The Chemistry of Caffeine 




I WHAT IS CAFFEINE:

Caffeine Synonyms: 1-methyltheobromine

7-methyltheophylline
methyltheobromide
3,7-dihydro-1,3,7-trimethyl-1h-purine-2,6-dione
1,3,7-trimethyl-2,6-dioxopurine
theine
caffeine
thein
guarainine
no-doz
eldiatric c
nci-c02733
organex
1,3,7-trimethyl-2,6-dioxo-1,2,3,6-tetrahydopurine
caffenium
anhydrous caffeine
alert-pep
cafeina
cafipel
koffeine
mateina
refresh’n
stim
tri-aqua
The most common names for caffeine are 3,7-dihydro-1,3,7-trimethyl-1h-purine-2,6-dione and 1,3,7-trimethylxanthine.

Figure
 

             CH3
                  |
                  N
                 / \
           N----C   C==O
          ||   ||   |
          ||   ||   |
          CH    C   N--CH3
            \  / \ /
             N    C
             |    ||
            CH3   O
 
 

Also see
www.geocities.com/CapeCanaveral/Launchpad/6202/che.htm

Physical Properties: Molecular Formula = C8H10N4O2
Molecular Weight = 194.19
Number of Chiral Centers: Zero
Optical Activity: None
UV max (10mM HClO4 + 10mM NaClO4 70%) + (CH3CN 30%): 210nm, local max at 275nm
Half-Life: in human body varies between 3 to 7 hours
Properties: Soft, white crystal or powder, odorless, slightly bitter taste
Melting Point: 235-238oC

Caffeine is classified as a central nervous system stimulant and it belongs to xanthine chemical group. There are three distinguished compounds in xanthine group:
Caffeine: 1,3,7-trimethylxanthine
    Sources: Coffee, tea, cola nuts, mate, guarana
    Effects: Stimulant of central nervous system, cardiac muscle, and respiratory system, diuretic Delays fatigue
Theophylline: 1,3-dimethylxanthine
    Sources: Tea
    Effects: Cardiac stimulant, smooth muscle relaxant, diuretic, vasodilator
Theobromine: 3,7-dimethylxanthine
    Sources: Principle alkaloid of the cocoa bean, Cola nuts, and tea
    Effects: Diuretic, smooth muscle relaxant, cardiac stimulant, vasodilator

They are very similar and differ only by the presence of methyl groups in two positions of the chemical structure. They are easily oxidized to uric acid and other methyluric acids, which are also similar in chemical structure.

II SOURCES OF CAFFEINE:

Drinks:
 
Item Item Size Caffeine Content (mg)
Tea 150 ml 2-5
Hot Cocoa 150 ml 1-8
Chocolate Milk 225 ml 2-7
Jolt Cola 12 oz 71
Josta 12 oz 58
Mountain Dew 12 oz 54
Kick Citrus 12 oz 54
Mello Yellow 12 oz 53
Surge 12 oz 51
Tab 12 oz 47
Diet Coca Cola 12 oz 46
Coca Cola 12 oz 46
Dr. Pepper 12 oz 41
Mr. Pibb 12 oz 40
Pepsi Cola 12 oz 38
Aspen 12 oz 36
Canada Dry Cola 12 oz 30
RC Cola 12 oz 18
Mug Root Beer 12 oz 0
Sprite 12 oz 0
7-Up 12 oz 0

Coffee:
 
Item Item Size Caffeine Content (mg)
Coffee, Brewed 8 oz 135
General Foods International Coffee, Orange Cappuccino 8 oz 102
Coffee, instant 8 oz 95
General Foods International

Coffee, Café Vienna

8 oz 90
Maxwell House Cappuccino, Mocha 8 oz 60-65
General Foods International Coffee, Swiss Mocha 8 oz 55
Maxwell House Cappuccino, French Vanilla or Irish Cream 8 oz 45-50
Maxwell House cappuccino, Amaretto 8 oz 25-30
General Foods International Coffee, Viennese Chocolate Café 8 oz 26
Maxwell House Cappuccino, Decaffeinated 8 oz 3-6
Coffee, Decaffeinated 8 oz 5

Food:
 
Item Item Size Caffeine Content (mg)
Ben/Jerry No Fat Coffee Fudge Froz. Yog. 1 cup 85
Starbucks Coffee Ice Cream 1 cup 40-60
Dannon Coffee Yogurt 8 oz. 45
Chocolate Bar 50 g 3-63
Chunky Bar 1 bar (40g) 11.6
100 Grand Bar 1 bar (43g) 11.2
Nestle Crunch Bar 1 bar (40g) 10
Krackel Bar 1 bar (47g) 8.5
Peanut Butter Cup 1 pk (51g) 5.6
Kit Kat Bar 1 bar (46g) 5
Mr. Goodbar 1 bar (50g) 5
Raisinets 10 pieces (10g) 2.5
Butterfinger Bar 1 bar (61g) 2.4
Baby Ruth Bar 1 bar (60g) 2.4
Special Dark Sweet Chocolate Bar 1 bar (41g) 31
Chocolate Brownie 1.25 oz 8
Chocolate Chip Cookie 30 g 3-5
Chocolate Ice Cream 50 g 2-5
Milk Chocolate 1 oz 1-15
Bittersweet Chocolate 1 oz 5-35
After Eight Mint 2 pc (8g) 1.6
Jell-O Pudding Pop Chocolate 1 bar (77g) 2
Jell-O Mix Chocolate Mousse  95 g 6
Jell-O Chocolate Fudge Mousse  86 g 12

Non-prescription Drugs:
 
Item (1 tablet or capsule) Caffeine Content (mg)
Dextrim 200
Vivarin 200
No Doz 100
Excedrin 65
Vanquish 33
Anacin 32
Midol 32
Triaminicin 30
Dristan 16

III HOW CAFFEINE WORKS:

To a nerve cell, caffeine looks like adenosine that causes drowsiness by slowing down nerve cell activity. Caffeine therefore binds to the adenosine receptor. However, it does not slow down the cell/s activity like adenosine would. So the cell cannot see adenosine anymore because caffeine is taking up all the receptors adenosine binds to. Therefore instead of slowing down because of the adenosine level, the cells speed up. You can see that caffeine also causes the brain’s blood vessels to constrict, because it blocks adenosine’s ability to open them up.

IV OVERDOSE:

The lethal dosage varies from individual to individual according to weight. In massive doses, caffeine is lethal. A fatal dose of caffeine has been calculated to be more than 10 grams, about 80 to 100 cups of coffee in rapid succession.
 


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