X-ray single crystal analysis of 20-hydroxyecdysone (20E, 2), an important insect moulting hormone, isolated from Sesuvium portulacastrum Linn. was found to exhibit a unique stereochemical configuration revealing it to be a different conformer (polymorph) possessing the aliphatic chain atoms in a trans configuration. Moreover, the analysis also revealed the presence of three molecules of water of crystallisation thereby restricting the freedom of the aliphatic side chain.
S. Rele, Banerji, A., Chintalwar, G., Kumar, V., and Yadava, V., “A new conformer of 20-hydroxyecdysone from Sesuvium portulacastrum: an X-ray crystallographic study”, Natural product research, vol. 17, pp. 103–108, 2003.