V. N. Odinokov

Phytoecdysteroids from the juice of Serratula coronata L. (Asteraceae)

Seven phytoecdysteroids have been isolated from Serratula coronata L. One of them is a new phytoecdysteroid, 3-epi-20-hydroxyecdysone. Two further ecdysteroids, 20-hydroxyecdysone 22-acetate and taxisterone, are isolated from this species for the first time in addition to the typical S. coronata ecdysteroids, 20-hydroxyecdysone, ecdysone, ajugasterone C and polypodine B. The juice squeezed from aerial parts of fresh plants of S. coronata was extracted with ethyl acetate. The ecdysteroids were isolated by a combination of chromatographic techniques (mainly HPLC) and identified by 1D and 2D (1)H and (13)C NMR experiments and mass-spectrometry. The biological activities of 3-epi-20-hydroxyecdysone (EC(50)=1.6 x 10(-7) M), taxisterone (EC(50)=9.5 x 10(-8) M) and ajugasterone C (EC(50)=6.2 x 10(-8) M) have been determined in the Drosophila melanogaster B(II) bioassay for ecdysteroid agonist activity.

Identification and Biological Activity of Volatile Organic Compounds Emitted by Plants and Insects. IV. Composition of Vapor Isolated from Certain Species of Artemisia Plants

The components of fragrance from four wormwood species of theArtemisiaL. genus were analyzed by GC-MS. The major and minor components of volatile essential oils typical of the studied plant species were determined.

Synthesis of lupane triterpenoids with triphenylphosphonium substituents and studies of their antitumor activity

New derivatives of lupane triterpenoids, viz., 20,29-dihydrobetulinic and 3-epi-20,29-dihydrobetulinic acid derivatives containing triphenylphosphonium fragments as substituents were synthesized. These compound considerably exceed betulinic acid in antitumor activity.

Ozonolysis of Alkenes and Study of Reactions of Polyfunctional Compounds: LXVI.2* Ozonolysis and Hydrogenation of Diacetonides of 24,25- and 25,26-Anhydro-20-hydroxyecdysones. Synthesis of Ponasterone A

Ozonolysis of 2,3:20,22-diacetonides of 24.25-and 25,26-anhydro-20-hydroxyecdysones afforded the corresponding ω-carbonyl derivatives. The hydrogenation of the mentioned dehydration products of 20-hydroxyecdysone acetonide yielded diacetonide of ponasterone A that provided ponasterone A and its 29,22-acetonide at hydrolysis.

7,8-dihydro analogs of ecdysteroids

Reactions of 20-hydroxyecdysone, its diacetonide, and 24,25(25,26)-anhydro derivative with lithium tetrahydridoaluminate gave the corresponding 6α- and 6β-epimeric alcohols and 7,8-dihydro analogs.

Synthesis of 20-hydroxyecdysone oxime, its diacetonide, and their 14,15-anhydro derivatives

Abstract20-Hydroxyecdysone oxime, its diacetonide, and the corresponding 14,15-anhydro derivatives were synthesized. Conditions were found for the preparation of the Z-and E-oximes, and their characteristics 1H and 13C NMR parameters were determined.

Transformation of 20-Hydroxyecdysone Acetonides into Podecdysone B

Hydrogenation of 20-hydroxyecdysone 2,3:20,22-diacetonide and 20,22-acetonide over palladium catalyst yields podecdysone B 20,22-acetonide. Acid hydrolysis of the latter affords podecdysone B which is a natural phytoecdysteroid.

Identification and biological activity of volatile organic substances emitted by plants and insects. I. Components of the native scents ofLeptinotarsa decemlineata andSolanum tuberosum

The sesquiterpenestrans-caryophyllene and germacrene have been detected in the native scents of male and female individuals of the Colorado beetleLeptinotarsa decemlineata Say by gas-chromato-mass-spectral analysis.trans-Caryophyllene has also been detected in the volatiles emitted by leaves of the potatoSolanum tuberosum L. which indicates its role as food attractant of the Colorado beetle.

Stereochemistry of Hydride Reduction of 20-Hydroxyecdysone Derivatives

The 6-oxo group in 2,3:20,22-di-O-isopropylidene derivatives of 20-hydroxyecdysone and its 24,25/25,26-anhydro analog is reduced with NaBH4-CeCl3 in a stereoselective fashion to afford the corresponding 6α-alcohols. In the first case, the reaction is accompanied by dehydration to give Δ14-bond. Reduction of the same substrates with NaBH4 or LiAlH4 in the absence of CeCl3 leads to mixtures of 6α- and 6β-hydroxy derivatives, the latter prevailing. In all cases, epimerization at C5 occurs.

Orifluoroacetylation and dehydration of 20-hydroxyecdysone acetonides. Synthesis of stachisterone B

Orifluoroacetylation of the 25(OH)-group with subsequent dehydration of the 14(OH)-group takes place in the reaction of 20-hydroxyecdysone 20,22-acetonide and 2,3:20,22-diacetonide with trifluoroacetic anhydride in the presence of pyridine. Dehydration of the 14(OH)-group gives rise to stachisterone B derivatives, which are hydrolyzed to give the phytoecdysteroid stachisterone B.