A new taxane from <Emphasis Type="Italic">Taxus canadensis</Emphasis> needles

A new 6/8/6-membered taxane was isolated from the needles of Taxus canadensis. The structure was characterized as 10β,13α-diacetoxy-5α,9α-dihydroxytaxa-4(20),11-diene (1) on the basis of 1D and 2D spectrascopic data.     

Two new ceramides from <Emphasis Type="Italic">Zephyranthes candida</Emphasis>

Two new ceramides were isolated from the bulbs of Zephyranthes candida. Their structures were established as (2S,3S,4R,13E)-1,3,4-trihydroxy-2-[(2′R)-2′-hydroxytetracosanoylamino]-13-octadecene, named zephyranamide A (1) and (2S,3S,4R)-1,3,4-trihydroxy-2-octacosanoylaminohexadecene, named zephyranamide B (2). The structures of the new compounds were elucidated by spectral techniques including ¹H NMR, ¹³C NMR, as well as HSQC, HMBC, DEPT, and COSY.     

Two new coumarins from <Emphasis Type="Italic">Euonymus hamiltonianus</Emphasis>

Two new coumarins, euonidiol (1) and euoniside (2), and a known flavone, luteolin 7-methyl ether, were isolated from the aerial parts of the plant Euonymus hamiltanianus Wall. All the compounds were characterized on the basis of spectral analysis viz. ¹H NMR, ¹³C NMR, DEPT, IR, UV, ESI-MS, and elemental analysis. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 10–11, January–February, 2008.     

<Emphasis Type="Italic">Z</Emphasis>-and <Emphasis Type="Italic">E</Emphasis>-conformers of <Emphasis Type="Italic">N</Emphasis>-chloroacetylcytisine

N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated.     

A new <Emphasis Type="Italic">N</Emphasis>-containing cucurbitacin from <Emphasis Type="Italic">Hemsleya endecaphylla</Emphasis>

A new cucurbitacin, endecaphyllacin C, was isolated from the tubers of Hemsleya endecaphylla. The structure was elucidated as 2β,16α,20β,25-tetrahydroxy-24-acetylaminocucurbita-5-en-3,11,22-trione (1) on the basis of extensive 1D and 2D NMR techniques, including COSY, HMBC, HMQC, and NOESY correlations, as well as HR-FAB-MS analysis.     

Triterpene glycosides from <Emphasis Type="Italic">Lonicera</Emphasis>. Isolation and structural determination of seven glycosides from flower buds of <Emphasis Type="Italic">Lonicera macranthoides</Emphasis>

The structures of seven triterpene glycosides (1–7), of which the 23-O-acetyl, 28-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin 3-O-β-D-glucopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside (2) was new, from the flower buds of Lonicera macranthoides were established using chemical and NMR spectroscopic methods. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 32–34, January–February, 2008.     

Two new isomeric lignans from <Emphasis Type="Italic">Eusideroxylon zwageri</Emphasis>

Two new lignans were isolated with two other known compounds, eusiderin A and eusiderin I, from Eusideroxylon zwageri (billian). The two new lignans have isomeric structure. The structures of the new lignans were determined to be (2R,3R,4S)-2,3-dimethyl-6,7-dimethoxy-4-ethoxy (3′,4′,5′-trimethoxybenzene)-1,5-dihydroxytetralin and (2R,3S,4S)-2,3-dimethyl-6,7-dimethoxy-4-ethoxy(3′,4′,5′-trimethoxybenzene)-1,5-dihydroxytetralin. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 303–305, May–June, 2009.     

A new 3,4-dihydroisocoumarin isolated from <Emphasis Type="Italic">Botryosphaeria</Emphasis> sp<Emphasis Type="Italic">.</Emphasis> F00741

A new 3,4-dihydroisocoumarin, named botryoisocoumarin A (1), was obtained from the fermentation culture of Botryosphaeria sp. F00741, together with two known ones, 3,8-dihydroxy-3-methylisochroman-1-one (2) and 4,8-dihydroxy-3-methylisochroman-1-one (3). Their structures were elucidated by spectroscopic analyses, including 1D and 2D NMR experiments and ESI mass spectrometry, and by comparison with those reported. Compound 1 was evaluated for its antitumor and antimicrobial activities in vitro.     

Triterpene glycosides from <Emphasis Type="Italic">Lonicera</Emphasis>. II. Isolation and structural determination of glycosides from flower buds of <Emphasis Type="Italic">Lonicera macranthoides</Emphasis>

Two new triterpenoid saponins, lonimacranthoide II (8) and III (9), were isolated from the flower buds of Lonicera macranthoides Hand.-Mazz. (Caprifoliaceae), as well as one known saponin 10. The structures of the saponins were established based on chemical and spectral methods.     

Copolymer of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride with maleic acid as drug carrier

A copolymer of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid of constant composition was prepared under the conditions of radical initiation. The possibility of the functionalization of the copolymer with drugs containing amino groups by polymer-analogous transformations was examined. Conditions were found for preparing conjugates of the copolymer with isoniazid. The structures and the quantitative compositions of the conjugates were determined by ¹³С NMR spectroscopy, and the possibility of preparing conjugates with controlled drug content was demonstrated.     

Molecular properties of the copolymers of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride and maleic acid

The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes. In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm. The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along the chain contour.     

Two new isoflavonoid monogalactosides from <Emphasis Type="Italic">Trifolium pratense</Emphasis> roots

Formononetin and the new isoflavonoid glycosides formononetin-7-O-β-D-galactopyranoside and inermin-3-O-β-D-galactopyranoside were isolated from Trifolium pratense L. roots. The structures of the isolated compounds were proved using chemical transformations and UV, PMR, and ¹³C NMR spectra. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 21–23, January–February, 2008.     

Lipids from <Emphasis Type="Italic">Halostachys caspica</Emphasis> and <Emphasis Type="Italic">Halocharis hispida</Emphasis>

The composition of lipids from the aerial parts of two species of halophytes from the family Chenopodiaceae, Halostachys caspica C. A. Mey. and Halocharis hispida Bge. was determined. Neutral lipids (NL, 62.1 and 54.2%, respectively) dominated the total lipids (TL) of these plants. More than a third of the NL were esters of aliphatic alcohols and phytosterols (FAE). Fatty acids 16:0, 18:1, and 18:2 dominated the acids of FAE; 16:0, 18:1, and 18:3, the phospholipids. The principal fatty acids of glycolipids were unsaturated acids (68.3 and 75.1%) with linolenic acid dominating (44.9 and 43.5%). Presented at the 7th International Symposium on the Chemistry of Natural Compounds, Tashkent, October 16–18, 2007. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 276–278, May–June, 2009.     

<Emphasis Type="Italic">seco</Emphasis>-Kaurane skeleton diterpenoids from <Emphasis Type="Italic">Croton oblongifolius</Emphasis>

A new seco-kaurane type diterpenoid, ent-3,4-seco-17-oxo-kaur-4(19),15(16)-dien-3-oic acid, and a known compound, ent-3,4-seco-kaur-4(19),16(17)-dien-3-oic acid, were isolated from the stem bark of Croton oblongifolius. The structures of these compounds were established on the basis of spectroscopic data.     

Triterpene glycosides from <Emphasis Type="Italic">Astragalus</Emphasis> and their genins. XC. Askendoside K from <Emphasis Type="Italic">Astragalus taschkendicus</Emphasis>

A new triterpene cycloartane glycoside called askendoside K was isolated from roots of Astragalus taschkendicus Bunge (Leguminosae). The structure of this glycoside was established using chemical and biochemical transformations and spectral data. Askendoside K was a bisdesmoside of cycloorbigenin C and had the structure 23R,24R-cycloartan-3β,6α,16β,23,24,25-hexaol 3-O-[(α-L-arabinopyranosyl)(1 → 2)-β-D-xylopyranoside],23-O-[(β-D-glucuronopyranosyl)(1 → 2)-β-D-glucopyranoside].