Secondary metabolitesB.C. MuthubharathiIII B.Sc., Biotechnology

Introduction

Have no function in growth Produced by restricted group of microorganisms Unusual chemical structures Derived by unique biosynthetic pathway from primary metabolites

Profits

Floral scent volatile and pigments attracts insect pollination enhance fertilization

Synthesis toxic chemicals Suppress the growth of neighboring plants

Prevent spoilage of fruits Act as a signal of presence of potential rewards for animals Cellular function Unique to particular plant ( resistant to salt and

drought) Play a role in reinforcement of tissues and tree bodies Protection against insect and disease

Characteristics

Secondary metabolism Formed in specific organism or group of organisms Enzymes catalyze specific metabolic reaction 20000 – 60000 genes in plant genome 15% - 25% for secondary metabolites

Classes

Polyketanoids and fatty acids Terpenoids and steroids Phenyl propenoids Alkaloids

Polyketanoids – Linear combination of acetate units Fatty acids – long chain monocarboxylic acids Leaf waxes and seed coating

Terpenes5 carbon unitsMonoterpenes, sequiterpenes, tripterpenes

Phenolic compoundsWood and barkDerived from phenyl propanoid structures

Numbers of C Basic skeleton Names

6 C6 Benzoquinones

10 C6-C4 Naphthoquinones

14 C6-C2-C6 Stilbenes

15 C6-C3-C6 Flavonoids

17 C6-C3-C2-C6 Norlignans

18 (C6-C3)2 Lignans

n (C6-C3-C6)n Condensed tannins

Alkaloids

Basic compound Nitrogen based heterocyclic ring Types

Monocyclic Bicyclic Polycyclic

Uses

Myrcene – Oil of bay leaf Perfume

Geranoil – Oil of roses, lemon grass

Menthol - Oil of peppermint

Lignan - Antiviral, antitumor, biocidal, bioactive agents

Morphine – Painkiller

Vinblastin – Treatment of cancer