Chemical constituents from seeds of <Emphasis Type="Italic">Lactuca sativa</Emphasis>

A new flavonol glycoside with a rare structure type, lactucasativoside A (1), was isolated from the seeds of Lactuca sativa, together with three known compounds, japonicin A (2), isoquercitrin (3), and caffeic acid (4). Their structures were established on the basis of extensive spectroscopic analysis. Compound 2 was obtained from the genus Lactuca for the first time.     

Chemical constituents from the fruits of <Emphasis Type="Italic">Ligustrum lucidum</Emphasis>

One new δ-valerolactone (1) and one new natural phenolic glycoside 2, together with four known compounds 3–6, were isolated from the fruits of Ligustrum lucidum. Their structures were elucidated on the basis of spectral data. The chemical transformation from 2 to 3 was observed. The immunomodulatory activities of the compounds were also evaluated.     

<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.     

Glucofructans from <Emphasis Type="Italic">Taraxacum officinale</Emphasis> roots

The structure of glucofructans from Taraxacum officinale roots growing in Buryatia was studied by chemical, chromatographic, and spectral methods. It was found that fructose,glucose, saccharose, 1-kestose, and nystose were present in the free state. The structures of the two dominant polymeric compounds, TGf-1 (5.7 kDa) and TGf-2 (2.6 kDa), which were linear inulin-type macromolecules consisting of fructofuranose units bonded through β-(2→1)-bonds, were studied. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 125–127, March–April, 2009.     

Chemical constituents isolated from the fungus <Emphasis Type="Italic">Monascus</Emphasis> sp.

Further study of a 95% EtOH extract of red mold rice fermented with the yellow mutant of the fungus Monascus sp. led to the isolation of one new chroman derivative, namely monascuskaochroman (1), together with nine known compounds. The structure of the new compound was determined as 4-(1-hydroxy-1-methyl- ethyl)-chroman-4-carboxylic acid amide. The known compounds were identified as monascin (2), ankaflavin (3), (3R,6R,7E)-(+)-3-hydroxy-4,7-megstigmadien-9-one (4), vanillin (5), syringic acid (6), 3,4,5-trimethoxybenzoic acid (7), trans-methyl p-coumarate (8), ferulic acid (9), and methyl N-methyl anthranylate (10).This is the first report of a naturally occurring chroman skeleton isolated from Monascus species. Compounds 4–10 were isolated from this species for the first time. Their structures were elucidated by 1D and 2D NMR spectroscopy together with HR-ESI-MS analysis, and comparison of the spectroscopic data with those reported for structurally related compounds.     

Glucofructans from <Emphasis Type="Italic">Saussurea lappa</Emphasis> roots

Glucofructans from Saussurea lappa (Asteraceae) roots were studied. It was found that free fructose and oligomeric glucofructans (saccharose, 1-kestose, nystose, 1^F-β-fructofuranosylnystose, and 1^F-β-fructofuranosyl-1^F-β-fructofuranosylnystose) were present. The dominant polymer Sl-GF (MW 51.4 kDa), which was a linear inulin-type glucofructan consisting of β-(2 → 1)-bonded fructofuranose units, was isolated and characterized. The total content of glucofructans in Saussurea lappa roots was 476.97–578.27 mg/g.     

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.     

Chemical and biologically active constituents of <Emphasis Type="Italic">Salsola collina</Emphasis>

A new natural product (N-acetyltryptophan), together with 22 known constituents, including seven alkaloids, six flavonoids, six organic acids, and other compounds, were isolated from Salsola collina Pall. Their structures were elucidated on the basis of chemical reaction and spectral evidence. Among the isolated compounds, N-acetyltryptophan (8) showed moderate inhibition of a-amylase activity, and terrestric acid (9) showed positive antifungal activity.     

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.     

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.     

New lignans from <Emphasis Type="Italic">Syringa reticulata</Emphasis> var. <Emphasis Type="Italic">mandshurica</Emphasis>

In the search for platelet-activating-factor (PAF) antagonists, two new lignan compounds were isolated from the leaves of Syringa reticulata Hara var. mandshurica. Their structures were elucidated as (7R,8S, 8'S)-3,4,3',4'-dimethylenedioxy-8,9-dihydroxy-8.8', 7-O-9'-lignan (mandshuricol A) and (7R,8S,8'S)-3',4'methylenedioxy-4-methoxy-3,8,9-trihydroxy-8.8', 7-O-9'-lignan (mandshuricol B), Mandshuricol A and B showed antagonistic activity on PAF in the [³H] PAF receptor binding assay with IC₅₀ values of 4.8 × 10^–5 M and 3.5 × 10^–5 M, respectively.