Polish student Marcin Mielecki emailed to ask where he might find a 3D, as opposed to 2D, structure for the compound Avenacoside B. A very quick Google brought me almost immediately to this page (by searching for “avenacoside b mol file”: http://www.genome.jp/dbget-bin/www_bget?cpd+C08888, which provides the flat molecular structure and a link to the MDL mol file for this molecule. If Marcin has Chime or another mol reader installed in his browser clicking that link will spawn the 3D structure he requires. It’s also in Pubchem of course, which can be searched via the Chemspy Chemical Search site.
Marcin’s research focuses on the biological role of the avenacosides, which are steroidal saponins from Avena sativa.