Nat Prod Res. 2003 Apr; 17(2): 103-8.

A new conformer of 20-hydroxyecdysone from Sesuvium portulacastrum: an x-ray crystallographic study.

Rele S, Banerji A, Chintalwar G, Kumar V, Yadava V.

Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India. [email protected]

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.