Minor Ecdysteroid Components of Leuzea carthamoides

Abstract

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 (24Z)-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.The abundant occurrence of ecdysteroids in Leuzea carthamoides DC. (syn. Rhaponticum carthamoides (Willd.) Iljin) is interesting from several viewpoints. First is the large structure variability of all so far isolated ecdysone analogues 2-8 and second is their high content in the roots or seeds of this plant 9 . L. carthamoides is endemic in Siberia, but is also cultivated as a medicinal plant on a large scale in Europe. This is why L. carthamoides can serve as a rich source of ecdysteroids, insect moulting hormone analogues,

Low-Polarity Phytoecdysteroids from the Juice of Serratula coronata L. (Asteraceae)

“…Four of them are novel ecdysteroids, i.e. ecdysone 22-acetate (7) Several further ecdysteroids had been previously isolated from plant sources; makisterone C (1) 8 , 20-hydroxyecdysone 20,22-acetonide (2) 9 , ajugasterone C 20,22-acetonide (3) 10 , 20-hydroxyecdysone 2-acetate (4) and 20-hydroxyecdysone 3-acetate (5) 11 and viticosterone E (6) 12 were identified by means of 1 H and 13 C NMR spectra (Tables II and III), which are very similar to those published earlier 13 . Some slight differences in the 1 H NMR spectra can be attributed to solvent effects, since the spectra of compounds isolated by us were obtained in D 2 O.…”

Separation of organic compounds binding trace elements in seeds of Leuzea carthamoides (Willd.) DC

“…1). The extraction time of each of first three fractions was 24 h and the time for following four extractions was 48 h. Extraction was performed at laboratory temperature (22)(23)(24) • C). Water temperature for extraction was 55-60…”

Systemic effects of phytoecdysteroids on the cabbage aphid Brevicoryne brassicae (Sternorrhyncha: Aphididae)

“…PolyB is a derivative of 20E with one additional hydroxyl in position 5 (in the beta configuration). The minors: makisterone A and inokosterone are also closely related struc- (Píš et al, 1994 andVoká et al, 2002). For chemical structures see Lafont et al (2002).…”

“…Later reports turned their main attention towards the content of ecdysteroids. The roots and, later, also the seeds were used as a rich source of major phytoecdysteroids, especially 20-hydroxyecdysone, ajugasterone C, polypodine B, and also a set of their structural analogues (Píš et al, 1994;Voká et al, 2002). We decided to use a selection of these ecdysteroids for assessing their activity on aphids.…”