The document discusses chemosystematics, which is the use of chemical features of plants to develop classifications and solve taxonomic problems. Certain chemical markers like alkaloids, flavonoids, terpenoids have been useful in chemosystematics. The document provides examples of how these chemical markers have supported taxonomic classifications in various plant families. It also discusses the historical development and applications of chemosystematics from ancient times to modern use in plant taxonomy.

1. CHEMOSYSTEMATICS
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

2. Chemical features of plants are used in
developing classifications or in solving
taxonomic problems
Chemotaxonomy
Chemosystematics
Chemical Taxonomy
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

3. MARKERS
Alkaloids
Flavonoids
Carotenoi
ds
Polysaccha
rides
Terpenoid
s
Fatty acids
Amino
acids
Aromatic
Compoun
ds
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

4. Evidences of SUCCESS
Aromatic plants in Juglandales
Betalins in Caryophyllales
Aromatic compounds in Lamiaceae
Alkaloids in Solanaceae
Tannifeorus materials in Sapindaceae
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

5. WHERE we can APPLY?
Starting from the rank of ‘variety’ up to the rank of
‘division’
Starting from simple organisms to highly
specialized group of angiosperms
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

6. PURPOSES
To develop taxonomic
character which may
improve the existing
system
To develop the present
day knowledge of
phylogeny
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

7. HISTORY
HEMLOCK (Conium
maculatum)
SOCRATES
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

8. DIOSCORIDES
1st Century
AD
Aromatic
Mints
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9. Modern phase of Chemotaxonomy began with
the work of Abbott (1886) in Botanical Gazette
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10. McNair published a series of papers from
1917 to 1945
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

11. Taxonomically significant phytochemicals
1. Directly visible- starch grains; raphides; crystals
2. Chemical test characters- phenolics; betalins;oils;
fats; waxes; alkaloids
3. Proteins
 Micromolecules
 Macromolecules
 Sematides
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

12. Flavonoids
Phenolic glycosides having two benzene rings
linked together through a heterocyclic pyrane
ring
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

13. Why flavonoids became significant in
taxonomy?
Wide spread distribution
chemical complexity
physiological stability
quick and easy identification
structural variation
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

14. Classes of Flavonoids with systematic
significance
Anthocyanidins Cyanidin, Delphinidin
Flavones Apigenin, Levtolin
Biflavonyls Amentoflavone
Flavanols Kaempferol, Quercetin
Flavonones Naringenin
Isoflavones Orobol
Isoflavonoids Ferreirin
Chalcones Butein
Aurones Sulphuretin
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

15. Betalins
Nitrogeneous
anthocyanins
Include red to violet
betacyanins and
yellow betaxanthins
Aizoaceae, Amaranthaceae,
Basellaceae, Caryophyllaceae,
Chenopodiaceae, Didieraceae,
Molluginaceae, Nyctaginaceae,
Phytoalecaceae and Portulacaceae
produce betalins and are placed
together in a single order
Caryophyllales
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16. • Also called isoprenoids
• Polymers of isoprene units
• Mevalonic acid is the precursor
• Used extensively in chemosystematics of Mints,
Umbellifers, Citrus plants and Gymnosperms
Terpenoids
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1

17. Terpenoids and systematics
Volatile
monoterpenoids and
sesquiterpenoids
Major components of
essential oils
Magnoliales, Laurales,
Austrobaileyales,
Piperales
Sesquiterpene Asteraceae, Apiaceae, Magnoliaceae, Lauraceae
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Triterpenoid ‘Betulin’ Seen in the bark of Betula papyrifera and
relatives

18. Triterpene saponins Apiaceae and Pittospraceae
Triterpenoid derivatives ‘limonoids’ &
‘Quassinoids’
Limited to Rutaceae, Meliaceae and
Simaroubaceae (of Sapindales)
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19. • Triterpene derivative
• Alcohols or esters having two methyl groups
• Located in plant cutins
• Perform the function of water proofing
• Helpful for the taxonomy of the genera of
tribe Veratreae of family Liliaceae
Steroids
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20. Iridoids
Monoterpenoid cyclopentanoid lactones
Found in many families of the Asterid clade
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Seco-iridoids Gentianales, Dipsales, and many
families of Cornales and
Carbocyclic iridoids Lamiales, except for Oleaceae,
Tetrachondraceae and
Gesneriaceae

21. Alkaloids
Basic nitrogen-containing organic compounds, with
heterocyclic ring
Derived from different amino acids or mevalonic
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22. Secologanin-type indole alkaloids Apocyanaceae, Gelsemiaceae,
Loganiaceae and Rubiaceae
Tropane alkaloids Solanaceae & Convolvulaceae
Benzylisoquinoline alkaloids Magnoliales, Laurales, Ranunculales
Isopremoid alkaloids Scattered distribution
Less systematic interestPyrrolizidine alkaloids
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23. Glocosinolates
Thioglucosides which on hydrolysis form a glucose
and a corresponding isothiocyanate
Mustard oil glucosides
Synapomorphic for Brassicales
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24. Cyanogenic Glycosides
Defensive compounds
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Cyclopentanoid cyanogenic
glycosides
Restricted to Achariaceae,
Passifloraceae, Turneraceae &
Malesherbiaceae
CG from leucine Rosaceae
CG from tyrosine Magnoliales and Laurales

25. Polyacetylenes
Non-nitrogeneous secondary metabolites
Asterid families-Asteraceae, Apiaceae,
Pittosporaceae, Campanulaceae, Goodeniaceae
and Caprifoliaceae
Falcarinone polyacetylenes restricted to
Araliaceae and Pittosporaceae
SHAIJU PUSHPANGADAN, FMNC, KOLLAM-1