Cellobiose is interesting because it is the building block of cellulose. As I understand it, the important structural feature is the hydrogen bond between the ring O and the 4' OH. It gives rigidity to cellulose strands.
In my GAMESS 3-21G calculation the hydrogen bond has a bonding order of .08 which is not really a lot. But this may just be a problem of the calculation. I don't know how to add extra functions just to the atoms I am interested in. And even the way I did it, it took 3 hours of geometry optimisation and it wasn't even quite stationary then.
This post is mostly to show a few nice pictures, though. I like making them and it seems that most of the google hits are going for them. Here's another one.
To give credit to all the nice free (or formerly free) programs I used: The structure was drawn, MM optimised and semi-empirically optimised in ArgusLab. Then I rearranged the structure with PyMOL's sculpting function to get the O and OH together. Structure optimisation in GAMESS, data extraction in ChemCraft, pictures again in PyMOL.
Macrocycles, flexibility and biological activity: A tortuous pairing - Here's an interesting paper from the Jacobson, Wells and Walsh labs at UCSF and Stanford that seeks to demonstrate how restricting the flexibility of macr...
3 days ago