Podocarpus nakaii

Ponasterones A, B, C D Chenopodium, Rhagodia, Spinacia (Chenopodiaceae), Ajuga, Lamium (Lamiaceae), Lloydia (Liliaceae), Polypodium (Polypodiaceae) spp. Podocarpus nakaii (Podocarpaceae) ECDY-R agonists... 

Sterols. A considerable amount of work was devoted to the study of backbone rearrangements. - While partial syntheses of an insect moulting hormone, ecdysone, were announced by several groups, evidence is accumulating on the widespread occurrence in natxire of its hydroxylated derivatives. This year saw the isolation of 20-hydroxy-ecdysone - - from silkworm (ecdysterone), crayfish - (crustecdysone), oak-silk moth, tobacco hornworm, and from plants such as Podocarpus nakaii, Podocarpus elatus, and Achyranthis. The ready isolation of insect-moulting hormones from plants in contrast to -the extremely poor... 

Ponasterone A 2 3,3 3, 14a, 20a(f ),22p(/ )-penta-hydroxy-5 3-cholest-7-en- 6-one, a phytoecdysone (see Ecdysone), 464.65, m.p. 260°C, [a]p -f90° (methanol). P. A was isolated from the fern Podocar-pus nakaii Hay, and it has molting hormone activity in insects. The closely related ponasterone B and ponasterone C were also isolated from Podocarpus they differ from P. A in that P. B has the opposite configurations at C2 and C3, while P. C possesses an additional hydroxyl group at C24. 

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