Plant Chemistry (wks 1, 2)

Question 1

Define a secondary metabolite

Answer 1

compounds not directly involved in growth, reproduction or photosynthesis. dervied from primary metabolites (which are required for growth, reproduction and photosynthesis). Associated with defense, attraction, protection.

Question 2

Define pharmacognosy

Answer 2

study of the physical, chemical, biochemical and biological properties of drugs, drugs substances or potential drugs of natural origin

Question 3

What is a phenolic compound?

Answer 3

Benzene aromatic ring with an OH group

Common properties: resonance stabilization, antioxidant, anti-inflammatory, anti-cancer, colorful pigments

Question 4

What are some examples of a simple phenolic?

Answer 4

Eugenol, Vanillin, Methyl Sailcylate (in Wintergreen and birch)

Question 5

What are tannins?

Answer 5

Astringents (implicated in open wounds, leaky gut, diarrhea, varicosities…)
phenolic acids with ester linkages to a central glucose
Eg: geraniin
Plants high in tannins: quercus, hamammelis virginiana, aesculus hippocastanum, camellia sinensis, cinnamomum, rheum

Question 6

What are Coumarins?

Answer 6

a-pyrone derivatives
aromatic, “fresh cut grass” aroma
Eg: archangelicin, umbelliferone, aesculetin
May inhibit CYP3A4/CYP3A5 (grapefruit effect)

Question 7

What are furanocoumarins?

Answer 7

a-pyrone derivatives with a 5-membered ring
photosensitizing effect, “fresh-cut grass” aroma
May also inhibit CYP3A4/CYP3A5 (grapefruit effect)
Found in celery, citrus, parsely
Eg: Bergapten, Psoralen

Question 8

What are chromones?

Answer 8

benzo-g-pyrone derivatives
(bitter tasting)
Found in: carrots, cloves (eugenin)

Question 9

What are furanochromones?

Answer 9

benzo-g-pyrone derivatives with a 5-membered ring
bitter
found in Khella (khellin) and Ammi visnaga (visnagin)
bronchodilator

Question 10

What are anthraquinones?

Answer 10

polyphenolic compounds, tricyclic
pigments, laxatives, irritant-laxatives, purgatives
Many occur as glycosides
Eg: Hypiricin (non-laxative in St. Johns wort), Sennidin (senna), Aloin (aloe), Emodin and frangulin (Rhamnus)

Question 11

What are lignans?

Answer 11

dimeric compounds formed by two phenylpropene derivatives
phytoestrogens, anti-oxidants, hepatoprotective (silybin, silymarin)
may have some toxicity
Found In: Flax, Milk Thistle, Schisandra, Eleutherococcus

Question 12

What are flax lignans?/ How do they differ from lignans?

Answer 12

Secoisolariciresinol is the dominant flax lignan, it’s actually a lignan precusor that is metabolized in the gut into enterolactone by gut bacteria.

Question 13

What are neolignans?

Answer 13

polypropelen units linked head to head/ head to tail
affect GABA, anti-seizure, anti-anxiety
eg: Magnolol, Honokiol

Question 14

What are Stilbenes?

Answer 14

anti-oxidant

eg: Reservatrol

Question 15

What are flavonoids?

Answer 15

colorful, cooling, anti-inflammatory
made of 3 aromatic rings (“3-ring circus”)
Flavus=yellow

Question 16

What are the different types of flavonoids?

Answer 16

Flavones- ketone (eg. passiflora, cynara scolymus)
Flavonols- ketone, alcohol (eg. quercitin)
Flavanones- ketone in non-aromatice center ring (eg. eriodictyol, hesperitin)
Flavan-3-ols- alcohol at 3rd C, catechins (eg. green tea)
Isoflavones: (eg. genestein, diadzein) phytoestrogens in soy
Biflavones: (eg. ginkgo, hypericum, rhus)

Question 17

Which of these compounds are volatile?
Simple phenolic
Tannins
Coumarins and Furanocoumarins
Chromones and Furanochromones
Anthraquinones
Lignans
Stilbenes
Flavanoids

Answer 17

Simple Phenolics
Coumarins, Furanocoumarins
Chromons, Furanochromones (?)
(also terpenes)

Question 18

What is a glycoside?

Answer 18

molecule with a sugar moiety

Question 19

What is a glycone?

Answer 19

The glucose molecule in a glycoside that is made with glucose as a sugar

Question 20

What is an aglycone?

Answer 20

The molecule part of the glycoside

Question 21

How are Anthraquinones used medicinally?

Answer 21

irritant laxatives, purgatives, pigments

constipation

Question 22

What is the difference between anthocyanins, anthocyanidins, and proanthocyanidins

Answer 22

Anthocyanidins: flavone-related but with charge; PIGMENTS

Anthocyanins: anthocyanidin glycosides; odorless, flavorless, mildly astringent

Proanthocyanidins: HUGE, oligomers, polymers; drying, astringent

Question 23

Which classes of phenolic compounds act as phytoestrogens.

Answer 23

Isoflavones, Lignans

Question 24

why, from a chemical standpoint, phenolic compounds have antioxidant properties

Answer 24

Resonance stabilization

Question 25

How many carbon are in a monoterpene, a sesquiterpene, a diterpene, a triterpene, and a tetraterpene.

Answer 25

Monoterpene: 10 Carbons
Diterpene: 20 Carbons
Triterpene: 30 Carbons
Tetraterpene: 40 Carbons (aka carotenoids)
Sesquiterpene: 15 Carbons

Question 26

Which classes of terpenes are volatile?

Answer 26

monoterpenes

sesquiterpenes

Question 27

Define a resin

Answer 27

“a more or less solid, amorphous product of a complex chemical nature”
“a hydrocarbon secretion of many plants, particularly coniferous trees”
mixture of terpenoids, aromatic compounds. Usually di-/tri-terpenes, mono and sesquiterpenes
Gum resins have a polysaccharide component as well

Question 28

Define amphipathic

Answer 28

A molecule that has both hydrophilic and hydrophobic areas

Question 29

What is a saponin?

Answer 29

A molecule (usually a terpenoid) with 2+ sugar moieties attached.

Question 30

Define mucilage

Answer 30

soothing emollient made of polysaccharides. May encompass immune-modulating polysaccharides

Question 31

What are the basic properties of an alkaloid?

Answer 31

Nitrogenous molecules- often with the N in a heterocyclic ring. Many occur as salts or N-oxides and often soluble in hydroethanolic menstrum (water-ethanol mix)

Question 32

How are alkaloids classified?

Answer 32

classified by base nitrogen-containing compount (purine, pyridine, pyrrole ring, piperidine ring…etc)