Phytoecdysteroids of plants of the genus Silene. XV. 2-Deoxy-α-ecdysone 22-O-benzoate from Silene wallichiana

A new phytoecdysteroid, 2-deoxy-α-ecdysone 22-O-benzoate, has been isolated from the epigeal organs ofSilene wallichiana Klotzch.     

Phytoecdysteroids of plants of the genus Silene. XIV. Ecdysterone 20-O-benzoate from Silene tatarica

A new ecdysteroid, which has proved to be ecdysterone 20-O-benzoate, has been isolated from the whole plantSilene tatatica (L.) Pers.     

Phytoecdysteroids of plants of the genus Silene. XVII. Ecdysterone 22,25-di-O-benzoate from Silene scabrifolia

The new phytoecdysteroid ecdysterone 22,25-di-O-benzoate (IV) has been isolated from the epigeal organs ofSilene scabrifolia Kom. The alkaline hydrolysis of (IV) gave ecdysterone 25-O-benzoate and ecdysterone (I). Details of the IR, UV, mass, PMR, and¹³C NMR spectra of compound (IV) are given.     

Phytoecdysteroids of plants of the genus Silene. IX. Ecdysterone 22-O-benzoate from Silene scabrifolia

An ecdysteroid which has proved to be ecdysterone 22-O-benzoate has been isolated from the epigeal organs ofSilene scabrifolia Kom.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 77–80, January–February, 1986.     

Phytoecdysteroids of plants of the genus Silene. XIV. Ecdysterone 20-O-benzoate from Silene tatarica

A new ecdysteroid, which has proved to be ecdysterone 20-O-benzoate, has been isolated from the whole plantSilene tatatica (L.) Pers.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 850–852, November–December, 1987.     

Phytoecdysteroids of plants of the genus Silene. XVII. Ecdysterone 22,25-di-O-benzoate from Silene scabrifolia

The new phytoecdysteroid ecdysterone 22,25-di-O-benzoate (IV) has been isolated from the epigeal organs ofSilene scabrifolia Kom. The alkaline hydrolysis of (IV) gave ecdysterone 25-O-benzoate and ecdysterone (I). Details of the IR, UV, mass, PMR, and¹³C NMR spectra of compound (IV) are given.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 363–366, May–June, 1990.     

Ecdysteroids from Silene claviformis

The ecdysteroid content ofSilene claviformishas been analyzed and the four major compounds have been identified as 20-hydroxyecdysone, 2-deoxy-20-hydroxyecdysone, 2-deoxyecdysone, and integristerone A. Two new minor compounds have also been identified An erratum to this article can be found at     

Phytoecdysteroids of plants of the genus Silene. XVI. Viticosterone E 22-O-benzoate from Silene wallichiana

A new phytoecdysteroid, viticosterone E 22-O-benzoate (I), C₃₆H₅₀O₀, mp 147–149°C (methanol-water), [] _D ²⁰ +63.2° (methanol), has been isolated from the epigeal organs ofSilene wallichiana Klotzsch. The alkaline hydrolysis of (I) led to viticosterone E and benzoic acid. The acetylation of (I) gave the 2,3-diacetate (II), C₄₀H₅₄O₁₁, mp 152–153°C (methanol-water), [] _D ²⁰ +65.5° (methanol). Details of the IR, PMR, and mass spectra of (I) and (II) are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 546–549, July–August, 1988.     

Phytoecdysteroids of Plants of the Silene Genus. 2-Deoxyecdysterone-25-Acetate from Silene wallichiana

The new ecdysteroid 2-deoxyecdysterone-25-acetate was isolated from roots of Silene wallichiana Klotzsch.     

Chemical constituents of Silene montbretiana

A new steroidal glycoside, 3-O-β-d-glucopyranosyl-3β,25-dihydroxy-5β-cholest-7-en-6-one 25-O-β-d-glucopyranoside (1), together with six known steroidal derivatives (2-7), one cerebroside (8) and one flavonoid (9) were isolated from Silene montbretiana Boiss (Caryophyllaceae), a perennial herb growing mainly in the Middle and East Anatolia, Azerbaijan, Iran, and Turkey. Their structures were established by the extensive use of 1D and 2D NMR experiments along with ESI-MS analyses. The cytotoxicity against the cancer A549 (human alveolar basal carcinoma) and Hela (human epitheloid cervix carcinoma) cell lines has been evaluated. None of the tested compounds, in a range of concentrations between 12.5 and 100 μM, caused a significant reduction of the cell number.     

Phytoecdysteroids of Silene viridiflora

The known ecdysteroids polipodin B, 2-deoxyecdysterone, ecdysterone, 26-hydroxypolipodin B, integristerone A, and sileneosides A and D were observed in the aerial part of Silene viridiflora L. (Caryophyllaceae). 26-Hydroxypolipodin B was observed in this species for the first time.     

Pentacyclic Triterpenoid Saponins from Silene viscidula

Three new pentacyclic triterpenoid saponins, viscidulosides A and B ( 1 and 2 , resp.), and silenoviscoside D ( 3 ), were isolated from the roots of Silene viscidula, together with two known saponins, sinocrassulosides VIII and IX ( 4 and 5 , resp.). Their structures were elucidated by spectroscopic data and chemical methods. Compounds 1 / 2 and 4 / 5 were two inseparable mixtures, which are glycosides of quillaic acid whose fucose residue is acylated by (E)‐ or (Z)‐4‐methoxycinnamic acid.     

Phytoecdysteroids of plants of the genusRhaponticum polypodin B 22-O-benzoate fromRhaponticum carthamoides

A known ecdysteroid — -ecdysone- and a new phytoecdysteroid — polypodin B-22-O-benzoate — have been isolated from the seeds ofRhaponticum carthamoides (Willa) Iljin. Alkaline hydrolysis of the latter gave polypodin B. Its structure has been established on the basis of chemical transformations and spectral characteristics.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 851–853, November–December, 1997.     

Stereoselective Activation of Small Molecules by a Stable Chiral Silene

The reaction of the dilithium salt of the enantiopure (S)-BINOL (1,1’-bi-2-naphthol) with two equivalents of the amidinate-stabilized chlorosilylene [L^PhSiCl] (L^Ph=PhC(NtBu)₂) led to the formation of the first example of a chiral cyclic silene species comprising an (S)-BINOL ligand. The reactivity of the Si=C bond was investigated by reaction with elemental sulfur, CO₂ and HCl. The reaction with S₈ led to a Si=C bond cleavage and concomitantly to a ring-opened product with imine and silanethione functional groups. The reaction with CO₂ resulted in the cleavage of the CO₂ molecule into a carbonyl group and an isolated O atom, while a new stereocenter is formed in a highly selective manner. According to DFT calculations, the [2+2] cycloaddition product is the key intermediate. Further reactivity studies of the chiral cyclic silene with HCl resulted in a stereoselective addition to the Si=C bond, while the fully selective formation of two stereocenters was achieved. The quantitative stereoselective addition of CO₂ and HCl to a Si=C bond is unprecedented.     

Chemical composition of Silene morganae Freyn volatile oil

The essential oil composition of flowering aerial parts of Iranian Silene morganae Freyn (Caryophyllaceae) was analysed for the first time using gas chromatography and gas chromatography–mass spectrometry. Thirty-one compounds consisting of 90.3% of the volatile oil were detected. The major constituents were benzaldehyde (11.6%), (Z)-3-hexenyl acetate (9.6%), (E)-β-ocimene (8.2%) and linalool (7.4%). Terpenoids (43.5%), particularly monoterpene hydrocarbons (24.2%), had the highest contribution in S. morganae Freyn flowering aerial parts oil.     

Mechanism of the Thermal Z⇌E Isomerization of a Stable Silene; Experiment and Theory

The E and Z geometric isomers of a stable silene (tBu₂MeSi)(tBuMe₂Si)Si=CH(1‐Ad) ( 1 ) were synthesized and characterized spectroscopically. The thermal Z to E isomerization of 1 was studied both experimentally and computationally using DFT methods. The measured activation parameters for the 1Z ? 1E isomerization are: E_a=24.4 kcal mol^?1, ΔH^≠=23.7 kcal mol^?1, ΔS^≠=?13.2 e.u. Based on comparison of the experimental and DFT calculated (at BP86‐D3BJ/def2‐TZVP(‐f)//BP86‐D3BJ/def2‐TZVP(‐f)) activation parameters, the Z?E isomerization of 1 proceeds through an unusual (unprecedented for alkenes) migration–rotation–migration mechanism (via a silylene intermediate), rather than through the classic rotation mechanism common for alkenes.     

Steroid saponins and sapogenins of Allium X. Neoagigenin 6-O-benzoate from Allium turcomanicum

Summary From the epigeal parts ofAllium turcomanicum Rgl., in addition to the known spirostans yuccagenin, neoagigenin, neoagigenone, neoagigenin, and alliogenin, we have isolated a new steriod sapogenin the structure of which has been established as neoagigenin 6-O-benzoate.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 534–537, July–August, 1977.     

Phytoecdysteroids of plants of the genusSilene XII. 5α-Ecdysterone 22-O-benzoate fromSilene scabrifolia

The new phytoecdysteroid 5α-ecdysterone 22-O-benzoate (I), C₃₄H₄₈O₃, mp 262–274°C (methanol-water) [α] _D ²⁰ +45.8° (methanol), has been isolated from the epigeal organ ofSilene scarbiofolia Kom. The alkaline hydrolysis of (I) led to 5α-ecdysterone (II) and benzoic acid. The isomerization of ecdysterone (0.6% KHCO₃ in CH₃OH) has yielded (II). Details of the IR, mass, and NMR spectra of compound (I) are given.