Steroid glycosides from the starfishSolaster dawsoni (Verrill)

Two novel glycosides from the starfishSolaster dawsoni (Verrill) have been isolated and characterized: 24-O-(-D-xylopyranosyl)-5-cholestane-3,6,15,24,26-pentaol (solasteroside S₁) and (24R)-29-O-[-D-galactofuranosyl-(16)--D-galactofuranosyl]-24-ethyl-5-cholestane-3, 6,8,15,16,29-hexaol (solasteroside S₂).Translated fromIzvestiya Akademu Nauk. Seriya Khimicheskaya, No. 5, pp. 980–982, May, 1993.     

New triterpenoid glycosides fromThalictrum minus L.

Two triterpenoid diglycosides of the cycloartane series were isolated from the terrestrial part ofThalictrum minus L. (Ranunculaceae). Genins of these glycosides are side-chain structural isomers—3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20(S)-lanost-24(Z)-ene-3β, 16β, 22(S), 26, 29-pentaol and 3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20(S)-lanost-25-ene-3β, 16β,22(S), 24ζ, 29-pentaol. The structures of these glycosides were established using 1D and 2D NMR spectroscopy and FAB mass spectrometry. For Part 9, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1434–1437, July, 1998.     

Steroid polyols from the Far-Eastern starfish Henricia sanguinolenta

A new polyhydroxylated steroid (20R,24S)-5-cholestane-3,6,15,24-tetraol and a known glycoside, laeviuscoloside G, was isolated from the Far-Eastern starfish Henricia sanguinolenta, collected in the sea of Okhotsk, and characterized.     

Triterpene glycosides from Pulsatilla chinensis

Four triterpene glycosides were isolated from the roots of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae). Two new glycosides, chinensiosides A (1a) and B (2), were identified as 3-O-[-L-rhamnopyranosyl-(12)--L-arabinopyranosyl]-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid and 3-O-{-L-rhamnopyranosyl-(12)-[-D-glucopyranosyl-(14)]--L-arabinopyranosyl}-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid. The other two glycosides were identified as previously known hederasaponin C (3) from Hedera helix and glycoside III (4) from Pulsatilla cernua.     

Steroid compounds from the starfish Lysastrosoma anthosticta collected in the Sea of Japan

Six polyhydroxylated steroids and their derivatives were isolated from the starfish Lysastrosoma anthosticta collected in the Posyet Bay, Sea of Japan. These include a new glycoside of the steroid polyol, lysastroside A (1), which was identified as (25S)-26-O--d-xylopyranosyl-5-cholestane-3,6,8,15,16,26-hexaol, and the previously known pycnopodioside C monoglycoside (2), marthasterone sulfate (3), (25S)-5-cholestane-3,6,8,15,16,26-hexaol (4), (25S)-5-cholestane-3,6,7,8,15,16,26-heptaol (5), and (25S)-5-cholestane-3,6,7,8,15,16,26-heptaol (6). The compounds were tested for the haemolytic activity and the action on the embryogenesis of the sea urchin Strongylocentrotus intermedius.     

Steroidal polyols from Far-Eastern starfishes Henricia sanguinolenta and H. leviuscula leviuscula

Two new compounds were isolated from two Far-Eastern starfish species, Henricia sanguinolenta and H. leviuscula leviuscula, collected in the Sea of Okhotsk, viz., the glycoside sanguinoside C, (20R,22E,24R,25S)-3-O-(2,3,4-tri-O-methyl--xylopyranosyl)-24-methyl-5-cholest-22-ene-3,4,6,8,15,26-hexol, and a steroidal ketone, (20R,24S)-3,6,24-trihydroxy-5-cholestan-15-one. They exhibit moderate cytostatic activity with respect to the eggs of sea urchin Strongylocentrotus intermedius.     

Flavonoid glycosides fromThalictrum squarrosum St. ex Willd. andThalictrum minus L.

Two flavonoid allose diglycosides were found in the terrestrial part ofThalictrum squarrosum St. ex Willd. andT. minus L. (Ranunculaceae). 7,4′-Di-O-β-allopyranosylapigenin was isolated fromT. minus. InT. squarrosum, its monoacetate was also found and characterized as 7-O-(6-O-acetyl-β-allopyranosyl)-4′-O-(β-allopyranosyl)apigenin. The sites of attachment of the carbohydrate residues were determined by HMBC; the location of the acetate group was identified by ROESY. Both substances were isolated from these plants for the first time. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 392–394, February, 1999.     

Steroid compounds from the Pacific starfish Lysastrosoma anthosticta

Two new steroid compounds, 3,6-dihydroxy-5-cholesta-9(11),24-dien-23-one 3-sulfate and 3,6-dihydroxy-5-cholest-9(11)-en-23-one 3-sulfate, were isolated from the Pacific starfish Lysastrosoma anthosticta as the corresponding sodium salts and identified. Two previously known glycosides of 24(S)-5-cholestane-3,6,8,15,24-pentol were also isolated and identified as sodium 24-O--d-glucopyranoside 6"-sulfate (pycnopodioside C) and sodium 24-O--d-xylopyranoside 4"-sulfate (luridoside A).     

New flavonoid oligoside fromAconitum barbatum Pers.

A new flavonoid oligoside,viz. 3-O-[3,4-)di-O-acetyl-β-xylopyranosyl)-α-rhamnopyranosyl]-7-o-(α-rhamnopyranosyl)kaempferol, was isolated from the above-ground part of the plantAconitum barbatum Pers. The product was identified by spectral methods. Published inIzvestiyu Akademii Nauk. Seriya Khimicheskaya. No. 11, pp. 1935–1937, November, 2000.     

Steroidal saponins and pregnane glycosides from Smilax microphylla

Six steroidal saponins and two pregnane glycosides were isolated from the BuOH subfraction of 70% EtOH extract of Smilax microphylla C.H.Wright, among them two were new compounds (1 and 7). Pregnane glycosides were firstly isolated from the genus Smilax (Smilacaceae). Structures of the new compounds were determined on the basis of HR‐ESI‐MS, 1D and 2D NMR spectroscopic analysis. Copyright © 2012 John Wiley & Sons, Ltd.     

New lipids from the soft corals of the Andaman Islands

Sphingolipids and glycolipids including previously unknown (2S,3S,4R)-1,3,4-trihydroxy-2-(2-(R)-hydroxyoctadecanoylamino)octadec-8E-ene, (2S,3R)-1,3-dihydroxy-2-octadecanoylamino-4E,8E-hexadecadiene, and (2-hydroxy-3-hexadecyloxypropyl)--L-fucopyranoside were isolated from soft corals collected on the shelf near the Andaman Islands (Indian Ocean). The structures of all compounds were established by spectroscopic methods and chemical analyses. The lipids possessed antibacterial activity against Bacillus subtilis, Bacillus pumilus, Escherichia coli, and Pseudomonas aeruginosa and antifungal activity against Aspergillus niger, Rhizopus oryzae, and Candida albicans.     

Structure elucidation and NMR spectral assignments of three new lignan glycosides from Akebia trifoliata

Three new lignan glycosides (1-3) were isolated from the stems of Akebia trifoliata. Their structures were elucidated as (7R,8R,7'R,8'R)3,3',5,5'tetramethoxy-4,4'dihydroxy-7,9':7',9-diepoxylignan-4-O-beta-D-glucopyranoside (1), (7S,8S,8'R)-4,4',9-trihydroxy-3,3',5,5'-tetramethoxy-7,9'-epoxylignan-7'-one 9-O-beta-D-glucopyranoside (2), (7R,8R,8'S)-4,4',9-trihydroxy3,3',5,5'-tetramethoxy-7,9'-epoxylignan-7'-one 9-O-beta-D-glucopyranoside (3) by spectral analyses, primarily NMR, MS and CD. The NMR assignments for the compounds were carried out using 1H, 13C, DEPT, COSY, HSQC, HMBC and ROESY NMR experiments.     

Comparison of the effects of the intra- and intermolecular hydrogen bonds C-H...X (X = O,N) in1H and13C NMR spectra

A similarity between manifestations of the effects of the intra- and intermolecular hydrogen bonds C-H...X (X = O, N) in¹H and¹³C NMR spectra has been shown. A correlated increase in the direct spin-spin coupling constant¹³C—¹H and the chemical shifts of the proton participating in the interaction has been observed.Translated fromIzvestiya Akademii Nauk. Seriyo Khimicheskaya, No. 5, pp. 1205–1207, May, 1996.     

Brauhenefloroside E and F; acylated flavonol glycosides from Stocksia brauhica Linn

Two new acylated flavonol glycosides, 3‐O‐{[2‐O‐β‐D ‐glucopyranosyl]‐3‐[O‐β‐D ‐glucopyranosyl]‐4‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]}‐α‐L ‐rhamnopyranosyl‐kaempferol 7‐O‐α‐L ‐rhamnopyranoside and 3‐O‐{2‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]‐3‐[O‐β‐D ‐glucopyranosyl]‐4‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]}‐α‐L ‐rhamnopyranosyl‐kaempferol 7‐O‐α‐L ‐rhamnopyranoside, trivially named as brauhenefloroside E (1) and F (2), respectively, were isolated from the fruits of Stocksia brauhica and their structures were elucidated using spectroscopic methods, including 2D NMR experiments. Copyright © 2010 John Wiley & Sons, Ltd.     

Structural study of oxalamide compounds: H, C, and DFT calculations

The conformational properties of some N-alkyl, N,N′-dialky, and tetraalkyloxalamides have been investigated, in vacuo and in solvent using DFT methods at the B3LYP/6-31G^∗∗ computational level. Special emphasis has been given on oxalamides with substituents of the type -CH₂CH₂OH. In oxalamides with the N-H group (N-alkyl and N,N′-dialky), the most stable conformations are those in which the oxalamide moiety adopts a planar s-trans arrangement and the amide bonds are trans. A different situation appears in the case of tetraalkyloxalamides, in which the oxalamide moiety always adopts a skewed arrangement and there are conformations with similar energy. A careful study of ¹³C and ¹H NMR spectra together with theoretical calculations (GIAO method) allowed the assignment of the signals of these conformers. The presence of the -CH₂CH₂OH chain produces numerous rotamers. The most stable rotamers, in vacuo, are those with strong intramolecular hydrogen bonds, however in solvent, hydrogen bonds are not crucial to establish the most stable specie and depend on the solvent used.     

Synthesis and Stereochemistry of New N-Substituted Cytisine Derivatives

A series of new N-substituted cytisine derivatives was synthesized. The ¹ H and ¹³ C NMR spectra of certain compounds exhibit a doubled set of signals. This is explained by formation of diastereomeric pairs in compounds containing an asymmetric center in the substituents. The signal splitting in -COHC=CHCO ₂ H and HC=O (formyl) derivatives is explained by the existence of Z and E invertomers. Their stereochemical features are discussed. Amide conjugation is confirmed by temperature experiments.     

1-(1-Adamantyl)diaziridine

The reaction of 1-aminoadamantane with CH₂O and H₂NOSO₃H in the presence of K₂CO₃ under phase-transfer conditions leads to hitherto unknown 1-(1-adamantyl)diaziridine and (1-adamantyl)aminoacetonitrile, characterized by spectral data. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 861–862, April, 1997.     

Serratene triterpenoids fromLycopodium clavatum L. (Lycopodiaceae)

Three serratene triterpenoids, 3\,21α-dihydroxy-26-nor-8,14-sekogammaser-14(27)-en-n-8-one (1), 3ß,21a-dihydroxy-8,14-sekogammasera-8(26),14(2?)-diene (2), and 3α,21ß,24-trihydroxyserrat-14-ene (3), were isolated from the Siberian chemorace ofLycopodium clavatum L. and identified. Compound1 was isolated fromL. clavatum L. for the first time.     

Steroid compounds from the Pacific starfishesLuidia quinaria andDistolasterias elegans

One new and four previously known steroid compounds were identified from the Pacific starfishesLuidia quinaria andDistolasterias elegans. The structure of the new steroid was established from spectral data and chemical correlations with other steroids such as 5-cholestane-3,5,6,15,16,26-hexaol 3-sulfate (1). The previously known compounds were identified as 5-cholestane-3,5,6,15,26-pentaol 15-sulfate (2) fromLuidia quinaria and sodium (24S)-O-(-d-giucopyranosyll-5-cholestane-3,6,8,15,24-pentaol 6-sulfate (3), sodium (24S)-5-cholestane-3,6,8,15,24-pentaol 24-sulfate (4), and sodium tornasterol A sulfate (5).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 473–476, February, 1996.