SAIFUL IRWAN ZUBAIRI PMIFT, Grad B.E.M. B. Eng. (Chemical-Bioprocess) (Hons.), UTM

M. Eng. (Bioprocess), UTM

ROOM NO.: 2166, CHEMISTRY BUILDING,TEL. (OFF.): 03-89215828,

FOOD SCIENCE PROGRAMME,CENTRE OF CHEMICAL SCIENCES AND FOOD TECHNOLOGY,

UKM BANGI, SELANGOR

PHYTOCHEMICALSPHYTOCHEMICALS

Phytochemicals

Phyto comes from the Greek wordmeans plant.

Chemicals

Chemicals present naturally in plants

Phytochemicals include secondary plant metabolites:

Essential oilsOleoresinPhenolic compounds-flavonoidsGlycosidesAlkaloids

Bioactive compounds

PLANT LIPIDSPLANT LIPIDS

Defined as substances that can be extracted from cells & tissues by nonpolar organic solvents.

Devided into two major classses:

1) Simple lipids

2) Complex lipids

Simple lipids

1) Steroids

2) Prostaglandins

3) Terpenoids

4) Fat-soluble vitamins

Those that are not easily hydrolysed by aqueous acid or base

Seem inappropriate because many so-called “simple” lipids are quite complex molecules

Steroids

HO

CH3 H

H H

HCH3

Cholesterol

- Common biological intermediate

- Believed to be the biosynthetic precursor to other steroids

ProstaglandinsO

HOH

OH

H

H

COOH

PGE1

- Prostaglandins – first isolated from secretion of prostate gland

- regulate diverse functions

eg: blood pressure, blood clotting, allergic, inflammatory etc.

Complex lipids

- Those that easily hydrolysed to simple constituents

- Mostly esters of long-chain carboxylic acids called fatty acids

Triglicerides

Waxes

Trigliseride

- Esters of gliserol

- Liquid (oil)

- Solid (fat)

CH2

CH

CH2

O CO

(CH2)16CH3

O

O

C

C

O

O

(CH2)16CH3

(CH2)16CH3

Tristearin (a fat)

Waxes- Esters of long chain fatty acids with long chain alcohols

- Serve a number of purposes in plants & animals

eg: Beeswax – a mixture of waxes that bees use to

form their honeycombCH3(CH2)29 O C (CH2)24CH3

O

(a component of beeswax)

- Carnuba waxes – secreted by carnuba plant to coat its leaves to prevent excessive loss of water by evaporation

BIOSYNTHESIS OF PHYTOCHEMICALSBIOSYNTHESIS OF PHYTOCHEMICALS

CO2 + H2O

Carbohydrates

CH3COCOOHPyruvic acid

CH3COOHAcetic acid

Fatty Acids &Polyketides

CH3CCH2COOH

OH

CH2CH2OH

Mevalonic acid

TerpenesSteroids Purines

ProteinPeptidesAlkaloids

AromaticAminoAcids

Phenylpropanoids

Flavonoids

Nucleic Acid

PO43-

Shikimic Acid

AminoAcid

Tannin

N2

Photosynthesis

OH

OHHO

O OH OH

OH OH

O

O

Chorismic Acid

ESSENTIAL OILSESSENTIAL OILS

Volatile aromatic compounds obtained via steam or hydrodistillation Mainly terpenes and terpenoids (mono and sesqui)

Some esters and alcohols

Concretes

- Solvent extracted product contains volatile & non volatile components

Absolutes- Ethanol soluble concretes

Oleoresin- Solvent extracted product

Tincture- Product obtained by soaking dry plant materials in 50-95% ethanol in a ratio of 1:5 (herbs material : solvent)

TERPENOIDSTERPENOIDS

Natural products derived from mevalonic acid

Consist of isoprene units - C5

Contain oxygen in variety of functional groups

• Alcohol• Ketone/ aldehyde• Ester• Ether• Carboxylic acids

Subdivided/ classified according to the number of carbons

•mono, sesqui, di, tri, tetra, etc.

CLASSIFICATION OF TERPENOIDSCLASSIFICATION OF TERPENOIDS

MONOTERPENOIDS

SESQUITERPENOIDS

DITERPENOIDS

C10 Skeleton

C15 Skeleton

C20 Skeleton

Essential Oils(aroma)

TRITERPENOIDS C30 Skeleton (Steroids skeleton)

TETRATERPENOIDS C40 Skeleton

ß-carotene pigment in carrot Vitamin ALycopene pigment in tomato

ESSENTIAL OILSESSENTIAL OILS

Perfumes & Flavours

Flowers Mixture of Terpenes & Terpenoids

Oil of Celery Celery β - Selinene

Oil of anise Anise Seed

Oil of Coriander Coriander seed

Mango flavour Curcuma mangga

Source Components

MeO

OH

Anethole

Linalool

Myrcene

CONSTITUENTS OF ESSENTIAL OILS & ESSENTIAL OIL DRUGSCONSTITUENTS OF ESSENTIAL OILS & ESSENTIAL OIL DRUGS

MONOTERPENOIDS - ALCOHOL

(-)-β-citronellol(-)-linaloolgeraniol

(+)-α-terpineol(-)-β-menthol (+)-Borneol

OH

OH

OH

HO

HO

OH

(+)-camphor

KETONESKETONES

(+)-limonene(+)-carvone

Used in liniments against rheumatic pains~ 3% solution in ethanol sooth itching

- From caraway- used as spice

- From lemon, orange, grape fruit- For flavouring- Food & perfumery industries

Citral

- from ginger- For flavouring

O

O

CHO

PHENOLS PHENOLS

Thymol

Carvacrol

Thymi herbaThe extract is used in cough mixture as an expectorant

PHYRETROIDS PHYRETROIDS

- Flower of Chrysanthimum sp.- Insecticides

OO

O

OPyrethrin

ALKALOIDSALKALOIDS

1. Contain nitrogen, N–usually derived from amino acids2. Bitter tasting, usually in the forms of solids/ crystals3. Precipitate with heavy metal iodides.4. Testing the presence of alkaloids. - Mayer’s reagent ( Potassiomercuric iodide solution).

Cream coloured precipitate. - Dragendoff’s reagent (solution of potassium bismuth iodide). Orange coloured precipitate.5. Alkaloids are basic-form water-soluble salts.Most alkaloids are

well defined crystalline substances, which react with acids to form salts. In plants, they may exist :

- as free state - as salts - as N-oxides

AlKALOIDSAlKALOIDS

Nicotine – alkaloid from tobacco

Cocaine – local anaestatic

Morphine – Analgesic

Codeine – Analgesic, antitussive

Vincristine & vinblastine – anticancerFrom Catharanthus roseus (Kemunting Cina)Terpenes/ steroids also build into final alkaloid skeleton

N

NCH3

O

HO

RO

H H

NCH3

Morphine, R=HCodeine, R=CH3

GLYCOSIDESGLYCOSIDES

Glycosides are compounds containing carbohydrates and noncarbohydrate residue in the same molecule

The carbohydrate residue is attached by an acetyl linkage at carbon atom 1 to a noncarbohydrate residue or AGLYCONE

The nonsugar component is known as the AGLYCONE. The sugar component is called GLYCONE

If the carbohydrate portion is glucose, the resulting compound is a glucosides

Example

Methyl glucoside will be formed when a solution of glucosein boiling methyl alcohol is treated with 0.5 % HCl as catalyst

O

CH2OH

HO

OH

OH

OH

O

CH2OH

HO

OH

OH

OCH3

CH3OH0.5 % HCl

Glucose Methyl Glucoside

or or

CLASSIFICATION OF GLYCOSIDESCLASSIFICATION OF GLYCOSIDES

GLYCOSIDES

Alcoholgroup

Saponingroup

Anthraquinonegroup

Aldehydegroup

Carboxylicgroup

Tannin

Lactonegroup

Cyanategroup

Isothiocyanategroup

Phenolgroup

Flavonolgroup

SAPONIN GLYCOSIDES

Saponin glycosides are devided into 2 types based on the chemical structure of their aglycones (sapogenins) E.g. : Dried rhizome and root Glycyrrhiza glabra (licorice) from Leguminosae family.

SAPONIN

GlyconeAglycone

SugarSapogenin

- Glucose- Arabinose- xylose- glucronic acid

- NeutralSaponin- Steroids

- Saponin Acid- Triterpenoids

The main pathway leading to both types of sapogenins is similar and involves the head to tail coupling units. However, a branch occurs, after the formation of the triterpenoids hydrocarbon, squalene, that leads the steroids in one direction and to cyclic triterpenoids in the other.

PHENOLICPHENOLIC

Most phenolic compounds belong to the flavonoids.

Lignin the primary substances of wood is the most common member of this group

The flavonoids are polyphenolic compounds possessing 15 carbon atoms; two benzene rings joined by a linear three carbon chain.

FLAVONOIDSFLAVONOIDS

The skeleton can be represented as C6 – C3 – C6

Many flavonoids are easily recognized as flower pigments in most angiosperm families (flowering plants)

Most characteristic compounds in plants

HO OH

OH O

C6 C3

C6

FLAVONOIDFLAVONOID

Chalcones - can be found in

cinnamon

HO OH

OH O

Flavones - generally in herbaceous families, e.g. Labiatae, Umbelliferae,

Compositae

FLAVONOIDFLAVONOID

HO O

OH O

Flavonol - generally in woody angiosperms

- kaemferol (Sambucus nigra, Cassia Senna,

Equisetum arvense, Lamium album)

FLAVONOIDFLAVONOID

HO O

OH O

OH

OH

Flavones- Can be found in genus Citrus.

such as lemon, orange etc.

FLAVONOIDFLAVONOID

OHO

OH O

Antocyanins - Occur in the form of salt - Can be found in fruits such as oil

palm, bilberry flowers eg: Roselle,

Hibiscus - Give different colour in different

media (pH)

FLAVONOIDFLAVONOID

OHO

OH

OH

OH

OH

Cl

Isoflavonoids -Most commonly found in soya bean -Roots of Leguminosae

FLAVONOIDFLAVONOID

OHO

OHOH

O

Aurone

FLAVONOIDFLAVONOID

OHO

OH

CH

OH

O

Special class of flavonoidIt has five membered ring in the 2nd ring

The Most Important Classes of Phenolic Compounds in Plants

Number of C-atoms Basic skeleton Class

6 C6 Simplephenols,benzoquinones

7 C6- C1 Phenolic acids

8 C6- C2 Acetophenone,phenylaceticacids

9 C6- C3 Hydroycinnamicacid,polypropene,coumarin,

isocoumarin

10 C6- C4 Naphtoquinone

13 C6- C1 - C6 Xanthone

14 C6- C2- C6 Stilbene,anthrachinone

15 C6- C3- C6 xanthone

18 (C6- C3)2 Flavonoids,isoflavonoids

30 (C6- C3- C6)2 biflavonoids

n (C6- C3)n

(C6)n

(C6- C3- C6)n

LigninsCatecholmelanine

(Condensed tannins)

The Most Important Classes of Flavonoids and their Biological Significance

Class Number of knownmembers

Biological significance

Anthocyanins 250 Red and blue pigments

Chalcones 60 Yellow pigments

Aurones 20 Yellow pigments

Flavones 350 Cream-colored pigmentsof flower

Flavonols 350 Feeding repellents inleaves

Dihydrochalcones 10 Some taste bitter

Proanthocyanidins 50 Astringent substances

Catechins 40 Some have properties likethose of tannins

Biflavonoids 65 Gingko

Isoflavonoids 15 Estrogen effect, toxic forfungi

The Ecological Meaning of Some Phenolic Compounds for Plants

Function Group Example(s) and plant specieswhere the effect was studied

Flower pigments AnthocyanesChalconesAurones

Yellow flavonoidsFlavones

Cyanidins-3, 5-diglucoside inRosa

Coreopsin in Coreopsis tinstoriaAureusin in Anthirrhinum majus

Gossypetine-7-glucoside inGossypium

Apegenin-7-glucoside in BellisPerennis

Fruit pigments AntocyaninesIsoflavonesChalcones

Petunidin glucoside in Atropabelladonna

Osajin in Maclura pomiferaOcanin in Kyllingi breviofolia

Allelopathicsubstances

QuinonesPhenols

Phenolcarboxylicacids

Hydrocinnamic acids

Juglon in Juglans regiaHyroquinone in ArctostaphylosSialic acid in Quercus falcateFerulic acid in Adenostoma

The Ecological Meaning of Some Phenolic Compounds for Plants

Function Group Example(s) and plant specieswhere the effect was studied

Protection against pests

QuinonesTanninesFlavonols

Juglone in Carya ovataGallotannine in Quercus robur

Quercitine-glycosids inGossypium

Fungicides IsoflavonesPhenolcarboxylic

acidsDihydrochalcones

Luteon in LupinusProtocatechunic acid in Allium

Phloridcine in Malus pumila

Phytoalexines StilbensPhenylanthrenes

IsoflavanesPterocarpens

PhenylpropanoidsFucocoumarins

Reservatrol in Arachis hypogaeaOrchinol in Orchis militaris

Vestitol in Lotus corniculatusPisatin in Pisum sativum

Coniferyl alcohol in Linumusitiltissimum

Psoralen in Petroselinum crispum