Terpenoids of Crepis tectorum. Molecular and crystal structure of the sesquiterpene lactone 8-epideacylcynaropicrin

Sesquiterpene lactones of the guaianolide type — isolipidiol (I) and 8-epideacylcynaropicrin (II) — have been isolated from narrow-leaf hawk's-beard,Crepis tectorum L. On the basis of the results of an x-ray experiment the structure of (1R, 3S, 5R, 6R, 7R, 8R)-3,8-dihydroxy-cis,trans-guaia-4(15),10(14),-11(13)-trien-6,12-olide is proposed for (II).Institute of Organic Synthesis and Coal Chemistry, Kazakh Academy of Sciences, Karaganda. A. N. Nesmeynaov Institute of Organometallic Compounds, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 638–642, September–October, 1991.     

Molecular and crystal structure of the germacranolide argolide from Artemisia glabella

The new germacranolide argolide has been isolated from the epigeal part ofArtemisia glabella, and its structure has been shown by its conversion into oxopelenolide B. From the results of an x-ray investigation it is suggested that argolide has the spatial structure of 3-oxo-4,7,6(H)-germacra-1(10),11(13)-dien-6,12-olide.Institute of Organic Synthesis and Coal Chemistry, Kazakh Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Organometallic Chemistry, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 653–657, September–October, 1991.     

Ajanolide A, a new germacranolide fromAjania fruticulosa

A new germacranolide, ajanolide A, was isolated from aerial parts ofAjania fruticulosa by means of extraction with CHCl₃ and adsorption chromatography. This compound was identified as (1(10)E,3S,4Z,6R,7S,11R)-3-acetoxygermacra-1(10),4-dien-12,6-olide ((1S,7S,10R,13R)-7-acetoxy-4,8,13-trimethyl-11-oxabicyclo[8.3.0]trideca-4(E),8(Z)-dien-12-one) by X-ray diffraction analysis. 2D¹H−¹H (COSY) and¹³C−¹H (COSY) NMR spectroscopy was used for assigning the¹H and¹³C NMR signals in the spectra of ajanolide A. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 167–170, January, 1998.     

Synthesis and antioxidant activity of phenolic derivatives ofα-santonin

Phenolic derivatives of-santonin have been synthesized and their antioxidant effect has been studied.Institute of Phytochemistry, National Academy of Sciences of the Republic of Kazakhstan, Karaganda. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 247–249, March–April, 1997.     

[4+2]-Cyclodimer of sabinone: formation,crystal structure,and NMR spectra

Oxidation of (+)-sabinol, (1S,3R,5S)-1-isopropyl-4-methylidenebicyclo[3.1.0]hexan-3-ol, by active MnO₂ afforded not the expected sabinone but only its [4+2]-cyclodimer. The molecular structure of the latter was established by X-ray diffraction analysis. The ¹H and ¹³C NMR spectra of this cyclodimer were interpreted using 2D NMR spectroscopy.     

A chemical investigation ofAchillea nobilis

From the flower heads and leaves ofAchillea nobilis collected in the flowering phase close to Balytkykol, Egindybulak region, Karaganda Province, Kazakh SSR, by extraction with chloroform and chromatography of the combined substances on a column of silica gel we have isolated a new sesquiterpene lactone anobin C₁₅H₂₀O₅, mp 175.5–177.5°C and have identified for the first time estafiatin, C₁₅H₁₈O₃, mp 102–104°C []²⁰ –10.3° (chloroform); hanphyllin, C₁₅H₂₀O₃, mp 189°C (decomp), [] _D ²⁰ + 58.6° (c 0.39; chloroform), and 3,5-dihydroxy-6,7,8-trimethoxyflavone, C₁₈H₁₆O₇, mp 148–150°C. On the basis of chemical and spectral characteristics it has been established that anobin has the structure of 4,10-dihydroxy-2,3-epoxy-5,7(H),6(H)-guai-11(13)-en-6,12-olide. It has been established that estafiatin possesses a pronounced growth regulating activity.Deceased.Chemical and Metallurgical Institute, Academy of Sciences of the Kazakh SSR, Karaganda. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 603–607, September–October, 1984.     

Chemical modification of estafiatin

The halogenation, epoxidation, acetylation, and oxidation of the sesquiterpene--lactone estafiatin (I) has given eight derivatives. It has been shown that during the epoxidation of estafiatone (IV) the formation of a -lactone takes place as the result of the Bayer-Villiger oxidation of the cyclopentanone fragment. A stereoselective conversion of estafiatin into the known natural guaianolide isozaluzanin C is described. The structures of the derivatives synthesized were established on the basis of their IR, UV, PMR, and mass spectra.Institute of Organic Synthesis and Coal Chemistry, Kazakh Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 648–653, September–October, 1991.     

Transannular cyclization of the E,E-germacradienolide hanphyllin

The results are reported of the interaction of the trans,trans-germacradienolide hanphyllin with m-chloroperbenzoic acid and with 50% sulfuric acid. This leads to a cyclization reaction with the formation of eudesmanolides: 1-hydroxy-3-oxo-1,4,5,7(H),6(H)-eudesm-11(13)-en-6,12-olide, ridentin B, and 3-hydroxy-5,7(H),6(H)-eudesma-4(15),11(13)-dien-6,12-olide; and also products of the opening of the lactone ring as a consequence of transesterification. The structures of the compounds obtained are discussed on the basis of spectral results (IR, PMR, and mass spectra) and of x-ray structural analysis.Institute of Organic Synthesis and Coal Chemistry, Kazakhstan Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 508–517, September–October, 1992.