Phytoecdysones ofRhaponticum integrifolium III. Integristerone B
SummaryFrom the flower heads ofRhaponticum integrifolium we have isolated a new phytoecdysone — integristerone B. It has been shown that it is 1β, 2β, 3β, 5β, 14α, 20R, 22R, 25-octahydroxy-5β-cholest-7-en-6-one.
Insect Moulting Hormones: Dacrysterone, a New Phytoecdysone From Dacrydium intermedium
Dacrysterone, a new phytoecdysone, has been isolated from the bark of Dacrydium intermedium and shown to be 5β-hydroxymakisterone A (6). Makisterone A also occurs in this plant.
The determination of absolute configuration at C-24 of the phytoecdysone makisterone A
Makisterone A was found to have an R-configuration at C-24; therefore its complete defined structure is 2β,3β,14α,20,22,25-hexahydroxy-5β,(20R, 22R,24R)-ergost-7-en-6-one (II).