CAFFIENE presentaion by Fayza syed UOP

8/8/2019 CAFFIENE presentaion by Fayza syed UOP

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CAFFEINE


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Caffeine is a bitter, white crystalline xanthine alkaloid that is apsychoactive stimulant drug.

More than 60 plants produce Caffeine. Caffeine is foundnaturally in coffee, tea, and chocolate. Colas and some othersoft drinks also contain it. Caffeine also comes in tablet andcapsule forms. Some pain relievers and medicines for migraine

headaches also contain caffeine. It is said to be most widelyused drug in the world.

It is soluble in water and many organic solvents, and it appearsin pure form as white crystals.

Caffeine affects the central nervous system by binding toadenosine receptors in the brain, thereby inhibiting the sleep-promoting actions of adenosine that normally increase withprolonged wakefulness.

Its chemical name is 1,3,7-trimethylxanthine.

INTRODUCTION


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CAFFEINE

1,3,7-trimethylxanthine

XANTHINE

3,7-Dihydropurine-2,6-dione


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HISTROY

There is no doubt that human beings have consistently consumedcaffeine since the Stone Age. It is hypothesized that ancientpeople discovered that chewing on certain plants had stimulatingeffects on the body and mind. The Ethiopian myth describes thestory of a goatherd named Kaldi, whose goats nibbled on a bushcovered in red berries. After the goats had consumed the berries,they became frisky and started to dance on their hind legs. Kaldiwas intrigued by the strange actions of his goats and decided totry the berries for himself. After tasting the magical berries he toobecame energized and started to dance with his goats. A localmonk noticed the goatherds behavior, and came to the realizationthat the invigorating effects of this bean could help monks remainalert and awake during long religious sessions of prayer. It wasthen that the


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monk brewed the first cup of coffee. The consumption ofcoffee spread across northern Africa, and then into Arabia.And by the sixteenth century, coffee had become a staplethroughout the Arab world and was considered to be asimportant as bread or water.

Caffeine was first isolated by the German chemist FriedrichFerdinand Runge in 1819.Much of the work leading to the fullcharacterization of caffeine's molecular structure wascompleted by the German chemist Emil Fischer (1852-1919).Fischer first synthesized the compound from materials in

1895, and two years later derived its precise structuralformula.


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CAFFIENE CHEMISTRY

Caffeine is thought to act on the brain by blocking adenosine receptors.Adenosine, when bound to receptors of nerve cells, slows down nerve cellactivity; this happens, among other times, during sleep. The caffeinemolecule, being similar to adenosine, binds to the same receptors butdoesn't cause the cells to slow down; instead, the caffeine blocks thereceptors and thereby the adenosine action. So the main action ofcaffeine is to block adenosine receptors.

The resulting increased nerve activity causes the release of thehormone epinephrine (adrenaline), which in turn leads to several effectssuch as higher heart rate, increased blood pressure, increased blood flowto muscles, decreased blood flow to the skin and inner organs, andrelease of glucose by the liver. In addition, caffeine increases the levels ofthe neurotransmitter dopamine in the brain.

Caffeine is quickly and completely removed from the brain and, unlikeotherCNS stimulants oralcohol, its effects are short lived.


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CAFFEINE ACTION ON ADENOSINE

RECEPTORS

What happens when you drink coffee or an energy drinklike Red Bull??? Let's take a look.

In the images above, you can see that caffeine moleculesattach to adenosine receptors on the nerve endings. Becausecaffeine blocks the receptors, the nerves can't get adenosine,which causes neurons in the brain to fire


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And here you can see that the pituitary gland senses theincreased neuron activity in the brain and releases

adrenaline into the body. The adrenal glands pumpadrenaline throughout the body, making the heart beatfaster and the liver release extra sugar for energy.


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Caffeine Metabolism

Caffeine is metabolized (demethylated) in the liver by CYtochrome P450enzymes known as 1A2 (orCYP1A2). The first products of metabolism areall dimethylxanthines

1.Paraxanthine (1,7-dimethylxanthine)

2.Theobromine ( 3,7-dimethylxanthine) raw and

3.Theophylline (1,3-dimethylxanthine).

Paraxanthine has the effect of increasing lipolysis(break down of lipid),leading to elevated glycerol and free fatty acid levels in the blood plasma.

Theophylline relaxes smooth muscles of the bronchi and has been usedfor this purpose in the treatment of asthma.

Theobromine is a diuretic (increases urine production) that can dilate bloodvessels and reduce blood pressure

Each of these metabolites is further metabolized and then excreted in theurine. The half-life for caffeine metabolism is typically 5-6 hours in an adult.


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CAFFIENE ISOLATION

Caffeine was first isolated in 1819 by the French chemist Pierre

Jean Robiquet, from coffee. In its pure state it is an intensely

bitter white powder. Caffeine acts as a stimulant of the central

nervous system, cardiac muscle and respiratory system as well

as a diuretic. As such, it is found to delay fatigue. Caffeine canbe isolated directly from tea leaves.The chief problem with

isolation is that caffeine does not exist alone in tea leaves but

is accompanied by other natural substances from which it must

be separated. Caffeine constitutes as much as 5% by weight of

the leaf material in tea plants and is water soluble.

Unfortunately, Tannins in the tea leaf are also water soluble.Fortunately, Caffeine is soluble in non-polar organic solvents

whereas the Tannins are not. Thus, we can carry-out the

isolation of caffeine from tea leaves in the following steps


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STEPS1.Take 100ml of boiling water and add 4-6 tea bags into it to

make it concentrated. More concentrated solution is preferred.

It is then followed by filteration.

2. To a clean 500 mL conical flask, add this 100 mL of tea extract prepared

in step 1 into it.

3. Add approximately two grams of sodium carbonate (NaCO3) to this

tea/coffee solution. This is to convert Tannins to Phenoxides, which willremain in the aqueous phase during extraction of the caffeine.

Phenolic Tannins + Sodium Carbonate Sodium Phenoxides

4. Add 25 mL of methylene chloride (CH2Cl2), and vigorously swirl the

mixture for 10 minutes so that caffeine can dissolve in to it.

5. Allow the mixture to stand until 2 layers forms in the flask

=>a dark aqueous top layer and

=>a clear methylene chloride bottom layer.


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6. Carefully pour off into a beaker, as much of the top layer as you

can, without removing the bottom layer. This process is calleddecanting.

7. Place a fluted filter paper in a long stem glass funnel. Put the funnelin a small iron ring and suspend it over a 250 mL flask.

8. Slowly and carefully pour the methylene chloride/water mixture intothe fluted filter paper. The excess water will drain through and themethylene chloride solution of caffeine will remain on the filter paper.

9. Using a pipette, transfer the methylene chloride solution to a 50 mLconical flask. To this solution, add a scoop of anhydrous sodiumsulfate (Na2SO4), in order to remove the last traces of water.

10.While the solution is drying, weigh a 50 mL beaker to the nearest0.001 g on a balance. Record this reading.


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11.Using a pipette, transfer the dried solution to the tared(empty w.td)50mL beaker.

12.Evaporate most of the methylene chloride on a warm hot plate.When only a fraction of a milliliter of liquid is left, remove the

beaker from the hot plate. Allow the beaker to stand for a minuteor two.The heat remaining in the glass will cause the last amountof methylene chloride to evaporate and produce a solid residueof crude caffeine.

13. In order to determine your recovery of caffeine, reweigh the cool

beaker and record this mass.

14. Pure caffeine is a white solid.


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Side Effects of Caffeine Consumption

In large doses and usually over a period of time, consumption of

caffeine (less than 600 mg/day) present in tea and coffee can trigger

"caffeinism". The condition in turn is characterized by not only an

excessive caffeine addiction but also mental and physical conditions

like anxiety, restlessness, irritability, muscle twitching and caffeine

induced sleep disorders. In fact, the negative effects of caffeine on

the body include anxiety and panic attacks and may also result in

heart palpitations. It has also been reported that chronic, heavy

caffeine ingestion may be associated with depression, dizziness,headaches and impotence in men.


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Gastrointestinal Side Effects: Gastrointestinal side effects associatedwith caffeine include gastrointestinal distress, constipation, diarrhea,

nausea, vomiting and cramping after consuming caffeine.Psychiatric and Nervous System Effects: Psychiatric side effects haveincluded confusion and psychotic symptoms such as anxiety, lightdepression and fatigue. The side effects on the nervous systemassociated with caffeine consumption include central nervous systemstimulation such as nervousness, irritability, restlessness, and a jittery

feeling.Cardiovascular Side Effects: The most common cardiovascular sideeffect or caffeine side effect on the heart includes an increasedheartbeat and heart rate along with an elevated blood pressure.Research has also qualified the effect of caffeine in exerting an acuteunfavorable effect on aortic stiffness in treated hypertensive patients.

To know more about the effects on blood pressure read more oneffects of caffeine on blood pressure.

Endocrine Side Effects: A decrease in insulin sensitivity in individualswas observed following excessive caffeine consumption. Themechanism leads to elevated serum epinephrine levels.


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Renal Side Effects: Excessive caffeine consumption results inincreased urine flow and sodium and calcium excretion.

Caffeine and Pregnancy: Studies have also shown thatexcessive caffeine during pregnancy may lead to increasedchances of a miscarriage. In addition to that caffeine causesconstricted blood vessels of the placenta, leading to reducedblood flow. Also, caffeine may directly affect the developing cellsof the baby as it crosses the placenta.

Like adults, caffeine side effects in children include obesity andweight gain, dehydration, jitteriness, upset stomach, nervousnessand difficulty in concentrating and sleeping. However, a suddenwithdrawal from caffeine can trigger certain caffeine withdrawalsymptoms like cravings, apathy, constipation and throbbingpressure headaches. So the best course of action in this case

would be to limit caffeine intake.When consumed in moderation, caffeine speeds up our

metabolism and also increases the breakdown of fat thus freeingfatty acids, which are used in energy production during exercise.It can also increase stamina and help in fighting diseases likediabetes and Parkinson's disease.


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DECAFFEINATION

Decaffeination is the act ofremoving caffeine from coffee beans, cocoa, tea leaves andother caffeine-containing materials. Despite removal ofcaffeine, many decaffeinated drinks still have around 1-2%of the original caffeine remaining in them.


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Boiling point: 178 C

Melting point: 238 C

Density: 1.2 g/cm

Volatility: 0.5%

Vapor pressure: 101 Kpa @ 178 C

PH

: 6.9 (1% solution) Solubility in water:2.17%

Vapour density: 6.7 g/m

Molecular weight: 194.19 g/mol

Molecular Formula:

C8 H10 N4 O2

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CAFFIENE presentaion by Fayza syed UOP