Plant Chemistry

Question 1

Pharmacognosy is:

Answer 1

the study of the physical, chemical, biochemical and biological properties of drugs, drug substances, or potential drugs or drug substances of natural origin as well as the search for new drugs from natural sources

Question 2

Why should we study pharmacognosy?

Answer 2

to inform our decisions about crafting medicines, how to administer, potential interactions, and physiologic actions.

tea or tincture? how is it absorbed? stability of constituents? constituents present in essential oil? etc

Question 3

What are secondary metabolites?

Answer 3

compounds not directly involved in the growth, reproduction, or photosynthesis of plants.

generally associated with defense, attraction of pollinators and symbiotes, & protection from environment (like UV)

Question 4

Aromatic (benzene) ring with an -OH group:

Answer 4

Phenolics

Question 5

Properties of phenolic constituents:

Answer 5

• resonance stabilization
• antioxidants
• anti-inflammatories
• anti-cancer
• colorful pigments

Question 6

T/F: Plant chemicals are group according to their chemical action on the body.

Answer 6

False!

they’re organized by their chemical structure

Question 7

Simple phenolic compounds - properties:

Answer 7

single aromatic ring
smaller molecules are volatile
often form glycosides

Question 8

Phenolic glycosides - properties:

Answer 8

phenolic with a sugar group

[aglycone + glycone]

Question 9

Phenolic acids - properties:

Answer 9

at least one phenolic ring with an acidic carboxyl group

Question 10

Tannins - properties:

Answer 10

astringents
phenolic acids w/ester [-o-] linkages to a sugar molecule
tighten tissues - taste dry in your mouth!

Question 11

Derivatives of α-pyrone:

Answer 11

Coumarins

Question 12

Coumarins with an additional O-heterocycle:

Answer 12

Furanocoumarins

these are photosensitizing

Question 13

Properties of coumarins:

Answer 13

• antioxidant
• anti-inflammatory
• appetite suppressant

Question 14

Pigmented molecules:

Answer 14

Naphthoquinones

Question 15

Properties of naphthoquinones:

Answer 15

• fungicidal
• antibacterial
• insecticidal
• phytotoxic
• cytostatic
• anticarcinogenic
• antihelminthic

Question 16

Polyphenolic compounds based on tri-aromatic ring structure with opposite phenolic groups on the middle ring:

Answer 16

Anthraquinones

Question 17

Properties of anthroquinones:

Answer 17

• laxative and purgatives
• many are pigments
• many are glycosides

Question 18

Properties of flavonoids:

Answer 18

• anti-cancer
• anti-inflammatory
• cooling
• colorful

Question 19

3-ring molecules with one benzene ring connected by only one carbon bond (usu 2 or 3):

Answer 19

flavonoids

Question 20

Structurally similar to flavonoids, but carrying a charge:

Answer 20

anthocyanidins

called anthocyanins when they have a glycoside

Question 21

Properties of anthocyanidins:

Answer 21

• sap pigments (color depends on pH)

Question 22

Properties of anthocyanins:

Answer 22

• odorless
• flavorless
• mildly astringent

Question 23

Properties of proanthocyanidins:

Answer 23

• related to flavonoid pigments
• no sugar moiety
• oligomers & polymers of flavon-3-ol’s

Question 24

Dimeric compounds formed by two phenylpropene derivatives:

Answer 24

Lignans

Question 25

Properties of lignans:

Answer 25

* major class of phytoestrogens * antioxidant function * some have toxicity * some are hepatoprotective

Question 26

Phenylpropene units linked head-to-head or head-to-tail:

Answer 26

Neolignans

Question 27

Synthesized from DMAPP and IPP 5-C precursors:

Answer 27

Terpenoids

Question 28

Characteristics of monoterpenes:

Answer 28

10-C molecules low molecular wt structural variations: monocyclic, bicyclic, acyclic component in essential oils small change in structure -> big change in action

Question 29

Cyclic structure with an Oxygen in the ring neighboring a ketone:

Answer 29

Lactone

Question 30

A cyclopentane ring fused to a 6-membered oxygen heterocycle, often occur as glycosides:

Answer 30

Iridoid - these are bitters

Question 31

Characteristics of sesquiterpenes:

Answer 31

15-C molecules volatile structural variations: monocyclic, bicyclic, acyclic

Question 32

A mixture of terpenoid molecules & aromatic compounds that combine to form a (semi-)solid substance that is excreted by plants for protection or in response to injury. :

Answer 32

Resin The (semi-)solid portions are often di- & triterpenes The aromatic portion is commonly mono- and sesquiterpenes

Question 33

Resins that have a polysaccharide component as well as volitile oils and heavier terpenes:

Answer 33

Gum resin

Question 34

Characteristics of triterpenes:

Answer 34

``` 30-C molecule usu pentacyclic precursor to plant steroids usu water-soluble saponins aglycones are oil soluble ```

Question 35

Amphipathic:

Answer 35

a chemical compound possessing hydrophilic and lipophilic properties. e.g. triterpenoid saponins like glycyrrhizin

Question 36

Characteristics of steroidal saponins:

Answer 36

27-C molecule multiple sugar units attached (usu 3-5) many anti-inflammatory & adaptogenics in this class "-genin" denotes the aglycone

Question 37

Characteristics of phytosterols:

Answer 37

tetracyclic plant equivalent to cholesterol in animal cell membranes plant growth regulators found in plant oils and lipophilic extracts

Question 38

Characteristics of cardiac glycosides:

Answer 38

Tetracyclic sterol skeleton w/5-membered lactone ring | cardioactive substances from plants (digitalis, convallaria)

Question 39

Characteristics of tetraterpenes:

Answer 39

40-C molecules lipophilic - multiple conjugated double bonds terminal cyclic structures lycopene is precursor carotenoids concentrate in tissues providing antioxidant protection

Question 40

Oxygenated carotenoids are called:

Answer 40

Xanthophylls they have ketone, hydroxyl, and epoxide groups on their rings

Question 41

Characteristics of alkaloids:

Answer 41

nitrogenous molecules (N in the ring) occur as salts or N-oxides in plants alkaline nature soluble in hydroethanolic menstrum

Question 42

How do amines differ from alkaloids?

Answer 42

In amines, the N is not within the ring.

Question 43

Toxic alkaloids that build up in tissues over time and have a hepatotoxic & hepatocarcinogenic effect:

Answer 43

Pyrrolizidine alkaloids Comfrey, butterburr, colt's foot

Question 44

Characteristics of inulin:

Answer 44

``` oligosaccharide prebiotic soluble fiber named for inula helenium sources: chicory, onion, garlic, artichoke, dandelion, burdock ```

Question 45

Heteropolysaccharides that can trap water in a 3D structure:

Answer 45

Pectins * soluble fiber * helical galacturonic acid backbone, various sugar side groups

Question 46

Characteristics of a mucilage:

Answer 46

forms gel/slime with water soothing & emollient significant crossover btw mucilages & immunomodulating polysaccharides found in althea off, ulmus fulva

Question 47

Complex mix of heteropoly- & polysaccharide protein complexes that effect immune system function:

Answer 47

Immunomodulating polysaccharides * arabinogalactans * acemannans * beta-glucans