Synthesis and structural elucidation of a new zooecdysteroid gerardiasterone

Marine natural products

“…404 The stereochemistry of gerardiasterone 597, which is an ecdysone analog from the Mediterranean zoanthid Gerardia savaglia, 405 was established by synthesis. 406 Two steroidal glycosides 598 and 599 were isolated from Andaman and Nicobar Island specimens of Sinularia grandilobata and S. gibberosa, respectively. 407,408 The marine hydroid Tridentata marginata contained the unusual aromatic alkaloids tridentatols A-C 600-602, only one of which, tridentatol A 600, inhibited feeding by the planehead filefish.…”

Steroids: reactions and partial synthesis

“…204 Stereoselectivity in the epoxidation 205 and hydroxylation 206 of side chain double bonds has been examined. The results have been used in the elucidation of the structure of an ecdysteroid, gerardiasterone, 93, 206 and in the preparation 207 of possible intermediates in the formation of bile acids from cholesterol. The synthesis of deuterium labelled plant sterols 208 and of 26,27-hexadeuteriocholesterol 209 have been reported.…”

Isolation and Structural Elucidation of Two Plant Ecdysteroids, Gerardiasterone and 22-Epi-20-hydroxyecdysone

“…One of them, 22-epi-20hydroxyecdysone (1), is a new natural product, while 2, gerardiasterone, has been previously described as an animal metabolite from the Mediterranean Zooanthid Gerardia savaglia, 6 and more recently, its structure was confirmed by chemical synthesis. 7,8 TLC analyses of the MeOH extract of S. tinctoria indicated the presence of two ecdysteroids having chromatographic behavior on silica similar to that of 20hydroxyecdysone. At the same time, their chromatographic behavior (R f values) suggested that they may not have been isolated before from this plant.…”

“…This paper describes the isolation, structural elucidation, and/or identification of two minor ecdysteroids ( 1 , 22-epi-20-hydroxyecdysone, and 2 , gerardiasterone) from the aerial parts of S. tinctoria . One of them, 22-epi-20-hydroxyecdysone ( 1 ), is a new natural product, while 2 , gerardiasterone, has been previously described as an animal metabolite from the Mediterranean Zooanthid Gerardia savaglia , and more recently, its structure was confirmed by chemical synthesis. ,

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“…The 1 H NMR data indicated that the location of this additional OH is at position 23. This compound was determined to be gerardiasterone. − Finally, comparison with an authentic sample (kindly provided by Profs. Guerriero and Honda) showed that both compounds have the same retention time on normal-phase HPLC and superimposable 1 H NMR and 13 C NMR spectra.…”