Chemical modifications at the 22-hydroxyl group of ecdysteroids: alternative structural requirements for high moulting activity.
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.
Suksamrarn
Apichart
A
Department of Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand. apichart@ram1.ru.ac.th
Pattanaprateep
Prasert
P
Tanachatchairatana
Tanud
T
Haritakun
Woraphot
W
Yingyongnarongkul
Boon-ek
BE
Chimnoi
Nitirat
N
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
D004441:Ecdysterone