Triterpene glycosides of Thalictrum squarrosum. IV. Structures of squarrosides A1, A2, B1, and B2

Four new cycloartane glycosides have been isolated from a methanolic extract ofThalictrum squarrosum Stephan ex Willd.: squarroside A1 (I) — (21R, 22S, 23R)-3-(-D-glucopyranosyloxy)-21-methoxy-21,23-epoxycycloart-24-ene-22,30-diol, C₃₀H₆₀O₁₀; squarroside A2 (II) — the (21S)-epimer of compound (I); squarroside B1 (III) (21R, 22S, 23R)-3gb-[O--L-rhamnopyranosyl-(1 6)--D-glucopyranosyloxy]-21-methoxy-21,23-epoxycycloart-24-ene-22,30-diol, C₄₃H₇₀O₁₄; and squarroside B2 (IV) — the (21S)-epimer of compound (III). The proposed structures were determined on the basis of¹H and¹³C NMR spectroscopy, FAB mass spectrometry, and chemical transformations.Irkutsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 516–523, July–August, 1989.     

Triterpene glycosides of Thalictrum squarrosum. III. Structures of squarrogenins 1 and 2

Two genins — squarrogenin 1 and squarrogenin 2 — have been isolated from nodding meadow rue by the hydrolysis of squarrosides A1 and A2. The compounds are epimeric at C-21 and have the following structures: 1 — (21R, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3,22-30-triol, C₃₁H₅₀O₅, mp 169–171°C (hexane-acetone), [] ₅₄₆ ²⁰ –11.06° (c 4.52; pyridine); and 2 — (21S, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3,22,30-triol, C₃₁H₅₀O₅, mp 190–193°C (hexane-acetone), [] ₅₄₆ ²⁰ +106.6° (c 0.3; pyridine). The results of¹H and¹³C NMR spectroscopy and of mass spectrometry for the new compounds are given.Irkutsk Institute of Organic Chemistry, Siberian Division of the USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 510–516, July–August, 1989.     

Triterpene glycosides of Thalictrum squarrosum. III. Structures of squarrogenins 1 and 2

Two genins — squarrogenin 1 and squarrogenin 2 — have been isolated from nodding meadow rue by the hydrolysis of squarrosides A1 and A2. The compounds are epimeric at C-21 and have the following structures: 1 — (21R, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3β,22β-30-triol, C₃₁H₅₀O₅, mp 169–171°C (hexane-acetone), [α] ₅₄₆ ²⁰ ?11.06° (c 4.52; pyridine); and 2 — (21S, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3β,22β,30-triol, C₃₁H₅₀O₅, mp 190–193°C (hexane-acetone), [α] ₅₄₆ ²⁰ +106.6° (c 0.3; pyridine). The results of¹H and¹³C NMR spectroscopy and of mass spectrometry for the new compounds are given.     

Steroids of the furostan and spirostan series from Nolina microcarpa II. structures of nolinospiroside D and nolinofurosides D,E, and F

In addition to the know steroid sapogenin (25S)-ruscogenin (I), three new glycosides have been isolated from the leaves ofNolina microcarpa S. Wats. (family Dracaenacea), and the following structures are suggested for them: (25S)-spirost-5-ene-1β,3β-diol 1-O-β-D-fucopyranoside (nolinospiroside C, II), (25S)-furost-5-ene-1β,3β,22α,26-tetraol 1-O-β-D-fucopyranoside (nolinofuroside A, III), and (25S)-furost-5-ene-1β, 3β, 22α, 26-tetraol 1-O-β-D-fucopyranoside 26-O-β-D-glucopyranoside (nolinofuroside C, V). M. V. Frunze Simferopol' State University. Institute of Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 672–678, September–October, 1991.     

New polyhydroxysteroids and steroid glycosides from the far east starfishCeramaster patagonicus

Two new polyhydroxysteroids and five new glycosides were isolated from the starfishCeramaster patagonicus and their structures were elucidated: 5α-cholestane-3β,6α,15β,16β,26-pentol, (22E)-5α-cholest-22-ene-3β,6α,8,15α,24-pentol, (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,4β, 6α,8,15β,16β,28-heptol (ceramasteroside C₁), (22E)-28-O-[O-(2,4-di-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β, 6α,8,15β,16β,28-hexol (ceramasteroside C₂), (22E)-28-O-[O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,6α,8,15β,16β 28-hexol (eramasteroside C₃), (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-methyl-5α-cholest-22-ene-3β,4β,6α,8, 15β, 26-hexol (ceramasteroside C₄), and (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-xylopyranosyl]-5α-cholest-22-ene-3β,6α,8,15β,24-pentol (ceramasteroside C₅)). Three known polyhydroxysteroids (24-methylene-5α-cholestane-3β,6α,8,15β,16β,26-hexol, 5α-cholestane-3β,6α,8,15β,16β,26-hexol, and 5α-cholestane-3β,6β,15α,16β,26-pentol) were also isolated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 190–195, January, 1997.     

Glycosylation of triterpenoids of the dammarane series. X. Regio- and stereoselective synthesis of 20(S)-protopanaxadiol 3-O-β-D-glucopyranoside (ginsenoside Rh2)

The regio- and stereoselective synthesis of ginsenoside R_h2, which possesses antitumoral activity, has been effected by the glycosylation of 12β-acetoxydammar-24-ene-3β,20(S)-diol. Condensation with α-acetobromoglucose was carried out in the presence of silver oxide in dichloroethane at room temperature, and the yield of the desired glycoside amounted to 50%. A method for the selective protection of the C-12-OH group of dammar-24-ene-3β,12β,20(S)-triol [20(S)-protopanaxadiol] has been proposed. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, Vol. 6, pp. 813–816, November–December, 1989.     

Triterpene glycosides fromTupidanthus calyptratus I. Structure of glycosides B1, B2, F1, and F2 from leaves of hooded tupidanthus

Chromatographically inseparable mixtures of oleanolic and ursolic 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranosides (glycosides B₁ and B₂) and their 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl esters (glycosides F₁ and F₂) are isolated from the leaves ofTupidanthus calyptratus Hook f. (Araliaceae). The structures of the isolated glycosides are established from chemical methods and¹H and¹³C NMR spectra. Glycoside F₂ is a new triterpene glycoside. Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 627–633, September–October, 1999.     

Triterpene glycosides of Hedera taurica VI. Structures of hederosides G,H1, H2, and I from the berries of Crimean ivy

We have isolated from Crimean ivy berries in addition previously known triterpene glycosides — 3-O-α-L-arabinopyranosyl-28-O-[O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glycopyranosyl-(1 → 6)-β-D-glucopyranosyl]hederagenin, 3-O-[O-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl]-28-O-[O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glucopyranosyl-(1 → 6)-β-D-glycopyranosyl]hederagenin, the new triterpene glycosides hederoside H₂-3-O-[O-β-D-glycopyranosyl-(1 → 2)-β-D-glycopyranosyl-(1 → 2)-β-D-glucopyranosyl]-28-O-[O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]oleanolic acid- and hederoside I-3-O-[O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyl]-28-O-[O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]hederagenin. Details of their¹³C NMR spectra are given. M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 779–783, November–December, 1990.     

Oxidation of steroidal diols and triols with air/NaH

Abstract  

The unusual air oxidation of steroidal triols and diols in the presence of sodium hydride in THF is described. The initial oxidation product, ketone or aldehyde, frequently undergoes further transformations in the reaction medium. The course of the reaction depends on the stereochemistry of the substrate. For example, oxidation of (20R)-20-hydroxymethyl-6β-methoxy-3α,5α-cyclopregnane-16β,17α-diol with air/NaH afforded 6β-methoxy-23,24,25,26,27-pentanor-3α,5α-cyclofurostane-16α,17α-diol in 60% yield whereas similar reaction of (20R)-20-hydroxymethyl-6β-methoxy-3α,5α-cyclopregnane-16α,17α-diol gave 6β-methoxy-D-homo-16a-oxa-3α,5α-cycloandrostan-16-one in 30% yield. The objective of this preliminary study was to select alcohols susceptible to air/NaH oxidation and to establish the effect of conditions on the course of the reaction.     

Evasteriosides A and B and other sulfated steroids from the Pacific starfish <Emphasis Type="Italic">Evasterias retifera</Emphasis>

Two new polar steroidal glycosides identified as sodium (20R,22E,24R,25S)-3-O-(β-d-xylopyranosyl)-24-methyl-5α-cholest-22-ene-3β,6β,8,15α,26-pentol 26-sulfate (evasterioside A) and sodium (20R,22E)-24-O-(β-d-xylopyranosyl)-5α-cholest-22-ene-3β,6β,8,15α,24-pentol 3-sulfate (evasterioside B) were isolated from the Pacific starfish Evasterias retifera collected in the Sea of Japan. Five known compounds, viz., coscinasterioside B, aphelasterioside A, marthasterone 3-sulfate and (20R)-cholest-7-en-3β-ol and cholesterol sulfates, were identified. The structures of the new natural compounds were established using their 2D NMR and mass spectra and some chemical transformations.     

Triterpene glycosides ofHedera canariensis III. Determination of the structures of glycosides L-F1, L-F2, and L-I2 from the leaves of Algerian ivy

The leaves of Algerian ivyHedera canariensis Willd. (Araliaceae) have yielded two new triterpene glycosides — caulophyllogenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside (L-F₂) and its 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-gentiobiosyl ester (L-I₂) - and also the previously known hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-β-D-glucopyranoside (L-F₁). The structures of the glycosides were established on the basis of chemical transformations and¹H and¹³C NMR spectroscopy. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 777–781, November–December, 1998.     

Triterpene glycosides of Astragalus and their genins XXXIX. Cycloaraloside D from Astragalus amarus

The structure of a triterpene glycoside of the cycloartane series — cycloaraloside D, isolated from the roots ofAstragalus amarus Pall. (Leguminosae) — has been established on the basis of chemical transformations and spectral characteristics. Cycloaraloside D is 20R, 24S-epoxycycloartane-3β, 6α, 16β, 25-tetraol 3-0-[0-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranoside]. Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 526–528, July–August, 1991.     

Triterpene glycosides ofHedera taurica. XI. Structures of taurosides St-G1, St-H1, and St-H2 from the stems of Crimean ivy

The previously known glycosides 3-O-α-L-arabinopyranosyl-28-O-[α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl]hederagenin and 3-O-[α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranosyl]-28-O-[α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl]hederagenin and the new triterpene glycoside tauroside St-H₁ — 3-O-β-D-glucopyransyl-28-O-[α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl]hederagenin — have been isolated from the stems ofHedera taurica Carr. M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 571–579, July–August, 1993.     

7-Ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone (echinochrome A): A DFT study of the antioxidant mechanism. 1. Interaction of echinochrome A with hydroperoxyl radical

The molecular geometry and electronic structure of hydroxy-substituted naphthazarin (NZ)-7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone (echinochrome A, (Et)NZ(β-OH)₃, 1) were calculated by the B3LYP/6-311G(d) method. The influence of the (i) character of the β-OH groups dissociation and (ii) conformational mobility of molecule 1 and the anions, radicals, and radical anions derived from 1 on the energy of their reactions with hydroperoxyl radical was studied by the (U)B3LYP/6-31G and (U)B3LYP/6-311G(d) methods. The enol-enolic tautomerism due to the transfer of hydrogen atoms of α-OH groups and rotational isomerism of the β-OH groups at the C(2) and C(3) atoms and of the α-OH groups at the C(5) and C(8) atoms were studied. The equilibrium in the gas-phase reaction 1 + ^•OOH ⇄ (Et)(HO-β)₂NZ(β-O^•) + HOOH (1) (quenching of hydroperoxyl radical) is shifted to the separated reagents. Heterolysis of the O—H bond in one of the three β-hydroxy groups considerably reduces the energy of subsequent O—H bond homolysis in either of the two remaining β-hydroxy groups. As a consequence, the reaction (Et)(HO-β)₂NZ(β-O⁻) + ^•OOH ⇄ (Et)(HO-β,⁻O-β)NZ(β-O^•) + HOOH (2) (quenching of hydroperoxyl radical) becomes exothermic and the equilibrium is shifted to the formation of hydrogen peroxide. The Gibbs energy gain in reaction (2) varies from −6.4 to −10.9 kcal mol⁻¹ depending on which β-hydroxy group is involved in the O—H bond homolysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 400–415, March, 2007.     

Phytoecdysteroids of Rhaponticum carthamoides. II. Rhapisterone B

A new ecdysteroid (rhapisterone B) has been isolated from the seeds ofRhaponticum cathamoides (Willd.) Iljin. (familyCompositae). It has been shown that it is 2β, 3β, 11α, 14α, 20R, 24ξ-hexahydroxy-5β-cholest-7-en-6-one. Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 806–808, November–December, 1991.     

Steroid compounds from ophiuroids II. Sulfated steroids from Ophiura sarsi and Ophiura leptoctenia

The previously described cholest-5-ene-3,4,21-triol 3-(sodium sulfate) has been obtained from extracts of the Far Eastern ophiuroidOphiura leptoctenia. Two new sulfated steroid polyols have been isolated from the ophiuroidO.sarsi; cholest-5-ene-3,4,21-triol 3,21-di(sodium sulfate) and cholest-5-ene-2,3,21-triol tri(sodium sulfate). The new polyol 4-acetoxycholest-5-ene-3,21-diol has been identified among the products of the desulfation of this ophiuroid.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 483–487, July–August, 1990.     

Steroids of the spirostan and furostan series from nolina microcarpa III. Structure of nolinofurosides G and H

Two new glycosides which have been called nolinofurosides G(I) and H(III), have been isolated from the leaves ofNolina microcarpa. Nolinofuroside G is the sodium salt of 26-β-D-glucofuranosyloxy-(25S)-furost-5,20(22)-diene-1β, 3β-diol 1-sulfate, and nolinofuroside H is the sodium salt of 1-β-D-fucopyranosyloxy-26-β-D-glucopyranosyloxy-(25S)-furost-5,20(22)-dinen-1β-3β-ol 3-sulfate. M. V. Frunze Simferopol' State University. Institute of the Chemistry of Plant Substances, Uzbek. Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 801–806, November–December, 1991.     

Molecular and crystal structure of the germacranolides salonitenolide and hanphyllin

A sesquiterpene lactone of the germacrane type, salonitenolide, has been isolated for the first time from the epigeal part ofCentaurea pseudomaculosa Dobrocz (spotted centaurea) and has been identified. The structures of the germacranolides and hanphyllin have been determined by the method of x-ray structural analysis: salonitenolide is 8-hydroxy-6β,8β(H)7α(H)-germacra-1(10),4,11(13)-trien-6,12-olide and hanphyllin is 3-hydroxy-3α,7α(H),6β(H)-germacra-1(10),4,11(13)-trien-6,12-olide. It has been established that the ten-membered rings of salonitenolide and hanphyllin are of the chair-chair type,₁D¹⁴,¹⁵D₅. On the basis of the results of CD spectroscopy, the chiral centers in the hanphyllin molecule have been assigned the 3S, 6R, and 7S configurations. Institute of Organic Synthesis and Coal Chemistry, Kazakh SSR Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Heteroorganic Compounds, USSR Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 781–785, November–December, 1989.     

Withasteroids of Physalis. IX. Physangulide — The first natural 22S-withasteroid

A new withasteroid — physangulide — has been isolated from the leaves ofPhysalis angulata L. It has been shown that physangulide is the first natural 22S-withanolide. Its structure has been determined as 3β,4β,20,24,25-pentahydroxy-1-oxo-5β,6β-epoxy-20R,22S,24S,25R-withanolide. Its¹H and¹³C NMR spectra, confirming this interpretation, are given. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 366–371, May–June, 1990.     

Artenolide — A new disesquiterpenoid fromArtemisia absinthium

A new steroid glycoside — alliospiroside B (I) — has been isolated from the collective fruit ofAllium cepa L. On the basis of chemical transformations and with the aid of physicochemical measurements it has been established that compound (I) has the structure of (25S)spirost-5-ene-1,3-diol 1-O-[O--L-rhamnopyranosyl-(1 2)--D-galactopyranoside. Compound (I) C₃₉H₆₂O₃, mp 200–202°C (from ethanol). [] _D ²⁰ –110.9±2° (c 1.01; pyridine) was obtained by extracting the collective fruit ofA. cepa with ethanol folowed by the column chromatographic separation of the combined glycosides on silica gel. The acid hydrolysis of (I) gave (25S)-ruscogenin (II), C₂₇H₄₂O₄, mp 189–191°C, [] _D ²³ –104.1±2° (c 0.98; pyridine). The¹H and¹³C NMR spectra are given for both compounds and the IR spectrum for compound (I).Institute of the Chemistry of Plant Substances of the Uzbek SSR, Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 589–592, September–October, 1986.