Pharmacology - oxycodone chemical diagrams

[spacejack26]

SWIM curious...Why, in some oxycodone diagrams, does it show CH3 into N, then pointing to another spot in the diagram, but with no additional lettering (no changes, etc.), while another diagram will show CH3 into N, then changing to CH2 and then going to that other site on the diagram. Is this the same exact chemical makeup? SWIM wonders because the first description tends to show for percocet and percodan and the second for roxicodone...plus oxycontin shows something different, still...SWIM thinks these diagrams were on rxlist.com.

And if there are differences, would they be different on gc/ms test?...SWIM tends to think these diagrams are really the same, but would really like confirmation...Please help!

[Oneiros]

I suspect that they are the same diagrams. If you could link me to the molecules in question, I could tell you exactly what's going on.

[spacejack26]

oneiros....

roxicodone link is http://www.rxlist.com/cgi/generic/oxyco1530.htm , perc link is http://www.rxlist.com/cgi/generic/oxyapap.htm , oxycontin is , http://www.rxlist.com/cgi/generic/oxycontin.htm

If you could explain if there are any differences, I'd appreciate it...I suspect they're the same also, but I'm no chemist, so....what do all the letters and numbers mean (god I felt like a moron writing that last sentence)

Thanks,

spacejack26

[Oneiros]

Yeah, they're the same. Organic chemists usually represent carbons (the C's) with a vertex or an endpoint. Its understood that there are enough hydrogens (the H's) surrounding it to satisfy its electron requirements. The lines in between the the vertices represent the chemical bonds between the elements.

Carbons can form bonds with four other elements. A -CH3 (carbon bonded 3 hydrogens) is called a methyl group. The methyl group bonds to one more element (four possible bonds, 3 of which are tied up with hydrogens). In Oxycodone, one methyl group is attached to the nitrogen (the N) at the top of the molecule and one to the oxygen (the O) at the bottom.

Who ever did the diagram for roxicodone decided to write CH2 (carbon with two hydrogens) instead of using lines and vertices. They both represent the same thing: a carbon that's in between two other elements in a chain, with the rest of its possible bonds going to hydrogens.

Get it? Let me know if you need some more clarification.

[spacejack26]

I think I get it ,oneiros, thanks...just for my own clarification, though, there is no difference between CH3 and CH2...I mean, they're the same "substance"...they would show the same on a drug test (gc/ms), right? I thought maybe because the release of oxycontin and roxicodone and percs are different the chemistry changes slightly, but you're telling me this is not the case...you said whoever drew the roxi diagram "decided" to put CH2 at the second binding site in the drawing...could that be CH3 as well or is CH2 correct?, because in the oxycontin diagram, I noticed the -C1 after the CH3 at the first binding site...does that mean a hydrogen molecule stays behind? a carbon molecule? (because it's -C1 not -H1)...

Maybe you could clear that up? You've helped a lot already, thanks

spacejack26 added 6 Minutes and 0 Seconds later...

(continued from previous post reply)...Oh, yeah, oneiros...the CH2 is a methyl group as well as the CH3? or just the CH3? (sorry if these are stupid questions).

spacejack26 added 265 Minutes and 1 Seconds later...

ok, oneiros, I think a little more just sank in (correct me if I am wrong, please)...at the first site, carbon is bonded with nitrogen and 3 hydrogen atoms (all available atoms, that is those that aren't bonded to other elements, bond to hydrogen?),,,at the second site, the carbon is bonded to nitrogen as well as oxygen, so there are only 2 atoms available to bond to hydrogen, hence the CH3 at the first site but CH2 at the second??? Or is nitrogen not even present at the second site??? If not what is the other element at the second site that prevents the CH2 from being a CH3?? Or am I totally lost?

[Oneiros]

I think I get it ,oneiros, thanks...just for my own clarification, though, there is no difference between CH3 and CH2...I mean, they're the same "substance"...they would show the same on a drug test (gc/ms), right? I thought maybe because the release of oxycontin and roxicodone and percs are different the chemistry changes slightly, but you're telling me this is not the case...you said whoever drew the roxi diagram "decided" to put CH2 at the second binding site in the drawing...could that be CH3 as well or is CH2 correct?, because in the oxycontin diagram, I noticed the -C1 after the CH3 at the first binding site...does that mean a hydrogen molecule stays behind? a carbon molecule? (because it's -C1 not -H1)...

CH2 means CH2 and CH3 means CH3. They are different. The difference is the number of hydrogens that are connected to the carbon. Depending on how many lines are connected to a vertex (a carbon), you know how many hydrogens are around it. Remember: the carbon wants to have four bonds. So if there's two lines connecting at a point, you know that there are two more hydrogens that aren't drawn on the diagram connected to that carbon (represented by the point). Look again at those CH2's. See the two lines connecting the first one to the nitrogen, the second one to the other CH2, the third to the bottom right point on the center ring? Those lines represent the bonds between the C's.

That's actually a Cl- (chloride ion) not a C1. In the oxycontin diagram, the N+ and Cl- show you where the HCl in Oxycodone HCl bonds to the molecule.

The difference between ER and IR is about the pill, not the drug.

Oh, yeah, oneiros...the CH2 is a methyl group as well as the CH3? or just the CH3? (sorry if these are stupid questions).

Methyl = CH3. CH2 is sometimes called a methylene group. Don't worry about functional groups yet, though. I would start learning the names of those after you've mastered the molecular diagram.

ok, oneiros, I think a little more just sank in (correct me if I am wrong, please)...at the first site, carbon is bonded with nitrogen and 3 hydrogen atoms (all available atoms, that is those that aren't bonded to other elements, bond to hydrogen?),,,at the second site, the carbon is bonded to nitrogen as well as oxygen, so there are only 2 atoms available to bond to hydrogen, hence the CH3 at the first site but CH2 at the second??? Or is nitrogen not even present at the second site??? If not what is the other element at the second site that prevents the CH2 from being a CH3?? Or am I totally lost?

Well, I'm a bit lost as to which CH3's you're talking about. To clarify: Look at the top of the molecule for percocet. You see N-CH3, right? That means the nitrogen has a single bond with the carbon. The rest of its four possible bonds are filled with hydrogens, hence CH3. Now look at the bottom left of the molecule. You see H3CO, right? means the carbon is singly bonded to the oxygen, and the rest of its bonds are tied up with 3 hydrogens.

Let's go over to the CH2's again, on the roxi diagram. The first CH2's carbon is bonded with a nitrogen and another CH2's carbon. The rest of the possible bonds are filled with 2 hydrogens. Hence CH2. The second CH2's carbon is bonded with the first CH2's carbon and the vertex on the bottom right of the ring (see that diagonal line?). That vertex is a carbon, remember?

Look at the percocet diagram again. No CH2's, right? Wrong. They're there, they are now just represented with those zigzagging lines starting at the nitrogen and going to the bottom right of the center ring. That's what I mean when I say the guy who did the roxi diagram decided to write in CH2 instead. He could have just drawn zigzags and it would have meant the same thing: a singly bonded carbon chain surrounded with enough hydrogens to fill all the possible bonds. The diagrams represent the same compound. The difference between them is strictly notational. If they are the same compound, the GC/MS would be the same for all of them.



Getting it?

[spacejack26]

Pretty sure I am getting it...like you said before, carbons are represented by vertices, so does that mean everywhere there is a "meeting point between hexagons, that's a carbon atom? If so, I understand how it is that the bottom ch2 is bonded to that carbon. Now, stupid question...Even though where the two CH2's are in the roxi diagram do not appear to be part of the geometric diagram, wherever they are shown (represented on the perc diagram by the unlabelled line that has a point (vertex?) in the middle) is a carbon atom, right? Indicated by the C? And the vertices at the points of the hexagons don't need to be labelled because they're always carbon? (Even if that question makes no sense to you, I really am understanding it a lot better...).

Another question (2 actually)....What is represented by the circle inside the left hexagon on the roxi diagram (the perc and oxy drawings show "doubled" hexagon walls). And why the double oxygen lines at the bottom right of the diagrams? Oh, and why are there "dotted" lines in the diagrams?

Thanks for all your help, oneiros

[Oneiros]

You got it. The "meeting points" of the hexagons are carbons. That bottom CH2 is bonded to that carbon. All four of that carbon's bonds are going to other carbons.

A vertex is just an intersection of two or more lines. Each time a line turns without being labeled as something else, its a carbon. Again, whoever did the roxi diagram thought that it would be clearer if he labeled the carbons in that ring with the nitrogen in it. All the other diagrams represent their CH2's with unlabeled points.

I'm glad you asked about the doubled walls. These represent double bonds. This means that two pairs of electrons are shared between the two atoms. It follows that when a carbon is double bonded to something, it can only form two more bonds.

Look at the perc diagram. Why do the double bonds have to be in those particular positions? Couldn't you shift all the double bonds clockwise or anticlockwise one carbon and still have the same chemical structure? This is where that circle comes in. In a ring like that (called a phenyl ring), some of the electrons (6 of them, actually) exist in what's called a delocalized orbital. That is to say, the electrons are shared throughout the entire ring and strengthen each bond equally. Kind of like a one-and-a-half bond for each of them. The circle is a more accurate way of describing the structure of the molecule.

To help you understand the dashed lines, here's a 3D picture of codeine, which has a very similar structure to oxycodone.

http://www.erowid.org/pharms/show_im...codeine_3d.jpg

Looks more complicated than the 2D one. As you can see, the molecule's rings are really at angles to each other, not flat on paper. This is what the dashed lines are trying to convey. The OxyContin diagram shows a line made up of descending vertical dashes. Descending dashes means that what ever it "points" to lies below the molecular plane. Ascending means above.

[spacejack26]

Excellent oneiros, you are quite a teacher, thanks...I have a couple questions regarding notation only:

Assuming hydrocodone and oxycodone only differ by one molecule, H, as opposed to OH, respectively, connecting the center hexagon to the top of the right hexagon, if you were to use the perc diagram: http://www.rxlist.com/cgi/generic/oxyapap.htm .

Why, on this hydrocodone diagram, is the dotted line used to note a hydrogen molecule at the top of the perc diagram not shown (the H is shown next to the N-CH3). Also, what is the (+) sign used to signify here, in between the N and CH3? http://www.rxlist.com/cgi/generic/hydrocod.htm . Is it for the same purpose as the (+) in the oxycontin diagram, only here to show bitartrate bonding to the hydro?

And what about the oxycodone and hydrocodone diagrams on this site? http://drugs-forum.com/opiate-chemistry.html . I notice M seems to signify CH3...is this some type of shorthand? Does it show the same thing as the other oxycodone diagrams? Because I notice there are no dotted lines showing the Hydrogen atom in these drawings, either...

Thanks Oneiros, I'll await your reply

[Oneiros]

There is no universally correct way to diagram complex organic compounds like these. The person who drew up the hydrocodone diagram didn't think that showing how the hydrogen bonded to the rest of the molecule was important, so he omitted it and left it as an "understood" hydrogen.

You're right on about the + sign.

Yeah, Me is shorthand for methyl, and methyl means CH3.

Yep, these are the same molecules. Once again, the dotted H became an "understood" H.

[spacejack26]

Thanks a ton, oneiros, really