PHENOLICS

Question 1

Plant bioactive secondary metabolites can be divided into three chemically basic group of compounds:

Answer 1

Phenolics
Alkaloids
Terpenoids

Question 2

4 important precursors from the primary metabolism

Answer 2

erythrose-4-phosphate
phosphoenolpyruvate
acetyl CoA
3-phospho-glycerate

Question 3

phenolic compounds can be synthesized to what pathways

Answer 3

shikimate pathway - more essential
malonic acid pathway - less essential

Question 4

Also known as the chorismate pathway, involves seven enzymatic steps to convert simple carbohydrate precursors derived from glycolysis and the pentose phosphate pathway to the aromatic acids.

Answer 4

shikimic acid pathway

Question 5

phosphoenolpyruvate + D-erythrose-4-phosphate = ___________ and the enzyme used is __________

Answer 5

3-deoxy-D-arabino-heptulosonate-7-phosphate; 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS)

Question 6

heptulose to _____________ and the enzyme used is ____________

Answer 6

3-dehydroquinate
3-dehydroquinate synthase (DHQS)

Question 7

3-dehydroquinate to _______________
and the enzyme used is ___________

Answer 7

3-dehydroshikimate
3-dehydroquinate dehydratase (DHQD)

Question 8

3-dehydroshikimate (3-dehydroquinate) to __________________ and the enzyme used is _________________

Answer 8

shikimate; shikimate dehydrogenase

Question 9

shikimate was first isolated in 1895 from the japanese star anise

Answer 9

shikimi flower

Question 10

what enzyme used to convert shikimate to shikimic acid?

Answer 10

shikimate kinase (SK)

Question 11

phosphorylation of shikimic acid to ________________ and the enzyme used is ______________

Answer 11

5-enolpyruvylshikimate-3-phosphate
5-enolpyruvylshikimate-3-phosphate synthase (EPSPS)

Question 12

5-enolpyruvylshikimate-3-phosphate to _____________________ and the enzyme used is _________________

Answer 12

chorismic acid; chorismate synthase (CS)

Question 13

chorismic acid to __________________
and the enzyme used ____________
the type of reaction______________

Answer 13

prephenic acid
chorismate mutase
claisen rearrangement

Question 14

Is the branch point to a group of benzoic acid derivatives and tryptophan.

Answer 14

Chorismic acid

Question 15

leads to the formation of phenylpropanoids, and some phenolics, the flavonoids, and the amino acids phenylalanine and tyrosine.

Answer 15

Prephenic acid

Question 16

decarboxylation of prephenate to _________________ and then undergo transamination (pyridoxamine transaminase) to yield __________________

Answer 16

phenylpyruvate;
phenylalanine

Question 17

oxidative decarboxylation of prephenate to ____________________ then by pyridoxamine transaminase yields ______________

Answer 17

4-hydroxyphenylpyruvate;
tyrosine

Question 18

is the precursor of a variety of important secondary metabolites, including flavonoids, coumarins, and lignans.
This pathway is found in microorganisms and plants, but not in animals.
an essential amino acid
is the end product of the shikimic acid pathway

Answer 18

phenylalanine

Question 19

The shikimate metabolites can be grouped according to the number of carbons atoms in the side chain
C6: _____________ and __________
C6-C1: _____________, including ____________
C6-C2: _____________
C6-C3: _____________
C6-C3-C6: ___________

Answer 19

C6: phenols and quinones
C6-C1: benzoic acid derivatives, including tannins
C6-C2: phenyl ethyl compounds
C6-C3: cinnamic acids
C6-C3-C6: flavonoids

Question 20

sometimes called phenolics, are a class of organic compounds consisting of one or more hydroxyl groups (−OH) bonded directly to an aromatic hydrocarbon group.

Answer 20

Phenols

Question 21

are oxidized derivatives of aromatic compounds (often from phenols) resulting in a fully conjugated cyclic dione structure.

Answer 21

Quinones

Question 22

major classes of phenolic compounds

Answer 22

polyphenols (flavonoids tannins)
simple phenols (phenolic acid)
other phenols (lignins, coumarins, etc.)

Question 23

functions of phenols

Answer 23

Antioxidant agents
Electron transporters
Pigment molecules
Signaling agents
Defense mechanism

Question 24

_____________is a compound that have a benzene ring with a carboxylic acid functional group (-COOH) attached to it. Its common derivatives include p-hydroxybenzoic acid, salicylic acid, gallic acid, and ellagic acid.
C6-C1 metabolites

Answer 24

Benzoic acid

Question 25

Two important benzoic acid derivatives are the ________and________ – reported to induce anti-inflammatory, gastroprotective, and anticarcinogenic activities

Answer 25

gallic acid and ellagic acid

Question 26

lactonization of hexahydroxydyphenic acid

Answer 26

ellagic acid

Question 27

colorimetric assays that measure the antioxidant properties of compounds

Answer 27

• 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) Radical Scavenging Assay
• 3-Ethylbenzothiazoline-6-Sulphonic Acid (ABTS) Assay ……….EBTSA
• Oxygen Radical Absorbance Capacity (ORAC) Assay
• Ferric Reducing Antioxidant Power (FRAP) Assay

Question 28

(commonly referred to as tannic acid) are typically large molecules composed of repeating units of phenolic compounds, such as gallic acid, catechin, and ellagic acid, which are linked together through ester or ether bonds.

Answer 28

Tannins

Question 29

Two main categories of tannins:

Answer 29

✓hydrolysable tannins (gallotannin and ellagitannin)
✓condensed tannins (proanthocyanidins)
(flavan-3-ol monomer, polymer formation)

Question 30

contains a benzene and an unsaturated carboxylic acid group forming 3-phenyl-2-propenoic acid. Its common derivatives include p-coumaric acid, caffeic acid, and ferulic acid, sinapic acid, chlorogenic acid

Answer 30

Cinnamic acid

Question 31

___________is a naturally-occurring anti-histamine compound from tsaang gubat plant.

Answer 31

Rosmarinic acid

Question 32

• The largest class of secondary
  metabolites having polyphenolic
  structure.
• Play a key role to provide
  pigments in plant as dark blue and
  red color of berries, yellow and
  orange color of citrus fruits.
• Composed of 15 carbon atoms,
  which are arranged in C6-C3-C6
  backbone skeleton rings, in which
  ring A and ring B are linked by
  three carbon ring C.

Answer 32

Polyphenol: Flavonoids

Question 33

types of flavanoids

Answer 33

flavonols (addition of OH)
flavanols (dissapearance of =O)
flavones (original)
isoflavones (mirror image of flavones)
flavanones (absence of unsaturation)
anthocyanidins (absence of =O, appearance of OH, anthocyanins)

Question 34

____________is a cyanogenic glycosides found in cassava

Answer 34

linamarin

Question 34

__________is composed of the sugar part, known as the glycone, and the non-sugar part called the aglycone (with a cyanide
group).

Answer 34

Cyanogenic glycoside

Question 35

linamarin upon the action of linamarase

Answer 35

glucose + acetone cyanohydrin ——— acetone, hydrogen cyanide

Question 36

—has far-reaching impacts on agriculture, industry and the environment, making its metabolism a globally important part of plant biochemistry
—second most abundant polymer on
earth, next to cellulose (made of glucose units)
—made of phenolics

Answer 36

lignins

Question 37

__________are the sugar- derivatives of the anthocyanidins (the aglycone). They are water-soluble pigments in flowers, leaves and fruits. They also impart many of the colors of fruit juices and wines.

Answer 37

Anthocyanins

Question 38

Leaf color is due to several
compounds:
____________ which is green, gives leaves its predominant color. It is responsible for photosynthesis.
__________ are responsible for the yellow, orange and gold hues.
________give rise to the reds, purple and magenta hues. They actively formed in the leaves during autumn.

Answer 38

Chlorophyll
Carotenoids
Anthocyanins