Okay, this is just cool.
For your viewing pleasure, I traced the structure and made a .jpg so you can see for yourself.
I posted this on K5 without any further comment, but I’ve since looked up the paper, and there are a couple of interesting things to note.
The paper is well-written enough that parts of it could percolate through my brain. Although my reading is unsophisticated, in synthetic organic chemistry terms, a couple of things struck me.
First, they reported negative results along with their success. This may be usual in chemistry papers, but in biomedical papers, it’s rare for investigators to report things that didn’t work unless the context demands it. Second, the actual Moebuis component of the molecule is stabilized by these wonderful additional rings on one portion of the molecule. Third, crystals of the Moebius isomer are red, but those of the the non-Moebius version are colorless.
It was a thorny synthetic problem, accomplished with photochemistry and a deep understanding of the physics of the orbital structures. Hat’s off!