Flavounoids

Question 1

Who isolated “Vitamin P” from oranges

Answer 1

Albert Szent-Györgyi credited with this isolation.

Question 2

What is the basic structure of flavonoids

Answer 2

γ-benzopyrone

Question 3

Flavonoids are more common in____ plants

Answer 3

Higher

Question 4

Largest naturally occurring phenols

Answer 4

Flavonoids

Question 5

What is responsible for colors of flowers fruits and occasionally leaves?

Answer 5

Flavonoids

Question 6

What gives petals their color

Answer 6

Anthocyanidins

Cyanidine- Red Delphinidine-Blue

Question 7

Flavonoids can occur as free state and as glycosides

T or F

Answer 7

True

Question 8

• The
yellow
anthochlor pigments of anthocyanadines
are
produced
from?

Answer 8

chalcones and aurones.

Question 9

Glycosidic flavonoids are soluble in?

Genins are soluble in??

Answer 9

Polar solvents

Aglycone - non polar organic

Question 10

What makesflavonoids good antioxidants and what increases its antioxidant capacity

Answer 10

ability to chelate Fe2+ and Cu2+ and scavenge free radicals renders them very good antioxidants.
• The greater the number of hydroxyl groups the greater the antioxidant capacity of the flavonoid.

Question 11

What are the types of flavonoids based on

Answer 11

Degree of oxidation of C ring and hydroxylation of C-3

Question 12

What are the four o glycosides if flavonoids

Answer 12

Quercetin, Kaempferol, Myricetin, Rutin.

KuMyRuQuer
Kumerica

Question 13

colourless pigments in the leaves of plants
They are building blocks of anthocyanins
• Beverages such as tea and red wine are also important sources

Answer 13

Flavanols

Question 14

What polymethoxylated flavones are the peels of citrus fruits rich in

Answer 14

Tagretin Nobiletin sinensetin

TNOS
The nose

Question 15

What are the three examples of flavones

Answer 15

Luteolin Apigenin Chrysin

LAC

Question 16

Present in all the citrus fruits and responsible for bitter taste of citrus fruit peels

Answer 16

Flavanones

Question 17

What are the three flavanones

HEN

Answer 17

Hesperitin
Naringenin
Eriodictyol

HEN

Question 18

Predominantly found in legumes and soyabeans

Occur in mycobacterium phlei

Answer 18

ISO-flavonoids

Question 19

What are the three iso-flavonoids

Answer 19

GDP

Genistein
Daidzen(phytoestrogens)
Prunetin

Question 20

The 5 anthocynanides

Answer 20

Cyanidin
Delphinidin
Malvidin
Pelargonidin
Peonidin

Question 21

Characterized by the absence of the 2nd ring of the basic structure and referred to as open chain flavonoids.

Answer 21

Chalkones

Eg include Phloridzin, Arbutin, Phloretin, Chalconaringenin

Question 22

Also referred to as “condensed tannins”

Responsible for astringency in many foods and medicinal herbs

Answer 22

Proanthocynanide

Question 23

are basically flavanols.
There are two chiral centers on the molecule; Carbons 2
and 3. Therefore, it has four diastereoisomers.

Answer 23

Flavan-3-ol

Question 24

What color do flavonoids give for FeCl3 Alkalis and AlCl3 and what makes them give those colors

Answer 24

Blue colour with FeCl3
Yellow colour with Alkalis
Yellow colour with AlCl3

Flavonoids contain the benzopyran nucleus, and occur either as aglycones or as
glycosides.
• The aglycones are pale yellow and their glycosides are colourless.