Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacognosy & Pharmaceutical Biology > Plant Glycosides > Flashcards

Plant Glycosides Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

glycosides contain a sugar molecule and a non-sugar molecule called an

A

aglycone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

there are 4 ways in which the sugar and aglycone are linked those include:

A
  • C glycosides
    • Carbon/carbon bond
    • resist acid and base hydrolysis
  • O glycosides
    • linked by oxygen, stable in acid solution
    • acid or enz hydrolysis
  • N glycosides
    • linked by amino group
  • S glycosides
    • linked through S atom, usually thiol group
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the most prominant type of glycosides in nature are

A

O-glycosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the sugars found in glycosides are generally

A
  • 4-5 carbon sugars
  • in alpha or beta form (most beta)
  • primarily glucose, can also include rhamnose or galactose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the role of the sugar in glycosides is primarily to

A
  • aid in absorption
  • protect the aglycone moiety from premature metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the number of sugars in the molecule impact these three things

A
  • polarity, solubility and chromatographic characteristics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

glycosides are commonly extracted with

A
  • dilute alcohol solutions
  • freed from contaminants by lead acetate precipitation
  • and individual components isolated by preparative chromatography
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

there are 5 groups of glycosides based upon the aglycone group present, these four groups are

A
  1. cyanogenetic glycosides
  2. Isothiocyante glycosides
  3. Antrhacene glycosides
  4. Phenol glycosides
  5. steroid glycosides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

phenol glycosides are further subclassed to include these four groups

A
  1. simple phenols
  2. phenolic acids
  3. flavanoids
  4. coumarins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

steriod glycosides include these 4 subcategories

A
  1. cardenolides
  2. bufadienolides
  3. steroid saponins
  4. triterpene saponins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

cyanoglycosides have this effect in humans

A

poisonous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are examples of plants that contain cyanide

A
  • the seeds of apricots, peaches, cherries and almonds
  • cassava
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the glycosides from almonds, cherry bark and linseed that are considered poisonous

A
  • amygdalin
  • prunasin
  • linamarin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are cyanogentic glycosides commonly used for

A

flavouring agents with expectorant properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Anthracene glycosides are commonly used as (2 things) and include the following sources (5)

A
  • laxatives or purgatives
  • cascara, senna, frangula bark, rhubarb, aloe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

anthracenes are 3 fused rings of

A

benzene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

two common glycosides from senna and cascara are

A

sennosides

cascarosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

anthracene glycosides are in the

A
  • leaves, fruits, barks, rhizomes or juice of plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the mecahnism of action of anthrcene glycosides

A
  • more active as anthrone glycoside than free anthriquinone
  • prevents metabolism of the molecule until it reaches the colon where it gradually releases the anthrone stimulating the intestine to act, in the case of sennosides, defecate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the most active anthracene

A

sennosides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what assay is used to assess anthracene glycosides

A
  • qualitative colour test called Borntragers test
  • pink red colour obtained when anthraquinone form reacts with alkali
  • intensity of colour directly proportional to concentration of anthraquinone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are two analytical challenges in trying to assay senna

A
  • separation of sennoside from inactive anthraquinone is difficult, giving higher values
  • conversion of the dianthrone to quinone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how is the assay for senna performed

A
  • extract into ether
  • react with magnesium acetate
  • measure in spectrophotometer against standard or calibration curve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

phenolic glycosides include (5)

A
  • simple phenols
  • tannins
  • flavanoids
  • coumarins
  • lignans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

simple phenols have wide pharmacological activity including (5 properties)

A
  1. antibacterial
  2. anti-inflammatory
  3. antipyretic
  4. antiemetic
  5. antivrial and antirheumatic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

thymol is isolated from ________plant and has this pharmacological effect

rosemarinic acid is isolated from ________plant and has this pharmacological effect

A
  • thyme & antibacterial
  • lemon balm, rosemary and comfrey & antiviral and anti-inflammatory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the mechanism of action of rosemarinic acid

A
  • inhibits classical and alternative pathways of complement activation and
  • scavenges toxic oxygen from activated polymorphonuclear leucocytes
  • antiviral activity - inhibits binding of virus to host cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

this group of phenolic glycosides are polymers of simple phenols

A

tannis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

tannins can cross link with protein in animal skin to form leather, how is the action of significance for its clinical use

A
  • it provides a barrier to infections for wounds or burns allowing the healing process to occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what are two categories of tannins

A
  • hydrolysable and condensed aka proanthrocyanidins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what are some concerns over tannins in herbal teas. Are these concerns valid, why?

A
  • may interfere with drug absorption or minerals/vitamins
  • carcinogenic effects
  • not valid because regular tea has more tannins than herbal tea
32
Q

flavanoids are the smallest or largest group of naturally occurring phenols

A

largest

33
Q

most flavanoids exist as C,O,N, or S glycosides

A

O and C

34
Q

this group of glycosides is found universally in plants

A

flavanoids

35
Q

flavanoids have these properties (4)

A
  1. antiallergic - Quercetin
  2. antispasmotic - Chamomile
  3. cardiotonic - hawthorn
  4. cerebrovasular - Gingko
36
Q

what is the mechanism of action of the flavanoid quercetin

A
  • inhibition of lipoxygenage, inhibits release of leukotrienes from mast cells
37
Q

this group of phenolic glycosides are Benz - alpha-pyrones

A

coumarins

38
Q

coumarins have these physiological effects

A
  • inhibt grouwth of bacteria, yeast fungi
  • anticoagulant effect
39
Q

Lignans are complex dimeric molecules containing

A

two phenylpropanoid units linked by a C-c bond

40
Q

what is the best known lignan

A

podophyllotoxins

41
Q

podophyllotoxins possess this physiological effect

name two podophyllotoxins

A
  • cytotoxic
  • etoside and teniposide are used in chemotherapy
42
Q

what are three classes of steroid glycosides

A
  • Cardiac Glycosides
  • Steroid Saponins
  • Triterpene Saponins
43
Q

steroid glycosides are produces via which pathway

A

mevalonic

44
Q

cardiac glycosides have this effect

A

increase pumping action of heart

45
Q

what is the source of the most important cardiac glycoside

A
  • digitalis (foxglove) e.g. digoxin
  • also adonis, oleander, and lily of the valley
46
Q

cardiac glycosides contain two aglycones that are cardioactive

A
  • cardiotonic and cardiotoxic glycosides
47
Q

cardiac glycosides can be subcategorized as

A
  • cardenolides and
  • bufadienolides
48
Q

cardiac glycosides contain this number of carbons

A

C23 or C24

49
Q

this is the primary aglycone in cardiac glycosides

A

cardenolides

50
Q

cardenolides contain this type of lactone ring and Bufadienolides contain this type of lactone ring

A
  • C5
  • C6
51
Q

sugar moieties found in cardiac glycosides are (4 - two of which are primarily found)

A
  • digitose*
  • cymerose*
  • glucose
  • rhamnose
52
Q

Digitalis glycosides contain this number of glycosides

A

5

vary with number of OH groups

53
Q

purpea glycosides are also known as

A

deslanosides

54
Q

what is the activity of glycosides due to

A

the presence of a lactone ring

55
Q

what is the key element in the attachment of the glycoside to the receptor

A

carbonyl functional unit of the lactone ring

56
Q

effectiveness of glycoside is depenent upon

A

sugars which make the glycoside more soluble and assist in binding to cardiac muscle

57
Q

Digitoxin is most widely used because

A

it is more rapidly absorbed from G.I.T than purpurea glycosides

58
Q

Bufadienolide glycosides are less widely used becaus of

A

toxicity

59
Q

what plant contains bufadienolides

A

squill

60
Q

Chemical assays for cardiac glycosides are based on

A

chromogenic ID tests

61
Q

which reagent is used in TLC separation of digitalis glycosides

A

Kaiser’s reagent

62
Q

this reagent is most commonly used

A

baljet test detects lactone ring

63
Q

Saponin glycosides are water soluble and have these common characteristics making them easily identifiable

A
  • cause frothing by reducing surface tension
  • hemolyze RBCs by forming a complex with cholesterol from the RBC wall
  • paralyze fish gills
64
Q

what are the two types of sapogenins (aglycones) in saponin glycosides

A
  • steroidal
  • triterpenoidal
65
Q

steroidal saponins are isolated from ______while triterpene saponins are isolated from________

A
  • monocots such as agave
  • dicots such as yams
66
Q

which is the most widely used sapogenin

A

Diosgenin from mexican yam

67
Q

what are steroidal glycosides commonly used for

A

precursors for steroidal hormones such as cortisone, estrogens, progesterones etc

68
Q

two main types of triterpenoid saponins include

A
  • tetracyclic triterpenese (trimethylsteroids) C27
  • pentacylic triterpenes (C30)
69
Q

pentacyclic triterpenoidal saponin glycosides include these four series of sapogenins. which is the most significante

A
  • ursane
  • hopane
  • lupane and
  • oleanane series*
70
Q

Oleanane sapogenins are isolated from

A

senega, primrose, horse chesnut and quillaia ivy

71
Q

triterpenoidal saponins have these physiological effects

A
  • antimitotic
  • anti-cancer
  • anti inflammatory
  • analgesic
  • antipyretic
  • anti ulcerogenic
  • sedative
  • cardiac
  • antithrombotic
  • molluscicidal
  • spermicidal
72
Q

aescin from horse chestnut is used for treatment of_________because of its _______effect

A
  • hemorrhoids
  • antagonist effect on edema of blood vessels
73
Q

an important triterpenoid is______because of its _________properties it can be used to treat this parasitic disease

A
  • ginsing
  • molluscidal
  • schistosomiasis
74
Q

ginsing is sourced from leaves of__________and is widely used because of its_________effects

A
  • panax ginseng
  • protective effects on the body against fatigue and stress, slowing down the degenerative effects of ageing
75
Q

liquorice root contains the glycoside__________which is used to treat___________

A
  • glycrrhizin
  • ulcers and inflammation
76
Q

what are some common side effects of glycrrhizin

A
  • hypertension
  • adreno and mineral corticoid activity

Pharmacognosy & Pharmaceutical Biology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions