Brainscape's Knowledge GenomeTM

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


See full index

PHA6117 lab > Tannins > Flashcards

Tannins Flashcards

1
Q

Polyphenolic substances found in many plants

A

Tannins

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

T or F: Tannins are a product of secondary metabolism

A

True

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

T or F: Tannins are water-soluble in nature which allows for easy extraction

A

True

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

Tannins causes __________

A

Precipitation of proteins and alkaloids

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

T or F: Tannins are complex, organic, non-nitrogenous, has high MW and can be crystallized

A

False, cannot be crystallized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Medicinal use of Tannins

A

Astringent, antioxidant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Industrial use of Tannins

A

Leather manufacturing, Dyeing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Color of Tannins

A

Pale yellow to light brown-red amorphous substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T or F: Tannin solutions are basic and have an astringent taste

A

False, acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Tannins have ________ taste

A

Sharp puckering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Tannins are soluble in _________ but only sparingly soluble in _________

A

Dilute alkali, alcohols, acetone

Other organic solvents

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

Tannins are isolated from

A

Oak bark, sumac, galls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Tannins are _____ glycosides

A

Phenol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tannin-containing drugs precipitate proteins and have been traditionally used as _______ and internally for _________

A

Styptics - to stop hemorrhaging; Protection of inflamed surfaces of mouth and throat

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

Tannins also play an important role in the treatment of ______ by forming a mild antiseptic protective layer on the surface of the skin

A

Burns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Tannins can also act as _________ although not recommended as they usually delay elimination of bacterial toxins from the body

A

Anti-diarrheals

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

T or F: Tannins are employed as antidotes against poisoning by heavy metals, alkaloids, and certain glycosides

A

True

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

2 Major Classifications of Tannins

A

True Tannins and Pseudotannins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Under True Tannins, there are 3, what are they?

A

Hydrolysable or Pyrogallol
Non-hydrolysable or Condensed/Catechols
Complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hydrolysable Tannins have 2 types

A

Gallitannins and Ellagitannins

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

T or F: On wet distillation, Gallic acid and other components get converted to pyrogallol

A

False, dry distillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Hydrolysable Tannins respond to ____________ solution producing __________ color

A

Ferric chloride, blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Also called phlobatannins or proanthocyanidins

A

Non-hydrolysable Tannins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

On dry distillation, non-hydrolysable tannins yield what?

A

Catechol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Non- Hydrolysable Tannins reacting with ferric chloride will yield what color?

A

Brownish green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sub-group of tannins that do not obey gold-beaters skin test and have low MW

A

Pseudotannins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Extraction of Tannins (8)

A
  1. Conventional extraction with organic solvents
  2. Extraction with hot water
  3. Extraction with ionic liquids
  4. Extraction with supercritical fluids
  5. Extraction with pressurized hot water or subcritical water
  6. Extraction assisted by microwave
  7. Extraction assisted by ultrasound
  8. Comparison of tannins extraction with several extraction methods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Most traditional method for tannin extraction

A

Solid-liquid extraction

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

Solvents for Solid-liquid extraction

A

Organic solvents, aqueous solutions, water, and ionic liquids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Techniques involved in Solid-liquid extraction

A

Infusion, Maceration

31
Q

Apparatus used in Solid-liquid extraction

A

Soxhlet apparatus

32
Q

High extraction yields are obtained by using _____ or _____

A

Water, methanol

33
Q

Poor extraction efficiency is achieved when ______ is used

A

Hexane

34
Q

Addition of ______, ______, and ______ improves yield

A

NaOH, Na2CO3, NaHSO3

35
Q

T or F: Longer contact time of solute and solvent increase yield

A

True

36
Q

Extraction time above 4.5 hours yields ________ amount of tannins because equilibrium was reached between tannin extraction in the plant matrix and the solvent (Fick’s law of diffusion)

A

Minimum

37
Q

T or F: An increase in temperature improves the solubility and diffusion coefficient

A

True

38
Q

Temperature _______ solvent viscosity promotes extraction

A

Decrease

39
Q

T or F: Too high temperature lead to higher amount of tannins

A

False, lower amount due to denaturation

40
Q

Qualitative Identification of Tannins

A

Phytochemical screening, Identification test, FTIR

41
Q

Quantitative Identification of Tannins

A

HPLC, Spectrophotometry

42
Q

To a solution of tannin (0.5mL), aqueous solution of 10% gelatin (0.5 mL) are added. 5% tannic acid solution as standard

A

Gelatin Test - (+) white buff colored precipitate confirming the presence of tannins and pseudotannins

43
Q

A small piece of goldbeater skin (membrane prepared from the intestine of an ox) is soaked in 20% hydrochloric acid, rinsed with distilled water and placed in a solution of tannin for 5 minutes. The skin piece is washed with distilled water and kept in a 1% solution of ferrous sulphate.

A

Goldbeater’s Skin Test - (+) brown or black color on the skin confirming the presence of tannins

44
Q

A 10ml of aqueous extract of a tannin and sodium acid phosphate is heated and cooled and filtered. A 2% solution of phenazone is added to the filtrate.

A

Phenazone Test - (+) bulky colored precipitate formation

45
Q

To about 0.5 ml of the sample fraction/ extract and the 5%tannic acid solution, add a few drops of 5% lead nitrate solution.

A

Lead Nitrate Test

46
Q

To about 0.5 ml of the sample fraction/ extract and the 5% tannic acid solution, add few drops of water to dilute the sample and add a drop of 5% FeCl3. Record observation.

A

Ferric Chloride Test - (+) Blue black = Hydrolysable Tannins, Brownish Green = Condensed Tannins

47
Q

To about 0.5 ml of the sample fraction/ extract and the 5% tannic acid solution, add a few drops of water to dilute the sample and add 1 or 2drops of Iodine solution.

A

Iodine Test

48
Q

To about 0.5 ml of the sample fraction/ extract and the 5% tannic acid solution, add a few drops of 10% KCN solution. Shake.

A

KCN Test

49
Q

A matchstick is dipped in aqueous plant extract, dried near burner and moistened with concentrated hydrochloric acid.

A

Matchsticks’ Test - (+) the matchstick wood turns pink or red due to formation of phloroglucinol

50
Q

What does FTIR mean

A

Fourier Transform Mid-Infrared

51
Q

Wave range of _________ in _________ seconds

A

4000-500 cm-1, 60

52
Q

Quantitative test for Total Tannin Content

A

Folin-Ciocalteu Method

53
Q

Quantitative Test for Total Flavonoid Content

A

Aluminum Chloride

54
Q

Quantitative Test for Phenolic Content

A

Folin-Ciocalteu Method

55
Q

SN of Nutgall (Nutgalls, Blue galls, Turkish galls)

A

Quercus infectoria (Fagaceae)

56
Q

Constituents of Nutgall

A

50-70% Gallotannic acid, 2-4% Gallic acid, Ellagic acid

57
Q

Uses of Nutgall

A

Medicinal: Local astringent in ointments and suppositories
Industrial: Tanning and Dyeing

58
Q

SN of Kino (Indian Kino Tree, Malbar Kino)

A

Pterocarpus marsupium (Fabaceae)

59
Q

Plant part used of Kino

A

Dried juice from stem bark

60
Q

Constituents of Kino

A

50-80% Kinotannic acid, Kino-red, K-pyrocatechin, Resin, Gallic acid

61
Q

Uses of Kino

A

Medicinal: Astringent for the tx of diarrhea and dysentery

62
Q

SN of Gambir (Gambier pale, pale catechu, catechu)

A

Uncaria gambier (Rubiaceae)

63
Q

Plant part used of Gambier

A

Leaves and young twigs

64
Q

Constituents of Gambier

A

7-30% Pseudotannin catechin, 22-55% Phlobatannin, Catachunnic acid, Kino-red, K-pyrocatechin, Resin, Gallic acid

65
Q

Uses of Gambier

A

Medicinal: Local astringent, General astringent for tx of diarrhea

66
Q

SN of Hamamelis (Witch Hazel)

A

Hamamelis virginiana (Hamamelidaceae)

67
Q

Plant part used in Hamamelis

A

Bark

68
Q

Constituents of Hamamelis

A

3-10% Tannins (Proanthocyanidins, gallotannins, gallates)

69
Q

Uses of Hamamelis

A

Skin care products, Astringent

70
Q

SN of Krameria (Para rhatany, Peruvian rhatany)

A

Krameria lappacea (Kramericeae)

71
Q

Plant part used in Krameria

A

Roots

72
Q

Constituents of Krameria

A

10-20% Condensed tannins

73
Q

Uses of Krameria

A

Astringent, antimicrobial and tonic herb, tx of diarrhea

PHA6117 lab (6 decks)

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