title: Chemical modifications at the 22-hydroxyl group of ecdysteroids: alternative structural requirements for high moulting activity.
abstract: A number of 22-O-alkyl ether and acyl ester derivatives have been prepared and their moulting activity determined, using the Musca assay. It was found that a free 22-hydroxyl group is not an essential structural requirement for an ecdysteroid to exhibit high moulting activity. The activity of a 22-O-substituted ecdysteroid may even be higher than that of the parent compound, providing that the substituent constitutes a functional group that can enhance biological activity. The moulting activity is not sensitive to steric factors at the 22-position. Ecdysteroid without a 22-hydroxyl group may exhibit high moulting activity if a functional group that can enhance activity is present at an appropriate position.
authors.affiliation: Department of Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand. apichart@ram1.ru.ac.th
authors.forename: Apichart
authors.initials: A
authors.lastname: Suksamrarn
authors.forename: Prasert
authors.initials: P
authors.lastname: Pattanaprateep
authors.forename: Tanud
authors.initials: T
authors.lastname: Tanachatchairatana
authors.forename: Woraphot
authors.initials: W
authors.lastname: Haritakun
authors.forename: Boon-ek
authors.initials: BE
authors.lastname: Yingyongnarongkul
authors.forename: Nitirat
authors.initials: N
authors.lastname: Chimnoi
mesh_terms: D000107:Acetylation; D000215:Acylation; D000818:Animals; D004441:Ecdysterone / Q000031:analogs & derivatives* / Q000737:chemistry; D006793:Houseflies; D008675:Metamorphosis, Biological; D015394:Molecular Structure; D013329:Structure-Activity Relationship
chemical_list: D004441:Ecdysterone