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.
Phytoecdysones ofRhaponticum integrifolium IV. 24(28)-Dehydromakisterone A
SummaryA new phytoecdysone has been isolated from the flower heads ofRhaponticum integrifolium, and for it the structure of 24(28)-dehydromakisterone A has been established.
Ecdysones from the pupa of the tobacco hornworm, Manduca sexta (Johannson).
Abstract Ecdysone titer was determined in tobacco hornworm pupae of different ages as a prerequisite to the isolation and identification of the molting hormones present in this insect. A maximum titer was found in 6- to 8-day-old pupae using house fly larvae as the test organism for assessing the biological activity. Two crystalline ecdysones were isolated from 7-day-old pupae and these were found to have equal biological activity in both the Calliphora test and the house fly assay. One of the hormones was found to be identical to the silkworm α-ecdysone (2β, 3β, 14α, 22R, 25-pentahydroxy- Δ 7 -5 β -cholesten-6-one). The more polar hormone, present in greater amounts in 7-day-old hornworm pupae, was structurally similar to α-ecdysone but was assigned an additional hydroxyl group at the C-20 position. The relationship among the hormones of the hornworm and the ecdysones isolated from other species is discussed.