshaj yog tiv thaiv cov kab tsuag ntawm qhov ncauj xws li aphids, leafhoppers thiab kab tsuag coleopteran.