Alkaloids
where are they found
secondary metabolites derived from amino acids (basic and/or aromatic) lysine and ornithine; tryptophan
- alkaloids are found in 40% of all plant families potato, tomato, tobacco, legumes, coffee beans, lupin, periwinkle, opium poppy, cocoa bean (chocolate), etc.
- opium (morphine) was one of the first drugs
discovered by humans (~4000 BC)
Assyrians, Greeks and Romans
used opium for pain reluief and as a sleeping
aidwhat was the first drug discovered by humans?
opium- morphine
alkaloid
toxicity
> 5,000 different alkaloids have been isolated from natural sources and many are biologically active
- generally, the bitter taste and toxic/weird side effects of alkaloid-containing plant consumption acted as a deterrent to their early use potato (4th in tonnage [~320 million tons] among food crops grown in the world [corn, wheat and rice]) was the exception -> poosible results-> strong anticholinesterase activity blocks the ‘normal’ breakdown of acetylcholine (neurotransmitter) bradycardia (significant slowing of the heart rate [insufficient production of oxygen rich blood to the body] -disruption of membrane function in the GI tract-> lesions, hemorrhaging, death Disruption of mitosis- dna damage/mutation/growth issues/cancer
- cardiac arrest cessation of heart action
- respiratory depression
- neuromuscular blockage numbness, motor weakness, respiratory failure
(7) Alkaloids
Examples
(a) solanine (glycoalkaloid)
- green potatoes: 80-100mg/100g-> peel consumption?
- limited water solubility (0.2-1.3mg/100g) and is heat stable (up to 245 degrees celcius)-> re-use/dring cooking water?
- LD50 (mice/rats): 590 mg/kg bwt; ADI: 16-17 mg/kg bwt
- cholinesterase inhibition; GI tract lesions
- ingestion symptoms: abdominal pain, diarrhea, drowsiness, elevated body temperature, vomiting {deaths reported in 2009 and 2011]
(7) Alkaloids
Examples
(b) Tomatine (glycoalkaloid)
- ripe tomatoes: 12-25mg/kg fresh weight; green tomatoes: up to 3000mg/kg fresh weight-> peel consumption
- limited water solubility (5.4mg/100g) and is heat stable (up to 260 degrees celsium
- LD50 (mice/rats): ~950 mg/kg bwt; estimated daily consumption:2.5mg (ADI?)
- same toxicity/ingestion symptoms as solanine
(7) Alkaloids
Examples
(c) caffeine
toxicity
benefits
- coffee: 80-175 mg/345 mL; tea (black): 40-60 mg/ 345 mL; Coke: 34 mg/345 mL; chocolate bar: 5-20 mg/100 g
- LD50 (mice/rats/dogs): ~250 mg/kg bwt; estimated daily consumption: 4.5-6.5mg/kg bwt/day (Canada)[3-4mg and 7 mg/kg bwt for the USA and Denmark, respectively]
- ADI:up (zero?) to 400mg/day (WHO,FDA/USA, Canada)
- no unequivocal clinical evidence on caffeine consumption blood pressure, CHD and bone/calcium loss (>1000mg/day/10L of coke)
Benefits (human behaviour)- increased alertness (response to stimuli), vigilance (wakeful and alert), vigour (physical strength)
- mood improvement(?)
(7) Alkaloids
Examples
(d) Theobromine (comes from cocoa bean)
) Theobromine (comes from cocoa bean)
- chocolate bar: 100-1,000 mg/100 g; Cocoa Puffs: 67 mg/30 g; coffee: 10-20 mg/345 mL; tea (black): 3-10 mg/345 mL;
mothers milk : 3.7-7.5 mg/L (not synthesized in the body- from the diet- example drinking coffe or eating chocolate
- LD50 (cats/dogs): 200-500 mg/kg bwt LD 50 (HUMANS)- 1000mg/kg bwt - estimated daily consumption: structure is very similar to caffeine- when you have caffeine you also get theobromine
- NOEL/NOAEL: 50MG/KG BWT/day
- no cmta (animal studies: 100-150 mg/kg bwt/day up to 1-year; 1% of diet for up to 61 weeks)
- ADI:0.50 MG/KG BWT/DAY (EDI is >ADI)
How is adi determined: 10 fold x 2
