Understanding the Diversity and Biosynthesis of Monoterpenoids in Plants

[Music] [Music] welcome to nptl online certification

course on pharmacognosy and metabolic engineering this is lecture 37 where I will speak about the diversity of

monoids let's go to the board okay so what I'm going to cover here the different types of

isoprenoids and diversity of monoterpenoids and if type permits I will talk about the product

diversification originated from monot tarpine synthesis otherwise I will cover this topic in the next class

so let's now go to the board so what we have seen in the previous class about the

different isoprenoid structures for

example C5 C5 the precursor of C5 compound originates from dma

PP and basically this belongs to hemar pins

okay hemens now uh examples are isoprenes so in the previous class I

have drawn the structure of isopren uh so like C

ch3 CH ch2

ch2 C5 compound now isopr itself they are emitted by the plant and when plants are under stress

when there is heat stress they emited and that actually gives protection to the plant particularly to the

membranes from oxidative damage now isoprene emission sometimes huge and depends on the particular geographical

locations they can form uh isoprene clouds sometimes which is called blue haze so it is also

observed in certain parts of the world the isopr emissions form form the cloud with blue that's called Blue ha so such

such that it emission is very important uh for the protect for protecting the plants against different abiotic stress

anyway that is not our discussion here so next is Cen which originates from gpp and these are

called monotor pins and next is C15 which originated from

a which are called squins okay uh excuse me with the

pin SCS q u i okay next is C30 we can put first that comes from that's basically the originate from

squallin examples are trar pins then C20

originates from ggpp examples of our D pins and then C40 originates

from phin is a tri

Tarpin even tetr Tarpin also well so what I'm going to do in the next slide is this

how these are formed that means how

this uh IPP and dmap joins and makes gpp so that is my point of discussion today okay uh what I have just mentioned about

the isoprene so uh if we go if I go back to the previous slide okay I can also talk

about here also so like dmap so double bond here so this is D

methy alile pyo phosphate or dimethy Aly D phosphate

okay so this by the action of isoprene

synthes isoprene synthes which removes PP

plus H+ that lead to the formation of isop so which

is [Music] volatile hemit typin which I have

mentioned just before so together with other monot Tarpin isopor emission is responsible

for this blue haze as I said which is observed in distinct geographical regions of the forest during the hot

weather now isopen pyrophosphate and uh dimethy alile

pyrophosphate spit okay so let's go to the board this

is ISO penile Pyro firstate so

this right the action of isomer can converted

into op so this is so I'm not not writing the full word

because of the time constant so this can also convered so this in the next

step joins with another molecule of IPP

so even PP out and

forms uh the enzyme is janile transfer is the sorry pile transfer is p r e n y l t r a

NS f e r a s e pile transference and it makes

uh so this is the structure of

gpp so the jile

Pyro phosphate which is C10 so in the next

reaction by the action of another molecule of

this okay and it makes file P phosphate so the file

means for wow no no I have to make this some

changes here okay okay this is

um so this is the structure of

parile pyro phosphate and

this subsequent L converted into ggpp

Again by joining another molecule of and which

means for this is

called Jano Jano g e r a n y l g e r a n y l janile janile

pyro phate or G p g PP which is

again c22 compounds and this is C15 this is called fpp this is

gpp right and here all these enzymes are pral transfer so here also

p transfer is here also pral transfer is p d n y

l s r and this eventually makes so higher molecular penile phosphates are formed

by head to tail addition so what is basically uh we we I put it here is this that higher

molecular prile phosphates are

formed by head to to

till addition of

active ISO Rin units so this is all about the

formation of gpp fpp and ggpp from the basic isop skeleton and the enzyme activities involved in that so

now I will give you an outline of a diversity of monotor NS so monot

toroids diversity of

mono tarps so monot Tarpin noids originate from the

gpp monot Tarpin noids are found inside

the plasted so this is the site of

monotaro synthesis and accumulation in

general sometimes these monotor noids may move into the vacle and stay there but normally this is generally the site

so when this is the site of synthesis that means the reaction that what is the precursor of

monoterpenoids is gpp and

gpp by the action of enzyme which is called Mono

tarpine synthes is a general generic name so specific names will come and it forms

different monot turpins I use the term monotaro because this

monotaro monot Tarpin having functional group attached to it so these are mostly oxygenated so that is why we will use

the term monotaro so monot Tarpin noids I I write it clearly m o n o t e r p e n o IDs so

monot toroids accumulate inside the plastid that is a thumb Rule and GP is the

precursor so uh we'll talk about the enzyme catalytic mechanisms later so before

that let me show you some of the diverse structures of monotor now monot these monoids can be

classified into different types so maybe as cylic or the cyclic so as cyclic monoids if I start giving example as I

click a c y c l i see as I click mono

terpenoids or in general you can okay a few structures may not contain oxygenated

group so that we cannot in true sense call monot Tarpin no so you can call monot tarpine but uh anyway so usually

we are calling all under as asyc monoids ayclick name itself indicates that uh there is no

cyclisation that means say if I draw this structure problem the

PIN so this is the structure of

mine this is the structure of neural

now this is the structure of geranial

okay now this one will not be there this is the okay this a structure of cyon

Nal and much

and this is the structure of LOL now

so here actually there will be ch3 there will be ch3 there will be

ch3 otherwise we if you wish you do not also put it so these are the examples of ayclick monot

typin okay so mine neural geranial cyron neurol LOL all contributing to the flavor and fragrance from different

plants including te uh including different flowers Rose Center geranium Rose itself uh so many

plants okay specific examples will come when I will uh go to when I will talk about specific cases now I'll give

example of cyclohexanoid monotes or cyclic monot for

Simplicity click mono

tapids this is basically the example of lemon lemon you will find it in the lemon okay so the lemon you have a thick

peel and they are like separ oil glands so if you squeeze it that whatever watery droplets come out so that is

basically the that contains lonin along with other metabolites other turpens

so lonin is a signature molecule of this root now another example let us say carbon so this is carbon

another one say minol

now this is 1 2 3 4 5 6 so in case of carbon this is at six position uh C6 position get

oxygenated whereas in case of Menthol it is three position so

the the precursor molecule lonin under goes different entic

reaction depends on the different plant so Menthol you find it the papermint p

pment p perment carbon you find it in udina that is uh spearm

Min pment experim okay lonin you find in the lemon

similarly there are other compounds for example uh

polygon poon is basically a precursor of the menthol

okay and then Menon from menol actually menthon Menthol is formed

sorry the other examples are Carval or isop okay I I I will put another important example which is

cineol this is called

18 cineol or eucalyptol similarly another compound is called

pendrin and I can also put example of C for and

pining which you find in the pine there two type of pining one is called Alpha pining one is called beta

pining this is Alpha fining and

here three here ch2

Vining another example is carvol or

wheel uh right so this is more or

less Cara okay two more things uh I will I will draw and finish this class one is

the thol tal and another is

carvacrol so you see that the product diversity of different cyclic monotor noids so they

all originate from gpp and through different uh through changes in the

reaction mechanism leading to formation of different uh monotor noids and as I said that uh monot Tarpin is a very

versatile enzyme sorry monot tarpine synthes and there are specific monot synthes which actually gives one product

formation whereas there are other monotoring syes we can which can be as many as eight

monoids catalyzed by a single reaction from gpp monot Tarpin synthes gives rise to eight different

monoterpenoids so in the next class we'll talk about that and we'll talk little bit of this type of skeletons and

then we'll go to the uh catalytic mechanism for the formation of this monot topers from the gpp which is

itself a bit complicated but I try to put it in a simplified way so that you can understand and uh the point is this

that uh what is this okay I have given you the example of this like thol you get it

in thy okay carvacrol you will find it in Lamas species Carval also pinin you find it in the conifers Cal eucalyptol

you find it in several plants including nikiana species as well as uh tube Rose so many camper you find in the camp for

plant itself like so many things Pon and menthon you find in the piper mint so the diversity is enormous and

accordingly the entic reaction is also very uh unique or or rather more diverse towards the formation of different

products so with this I end the class before I end the class let me see what I intend to cover so different type of

isoprenoids I cover diversity of monot I have covered but product diversification originated from monotor synthesis that I

will cover in the next class so with this I end the class here thank you