The Chemistry of Caffeine 

I WHAT IS CAFFEINE:

Caffeine Synonyms: 1-methyltheobromine

Figure
 

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

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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: 235-238^oC

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.