INTRODUCTION TO PHYTOCHEMICALS 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
PHYTOCHEMICALS Phytochemicals Phyto comes from the Greek word means plant. Chemicals Chemicals present naturally in plants Phytochemicals include secondary plant metabolites: Essential oils Oleoresin Phenolic compounds-flavonoids Glycosides Alkaloids Bioactive compounds
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
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
Common biological intermediate
Believed to be the biosynthetic precursor to other steroids
Prostaglandins PGE 1
Prostaglandins – first isolated from secretion of prostate gland
regulate diverse functions
eg: blood pressure, blood clotting, allergic, inflammatory etc.
Those that easily hydrolysed to simple constituents
Mostly esters of long-chain carboxylic acids called fatty acids
Esters of gliserol
Tristearin (a fat)
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 honeycomb
(a component of beeswax)
Carnuba waxes – secreted by carnuba plant to coat its leaves to prevent excessive loss of water by evaporation
BIOSYNTHESIS OF PHYTOCHEMICALS CO 2 + H 2 O Carbohydrates CH 3 COCOOH Pyruvic acid CH 3 COOH Acetic acid Fatty Acids & Polyketides Mevalonic acid Terpenes Steroids Purines Protein Peptides Alkaloids Aromatic Amino Acids Phenylpropanoids Flavonoids Nucleic Acid PO 4 3- Shikimic Acid Amino Acid Tannin N 2 Photosynthesis Chorismic Acid CH 3 CCH 2 COOH OH CH 2 CH 2 OH
Volatile aromatic compounds obtained
via steam or hydrodistillation
Mainly terpenes and terpenoids
(mono and sesqui)
Some esters and alcohols
Solvent extracted product contains volatile &
non volatile components
Ethanol soluble concretes
Solvent extracted product
Product obtained by soaking dry plant materials
in 50-95% ethanol in a ratio of 1:5
(herbs material : solvent)
Natural products derived from mevalonic acid
Consist of isoprene units - C 5
Contain oxygen in variety of functional groups
Subdivided/ classified according to the number of carbons
mono, sesqui, di, tri, tetra, etc.
CLASSIFICATION OF TERPENOIDS MONOTERPENOIDS SESQUITERPENOIDS DITERPENOIDS C 10 Skeleton C 15 Skeleton C 20 Skeleton Essential Oils (aroma) TRITERPENOIDS C 30 Skeleton (Steroids skeleton) TETRATERPENOIDS C 40 Skeleton ß -carotene pigment in carrot Vitamin A Lycopene pigment in tomato
ESSENTIAL OILS Source Components Anethole Linalool Myrcene Curcuma mangga Mango flavour Coriander seed Oil of Coriander Anise Seed Oil of anise β - Selinene Celery Oil of Celery Mixture of Terpenes & Terpenoids Flowers Perfumes & Flavours
- Dragendoff’s reagent (solution of potassium bismuth iodide).
Orange coloured precipitate.
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
AlKALOIDS Nicotine – alkaloid from tobacco Cocaine – local anaestatic Morphine – Analgesic Codeine – Analgesic, antitussive Vincristine & vinblastine – anticancer From Catharanthus roseus (Kemunting Cina) Terpenes/ steroids also build into final alkaloid skeleton Morphine, R=H Codeine, R=CH 3
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 glucose in boiling methyl alcohol is treated with 0.5 % HCl as catalyst or or
CLASSIFICATION OF GLYCOSIDES GLYCOSIDES Alcohol group Saponin group Anthraquinone group Aldehyde group Carboxylic group Tannin Lactone group Cyanate group Isothiocyanate group Phenol group Flavonol group
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.
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.
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.
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
- can be found in cinnamon
- generally in herbaceous families,
e.g. Labiatae, Umbelliferae, Compositae
- generally in woody angiosperms
- kaemferol ( Sambucus nigra, Cassia Senna,
Equisetum arvense, Lamium album )
- Can be found in genus Citrus.
such as lemon, orange etc.
- 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
- Most commonly found in soya bean
-Roots of Leguminosae
Special class of flavonoid
It has five membered ring in the 2 nd ring
Lignins Catecholmelanine (Condensed tannins) (C 6 - C 3 )n (C 6 )n (C 6 - C 3 - C 6 )n n biflavonoids (C 6 - C 3 - C 6 ) 2 30 Flavonoids,isoflavonoids (C 6 - C 3 ) 2 18 xanthone C 6 - C 3 - C 6 15 Stilbene,anthrachinone C 6 - C 2 - C 6 14 Xanthone C 6 - C 1 - C 6 13 Naphtoquinone C 6 - C 4 10 Hydroycinnamic acid,polypropene,coumarin, isocoumarin C 6 - C 3 9 Acetophenone,phenylacetic acids C 6 - C 2 8 Phenolic acids C 6 - C 1 7 Simple phenols,benzoquinones C 6 6 Class Basic skeleton Number of C-atoms The Most Important Classes of Phenolic Compounds in Plants
Estrogen effect, toxic for fungi 15 Isoflavonoids Gingko 65 Biflavonoids Some have properties like those of tannins 40 Catechins Astringent substances 50 Proanthocyanidins Some taste bitter 10 Dihydrochalcones Feeding repellents in leaves 350 Flavonols Cream-colored pigments of flower 350 Flavones Yellow pigments 20 Aurones Yellow pigments 60 Chalcones Red and blue pigments 250 Anthocyanins Biological significance Number of known members Class The Most Important Classes of Flavonoids and their Biological Significance
Juglon in Juglans regia Hyroquinone in Arctostaphylos Sialic acid in Quercus falcate Ferulic acid in Adenostoma Quinones Phenols Phenolcarboxylic acids Hydrocinnamic acids Allelopathic substances Petunidin glucoside in Atropa belladonna Osajin in Maclura pomifera Ocanin in Kyllingi breviofolia Antocyanines Isoflavones Chalcones Fruit pigments Cyanidins-3, 5-diglucoside in Rosa Coreopsin in Coreopsis tinstoria Aureusin in Anthirrhinum majus Gossypetine-7-glucoside in Gossypium Apegenin-7-glucoside in Bellis Perennis Anthocyanes Chalcones Aurones Yellow flavonoids Flavones Flower pigments Example(s) and plant species where the effect was studied Group Function The Ecological Meaning of Some Phenolic Compounds for Plants
Juglone in Carya ovata Gallotannine in Quercus robur Quercitine-glycosids in Gossypium Quinones Tannines Flavonols Protection against pests Luteon in Lupinus Protocatechunic acid in Allium Phloridcine in Malus pumila Isoflavones Phenolcarboxylic acids Dihydrochalcones Fungicides Reservatrol in Arachis hypogaea Orchinol in Orchis militaris Vestitol in Lotus corniculatus Pisatin in Pisum sativum Coniferyl alcohol in Linum usitiltissimum Psoralen in Petroselinum crispum Stilbens Phenylanthrenes Isoflavanes Pterocarpens Phenylpropanoids Fucocoumarins Phytoalexines Example(s) and plant species where the effect was studied Group Function The Ecological Meaning of Some Phenolic Compounds for Plants