Comprehensive Overview of Flavonoid Biosynthesis and Metabolic Pathways

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course on pharmacognosy and metabolic engineering uh this is lecture 53 where I will discuss flavonoid flavons

isoflavonoids and proanthocyanins in brief so and in the subsequent class I will bring the issue of several

interesting metabolic engineering applications including the anthos pathway so in this class first I'll make

an overview of different flavonoid root uh then flavon and isoflavonoids then proanthocyanins and aons these are the

things I'm going to cover now so biosynthetic pathway leading to the formation of flavonoids so

here uh I uh this is a brief overview of this so as the chalones so chalone is basically formed by joining

malan KO three molecules of Malon KO with one molecules of kumaro qu or the same joining can leads to the formation

of Steel vein which I have already covered in the previous class and steel veins accumulated into the into grapes

okay so these chel cones okay uh depends on the plant species where uh these chel cones

can uh lead to the formation of isoflavones and isoflavonoids or these chelon can lead

to the formation of antoin or this can take part

in the formation of flavonols so here where it where it

plays important role or in formation of uh say uh ISO flavons and isoflavonoids particularly what we find in case

of legumes so there are chalone synthes and chalone reductors will work together and eventually the pathway moves in this

Direction uh so uh so what is here that first chalone will be converted into ISO flavonones

so and then this is this step is called isomerization isomerization is there in both the cases and then flavone will be

converted into flavon and it is stored as such that is a dehydration or or flavonone can be

reduced to flavon for all which forms flavon foral and flavon for alls under go polymerization and

forms flen flen is a as a typical complex phenolic compounds which accumulates and forms the uh maroon

color and you'll find in the soram infloresence in in in muza flower the the

sped uh yeah so the there you will find this uh so the and so that is flen is a very unique compound uh and

but but important thing is that flavanone under go Hydrox

silation which makes dihydroflavonol and dihydroflavonol can take part in the

formation of flavonols or it will be subsequently

reduced and makes flavon 34 dioles which is called

Lico anthoine Lico antoin are colorless that may undergo reduction and form antoin which eventually forms

anthoine which are the colored components all these flavon 3on dioles will converted into flavon three OLS

which is which are the cin and epic cin components of green tea polyphenols and which eventually joins together and

form the condensed tanins so these are the different Roots which originate from the chalone so either it produce

flavonols or it produce flavons or it produce uh antoin or it produce isoflavonoids

depends on the different plants but uh but normally the flavons flavonols are present uh in in most of the plants but

the content may may very lower amount to get it detected so the first one is the chalone which we have studied and

chalone is formed by the chalone synthes so next one is the Flav so particularly there is an isomar I have shown the

isomerization isomerization here so this is basically the isomar enzyme which converts into

flavon so flavone makes flavon so flavonone makes flavon uh here it is flavon or flavon

can mix isoflavone or flavon can mix flavonol all this I have shown this is can make

flavonols or it can make antoin so flavonones are also very important molecules and uh

through different enzymatic root uh it makes different phenolic compounds now these are all basically derived from C6

C3 so this comes under the flavonoid uh so we can also tell that polyphenols because more than one uh Phile ring is

there so the reactions leading to different flavonoid group first is the chalone which is for

by joining melano KO and Kar KO and makes the product which is called Tetra hydroxy chalone so this under goes

isomerization uh which makes naringenin so the naringenin is this one or sometime it is called naren in

chalone this can convert it into arod dial uh so both arod dial and ningen comes from the

flavones and then subsequently by the Flav oid 3 hydroxy f3h is flavonoid 3 hydroxy which makes this

dihydroflavonol these are the dihydroflavonol which are either dihydro cerol or dihydro cotin or dihydro myin

so these are called dihydroflavonol so the enzyme is flavonoid three hydroxy so that basically as you see here at three

position o is added uh uh and uh then uh then uh what happens this can converted into dihydro questin by F3

Prime H so that means that another another H is added here or if3 prime 5 Prime H what is there one H added here

another H is added here so these structures maybe we'll see in one of in the subsequent class and then this

dihydroflavonols dihydroflavonols can be converted to the flavonols so what are the flavonols

quartin cherol and mtin these are the flavonols the enzyme is called flavonol synthes flavonol synthes so uh so this

is uh uh yeah this is the Flav yeah flavonol compounds and

yeah uh so what is the differences here that between dihydro and the cerol and the cerol is here is one

this double bond and then subsequently this converted into Lico Li anthoine which I have shown here this is uh Lico

anthos so which is by the reduction so reduction means that there the reducted enzyme and that is why it is called dfr

dihydroflavonol redu is so R stands for reduce s for reduce and then it makes Li antoin and then this will form the

anthos purposefully I not discussing the antoin in this class so here my purpose is to tell you the chalone

flavanone then dihydroflavonol then flavonol and lianin so Lu

anodin taking part in the formation of other products also that we will see so this is the LI

anthoine so as I said that plays one important role in the formation of anthocyanidins by anthoine synthes but

as I said this I will discuss in the next class but the point to mention here that this Liu anthoine by the action of

Lio antoin reduct is which makes flavonols which are epin or uh epin plus or minus epin so flavon

three OLS if you go here the flavon three alls so here this is the flavon three OLS which arein or EP or cin so

this is by the action of this reduce reduce and then this subsequently joins together and form Pro anthoine

which has big polymeric molecules and also it comes under the condens tannins okay so condens tannins are basically

formed by joining this flavon thols in multiple numbers and form the condens tannins whereas in the right side what

you see this is basically the green tea green tea green tea is basically a good source of polyphenol which is basically

dominated by epin EP G cin epig Galatin gallet Gallatin gallets so different so gallet

gallet is coming from the GIC acid GIC acid is coming from this simate root and kin is coming from this root and that

joins and it makes different complex polyphenols of green tea so but I'm not going to discuss that only I mention the

names like epic catin epig Galatin epig Galatin gallet Gallatin gallet they different compounds so once you make the

extract methanolic extract and run in hlc and if you have the standards you will able to identify this compounds

without any problem so the GIC acid as I said GIC acid and GIC acid can joins with the

glucose forms gluc galine this slide I have shown in the previous classes and that can also form the complex uh

hydrolyzable tannins anyway so formation of flavanones so

flaves okay now uh let's go back again here the flavanones is basically naringenin

and arod dicto so naringenin and arod dicts these are basically the flavanones so this

naringenin or arod dial can convert uh can catalyze uh can be used as a substrate uh uh for the enzyme called

flavon synthes and it makes either epine or leoline epinine and leoline these are

basically the flavons by the action of flavon synthes and it makes and you see the difference is is pretty similar only

the hydroxy at R1 position makes lolin and the this flavones can be converted into Flav

flavon foral by again a dihydroflavonol reduce if I go back to this one

uh here you see there is a reductors here flavanone by reductors it prints flavon for all

so and flavon foral which may be uh leral or epero but this finally makes the flen pigments as

I have mentioned here and uh this is basically the from flavonones this different either it produces the

flavons or flavon fals okay and now come to the aons so um flower color is dominated by mostly

antoin but also carotin but also by aons particularly in can species in monocot canes family so their aons are prevalent

not only that in some uh uh Snapdragon also the yellow color is also dominated by aons so aons are basically the

derivatives of chalons only as you see this is oron so oron could be either yellow or red in color so oron is

basically formed from tetr hydroxy chalone so tetr hydroxy chalone is the chalone so that by the action of

yes autocine synthes Aon is a group and the specific compound is called orine oroidin so a stander aidin

synthes aidin synthes so it's here and or the other root which operates in the

legum as I said that CHS and CHR will basically work together and makes ISO liquidity genine ISO liquidity

genine so which is also coming under chalone so tetrahydroxy chalone is a chalone which takes part in the

formation mostly for the flower color antoin where another type of chalone is called isol liquidity genine which is

formed in the legumes and that main role is formation of isoflavonoids so this once this isol liquidity genine is

formed that also by the action of oroidin synthes it makes orine so this is the called the aons and what we

see that how the other isop flavons are formed uh okay so this is again uh rision so chalone

synthes uh makes tetrah hydroxy chalone okay which is taking part in the formation of an ninenine and

subsequently to antoin whereas the another type of chalone is called isol liquid regen in which is again a chalone

that plays important role in the formation of uh isoflavonoids so here naringenin is a

flavone whereas another chalon this isomar is which makes two liquid genine which is basically a flavon

flavon okay so chalon then flavon right correct and then uh okay then let's go to the

next one so this is the reaction I have said in the previous class no point of discussing so now

the uh liquidity genine is formed and liquid regening by the subsequent entic steps

like ifs B methy transpares and several eventually it forms the uh compound uh for example if it is ifs that uh

isoflavone synthes then it makes diin or genistin so diin is basically it is an isoflavonoid so this

is a dietary phenolics or through other root it produces genistin this is also an

isoflavonoid and this pathway further moves and forms medicarpin medicarpin are also

isoflavonoids and uh so these are the complex molecules but it is basically uh restricted to the legums so legum in the

legumes these pathways are operating so these are isoflavones and isoflavonoids uh only what you need to

know that this isoflavonoid pathways are operating in legum so there the the flavanone is basically liquid in uh not

the naringenin so with this more or less I have uh covered the biosynthesis of uh

total flavonoid Group which consist of flavonone flavons flavonols isoflavonoids Flav and uh isoflavans and

Orin and oron pigments and also I mentioned about Pro anthoine which plays important role for the formation of

condensed tanins we also mention of flavon 34 diols which makes the formation of FL weapen I also mention

flavon three OLS which makes the form which actually are nothing but the epin epin gallet cins so which are the

components of green tea so this is in brief about the flavonoid group

and I will end the class here in the next class I will specifically talk about the anthos in biosynthetic

pathway with this I end the class here thank you