Pestacides Flashcards
Mammalian Selectivity Ratio
LD50 oral rat/LD50 dermal pest
Organophosphates
Parathion, Malathion, Diazinon, Chlorpyrifos
Organophosphates, mode of action
Inhibit Cholinesterases (irreversible)
Organophosphates, Absorption
skin, respiratory, GI
Organophosphates, Distribution
cross blood brain barrier
Organophosphates, Bioactivation
Parathion bioactivated by P450s to Oxons which is the active metabolite
Organophosphates, Targets a-e.
a. GI–Nausea, vomiting
b. Respiratory—excessive bronchial secretion
c. Cardiovascular —increase (as the dose increases)/decrease(initially) heart-rate/blood pressure
d. Skeletal muscles—weakness/paralysis
e. CNS—mental confusion/fatigue (affect neurotransmission)
If parasympathetic muscarinic receptors are affected you get…
SLUD and pinpoint eyes, and respiratory trouble.
If parasympathetic and sympathetic nicotinic receptors are affected you get…
tachycardia and muscle tension problems.
If acetylcholine receptors in the brain are negatively affected you get…
drowsiness or coma
Carbamates
Aldicarb, carbaryl
Carbamates, mode of action
Inhibit Cholinesterases (reversible)
*Antidote—atropine and 2-PAM
Carbamates, Bioactivation
None needed
Organochlorines
DDT, Heptachlor, Kepone, Mirex, Chlordane
dichlorodiphenyl ethanes structure
two 6 carbon rings attached to each other with one Cl attached to opposite sides of ether ring.
cyclodiene
a 6 carbon ring with a bridge attached to a 5 carbon ring, with Cls coming of of it.
chlorinated benzenes
benzenes with Cl sticking out
Organochlorines, mode of action
Inhibits NaKATPase of neuron continued
firing
Organochlorines, Persistence
Persistent—Biomagnifies in food chain
Organochlorines, Absorption
GI
Organochlorines, Target
CNS mostly, but also reproductive tract
Pyrethroids
cypermethrin, permethrin (similar to the natural pesticides in merry golds)
Pyrethroids, mode of action
inhibits Cl- channel; ionic ATPases
Pyrethroids, affect on humans
Esters right next to benzine rings and when hydrolyzed they become large phenolic compounds that look a lot like estrogen and are then endocrine disrupters.
Phenylpyrazole
Fipronil
Fipronil, mode of action
inhibits Gaba channel which normally mediates synaptic inhibition and regulates cellular excitability.
Tyrone Hase-
said atrazine affects frogs and Syngenta didn’t like it.
Bipyridyls
paraquat, diquat—dessicate plants
paraquat, affect on people
death if in mouth, typically via fibrosis in lungs
Chlorophenoxy Compounds
2,4-D and 2,4,5-T (Agent Orange 50:50 mixture) impurity—TCDD (dioxin)
TCDD (dioxin)
Chloracne - skin eruption of blackheads, cysts and nodules, which has been linked directly to dioxin exposure.
Teratogenicity
Carcinogenicity (most potent rodent carcinogen)
Dinitrophenol (DNP)
inhibits ATP synthesis (uncouples oxidative
phosphorylation) Proton vacuum at body pH and messes up mitochondrial electron transport chain
Hexachlorobenzene
chloracne (skin)
hepatomegaly (enlarged liver )
porphyria (a group of disorders caused by abnormalities in the chemical steps that lead to heme production.)
Phthalimides
fungicide not know to be harmful to people.
Dithiocarbamates
Maneb, Zineb
Rodenticides
Warfarin (inhibits vitamin K synthesis) anticoagulant
