Flavanoids

Question 1

What makes flavonoids ?

Answer 1

Most from higher plants

Question 2

What are the 4 physical properties of flavonoids

Answer 2

1. Water soluble
2. Lipophilic
3. Absorbs uv and visible light
4. Food & Colour

Question 3

How is methacin water solubility improved?

Answer 3

Through glycasatyion

Question 4

Where can flavonoids be found?

Answer 4

In fruits, vegetables and beverage

Question 5

What pathway does flavonoids come from?

Answer 5

The acetate melonate pathway and phenylalanine

Question 6

What are 4 type of clincal properties do they have ?

Answer 6

1.anti-inflammatory
2. Anti-oxidative
3. Anti mutagenic
4. Anti-carcinogenic

Question 7

Why do leaves change colour?

Answer 7

Chlorophyll breakdown & withdrawal chlorophyll reflection and absorption of blue & red will show when it is withdrawn

Question 8

Why is yellow and red the most colours we see in the fall

Answer 8

Due to anthrocyrins(red) and carotenoids (yellow)

Question 9

What 4 enzymes can flavonoids inhibit?

Answer 9

Xanthine oxidase
Cycloxygenase
Lipoxygenase
Phosphoinositise 3 kinase

Question 10

What are the 4 subgroup of flavonoids ?

Answer 10

1. Chalcones
2. Flavones
3. Flavonols
4. Isoflavones unique

Question 11

what can majority of flavanoids be found as ?

Answer 11

it is mostly in flower pigments but found in all parts of the flowers

Question 12

what 5 things are flavanoids responsible for in plants ?

Answer 12

1. colour and aroma flowers
2. attract pollinators
3. promote fruit dispersion
4. seed & spore germination
5. growth and development

Question 13

what are the 4 functions of flavanoids

Answer 13

1. Signal Molecules
2. Allopathic compounds
3. phytoalexins
4. detoxifying agents & anti microbial defense compounds

Question 14

how many flavonoids share the same skeleton ?

Answer 14

> 3000

Question 15

what is the role anthocyanins ?

Answer 15

it provides cyanic colour from scarlet, red, mauve to blue

Question 16

what is the role of aurones, chalcones, yellow flavonoids?

Answer 16

it is visible yellow colour and UV patterning in yellow flowers

Question 17

what is the role colourless flavones &flavonols ?

Answer 17

copigments to anthocyaninins and has some uv patterning in some yellow flowers

Question 18

what is the role of flavanones, dihydroflavonols, leucoanthocyanidins, catechins, flavans, isoflavonoids?

Answer 18

most are colourless but can interact with other flavonoids or can be uv screen or anti microbial

Question 19

what 4 type of flavonoids are glycosylated and what does it do ?

Answer 19

anthocyanins, flavones, flavonols, flavonones
it give the compound water solubility

Question 20

what makes a flavonoids lipophilic ?

Answer 20

being o-methylated , o acetylated

Question 21

what does chelate metals affect ?

Answer 21

they affect the colour that is being expressed

Question 22

what are 5 types of modification in flavonoids

Answer 22

1. glycosylated
2. methylated
3. acylated
4. chelate metals
5. dimerization(olgiomerization)

Question 23

when the B rings linked in position 3 of the C ring what is the type of flavonoids?

Answer 23

isoflavones

Question 24

when the B rings is linked in position 4 what type of flavonoids is it ?

Answer 24

neoflavonoids

Question 25

when the B ring is linked in position 2 what type of flavonoids is it ?

Answer 25

several groups like all the flavos catechins, anthocyanins chalcones

Question 26

what is a key fact about flavones?

Answer 26

have citrus fruit peels that have high concentrations of poly-methoxylated flavones that make it lipid soluble

Question 27

what are 3 key facts about flavanones?

Answer 27

1. present in oranges, lemons & grapes 2. has free radical activities 3. bitter taste in juice

Question 28

what are 3 examples of flavonones?

Answer 28

hesperetin, naringenin & eriodictyol

Question 29

which group is shown to have oestrogenic activity ?

Answer 29

isoflavonoids

Question 30

what are 3 key facts of isoflavonoids ?

Answer 30

1. found in soybeans and other legumes 2. precursor for the synthesis of phytoalexins 3. found in microbes

Question 31

what is the difference structurally between flavonoids and neoflavonoids?

Answer 31

neoflavonoids have no hydroxyl group

Question 32

what is a key fact about flavanols catechins ?

Answer 32

there are no double bonds between positions 2 & 3

Question 33

what 3 factors does the colour of anthocyanins depend on ?

Answer 33

1. pH 2. methylation 3. acylation

Question 34

what are 3 key facts about anthocyanins ?

Answer 34

1. responsible for colour 2. in outer cell layers of fruits 3. used alot in food industry

Question 35

what is a difference about chalcones ?

Answer 35

it is missing its c ring so its not cyclized and is an open chain

Question 36

how many classes and skeletons of flavonoids is there ?

Answer 36

there is 12 classes and 24 skeletons

Question 37

what is the general 4 step biosynthesis pathway of making flavanoids?

Answer 37

1. phenylpropanoid pathway (phenylalanine to 4 coumaroyl-COA) 2. 4- coumaroyl-coa + 3 malonyl-CoA to chalcone (committal step) 3. oxidation and reduction of the central pyran ring to 24 flavonoids 4. Modification of flavonoids

Question 38

what are 2 AA that we can use to make CoA?

Answer 38

phenyl and tyrosine , they also make lignin

Question 39

what is different about aurones ring ?

Answer 39

it has a central ring of 5 instead of 6

Question 40

what does oxidation and reduction of the pyran do?

Answer 40

it provides different subclasses

Question 41

where does the biosynthesis of flavonoids occur ?

Answer 41

in the cytoplasm

Question 42

where is the glycosyl group of flavonoids attached ?

Answer 42

in the vacoule

Question 43

what does the cyanic colour provide ?

Answer 43

it provides stability of colour and basis of colour variety

Question 44

why and what happens to anthocyanins if positive charge is attacked ?

Answer 44

when the positive charged is attacked by OH- due to pH change in vacuole the colour will be lost

Question 45

what are the 4 types of aggregates and what is it affects

Answer 45

1. intramolecular copigmentation 2. metal complexity 3. ipomoea 4. commelina changes in each arrangement will have a different colour

Question 46

what is self association and equation

Answer 46

as more pigment is added more absorption , A (absorbtion) = ecl , l is path length e is extinction co , c is concentration

Question 47

what is intramolecular co pigmentation and why is an acyl group addded in the aromatic ring

Answer 47

they are stable pigments with deep blue colour that can shift wavelength max and acyl is added to protect postitive charge on anthycyrin

Question 48

within self association if aggregation is occuring what will happen

Answer 48

concentration will not increase to the number of molecules,absorb as a single molecule

Question 49

what must be done for aggregates to form?

Answer 49

4 hydroxy must be free

Question 50

what is mg, anthocyrin and flavones seen as ?

Answer 50

a red dot, mg anto, blue flavones - yellow

Question 51

what forms yellow flower colouring

Answer 51

combination of anthocyanins and carotenoids

Question 52

what wavelength does anthocyrins abssorb ?

Answer 52

400- 500nm

Question 53

what wavelength does carotenoids absorb ?

Answer 53

450-550 nm

Question 54

what is the absorption together of antho and caro?

Answer 54

400-550nm

Question 55

what is the absorption of UVA and UVB and PAR.

Answer 55

320nm -400nm , UVA 290nm to 320 nm, UVB. 400nm-700nm PAR, visible light

Question 56

where does UVB reach in a leaf ?

Answer 56

upper epidermis

Question 57

where does visible PAR reach in a leaf

Answer 57

between the upper epidermis and mesophyll

Question 58

when does UVA reach in a leaf ?

Answer 58

the mesophyll

Question 59

what is the absorption of kaempferol ?

Answer 59

448- 610 nm