[4] GLYCOSIDES: FLAVONOID (FROM SHIKIMIC ACID PATHWAY)

Flavonoids are C___-C___-C___ compounds arising from the phenylpropanoid (prephenate) branch of the shikimate pathway

6-3-6

The C6 is derived from ______ pathway and is derived from 3 molecules of _______

polyketide; malonyl CoA

Most flavonoid glycosides have the ______ as nucleus

gamma-benzopyrone

Most flavonoid glycosides have the gamma-benzopyrone as nucleus, except _______

benzofuranone in aurones

Flavonoids are an important class of natural products that belong to a class of plant secondary metabolites having ______ structure

polyphenolic

Many flavonoids are easily recognized as ______ pigments in most plant families

flower

Flavonoids are abundantly found in foods and beverages of plant origin such as fruits, vegetables, tea, cocoa, and wine. Hence, they are called as __________

Dietary Flavonoids

Flavonoids have several subgroups which includes the following, EXCEPT

acids

What is the precursor of the C6-C3 unit of flavonoids together with the xanthones and some benzoquinones and naphthoquinones

p-Coumaric acid

Classifications of flavonoids: Alpha beta unsaturated ketones consisting of 2 aromatic rings known as ring a and b (linked by an allopathic 3 carbon chain

Chalcone

Classifications of flavonoids: precursor of many flavonoids classes

Chalcone

Classifications of flavonoids: what color does chalcone (“copper”) give to flowers

yellow

Classifications of flavonoids: a derivative of chalcone that gives a brighter yellow color to flowers than chalcones

Aurone

Classifications of flavonoids: has a middle pyranone ring structure

Flavanone

Classifications of flavonoids: are C2-C3 oxidized flavonoids

Flavone

Classifications of flavonoids: flavonoid polyphenols, hydroxylated at C3

Flavonol

Classifications of flavonoids: flavonoid polyphenols, where an example are Catechins

Flavan-3-ol

Classifications of flavonoids: flavan-3,4-diols and are colorless flavonoid compounds

Leucoanthocyanidin

Classifications of flavonoids: found naturally in soybeans and legumes

Isoflavone

Classifications of flavonoids: result of the further oxidation of pyranone ring structure at the middle

Anthocyanidin

Classifications of flavonoids: Highest percentage of bioflavonoids and naturally present as glycosides

Anthocyanidin

Classifications of flavonoids: Chromophore of anthocyanin which gives ________ colors in fruits, vegetables, and flowers

red, blue, and purple

Largest group of naturally occurring phenols (bioflavonoids) are from _____ fruits and _____

Citrus fruits and Soya

In Citrus fruits and Soya, _____ is refered to the yellow color flavonoids dissolve in alkali,

Flava

Flava of citruses and soya when dissolved in alkali yields a _____ solution and in acid yields a ______ solution

yellow; colorless

Anthocyanidins are ____

aglycones

proper term for the glycosides of Anthocyanidins

Anthocyanins

Anthocyanins are widely known as ________ because they are water-soluble pigments.

sap pigments

Anthocyanins, as sap pigments, their color changes based on the _____ of the cell sap

pH

Anthocyanidins precipitate in aqueous solution as _______ or picrates

Pb salts

What is added to sap pigments to hydrolyze or crystalize them

20% HC (organic solvents)

What is the source of anthocyanins (glycosides)

Bilberry

Scientific name and family of bilberry, a source of anthocyanins

Vaccinium myrtillus; Ericaceae

Significant Flavonoids: An Anti-H. pylori (Helicobacter pylori)

Hesperidin

Significant Flavonoids: major flavonoid that is present in lemon and sweet oranges

Hesperidin

Significant Flavonoids: A 7-glucoside metabolite of Hesperidin which has better bioavailability than Hesperidin

Hesperitin

Significant Flavonoids: a 7-rhamnoglucoside and it differs from Hesperidin by the presence of double bonds in the C-ring or middle ring

Diosmin

Significant Flavonoids: can be found in the skin of oranges and grape fruit. It is a 4,5,7-trihydroxy flavone 7- rhamnoglucoside and is 1000x sweeter than sucrose

Naringen

Significant Flavonoids: This flavonoid is the richest in soy

Isoflavonoids

Significant Flavonoids: Along with some coumestans and lignans, are called “phytoestrogens”

Isoflavonoids

Significant Flavonoids: Hesperidin includes the following, EXCEPT

phytoestrogens

Significant Flavonoids: Example of Isoflavonoids found in soybeans

Genistein and Daidzein

Significant Flavonoids: Commonly used standard for total flavonoid content

Quercetin

Significant Flavonoids: ______ is the flavonoid while ______ is the glycoside

quercetin; quercitrin

Significant Flavonoids: Pentahydroxy flavone that can be found in fruits, wine, and tea

Quercetin

Significant Flavonoids: Needed for Permeability factors

Vitamin P

Significant Flavonoids: Vitamin P is originally assumed to be “_____” in paprika/lemon peel

citrin

Significant Flavonoids: Vitamin P is a combination of ______ and _____

rutin and hesperidin

Significant Flavonoids: For treatment of capillary bleeding and increased capillary fragility

Vitamin P

Significant Flavonoids: For hypertension and radiation injuries

Vitamin P

Flavonoid glycosides qualitative tests: What reagent is used in Wilstatter “cyanidin” test

HCl

Flavonoid glycosides qualitative tests: What is used to test the presence of gamma benzopyrone nucleus

Wilstatter “cyanidin” test

Flavonoid glycosides qualitative tests: Most flavonoids will give positive results in this test

Wilstatter “cyanidin” test

Flavonoid glycosides qualitative tests: positive results of Wilstatter “cyanidin” test

orange to red to crimson and magenta occasionally green/blue

Flavonoid glycosides qualitative tests: What reagent is used in Bate-Smith & Metcalf test

HCl

Flavonoid glycosides qualitative tests: positive results of Bate-Smith & Metcalf test when there is a presence of chalcones and aurones

immediate red

Flavonoid glycosides qualitative tests: positive results of Bate-Smith & Metcalf test when there is a presence of leucoanthocyanins

Intense red color/violet

Flavonoid glycosides qualitative tests: What is used to test the presence of chalcones/aurones or leucoanthocyanins nucleus

Bate-Smith & Metcalf test

Flavonoid glycosides qualitative tests: What process is done in the Test for anthocyanins

extract with 1% HCl then boil

Flavonoid glycosides qualitative tests: positive results of the Test for anthocyanins

at boiling point, an orange red to blue red coloration

Synonym of Silybium marianum

Carduus marianus

Scientific Name of Milk thistle

Silybium marianum

Family of Milk thistle

Asteraceae (Compositae)

Constituent of Milk thistle

Silbinin (a mix of silybin A and silybin B)

Silbinin has a ______ effect, generally known as the brand name LiverAide®. It works by protecting by reducing the entry of toxic peptides and scavenging free radicals

hepatoprotective

A flavonol that consist of additional phenylpropane unit

silbinin

Scientific name of Soy isoflavones

Glycine soja

Family of Soy

Fabaceae (Leguminosae)

A phytoestrogen that can be found in foods and is known for its potential health benefits, particularly in hormone regulation

Soy isoflavones

After Soy is metabolized in the human gut it will become the following, EXCEPT

glycerin

Prevent the build up of fats and cholesterol in artery walls, hence preventing the onset of atherosclerosis

Soy isoflavones

Can increase memory and mental flexibility

Soy isoflavones

An alternative for menopausal symptoms (estrogenic activity)

Soy isoflavones

Scientific name of Tea cathechins

Camellia sinensis

Family of Tea cathechins

Theaceae

_______ of dry weight of tea cathechins are flavonoids

30-42%

Tea contains a number of Flavonols. It is particularly rich in catechins of which ______ is most abundant

EGCG

Controls lipid levels, prevents atherosclerosis and coronary disease

Tea cathechins

Epigallocatechin gallate (EGCG), the most abundant constituent of tea cathecins have potential ______ effects

anticancer

Scientific name of Cacao

Theobroma cacao

Family of Cacao

Malvaceae

Constituent of Cacao

catechins and procyanidins

Cacao contains ____ greater procyanidins than cranberry

10x

Source of cocoa powder and prevents atherosclerosis

Cacao

The following flavonoids are used to treat atherosclerosis, EXCEPT

Cranberry

Scientific name of Cranberry

Vaccinium oxycoccos

Family of Cranberry

Ericaceae

Constituents of cranberry

procyanidins and other flavonoids and polyphenols

Cranberry constituents help prevent adhesion of ______ such as E. coli and H. pylori in GIT and teeth

UTI-causing microbes

Potential use in periodontal diseases

Cranberry