Alkaloidy: Struktura a Účinky

Alkaloids

• Contain nitrogen, often in heterocyclic form
• Typically basic, found in plants as salts of carboxylic acids
• Poorly soluble in water, but soluble in polar solvents
• Produced as a defense mechanism in plants against predators
• Have significant biological effects on animals
• Often have bitter taste and toxicity
• Some act as hormones in animal bodies (e.g., serotonin, dopamine, melatonin)
• Plants sometimes use them to eliminate nitrogenous waste products

Specific Alkaloids

Nicotine

• Contains a pyridine cycle
• Formed by the methylation of pyridine
• Immiscible with water
• Found in tobacco leaves
• Abused as a drug

Quinine

• Contains a quinoline cycle
• Used as an antimalarial drug in tropical regions
• Lowers blood pressure
• Found in tonic
• Phosphoresces

Morphine

• Obtained from poppy capsules
• Has sedative effects, used as an anesthetic for severe pain
• Can be addictive—used only for patients in terminal stages as a result.
• Diacetylmorphine is a derivative

Codeine

• Used as an active ingredient in cough medications
• Can be easily converted to heroin
• Requires prescription after failure of other treatments

Atropine

• Contains a tropane cycle
• Toxic substance—increases heart rate
• Dilates pupils, reduces smooth muscle spasms.
• Is found in deadly nightshade, jimsonweed, and henbane

Cocaine

• Is found in coca leaves
• Stimulant drug, but has less severe consequences than some other drugs
• Has been part of Coca-Cola for some time

Lysergic Acid

• Product of ergot fungus
• LSD is extracted from it

Caffeine

• Found in coffee beans
• Stimulates the central nervous system, combating fatigue, and improving focus

Theobromine

• Found in chocolate

Theophylline

Colchicine

• Found in autumn crocus
• Has mild anti-inflammatory effects

Muscarine

• Found in some mushrooms
• Antidote is atropine, and it can have hallucinogenic effects

Tubocurarine

• Highly toxic substance
• Used by indigenous peoples as arrow poison—very fast-acting

Strychnine

• Found in nux vomica
• Blocks respiratory muscles
• First aid is artificial respiration
• Used as a rodenticide