Plant Metabolites & Ergastic Cell Plant Metabolites & Ergastic Cell ContentsContents

Primary MetabolitesPrimary Metabolites Primary metabolitesPrimary metabolites chlorophyllchlorophyll AA’sAA’s NucleotidesNucleotides Simple CHO’sSimple CHO’s Membrane lipidsMembrane lipids

*** ARE FOUND *** ARE FOUND THROUGHOUT THE THROUGHOUT THE PLANT KINGDOMPLANT KINGDOM

Fx: Important roles Fx: Important roles in growth and in growth and developmentdevelopment

photosynthesisphotosynthesis respirationrespiration solute transportsolute transport translocationtranslocation nutrient assimilationnutrient assimilation differentiationdifferentiation

Secondary MetabolitesSecondary Metabolites

Definition:Definition: All All organicorganic compounds compounds Have no direct function Have no direct function

in growth and in growth and developmentdevelopment

Also called secondary Also called secondary products or natural products or natural productsproducts

Differ from 1º metabolites Differ from 1º metabolites in that they have a in that they have a restricted distributionrestricted distribution in in the plant kingdomthe plant kingdom

Therefore: Only Therefore: Only particular secondary particular secondary metabolites are found metabolites are found in only one specific in only one specific plantplant species or a species or a taxonomically related taxonomically related group of species.group of species.

Secondary Metabolite FxSecondary Metabolite Fx Initially thought to be functionless end Initially thought to be functionless end

products of metabolism or metabolic waste products of metabolism or metabolic waste productsproducts

Responsible for characteristics, odours, Responsible for characteristics, odours, pungencies & colours of plants. Others pungencies & colours of plants. Others give plants their medicinal, culinary or give plants their medicinal, culinary or poisonous values.poisonous values.

They are synthesized to aid the producing They are synthesized to aid the producing plant’s survival.plant’s survival.

Secondary Metabolite FunctionSecondary Metabolite Function

Ecological functionsEcological functions in plants: protect in plants: protect against herbivoryagainst herbivory

Protect against Protect against infectioninfection by microbial by microbial pathogenspathogens

Attract Attract pollinatorspollinators & seed distributing & seed distributing animalsanimals

Act as agents for plant-plant Act as agents for plant-plant competitioncompetition

Evolution of 2Evolution of 2º Metabolitesº Metabolites 2º Metabolites evolved through mutations in the basic 2º Metabolites evolved through mutations in the basic

metabolic pathwaysmetabolic pathways appearance of new compoundsappearance of new compounds

happened to be toxic or a deterrent to herbivores and pathogenshappened to be toxic or a deterrent to herbivores and pathogens• As long as they were not toxic to the plant itself and were produced As long as they were not toxic to the plant itself and were produced

at a low metabolic costat a low metabolic cost

They gave the plants containing them greater They gave the plants containing them greater reproduction fitness than undefended plants (plant-reproduction fitness than undefended plants (plant-plant competition)plant competition)

Undefended plants therefore left more descendants Undefended plants therefore left more descendants while the protected plants left lesswhile the protected plants left less

And passed their defensive traits on to the next generationAnd passed their defensive traits on to the next generation

The defence compounds (secondary The defence compounds (secondary metabolites) that increase reproductive metabolites) that increase reproductive fitness of plants by warding off fungi, fitness of plants by warding off fungi, bacteria and herbivores, also make them bacteria and herbivores, also make them undesirable as food by humans.undesirable as food by humans.

Many NB crop plants have been artificially Many NB crop plants have been artificially selected for producing relatively low levels selected for producing relatively low levels of these compounds, which make them of these compounds, which make them more susceptible to insects and diseasemore susceptible to insects and disease

(e.g. of Wheat)(e.g. of Wheat)

3 MAIN GROUPS OF 2º 3 MAIN GROUPS OF 2º METABOLITESMETABOLITES

TERPENESTERPENES

PHENOLSPHENOLS

N2-CONTAINING COMPOUNDSN2-CONTAINING COMPOUNDS

TerpenesTerpenes

Terpenes are lipidsTerpenes are lipids

synthesized fromsynthesized from acetyl CoA acetyl CoA or from the or from the basic intermediates of basic intermediates of glycosidesglycosides

Phenolic compoundsPhenolic compounds

Phenolic compounds arePhenolic compounds are aromaticaromatic substancessubstances

Formed via the Formed via the Shikimic acid PathwayShikimic acid Pathway or the or the Malonic acid pathwayMalonic acid pathway

Nitrogen-containing compoundsNitrogen-containing compounds

e.g. e.g. alkaloidsalkaloids

synthesized fromsynthesized from AA’s AA’s

Active Plant ConstituentsActive Plant Constituents

CarbohydratesCarbohydrates

Sugars (glucose, Sugars (glucose, xylose)xylose)

Starches (energy Starches (energy stores)stores)

Cellulose (structural Cellulose (structural support)support)

Gums & mucilageGums & mucilage

Gums & MucilagesGums & Mucilages

Very complex CHO’sVery complex CHO’s Found in excellent Found in excellent

vulnerary, demulcent vulnerary, demulcent & emollient herbs.& emollient herbs.

E.g. Marshmallow & E.g. Marshmallow & PlantainPlantain

Gums & Mucilage FxGums & Mucilage Fx Relax Gut liningRelax Gut lining Relax Respiratory Relax Respiratory

SystemSystem Reduce irritation and Reduce irritation and

inflammation (GIT, inflammation (GIT, Respiratory, US)Respiratory, US)

MO: soak up large MO: soak up large amounts of wateramounts of water

sticky jelly: dry sticky jelly: dry irritated skin, irritated skin, inflamed/painful tissuesinflamed/painful tissues

Some stimulate Some stimulate immune system: e.g. immune system: e.g. Acemannan (Aloe Acemannan (Aloe vera)vera)

Plant AlcoholsPlant Alcohols

Occurs in plants in Occurs in plants in various formsvarious forms

Constituent of volatile Constituent of volatile oils & sterolsoils & sterols

Attar of RoseAttar of Rose Menthol in peppermintMenthol in peppermint Waxes (beeswax)Waxes (beeswax) Cutins Cutins

PhenolsPhenols

Phenol = basic building Phenol = basic building block for many plant block for many plant constituentsconstituents

Simple/complex in natureSimple/complex in nature

Fx: Fx: anti-inflammatoryanti-inflammatory Anti-septicAnti-septic

E.g. Salicylic acid E.g. Salicylic acid (Willow)(Willow)

Eugenol (Clove)Eugenol (Clove) Thymol (Thyme)Thymol (Thyme)

Volatile Oil FunctionVolatile Oil Function

Anti-spetic Anti-spetic (Garlic/Thyme oil)(Garlic/Thyme oil)

Stimulate tissue Stimulate tissue irritation e.g. irritation e.g. MustardMustard

numbing e.g. numbing e.g. Camphor oil).Camphor oil).

Aid digestionAid digestion CNS actionCNS action Insect repellentInsect repellent Anti-inflammatoryAnti-inflammatory Anti-allergenicAnti-allergenic

ProanthrocyaninsProanthrocyanins

Closely related to Closely related to tannins & flavonoidstannins & flavonoids

PhenolsPhenols Fx: powerful anti-Fx: powerful anti-

oxidantsoxidants Protect circulation Protect circulation

from damage: from damage: especially circulation especially circulation of the heart, hands, of the heart, hands, feet & eyes.feet & eyes.

E.g. Crataegus spp.E.g. Crataegus spp.

TanninsTannins Fx – give herbs their Fx – give herbs their

astringent & heamostypic astringent & heamostypic actionaction

Act on proteins and form Act on proteins and form a protective layer on the a protective layer on the skin & mucous skin & mucous membranesmembranes

Bind the tissues of the gutBind the tissues of the gut Reduce diarrhoea & Reduce diarrhoea &

internal bleedinginternal bleeding Externally: Rxing burns, Externally: Rxing burns,

sealing wounds & reducing sealing wounds & reducing inflammation.inflammation.

Heal infections of the eye, Heal infections of the eye, mouth, vagina, cervix & mouth, vagina, cervix & rectum (mucous membrane rectum (mucous membrane tissues)tissues) Tannins - phenolsTannins - phenols

CoumarinsCoumarins (smell of cut grass)(smell of cut grass) Limited effects on the Limited effects on the

bodybody Di-coumarol, (metabolite) Di-coumarol, (metabolite)

powerful anti-clotting powerful anti-clotting agent.agent.

Functions:Functions: Allopathic: Basis for Allopathic: Basis for

warfarin (thrombosis in warfarin (thrombosis in small doses): small doses): Horse Horse ChestnutChestnut

(Rat poison in large doses)(Rat poison in large doses) VisnagaVisnaga – powerful smooth – powerful smooth

muscle relaxantmuscle relaxant

AnthraquinonesAnthraquinones Plants containing Plants containing

anthraquinones anthraquinones effective purgativeseffective purgatives

(& good natural dyes)(& good natural dyes) Senna & AloeSenna & Aloe Also make stool more Also make stool more

liquid (Constipation)liquid (Constipation) Fx: gently stimulate Fx: gently stimulate

colon 8-12 hrs after colon 8-12 hrs after ingestion (stimulate ingestion (stimulate peristalsis) peristalsis)

Can only Fx when natural Can only Fx when natural bile is present.bile is present.

Tend to cause colonic Tend to cause colonic pain (over-stimulate colon pain (over-stimulate colon wall)wall)

GlycosidesGlycosides

FlavonoidsFlavonoids SaponinsSaponins Phenolic glycosidesPhenolic glycosides Cardiac GlycosidesCardiac Glycosides Cyanogenic GlycosidesCyanogenic Glycosides

FlavonoidsFlavonoids

One of the most common One of the most common group of plant group of plant constituentsconstituents

PolyphenolsPolyphenols Wide range of actionsWide range of actions Anti-spasmoidicAnti-spasmoidic Anti-inflammatoryAnti-inflammatory Anti-oxidantAnti-oxidant DiureticDiuretic Circulatory StimulantsCirculatory Stimulants Cardiac stimulantsCardiac stimulants Anti-viralAnti-viral hepatichepatic

SaponinsSaponins Pharmaceutical Chemists Pharmaceutical Chemists

synthesis of cortisone synthesis of cortisone (anti-inflammatory) & sex (anti-inflammatory) & sex hormoneshormones

Saponins in herbs do not Saponins in herbs do not act in the same way act in the same way body can use them as body can use them as building blocks to form building blocks to form appropriate chemicals.appropriate chemicals.

Fx: Fx: anti-inflammatoryanti-inflammatory ExpectorantExpectorant Aid nutrient absorptionAid nutrient absorption

Cardiac GlycosidesCardiac Glycosides

Discovered from Discovered from Foxglove (1785) Foxglove (1785) recognised to support a recognised to support a failing heartfailing heart

Many flowering plants Many flowering plants contain cardiac contain cardiac glycosidesglycosides

Fx: increase heart Fx: increase heart efficiencyefficiency

Steady tachycardia Steady tachycardia NO CARDIAC STRAINNO CARDIAC STRAIN Strong diureticStrong diuretic

Cyanogenic GlycosidesCyanogenic Glycosides

Based on cyanide Based on cyanide (toxic)(toxic)

Small dosesSmall doses SedativeSedative Relaxant effect on Relaxant effect on

heart & muscleheart & muscle

Wild cherry bark: Wild cherry bark: suppress & soothe suppress & soothe dry, irritating coughs.dry, irritating coughs.

Fruit kernels (apricot) Fruit kernels (apricot)

Bitter PrinciplesBitter Principles Group of chemicals with Group of chemicals with

an exceedingly bitter an exceedingly bitter tastetaste

Wide diversity of structureWide diversity of structure Most belong to the Most belong to the

iridoids, some to terpenesiridoids, some to terpenes Fx: stimulate digestive Fx: stimulate digestive

juices & appetitejuices & appetite Aid the liverAid the liver Anti-bioticAnti-biotic Anti-fungalAnti-fungal Anti-tumourAnti-tumour Play specific roles Play specific roles

depending on herb & depending on herb & chemical combination e.g. chemical combination e.g. Valerian & Devil’s clawValerian & Devil’s claw

AlkaloidsAlkaloids The most potent group of The most potent group of

plant constituentsplant constituents Effect: body & mindEffect: body & mind Some: effect on lungs, Some: effect on lungs,

liver, nerves, GITliver, nerves, GIT Fx in plant: Fx in plant: ± source of ± source of

excessive N2. (makes excessive N2. (makes them pharmacologically them pharmacologically active).active).

Divided into 13 groups Divided into 13 groups based on their chemical based on their chemical structure (no general structure (no general effects) effects)

E.g. Atropine (Atropa E.g. Atropine (Atropa belladonna) belladonna) reduce reduce spasms, relieve pain & spasms, relieve pain & dry up bodily secretionsdry up bodily secretions

GlucosilinatesGlucosilinates

Found exclusively in the Found exclusively in the Brassica Family (Mustard Brassica Family (Mustard & Cabbage)& Cabbage)

Instant blistering & Instant blistering & inflammatory effect on the inflammatory effect on the skinskin

Applied to painful areas Applied to painful areas to increase blood flowto increase blood flow

Helps remove excessive Helps remove excessive waste productswaste products

Eating: produce a strong Eating: produce a strong pungent taste.pungent taste.

VitaminsVitamins

Found in many Found in many medicinal plantsmedicinal plants Lemon peel: Vitamin Lemon peel: Vitamin

CC Carrot: Vitamin ACarrot: Vitamin A Brewers Yeast: B-Brewers Yeast: B-

vitaminsvitamins Nasturium/watercress: Nasturium/watercress:

Vitamin E Vitamin E

MineralsMinerals

Plants draw minerals Plants draw minerals from the soil and convert from the soil and convert them into a form which is them into a form which is easily absorbed & used easily absorbed & used by the body.by the body.

Kelp: I2Kelp: I2 Dandelion: KDandelion: K Horsetail: SilicaHorsetail: Silica Nettle: Fe & CaNettle: Fe & Ca Brewers Yeast: Brewers Yeast:

ChromiumChromium

CALCIUM OXALATE CALCIUM OXALATE CRYSTALSCRYSTALS

Calcium OxalateCalcium Oxalate

Numerous crystals occur in plantsNumerous crystals occur in plants Ca-oxalate is one of the most commonCa-oxalate is one of the most common Like trichomes & stomata, it also has Like trichomes & stomata, it also has

diagnostic valuediagnostic value XX polymorphs are characteristic in polymorphs are characteristic in xx plant plant

spp.spp.

Crystal SystemsCrystal Systems

In plants In plants 2 crystal systems exist 2 crystal systems exist All crystal polymorphs belong to one of All crystal polymorphs belong to one of

these systemsthese systems SystemsSystems

Tetragonal SystemTetragonal System Monoclinic SystemMonoclinic System

Systems differ Systems differ in the amount of water they attainin the amount of water they attain ODOD

Tetragonal Crystal SystemTetragonal Crystal System

Composition: Composition: CaCCaC22OO44.3H.3H2200

Arises from Arises from supersaturation of the supersaturation of the cell sap with calcium cell sap with calcium oxalateoxalate

IncludesIncludes PrismsPrisms Cluster crystals (rosette Cluster crystals (rosette

aggregates)aggregates) microsphenoidsmicrosphenoids

Monoclinic Crystal SystemMonoclinic Crystal System

Chemical composition: CaCChemical composition: CaC22OO44.H.H2200

Form in the presence of excess oxalic acidForm in the presence of excess oxalic acid Crystal forms includeCrystal forms include

Some prismsSome prisms Needle-like crystals (raphides)Needle-like crystals (raphides) Sphaero-crystalsSphaero-crystals

NB!!!NB!!!

When using Calcium When using Calcium oxalate crystal types oxalate crystal types as a diagnostic tool:as a diagnostic tool:

Crystal typeCrystal type SizeSize DistributionDistribution

Should all be noted.Should all be noted.

Crystal FunctionCrystal Function

UncertainUncertain More abundant in plants growing in arid More abundant in plants growing in arid

regions.regions. Ca: Causes epithelial cells to swellCa: Causes epithelial cells to swell Deter herbivory?Deter herbivory?

Crystal FormsCrystal Forms

PrismsPrisms

Cluster CrystalsCluster Crystals

MicrosphenoidsMicrosphenoids

RaphidesRaphides

Sheaero-crystalsSheaero-crystals

Prisms – Prisms – Elletaria cardamomumElletaria cardamomum

Found inFound in Cardamom Cardamom

• Small single prismsSmall single prisms• Starch masses in Starch masses in

parenchymaparenchyma

Prisms – Prisms – Hyosciamus nigerHyosciamus niger

Black henbaneBlack henbane• Single prismsSingle prisms

Some have a Some have a crystalline outgrowth crystalline outgrowth (plug)(plug)

• Twin prismsTwin prisms In crystal layer of In crystal layer of

spongy mesophyll spongy mesophyll cells (directly below cells (directly below palisade tissues)palisade tissues)

Prisms – Prisms – Cassia sennaCassia senna

SennaSenna

* Single prisms* Single prisms

* Occurs in * Occurs in parenchyma cellsparenchyma cells

* Surrounds bundles of * Surrounds bundles of pericyclic fibrespericyclic fibres

* Forms a crystal * Forms a crystal sheathsheath

Prisms – Prisms – Glycyrrhiza glabraGlycyrrhiza glabra

Found in LiquoriceFound in Liquorice

* Single prisms* Single prisms

* Occurs in parechyma * Occurs in parechyma tissuetissue

* Surrounds xylem & * Surrounds xylem & phloemphloem

* Forms an incomplete * Forms an incomplete crystal sheathcrystal sheath

Prisms – Prisms – Rhamnus purshianusRhamnus purshianus

Cascara senegaCascara senega Crystal sheathsCrystal sheaths Similar to liquoriceSimilar to liquorice Occurs with the Occurs with the

phloem fibresphloem fibres Complete crystal Complete crystal

sheathssheaths

MicrosphenoidsMicrosphenoids

Atropa belladonnaAtropa belladonna Aggregates occur in a Aggregates occur in a

crystal layercrystal layer Below palisade tissuesBelow palisade tissues

When a single cell When a single cell contains an aggregate contains an aggregate of microsphenoids of microsphenoids idioblast idioblast

RaphidesRaphides

OccurOccur SinglySingly

• E.g. IpecavanhaE.g. Ipecavanha

In bundlesIn bundles• E.g SquillE.g Squill

Diagnostic Value of Calcium Diagnostic Value of Calcium Oxalate CrystalsOxalate Crystals

Absence of crystalsAbsence of crystals Different formDifferent form Different sizeDifferent size

all used to identify adulterants or allied all used to identify adulterants or allied species from medicinal herbs. species from medicinal herbs.

Diagnostic Value of Calcium Diagnostic Value of Calcium OxalatesOxalates

E.g. E.g.

Digitalis purpurea:Digitalis purpurea: (used medicinally) no (used medicinally) no calcium oxalatescalcium oxalates

D. thapsi:D. thapsi: (not used (not used medicinally) - small medicinally) - small prismsprisms

Diagnostic Value of Calcium Diagnostic Value of Calcium Oxalate CrystalsOxalate Crystals

E.g. E.g.

Atropa belladonna:Atropa belladonna:

Leaves have micro-Leaves have micro-sphenoidssphenoids

Phytolacca leaves: Phytolacca leaves: have raphideshave raphides

Diagnostic Value of Calcium Diagnostic Value of Calcium Oxalate CrystalsOxalate Crystals

3 Solanaceous Herbs3 Solanaceous Herbs Atropa belladonnaAtropa belladonna

• MicrospenoidsMicrospenoids

Datura stramoniumDatura stramonium• Cluster crystalsCluster crystals

Hyoscyamus nigraHyoscyamus nigra• PrismsPrisms

LESSON TAKE-AWAYLESSON TAKE-AWAY

Definition & types/effects of adulterationDefinition & types/effects of adulteration Difference between 1Difference between 1º & 2º metabolites.º & 2º metabolites. E.g’s & Functions of metabolitesE.g’s & Functions of metabolites Types of Ca-O crystals (E.g’s & Dx value)Types of Ca-O crystals (E.g’s & Dx value)

End of LessonEnd of Lesson

Thank You!Thank You!