purine alkaloids

Purine (Xanthine) AlkaloidsPurine (Xanthine) Alkaloids The purines are consisting of The purines are consisting of a six-membered pyrimidinea six-membered pyrimidine ring fused to ring fused to a a

five-membered imidazole ringfive-membered imidazole ring. .

The pharmaceutically important bases of this group are all methylated The pharmaceutically important bases of this group are all methylated derivatives of derivatives of 2,62,6 dioxy-purinedioxy-purine (Xanthine)(Xanthine). This group includes mainly. This group includes mainly Caffeine, theobromine Caffeine, theobromine andand theophylline theophylline alkaloids. alkaloids.

These alkaloids are weak bases, they give no precipitate with Mayer's These alkaloids are weak bases, they give no precipitate with Mayer's reagent. reagent.

N

N N

N

H

Purine

1

2

34

56 7

8

9

HN

NH

N

HN

O

O

Xanthine

04/09/2304/09/23 11Dr. Harish Kakrani & Purvi Dr. Harish Kakrani & Purvi

KakraniKakrani

Caffeine, Theobromine Caffeine, Theobromine andand Theophylline Theophylline

CaffeineCaffeine Occurrence:Occurrence:

Tea leavesTea leaves (2- 5%), (2- 5%), Coffee seedsCoffee seeds (1-2 %), (1-2 %), Cola leavesCola leaves (2- 3%), (2- 3%), Gurana seedsGurana seeds (2.5- 5 %) and (2.5- 5 %) and Cacao seedsCacao seeds, (0.2- 0.5 %)., (0.2- 0.5 %).

Properties:Properties: 1- Water soluble. 2- Sublimable.1- Water soluble. 2- Sublimable.

Uses:Uses:Caffeine has a CNS stimulant effect, it is used mainly toCaffeine has a CNS stimulant effect, it is used mainly to relieve headache.relieve headache.

N

N N

N

R3

R2

R1

O

O

R1=R2=R3=CH3 CaffeineR1=H, R2=R3=CH3 TheobromineR1=R2=CH3, R3=H Theophylline


KakraniKakrani

TheobromineTheobromine Occurrence:Occurrence: CacaoCacao seeds. seeds.

Properties:Properties:

1- Sparingly soluble in water. 2- Sublimable. 3- Amphoteric.1- Sparingly soluble in water. 2- Sublimable. 3- Amphoteric.

Uses:Uses: Theobromine is used mainly as a diuretic.Theobromine is used mainly as a diuretic.

TheophyllineTheophylline Occurrence:Occurrence: Traces in Tea leaves, mostly synthetic.Traces in Tea leaves, mostly synthetic. Properties:Properties: 1- Sparingly soluble in water.1- Sparingly soluble in water.

Uses:Uses:Theophylline and derivatives are smooth muscle relaxant especially in the Theophylline and derivatives are smooth muscle relaxant especially in the upper respiratory tract. They used as bronchodilator. Theophylline also upper respiratory tract. They used as bronchodilator. Theophylline also act as duiretic.act as duiretic.


KakraniKakrani

Color tests:Color tests:

Murexide test: (caffeine, theobromine Murexide test: (caffeine, theobromine andand theophylline) theophylline)..

Crystals of caffeine + dropsCrystals of caffeine + drops of of concentrated HCl concentrated HCl andand traces of KClO traces of KClO3 3

→→evaporated on water bath evaporated on water bath →→ red color red color is produced wichis produced wich turns to turns to violet on exposure to ammonia vaporviolet on exposure to ammonia vapor. .

Tannic acid test: (caffeine Tannic acid test: (caffeine andand theophylline) theophylline)::

A concentrated solution ofA concentrated solution of the alkaloidthe alkaloid ++ tannic acid tannic acid →→ white white precipitateprecipitate is obtained that is obtained that dissolves in excess of the reagent.dissolves in excess of the reagent.

Ferrous sulfate test: (theobromine)Ferrous sulfate test: (theobromine)::

To a solution of the alkaloid +To a solution of the alkaloid + drops of drops of concentrated HClconcentrated HCl + few drops of + few drops of

BrBr22 water water + a drop of + a drop of FeSOFeSO44 + few drops of + few drops of ammonia ammonia →→ Blue color. Blue color.


KakraniKakrani

Steroidal AlkaloidsSteroidal Alkaloids

These contain the These contain the perhydrocyclopentano-phenanthreneperhydrocyclopentano-phenanthrene skeletonskeleton characteristic of sterols.characteristic of sterols.

They usually occur in They usually occur in glycosidal combinationglycosidal combination with sugars and thus with sugars and thus called called glucoalkaloidsglucoalkaloids e.g. e.g. SolanumSolanum and and VeratrumVeratrum alkaloids. alkaloids.

H

HO

H H


KakraniKakrani

1- 1- SolanumSolanum alkaloids alkaloids Occurrence:Occurrence: They occurs in They occurs in Solanum spp.Solanum spp. Consitituents:Consitituents: Solanine, Solasonine. Solanine, Solasonine.

Properties:Properties: They are glucoalklaloids with a sugar parts. They are glucoalklaloids with a sugar parts.

Uses:Uses: 1- The aglycone of both alkaloids are used as a starting material for the 1- The aglycone of both alkaloids are used as a starting material for the synthesis of steroidal drugs.synthesis of steroidal drugs.2- Solasonine is used as agricultural insecticide.2- Solasonine is used as agricultural insecticide.

NH

O

H H

H

H

GalGlcRha

H

O

HN

H

O

H H

H

H

GalGlcRha

CH3

Solanine Solasonine


KakraniKakrani

2- 2- VeratrumVeratrum alkaloids alkaloids They are of two types:They are of two types:

1- Typical or atypical steroidal alkamines containing one 1- Typical or atypical steroidal alkamines containing one or two non estrified hydroxyl groups e.g. Rubijervine and or two non estrified hydroxyl groups e.g. Rubijervine and Veratramine.Veratramine.

2- Highly oxygenated alkamines estrified with organic 2- Highly oxygenated alkamines estrified with organic acids e.g. Protoveratrines A& B.acids e.g. Protoveratrines A& B.

Uses:Uses:The second group posses hypotensive effect.The second group posses hypotensive effect.

N

OH

HO

Rubijervine

HO

N

HO

Veratramine04/09/2304/09/23 77Dr. Harish Kakrani & Purvi Dr. Harish Kakrani & Purvi

KakraniKakrani

DiterpeneDiterpene AlkaloidsAlkaloidsTaxolTaxol

Occurrence:Occurrence: Barks of Barks of Taxus brevifoliaTaxus brevifolia known as Pacific Yew. known as Pacific Yew. Yield:Yield: 0.015 %. 0.015 %. The bark The bark obtained from aboutobtained from about 4000 trees 4000 trees yields aboutyields about

oneone kg kg ofof Taxol Taxol.. The amount isolated from three trees is required from The amount isolated from three trees is required from treatment of only one cancer patient.treatment of only one cancer patient.


KakraniKakrani

Sources:1- Natural.1- Natural. 2- Semisynthesis from Baccatin III.2- Semisynthesis from Baccatin III.

Uses:Uses: Breast, Ovarian, lung and other solid tumors.Breast, Ovarian, lung and other solid tumors.

OAcO

OHAcO

O OH O

H

O

O

OH

NH

O

O


KakraniKakrani

Mechanism of Action:Mechanism of Action: Antimitotic agent.Antimitotic agent.


KakraniKakrani

purine alkaloids

Documents

h h ho7152011

o o h n n

n h hn

ac o nh o h oh o o h

harish caffeine

o n n ho o7152011

theophylline alkaloids

theophyllineo r1 n r3