Minor Ecdysteroid Components of Leuzea carthamoides

Fourteen minor ecdysteroid components were isolated and identified from the roots of Leuzea carthamoides (Willd.) DC. Two of them are new phytoecdysteroids: leuzeasterone ( 1 ) a six-member side-chain lactone, and (24 Z )-29-hydroxy-24(28)-dehydromakisterone C ( 4 ) a structurally related sitostane type analogue and assumed biogenetic precursor of 1 . The next one, 5α-20-hydroxyecdysone ( 6 ), is a rare A/B-ring trans-annelated epimer of the most common phytoecdysteroid 20-hydroxyecdysone. Further compounds: makisterone C ( 3 ), 3-epi-20-hydroxyecdysone ( 5 ), integristerone A ( 7 ), integristerone B ( 8 ), 22-oxo-20-hydroxyecdysone ( 10 ), taxisterone ( 11 ), rubrosterone ( 12 ), dihydrorubrosterone ( 13 ) and poststerone ( 14 ), are new constituents of L. carthamoides , though already reported as compounds isolated from other natural sources. Two earlier reported minor Leuzea ecdysteroids: the five-membered side-chain lactone carthamosterone ( 2 ) and the 11-hydroxy-substituted analogue isovitexirone ( 9 ), are also included because they are now better characterised. Certain previously described Leuzea ecdysteroids were not found in our material, which may indicate geographic, seasonal or cultivar variations.

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