Alkaloids 37

8/9/2019 Alkaloids 37

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Quinoline AlkaloidsQuinoline AlkaloidsCinchonaCinchona Alkaloids Alkaloids

Cinchona bark contain many alkaloids the majors are:Cinchona bark contain many alkaloids the majors are:

1- Quinine and Quinidine.1- Quinine and Quinidine.

2- Cinchonine and Cinchonidine.2- Cinchonine and Cinchonidine.

Cinchona alkaloids are presentCinchona alkaloids are presentas salts with Quinic andas salts with Quinic and

Cinchotannic acids.Cinchotannic acids.

They are diacidic bases form two types of salts:They are diacidic bases form two types of salts:

1- eutral salts !"onoacidic# !less water soluble.1- eutral salts !"onoacidic# !less water soluble.

2- Acidic salts !$iacidic# water soluble.2- Acidic salts !$iacidic# water soluble.

OHHO

OH

HO COOH

Quinic acid


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%oth Quinine and Quinidine& Cinchonine and Cinchonidine%oth Quinine and Quinidine& Cinchonine and Cinchonidineare $iastereoisomers. 'ach pair differs in theare $iastereoisomers. 'ach pair differs in the

stereochemistry at C-( and C-).stereochemistry at C-( and C-).

*+C,

*,

* *

*+C,

*,

* *

89

Quinine Quinidine


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Properties:Pro

perties: QuinineQuinine is ery slihtly soluble in *is ery slihtly soluble in *22,& soluble in,& soluble in

ethanol& chloroform& ether& ben/ene and other oranicethanol& chloroform& ether& ben/ene and other oranicsolents.solents.

QuinineQuinine is ais a diacidic basediacidic base. 0t forms 2 types of sulfates:. 0t forms 2 types of sulfates:

Quinine monosulfateQuinine monosulfate !!neutralneutral andand HH22O insolubleO insoluble#.#.

Quinine bisulfateQuinine bisulfate !!acidicacidic andand HH22O solubleO soluble#.#.

QuinineQuinine !!l l -isomer# ies-isomer# ies quinidinequinidine !!d d -isomer# amon-isomer# amon

other products when warmed with ,* in amylother products when warmed with ,* in amyl

alcohol.alcohol. Quinine is leorotatory& while uinidine is de3trorotatoryQuinine is leorotatory& while uinidine is de3trorotatory ..


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Separation of the 4 AlkaloidsSe

paration of the 4 Alkaloids

Powdered Bark

- Alk . CaO + NaOH + H2O

- Reflux with benzene &

- Filtration while hot

Benene filtrate (Alkaloidal bases)

dilute H2SO4

Acidic aqueous la!er (Alkaloidal bisulphates)

pH to 6.5 with Na2CO3

Precipitate

Quinine uinidine!

cinchonine " cinchonidineHot water ! Na2CO3

Quinine NaOH, ethe#

Aqueous la!er "ther la!er

CinchonineQuinidine " Cinchonidine

$HCl PH=! Na! % &a#t. salt

$ 'ilte#

Precipitate #iltrate

Cinchonidine ta#t#ate Quinidine ta#t#ate

Aqueous solution !onosulphates)!onosulphate)


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$ests for identification$ests for identification

%&%& #luorescence test:#luorescence test:

4olution of the alkaloid in o3yenated acids !e. *4olution of the alkaloid in o3yenated acids !e. *224,4,55& *,& *,++ ororphosphoric acid#phosphoric acid# blue fluorescence !6 e with uinine and uinidine#.blue fluorescence !6 e with uinine and uinidine#.

2& $halleoquine test:2& $halleoquine test: Aueous solution of the alkaloidal salt 6 %r Aueous solution of the alkaloidal salt 6 %r 22 7*7*22, !few drops till the, !few drops till the

appearance of yellow color# 6 *appearance of yellow color# 6 *

55,*,*

emerald reenemerald reen

colorcolor

!6 e with uinine and uinidine#.!6 e with uinine and uinidine#.

+-+- 'osequin test ("r!throquinine test):'osequin test ("r!throquinine test):

Aueous solution of the alkaloidal salt 6 dil *Cl 6 %r Aueous solution of the alkaloidal salt 6 dil *Cl 6 %r 22 7*7*22, !few drops till the, !few drops till the

appearance of yellow color# 6 C*Cl appearance of yellow color# 6 C*Cl++ 6 pot. 8errocyanide 6 *6 pot. 8errocyanide 6 *55,*,* redred color in the C*Clcolor in the C*Cl++ layer !6 e with uinine and uinidine#.layer !6 e with uinine and uinidine#.


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,soquinoline Alkaloids,soquinoline Alkaloids%&%& IpecacuanhaI pecacuanha AlkaloidsAlkaloids

Occurrence:Occurrence:

,pecac,pecac is the dried roots and rhi/omes ofis the dried roots and rhi/omes of Cephalis ipecacuanhaCephalis ipecacuanha !%ra/ilian!%ra/ilian

ipecacuanha# oripecacuanha# or Cephalis acuminataCephalis acuminata !Cartaena or ;anama ipecacuanha#!Cartaena or ;anama ipecacuanha#

8am. ?#& mainly e+etinee+etine !>9- @9 ? of total!>9- @9 ? of total

alkaloids#& withalkaloids#& with cephalinecephaline andand ps!chotrineps!chotrine ..

-

.eO

'O

-

O.eO.e

HH

* e ,etine

* H Cephaline

-

.eO

HO

-

O.eO.e

H

-schot#ine


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"+etine:"+etine: 0t is0t is non phenolicnon phenolic andand le/orotator!le/orotator!..

0t contains 2 basic nitroens.0t contains 2 basic nitroens.

Cephaline:Cephaline: 0t is0t is phenolicphenolic andand le/orotator!le/orotator!..

0t0t 0i/es e+etine0i/es e+etine onon +eth!lation with (CH+eth!lation with (CH11))22 SOSO44..

Ps!chotrine:Ps!chotrine:

,ccurs as yellow prisms.,ccurs as yellow prisms.

0t is0t is phenolicphenolic and iesand ies cephalinecephaline on reductionon reduction..

0t0t 0i/es e+etine0i/es e+etine onon reduction followed b! +eth!lationreduction followed b! +eth!lation..


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,solation of ,peca alkaloids:,solation of ,peca alkaloids:Powdered root and rhio+e- "xt. alcohol,#on$., lead acetate.

- Filtration

#iltrate 'esidue Non$alkaloidal sub.

- "%ap., dil. HCl & Filtration

Alkaloidal bases and salts

#iltrate (Alkaloidal HCl salts)

- Alk. with NaOH & "xt. with ethe#

"ther la!er

,etine

(-henolic alkaloids)

- H#l !Alkaloidal alt'

- Alk. (H)*H "xt. ethe#

Aqueous la!er "ther la!er

(-schot#ine) (Cephaline)

Aqalk solution


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$ests for identification of ,peca alkaloids:$ests for identification of ,peca alkaloids:

Alkaloidal solution in *Cl 6 Alkaloidal solution in *Cl 6 Ca h!pochloriteCa h!pochlorite

oran0eoran0e color.color.

"+etine"+etine andand cephalinecephaline 66 #roehd3s#roehd3s reaent:reaent: dirt! 0reendirt! 0reen color !thecolor !the

color with emetine fades by addition of *Cl#.color with emetine fades by addition of *Cl#.

Ps!chotrinePs!chotrine 66 #roehd3s#roehd3s reaent:reaent: pale 0reenpale 0reen color.color.

CephalineCephaline andand ps!chotrineps!chotrine 66 p p-nitrodia/oben/ene-nitrodia/oben/ene dye soluble indye soluble in

a,*a,* purplepurple color.color.

Ps!chotrinePs!chotrine 6 conc. *6 conc. *224,4,55 66 *,*,++ cherr! redcherr! red color color ..

EmetineEmetine + Liebermann's reagent+ Liebermann's reagent blackblack color.color.


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*ses:*ses:

"+etine"+etine andand cephaelinecephaeline haehae antitu+our antitu+our andand anti/iralanti/iral actiity& but are too to3ic for therapeutic use.actiity& but are too to3ic for therapeutic use.

"+etine and ps!chotrine"+etine and ps!chotrine are mainly used asare mainly used as e+etice+etic

dru0sdru0s

The crude dru is used asThe crude dru is used as epectorantepectorant !due to its saponin!due to its saponincontent# .content# .

"+etine"+etine *Cl and $ehydroemetine !$*'# hae an*Cl and $ehydroemetine !$*'# hae an

antia+oebic effect5antia+oebic effect5 and are used for the treatment ofand are used for the treatment of

amoebic dysentry andamoebic dysentry and Fasciola.Fasciola. 0peca alkaloids are0peca alkaloids are diaphoreticdiaphoretic& alone or in combination with& alone or in combination with

opium !e..opium !e.. 6o/er3s6o/er3s powder powder #.#.


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2& Curare Alkaloids2& Curare Alkaloids Occurrence:Occurrence: Curare or 4outh American arrow poison is the dried crude e3tract& obtainedCurare or 4outh American arrow poison is the dried crude e3tract& obtained

mainly frommainly from ChondrodendronChondrodendron tomentosumtomentosum !"enispermaceae# and certain!"enispermaceae# and certain44trychnostrychnos species& !oaniaceae#.species& !oaniaceae#.

Curare contains se/eral alkaloids (4&78)5 the +ost i+portant isCurare contains se/eral alkaloids (4&78)5 the +ost i+portant is d d &tubocurarine&tubocurarine

-

OH

.eO

-

H

H

.e

O.e

O

OH

O

.e

+.e


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Properties:Properties: d d &tubocurarine&tubocurarine !5ary alkaloid# is!5ary alkaloid# is freel! soluble in Hfreel! soluble in H22OO.. 0t is a0t is a phenolicphenolic

detrorotator!detrorotator! alkaloid. 0t is aalkaloid. 0t is a bisbis&ben!ltetrah!droisoquinoline&ben!ltetrah!droisoquinoline

alkaloidalkaloid

$ests:$ests: 4aturated aueous solution4aturated aueous solution ++ 8eCl+8eCl+ faint reen colorfaint reen color reen color.reen color.

4olution of the alkaloidal *C1 6 a2C, +4olution of the alkaloidal *C1 6 a2C, + yellow brown precipitate. yellow brown precipitate.

*ses:*ses: $ubocurarine chloride$ubocurarine chloride is mainly used by i.m. or i.. routes asis mainly used by i.m. or i.. routes as

skeletal +uscle relaantskeletal +uscle relaant.. 0t is used to0t is used to control and reduce con/ulsions of str!chninecontrol and reduce con/ulsions of str!chnine

poisonin and ofpoisonin and of tetanustetanus

0t is used as a dianostic aid in0t is used as a dianostic aid in +!asthenia 0ra/is+!asthenia 0ra/is..

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Alkaloids 37