Depending on the number and character of their functional groups, steroid molecules may show diverse reactivities. Moreover, the reactivity of a functional group varies according to its location within the molecule (for example, esters are formed readily by 3-OH groups but only with difficulty by the 11β-OH group). An important property of steroids is polarity —., their solubility in oxygen-containing solvents (., water and alcohols ) rather than hydrocarbon solvents (., hexane and benzene ). Hydroxyl, ketonic, or ionizable (capable of dissociating to form electrically charged particles) groups in a steroid molecule increase its polarity to an extent that is strongly influenced by the spatial arrangement of the atoms within the molecule.
The abstract was published in part in the proceedings of the BSAVA Congress 2008; the proceedings of the 20th Symposium of the ESVN, JVIM 2008; 22: 519–520 (abstract); the proceedings of the 10th Annual Congress of the European Society of Veterinary Clinical Pathology and the 8th Biennial Congress of the International Society for Animal Clinical Pathology, Barcelona, 2008; and the proceedings of the 21st Symposium of the ESVN, Rhodes, 2008. This work was done in the Division of Companion Animal Sciences, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK.