00:01
So today we are looking at this keto pentose and this aldopentos and watching with a mechanism or creating the mechanism of how these two pentoses react to form this keto heptose and this glyceride glyceroldehyde or aldo trials type functionality.
00:24
Okay, so these, as we can see here, what is basically happening is we're getting a lot of transfer of this aso group here.
00:35
So we're basically taking this unit over here and i'm going to color in green and we're placing it on top of our aldo pento's.
00:51
Okay, so as we can see here, what really gave that mechanism away was the fact that here that it ends that it is a ketose or yeah, this right here it is a ketone.
01:03
So when we say kitos, i mean like there's a ketone here, versus an aldous where it ends up, where we have an aldehyde present in the sugar.
01:13
Yeah, it's just some sugar chemistry.
01:15
So basically, as we can see that there is an ketose present in the functionality, and then an alde, an aldehyde or aldose, person in this functionality, we can make the suggestion that this asa group is transferred on top of this one, even behind like a hydroxyl type group that can then condense or then can be like reduced into or should say oxidized into a carbonyl type functionality while this one right here this we can add a hydrogen to this to allow it to form a um an alcohol we can reduce it and then add this type functionality so that it could be an aldose or a ketos, sorry.
02:08
So if it were to be the other way around, it would then have been a switch in which length of the chain was being aldeus versus a ketos.
02:19
Okay, so what they basically tell us is that this mechanism goes through something called ttp, or tpp, sorry, which is just thymine pyrophosphate.
02:31
So, yes, so if you look through the textbook, you'll see how that structure looks like.
02:38
But the main, most important like functionality of this thiamineine pyroposate is the thiosolium ring, which i'll just draw right here.
02:54
Okay.
02:58
So it's just this five -membered ring here.
03:02
Oh, wait, there's a nitrogen present.
03:05
So, okay, a five -membered ring.
03:10
With where we actually have a carbambered ring.
03:12
An ion present there double bond here and then here's the rest of the structure over there probably like the pyrophosphate groups and then there's a double bond at this end with actually a sulfur group present here the r prime on this end and and then i'm not going back and so anyways this is our tp and this is the yield which is the main um like active and catalytic or the main reactive portion the main reactive portion of our corn enzyme okay so what is basically the main mechanism of action is yes this by a zolium ring from rtpp is the one that's going to react first with our kidos okay so if i just draw the kitos over here yep since we're showing that this carbonyl or this isyl group is going to be attached to to our al -os, we can then say that the tpp will attach here to remove it.
04:27
It will basically remove this ttp, or t .p, it'll basically remove this asa group and then place it right on top back onto this aldo's here.
04:38
So let's just show that mechanism here.
04:42
Okay, so we just quickly draw out the rest of the sugar.
04:57
Okay, so since we know that this portion, the aesl portion of the group is what's going to be removed, we can then, and we see the carbon ions here, which is a pretty good nuclear file, we can know that, okay, it will attack the electrophilic site here of the carbonyl.
05:18
And then assuming that there's some acid present in solution, which generally there is some form of an available proton.
05:28
That will pick up, that will allow our oxygen here, this carbonate oxygen to pick up a proton and become an alcohol and be subsequently oxidized, or oxidized reduced.
05:47
So if i just redraw this arrow, yes, we can say that this oxygen will, the electrons and the double one will move up to the oxygen, and then we'll also then grab a hold of this proton over there, this v add into those electrons.
06:12
So then what we basically then get is attachment of our yield to this carbonyl flight where what was once a carbonyl is not an alcohol and has not been reduced or just basically picked up a proton.
06:28
So then what we get here is we have drop the yield sideways and draw in our function.
06:44
Functional groups, okay? so we have the first over there and okay, here is where we got the attachment and there's the now alcohol.
06:57
And there's a portion over there, and then okay, rch2.
07:06
There's also a phosphate on the end there.
07:11
Okay, so then you also have this thing on top.
07:17
Okay, so our yield has attached to the hidden carbonyl acyl group right there.
07:25
So then we'll be again after.
07:30
Is that an ion comes back that was like once acting as an acid, which is quite a very weak acid because yields are usually passed under basic conditions.
07:40
So now it's able to act as a good base that it probably is to pick up this proton over here, this adjacent proton, to turn, allow it to be oxidized back into our carbonyl.
07:56
Okay, and then we get the departure of this hidden acal.
08:06
Okay, so i think i can just drop.
08:10
Over here, what we're left off with then is our glyceroldehyde.
08:15
So that's carbonyl.
08:22
Then we had an oh on that side over there and then last carbon.
08:31
Okay.
08:32
All right, so then yes.
08:37
Basically, as this carbonyl compound was forming here, we got departure of the aiso leaving group as it's still being attached to the yield to form this all those over here.
08:51
And all those are just sugars with that end of office like aldehydes.
08:57
Okay.
08:59
And this is our glyceroldehyde 3 -phosphate for g3p.
09:04
What you might remember is probably part of that the glycos is happening.
09:09
Okay.
09:10
So now that we formed our first three member or three carbon sugar, we still have our yield attached to the aiso, the hidden acal.
09:21
So then what we basically get, once we formed this, the departure of this bond, or the departure of this glycerol de height, we also get, actually, doesn't leave just like that.
09:45
We get actually these electrons leaving towards this side to form a double bond there.
09:51
And you know this will then move those electrons over there because just a reasonable opt -tut and then that then forms yes the azo group still leaves while being doubly bonded to the yield okay so then just to draw what that structure looks like okay so there okay and then the other r group and then there's where the double bond has resonated too okay, so now, as you can see, this is now in the very, very characteristic part of the tpp mechanism, formation of the tpp enamine.
10:49
So if you ever see an anamine, like when your aiso group is like double bonded to the yield, and there's nitrogen over here, and then adjacent carbon is like, you know that you're on the right path because you can form the enamine.
11:08
Okay, so once we formed this ename, we know that we can now add this aitho group to the aldos, the other part.
11:24
The other aldo pentos.
11:27
Okay, so if i just draw it, let's say over here, because we know there is some nucleophile felicity there for it to attack this, ace group as well.
11:43
It's a bit long, but we don't really need this...