Lecture 23 Anthraquinone Glycosides - III

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PHARM. DChemical Pharmacognosy- I

Lecture 23April 28 th , 2011

ANTHRAQUINONEANTHRAQUINONEGLYCOSIDESGLYCOSIDES - - IIIIII

M.M. Ahsan Ahsan KhalidKhalid ,, B.PharmB.Pharm, Pharm. D, Pharm. DM.PhilM.Phil Scholar (RIPS/RIU)Scholar (RIPS/RIU)

HIPSHIPS--HUKICHUKIC



CASCARACASCARA



Cascara BarkCascara Bark- - RhamnaceaeRhamnaceae

Definition:Definition: OfficialOfficialcascara sagrada iscascara sagrada isthe dried bark of the dried bark of

Rhamnus purshianusRhamnus purshianus ..Bark is collected fromBark is collected fromwild treeswild trees

(depletion is leading(depletion is leadingto the increase of to the increase of cultivation)cultivation)



CascaraCascaraRhamnusRhamnus pershiana pershiana ((RhamnaceaeRhamnaceae) )bark extractbark extract

collected, dried and stored for 12collected, dried and stored for 12months (months ( anthraquinoneanthraquinone contentcontent - ->>

less toxic)less toxic)modern substancemodern substance

discovered 100 years agodiscovered 100 years agoRockyRocky MtnsMtns,, W.CoastW.Coast, US, US

more violent purgativemore violent purgativegriping actiongriping actionharder to eliminateharder to eliminate

UseUse: night before to clear bowels for : night before to clear bowels for xx--rays and barium mealrays and barium meal



Rhamnus purhsianusRhamnus purhsianus -- CascaraCascaraE tymologyE tymology

RhamnosRhamnos ± ± Greek, branch,Greek, branch,shiny shrub. Purshianashiny shrub. Purshianaafter Pursh, botanist 1after Pursh, botanist 1 stst

described herb in 1814.described herb in 1814.

Other Common NamesOther Common NamesBearwood, bitterbark,Bearwood, bitterbark,

buckthorn, coffeeberry,buckthorn, coffeeberry,mountain cranberry,mountain cranberry,persiana, sacred bark.persiana, sacred bark.



Cascara BarkCascara Bark - - HistoryHistory

Recently introducedRecently introducedto Modern Medicine.to Modern Medicine.Known to earlyKnown to earlyMexican and SpanishMexican and Spanishpriests.priests.Not introduced toNot introduced to

medicine until 1877.medicine until 1877.



CascaraCascara ± ± Collection & PreparationCollection & PreparationCollected from midCollected from mid- -April to end of April to end of

August, when it separates readily August, when it separates readilyfrom the rest of the trunk.from the rest of the trunk.

Longitudinal incisions are madeLongitudinal incisions are made10cm apart and the bark removed.10cm apart and the bark removed.

Tree is then usually felled and theTree is then usually felled and thebranch bark separated.branch bark separated.

Bark is then dried in the shadeBark is then dried in the shadewith the cork facing upwards. Thiswith the cork facing upwards. This

is referred to as µnatural¶ cascara.is referred to as µnatural¶ cascara.Commercial supplies areCommercial supplies arecomminutedcomminuted to give small, evento give small, evenfragments called µfragments called µevenizedevenized¶,¶,µprocessed¶, or µcompact¶ cascara.µprocessed¶, or µcompact¶ cascara.



Cascara BarkCascara Bark - - StorageStorage

During preparation and storage the bark shouldDuring preparation and storage the bark shouldbe protected from rain and damp (partialbe protected from rain and damp (partialextraction of constituents may occur or bark mayextraction of constituents may occur or bark may

become mouldy).become mouldy).

Should be stored for at least 1 year before use.Should be stored for at least 1 year before use.

Bark appears to increase in medicinal value upBark appears to increase in medicinal value upunto its 4 years old (stored bark)unto its 4 years old (stored bark)



Cascara BarkCascara Bark ± ± Why Stored for aWhy Stored for aYear?Year?

When stored for at least aWhen stored for at least ayear year ± ± better tolerated bybetter tolerated bypatient (less griping painspatient (less griping painsdue to increaseddue to increasedperistalsis)peristalsis)Yet as effective as freshYet as effective as freshbark.bark.

Reason?Reason?

Due to Hydrolysis andDue to Hydrolysis andother changes that occur other changes that occur during storage.during storage.

Bitter taste of Cascara canBitter taste of Cascara canalso be reduced by treatingalso be reduced by treatingthe bark with alkali (alkalithe bark with alkali (alkali



Chemical constituents:Chemical constituents:((ii) 4 primary glycosides) 4 primary glycosides

OO-- and Cand C- - linkageslinkages

(ii) C(ii) C--glycosidesglycosides - - twotwo aloinsaloinsbarbaloinbarbaloin ± ± derived from aloederived from aloe- -emodinemodinchrysaloinchrysaloin ± ± derived fromderived from chrysophanolchrysophanol

(iii) a number of O(iii) a number of O- -glycosidesglycosidesderived fromderived from emodinemodin oxanthroneoxanthrone, aloe, aloe--emodinemodin, , chrysophanolchrysophanol

(iv) various(iv) various dianthronesdianthronesincl.incl. emodinemodin, aloe, aloe--emodinemodin, , chrysophanolchrysophanol, , herterodianthronesherterodianthronespalmidinpalmidin A B C A B C

(v) aloe(v) aloe- -emodinemodin, , chrysophanolchrysophanol, , emodinemodin in free statein free state

To get aglycones FeCl 3

To get aloins oxidise with acid



Cascara BarkCascara Bark ± ± Constituents 1Constituents 1

4 main glycosides4 main glycosides ± ± Called CascarosidesCalled CascarosidesCascaroside ACascaroside A

Cascaroside BCascaroside BCascaroside CCascaroside CCascaroside DCascaroside D




2 aloins:2 aloins:CC ± ± GlycosidesGlycosides

Breakdown products of Cascarosides ABreakdown products of Cascarosides A- -DD

Barbaloin (derived from aloeBarbaloin (derived from aloe- -emodin)emodin)Chrysaloin (derived from chrysopanol anthrone)Chrysaloin (derived from chrysopanol anthrone)




OO--glycosidesglycosidesDerived fromDerived from

E modinE modinE modin oxanthroneE modin oxanthrone

Aloe emodin Aloe emodinchrysophanolchrysophanol




DianthronesDianthronesThose fromThose fromE

modinE

modin Aloe Aloe--emodinemodinChrysophanolChrysophanol

HetrodianthronesHetrodianthronesPalmidin A, B and C (Rhubarb)Palmidin A, B and C (Rhubarb)




E modinE modin Aloe Aloe--emodinemodin

ChrysophanolChrysophanol

(in the free state)(in the free state)



Cascara BarkCascara Bark - - SubstitutesSubstitutes

Rhamnus alnifoliaRhamnus alnifolia (too rare)(too rare)

Rhamnus croceaRhamnus crocea (bark is very different from(bark is very different fromofficial drug)official drug)

Rhamnus californicaRhamnus californica (so closely related to(so closely related toRhamnus purshianusRhamnus purshianus some botanists do notsome botanists do notconsider them to be separate species).consider them to be separate species).

Rhamnus fallax Rhamnus fallax



Cascara BarkCascara Bark - - UsesUses

PurgativePurgativeSimilar to SennaSimilar to Senna

Normally as a tabletNormally as a tablet Also used on animals Also used on animals



Cascara BarkCascara Bark ± ± Additional AdditionalPhysiological ActionPhysiological Action

Astringent (bark Astringent (bark ± ± tannins),tannins),bitter tonic, chologogue,bitter tonic, chologogue,emetic, hepatic, stomachic.emetic, hepatic, stomachic.

Medicinal UsesMedicinal UsesMove stagnation, clear heat.Move stagnation, clear heat.The most widely used laxativeThe most widely used laxative

worldworld--wide.wide.Topically:Topically: Used as a wash for Used as a wash for

herpes lesionsherpes lesions

E xcessive use:E xcessive use: nausea,nausea,vomiting, heamatorrhoea.vomiting, heamatorrhoea.Long term use:Long term use: WeakensWeakensintestinal muscles.intestinal muscles.

ContraContra- -indications:indications:children younger than 14,children younger than 14,during pregnancy,during pregnancy,lactation, IBS, Crohn¶s,lactation, IBS, Crohn¶s,intestinal obstruction, andintestinal obstruction, andidiopathic abdominalidiopathic abdominalpain.pain.



RHUBARBRHUBARB



RhubarbRhubarb - - PolygonaceaePolygonaceae

Definition:Definition:Rhubarb/ChineseRhubarb/ChineseRhubarb is theRhubarb is the

rhizome of rhizome of RheumRheum palmatum palmatum .. Other Other speciesspecies and hybridsand hybridsof of RheumRheum ,, exceptexcept R.R.rhaponticumrhaponticum , may, mayalso be included.also be included.



Chinese RhubarbChinese Rhubarb - - HistoryHistory

Chinese Rhubarb hasChinese Rhubarb hasa long history.a long history.Mentioned in a herbalMentioned in a herbal

of 2700BC.of 2700BC.Formed an importantFormed an importantarticle of commercearticle of commerceon the Chinese tradeon the Chinese trade

routes toE

urope.routes toE

urope.Still used medicinallyStill used medicinallytoday.today.



Chinese RhubarbChinese Rhubarb ± ± Collection &Collection &PreparationPreparation

Rhizomes are grown atRhizomes are grown athigh altitudes (+3000m).high altitudes (+3000m).Collected in Autumn or Collected in Autumn or

spring (6spring (6- -10yrs old)10yrs old)Cork is removed, cut.Cork is removed, cut.

Artificially dried. Artificially dried.Packed in tinPacked in tin- -linedlined

wooden cases.wooden cases.Inferior quality herbs areInferior quality herbs arepacked in hessian bagspacked in hessian bags



Chinese RhubarbChinese Rhubarb - - ConstituentsConstituents1.1. Anthraquinones Anthraquinones withoutwithout

a carboxyl groupa carboxyl group ± ±chrysophanol, emodin,chrysophanol, emodin,aloealoe--emodin &emodin &

physcion.physcion. Also the glycosides of Also the glycosides of these substances.these substances.

2.2. Anthraquinones Anthraquinones with awith acarboxyl groupcarboxyl group (rhein(rheinand its glycoside:and its glycoside:glucorhein).glucorhein).



Chinese RhubarbChinese Rhubarb - - ConstituentsConstituents

3.3. Anthrones and Anthrones anddianthronesdianthrones of of chrysophanol,chrysophanol,

emodin, aloeemodin, aloe- -emodin or physcoin.emodin or physcoin.

4.4. DianthroneDianthrone

glucosidesglucosides of rheinof rhein(Sennosides A and(Sennosides A andB).B).

5.5. HetrodianthronesHetrodianthronesderived from 2derived from 2different anthronedifferent anthrone

molecules:molecules: PalmidinPalmidin A A andand Palmidin BPalmidin B ..



Chinese RhubarbChinese Rhubarb - - ConstituentsConstituents

Free anthraquinonesFree anthraquinones ::chrysophanol,chrysophanol,emodin, aloeemodin, aloe- -emodinemodin

and rhein.and rhein.

Some of the aboveSome of the aboveconstituents may alsoconstituents may alsooccur as glycosides.occur as glycosides.



Chinese RhubarbChinese Rhubarb - - UsesUses

Bitter stomachicBitter stomachicDiarrhoea (low doses)Diarrhoea (low doses)

± ± contains tanninscontains tanninsPurgativePurgative (high(highdoses)doses) ± ± followed byfollowed byan astringent effect.an astringent effect.

Suitable only for Suitable only for occasional for occasional for occasional use, notoccasional use, notfor chronicfor chronic

constipation.constipation.



RhubarbRhubarb - - Additional AdditionalE tymologyE tymology

RheoRheo ± ± Greek, µto flow¶, inGreek, µto flow¶, inreference to the purgativereference to the purgativeproperties.properties.

Medicinal ActionsMedicinal Actions Anti Anti--helminthic, antihelminthic, anti- -bacterial, antibacterial, anti- -inflammatory, antiseptic,inflammatory, antiseptic,astringent (low doses),astringent (low doses),sialagoge, vulnerarysialagoge, vulnerary

Topical Uses:Topical Uses:Poultice to treat boils,Poultice to treat boils,burns, wounds. Used toburns, wounds. Used tostop bleeding (tanninsstop bleeding (tannins ± ±stypic and astringent).stypic and astringent).

Used as a mouthwash for Used as a mouthwash for oral ulcers.oral ulcers.

Other uses:Other uses: Acid content: Acid content:fresh root can be used tofresh root can be used topolish brass.polish brass.

CautionCautionLeaves should be avoidedLeaves should be avoided

± ± high calcium oxalatehigh calcium oxalate - -toxictoxic

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Lecture 23 Anthraquinone Glycosides - III