CHEMICAL PHARMACOGNOSY
▪ The branch of pharmacognosy where we are discussing the chemicals especially of secondary
metabolite.
▪ Enzyme dependent chemical reactions.
▪ The sequence of the chemical reactions in the presence of enzymes is called biosynthetic pathways.
▪ Product of metabolism is known as metabolite.
▪ There are two types of metabolites primary metabolite and secondly metabolite.
Primary Metabolites:
▪ Those metabolites which are essential for the life of plant.
▪ They are directly involved in normal growth reproduction and development etc.
▪ Primary metabolites provide a building block for secondary metabolism.
▪ It has role in nutrition.
▪ Example; protein, carbohydrates, and fats.
Secondary Metabolites:
▪ Those metabolites which are not essential for the life of plants.
▪ They are not directly involved in normal growth, development, and reproduction.
▪ But secondary metabolites are having important role ecology and defense mechanisms.
▪ Used for drug production.
Factors Affecting Secondary Metabolites:
1. Gene: specific gene produces specific type of secondary metabolite.
2. Plant tissue: specific plant tissue produces specific secondary metabolite. example Papaver
somniferum contains different alkaloids like morphine codeine present in latex.
3. Plant maturation: Different stages of plant contain different metabolite example mature leaf of the
Mentha piperita plant contains menthol while the immature leaf contains pulegone. Datura
stramonium ( thorn apple ) contains hyoscine in young plant which after maturation the hyoscine
becomes 30%.
4. Flower pollination: Vanila planifolia increases the vanillin production increases after 8 months of
flower pollination.
5. Biological factors: biological agents like nematodes, viruses and fungi may attack the plant as parasite
as a result phenolic compounds may be produced by the plant for defense.
6. Drought condition: depending upon the availability of water it may cause either large or small
production of secondary metabolites. E.g; Trigonella foenum-graecum triggers phenolic compounds.
, 7. Soil salinity: ↑soil salinity in →Mentha piperita & Trigonella foenum-graecum plant→↓essential oil
production. ↑ soil salinity in→ Matric recutita →↑essential oil production.
8. Temperature: ↑Temperature →↑alkaloid production. E.g in the Daucus carota (carrot) →↑
temperature →↑production of terpenes.
9. Altitude : Mentha spicata if it is present at high altitude it will give more and more anti-bacterial activity
as compared to if it is present at low altitude.
10. Fertilizers: Fertilizers contain phosphorus and act as nutrition of the plant so it leads to production of
different types of secondary metabolites in large amounts.
Role Of Secondary Metabolites In Plants:
1. Gums and Mucilage’s: During bacteria attack gums & mucilages in the form of matrix captures the
bacteria and act as antibacterial agents.
2. Phenolic Compounds:
▪ Types: a. Anthocyanin: gives red, violet & purple.
b. Carotenoids: gives red, orange & yellow.
( These colours are helpful in attracting insects for pollination.)
▪ Gossypium herbaceum Rotenone Limonene
↓ ↓ ↓
Contain gossypol Isoflavonoid ↓
in nature ↓
↘ ↓ ↙
Behave as insecticide’s
▪ Glycine Max (Soy bean plant) after fungus attack increase production of glyceollin metabolite;
& after 8hrs fungus cannot attack since glyceollin act as fungicidal agent.
3. Saccharides: Due to the presence of glycosides in carbohydrates percentage of carbohydrate
increases making the taste good & causing insects to eat them becoming a source of dispersion of
seeds.
4. Waxes: Waxes in Ficus carica (fig) increases UV reflection of sunlight & this reflection attracts other
insects for pollination.
5. Terpenes: Play a vital role in the plant defense. When any parasite tries to attack on the plant it may
cause injury in the plant which triggers the production of terpenes and since it is volatile in nature it
will attract the predators of attacking parasite/insect; to break the insect. This is the mechanical and
the indirect defense of terpenes.
6. Nitrogen compounds:
▪ The branch of pharmacognosy where we are discussing the chemicals especially of secondary
metabolite.
▪ Enzyme dependent chemical reactions.
▪ The sequence of the chemical reactions in the presence of enzymes is called biosynthetic pathways.
▪ Product of metabolism is known as metabolite.
▪ There are two types of metabolites primary metabolite and secondly metabolite.
Primary Metabolites:
▪ Those metabolites which are essential for the life of plant.
▪ They are directly involved in normal growth reproduction and development etc.
▪ Primary metabolites provide a building block for secondary metabolism.
▪ It has role in nutrition.
▪ Example; protein, carbohydrates, and fats.
Secondary Metabolites:
▪ Those metabolites which are not essential for the life of plants.
▪ They are not directly involved in normal growth, development, and reproduction.
▪ But secondary metabolites are having important role ecology and defense mechanisms.
▪ Used for drug production.
Factors Affecting Secondary Metabolites:
1. Gene: specific gene produces specific type of secondary metabolite.
2. Plant tissue: specific plant tissue produces specific secondary metabolite. example Papaver
somniferum contains different alkaloids like morphine codeine present in latex.
3. Plant maturation: Different stages of plant contain different metabolite example mature leaf of the
Mentha piperita plant contains menthol while the immature leaf contains pulegone. Datura
stramonium ( thorn apple ) contains hyoscine in young plant which after maturation the hyoscine
becomes 30%.
4. Flower pollination: Vanila planifolia increases the vanillin production increases after 8 months of
flower pollination.
5. Biological factors: biological agents like nematodes, viruses and fungi may attack the plant as parasite
as a result phenolic compounds may be produced by the plant for defense.
6. Drought condition: depending upon the availability of water it may cause either large or small
production of secondary metabolites. E.g; Trigonella foenum-graecum triggers phenolic compounds.
, 7. Soil salinity: ↑soil salinity in →Mentha piperita & Trigonella foenum-graecum plant→↓essential oil
production. ↑ soil salinity in→ Matric recutita →↑essential oil production.
8. Temperature: ↑Temperature →↑alkaloid production. E.g in the Daucus carota (carrot) →↑
temperature →↑production of terpenes.
9. Altitude : Mentha spicata if it is present at high altitude it will give more and more anti-bacterial activity
as compared to if it is present at low altitude.
10. Fertilizers: Fertilizers contain phosphorus and act as nutrition of the plant so it leads to production of
different types of secondary metabolites in large amounts.
Role Of Secondary Metabolites In Plants:
1. Gums and Mucilage’s: During bacteria attack gums & mucilages in the form of matrix captures the
bacteria and act as antibacterial agents.
2. Phenolic Compounds:
▪ Types: a. Anthocyanin: gives red, violet & purple.
b. Carotenoids: gives red, orange & yellow.
( These colours are helpful in attracting insects for pollination.)
▪ Gossypium herbaceum Rotenone Limonene
↓ ↓ ↓
Contain gossypol Isoflavonoid ↓
in nature ↓
↘ ↓ ↙
Behave as insecticide’s
▪ Glycine Max (Soy bean plant) after fungus attack increase production of glyceollin metabolite;
& after 8hrs fungus cannot attack since glyceollin act as fungicidal agent.
3. Saccharides: Due to the presence of glycosides in carbohydrates percentage of carbohydrate
increases making the taste good & causing insects to eat them becoming a source of dispersion of
seeds.
4. Waxes: Waxes in Ficus carica (fig) increases UV reflection of sunlight & this reflection attracts other
insects for pollination.
5. Terpenes: Play a vital role in the plant defense. When any parasite tries to attack on the plant it may
cause injury in the plant which triggers the production of terpenes and since it is volatile in nature it
will attract the predators of attacking parasite/insect; to break the insect. This is the mechanical and
the indirect defense of terpenes.
6. Nitrogen compounds:
