1. Human uses of phytochemicals Secondary plant chemistry and natural products
Definition of plant secondary metabolites
Basic kinds of plant 2º metabolites characteristics and examples of each
Ethnomedicine / ethnopharmocognacy

2. What are plant secondary metabolites?
Contrast with primary metabolites
1º metabolites are in all cells of all kinds of plants
required for basic functioning of cells
carbohydrates, proteins, lipids, nucleic acids
Secondary metabolites
2º metabolites are in some but not all plant groups
a left-over term from an old-fashioned concept
previously thought to be waste products
but have various functions in the plant:
respond to environment
plant defense against
herbivores
pathogens
competitors
protection from damaging radiation from sunlight

3. Secondary metabolites
glycosides (some compounds of the classes below may also be glycosides)
phenolics
terpenoids
nitrogen-containing compounds
sulfur-containing compounds Note that these basic kinds can overlap; they are not exclusive categories.

4. glycosides composed of glycone + aglycone
sugar part + active portion
active once hydrolysed (broken down)
some require specialized bacteria in large intestine to hydrolyse them and release the active portion
some kinds are toxic:
Cyanogenic glycosides (releases cyanide)
Cardiac glycosides (affect rhythm and strength of heartbeats)

5. Digitalis Cardiac glycoside
English folk healers used to treat “dropsy” (edema, fluid accumulation due to inadequate pumping of heart)
mentioned in Gerard’s herbal 1596
William Withering 1775 learned from “an old woman in Shropshire”
dosage problems!
source of cardiac glycosides digitoxin and digoxin, used to treat heart failure and heart arrhythmia
Francis Gwyn Jones
Barbara Tokarska-Guzik, University of Silesia,

6. Phenolics
Aromatic ring with at least one hydroxyl group (aromatic alcohols)
Simple phenols are antibacterial, antiseptic, anthelmintic
Salicylic acid and salicylates: salicin, methyl salicylate are found in what plants?
Acetylsalicylic acid (synthetic derivative) = ?
Warfarin (UW-Madison connection)
Flavors, essential oils (e.g., thymol)
phenol

7. Polyphenols: Antioxidants in red wine and green tea
proanthocyanidins or resveratrol?

8. Polyphenols: Tannins High molecular weight Astringent
May bind with proteins (enzymes)
Some kinds reduce inflammation and bleeding

9. Polyphenols: Flavonoids
Sometimes called “bioflavonoids”
May be free or glycosides
Plant pigments
Anthocyanins (red and blue pigments)
UV protection for plant
Antioxidant, scavenging of free radicals
Protect collagen from inflammation
Plant response to injury (phytoalexins)

10. Terpenoids Based on isoprene subunits aromatics – volatile molecules
Terpenoids
Based on isoprene subunits
aromatics – volatile molecules
some plant hormones
gibberellin, abscisic acid
carotenoids: carotenes & xanthophylls
tetraterpenoids (8 isoprene units)
-carotene, lycopene, lutein  zeaxanthin
images from Wikipedia

11. Terpenoids rubber (poly-isoprene) steroids saponins natural detergents
Terpenoids
rubber (poly-isoprene)
steroids
saponins
natural detergents
names: soapwort, soaproot, etc.
some toxins, some health claims
Why is Saponaria officinalis called “Bouncing Bet”?

12. Sulphur-containing compounds
glucosinolates (mustard oil glycosides)
Brassicaceae and other related families
garden nasturtium Tropaeolum
condiments: mustard, horseradish
anti-cancer effects of Brassica
antibiotic effects
but also anti-thyroid effects – livestock poisoning

13. Sulphur-containing compounds
disulphides
onions, garlic, & other Allium species
includes "lacrimatory factor"
antimicrobial effects
reduce blood clotting

14. Asafoetida Plant of the Day Ferula assa-foetida (Ferula foetida)
Plant family?
Merde du Diable (Fr), Devil's Dung
Used in Indian cuisine, especially by Jains (Why?)
Oleo-gum-resin
disulfides
vs. flu

15. Nitrogen-containing compounds
Cyanogenic glycosides
produce hydrocyanic acid when broken down
Amygdalin  HCN + benzaldehyde
common in Rosaceae
cassava processing to detoxify

16. Nitrogen-containing compounds
Alkaloids
bitter, alkaline
may be toxic or psychoactive
caffeine, nicotine, solanine and many others

17. Caffeine-producing plants
Alkaloids
Caffeine-producing plants
coffee
chocolate
tea
cola nut
yerba mate
guaraná

18. Alkaloids
Erythroxylum coca

19. Coca – Erythroxylum coca
Alkaloids
Coca – Erythroxylum coca
source of cocaine
traditionally chewed with an alkaline substance in Andes (e.g., ashes)
brewed as herb tea
legal in Peru and Bolivia

20. Coca – Erythroxylum coca
Alkaloids
Coca – Erythroxylum coca
source of cocaine
Coca cola history
coca wine
Freud, Sherlock Holmes
Coca Cola invented in 1885
What was the purpose?
How did it change in 1904?

21. Coca – Erythroxylum coca
Alkaloids
Coca – Erythroxylum coca
Evo Morales, president of Bolivia
appealed to UN to lift international ban
promotes coca leaf products as alternative to illegal trade

22. Quinine from Cinchona Alkaloids
alkaloid quinine isolated from cinchona bark in 1820.
synthesized in the laboratory 1944
chloroquine and primaquine
but resistant strains
Illustration of “Kinquina” from Pierre Pomet, Histoire generale des drogues. Paris: Jean Baptiste Loyson & Augustin Pillon, 1694, p. 132.

23. Rosy periwinkle Alkaloids
Vincristine and vinblastine and many other alkaloids
chemotherapy for childhood leukemia, Hodgkin's disease, and other cancers
Catharanthus roseus
Madagascar native now naturalized around tropics and subtropics and cultivated as an annual ornamental in temperate areas.

24. Opium poppy - Papaver somniferum
Alkaloids
Opium poppy - Papaver somniferum
morphine, codeine and other alkaloids
heroin - a synthetic derivative of morphine
What were the “Opium Wars” during 1839 to 1842 and 1856 to 1860 fought over?

25. Peyote Alkaloids Lophophora williamsii, L. diffusa
mescaline and other psychoactive alkaloids

26. Ethnomedicine / ethnopharmocognacy
random screens vs. targeted
taxonomic
ecological
ethnobotanical
HIV example from chapter of Walter Lewis: 15/50 (30%) vs. 1,429/16,886 (8.5%)

27. Taxol from Taxus spp. One success from modified random scan.
important for cancer chemotherapy

28. Synergy
Interaction in which combined effect is greater than the sum of the parts.
May include interaction of different herbs in formulas or different constituents within the same herb.

29. plant 2º metabolites phenol subunits isoprene subunits nitrogen sulfur
glycone and aglycone

30. Secondary metabolites
phenolics
terpenoids
nitrogen-containing compounds
sulfur-containing compounds
glycosides (may overlap with the above)