After my last blog post about molecule quilts for sale, a rush of orders and enquiries came in. One person asked whether it would be possible to make a quilt of cyclosporine (a drug used to help prevent rejection of transplanted organs).
The first structure I found for the molecule looked like the picture on the right. Not a terrible molecule, but see the abnormally long bond line on the bottom left? That's a symptom of poor layout of the atoms, which obscures a very interesting fact about this substance: It's a big ring! It's a very unusual cyclic peptide (short protein) made by a fungus.
I looked around for a nicer version, and found this lovely rendering, which makes the cyclic nature of the molecule very obvious! Unfortunately it's not ideal as a starting point for a quilt, because all that empty space in the middle is wasted, meaning the individual atoms would be too small.
So I took this starting point and rotated the longest of the protein side chains by 180 degrees so they point inwards, resulting in the design you see at the top of the article.
This should make for a really lovely quilt, and I hope someone orders it so I can stitch it and then post photographs of the real thing! (It's been added as a stock item, so you can buy one right now if you're just overwhelmed with how cool this molecule is.)
By the way, if you're wondering why I can just bend things around willy nilly without making the structure wrong in some sense, it's because this sort of 2D structure diagram is never really a true representation of the actual shape of the molecule. The uglier structure is in a sense more accurate in that it shows more bond angles closer to what they really are, but both are full of compromises. In any case the real molecule is 3D, not 2D. Here is what it actually looks like (from Wikipedia). Notice how lots of things are on top of each other: The only way to flatten this mess into a clear 2D diagram is to bend and shift it around in quite arbitrary ways. The cyclic structure is the one that most clearly illustrates the logical layout and connectivity of the molecule, which is what these diagrams (and quilts) are meant to do.