Antioxidant flavonoids from <Emphasis Type="Italic">Tamus communis</Emphasis> ssp. <Emphasis Type="Italic">cretica</Emphasis>

A new flavonoid, kaempferol-3,4′-di-O-α-L-rhamnopyranoside (1), and three known flavonoids (2–4) were isolated from the aerial parts of T. communis L. The structure of the new compound was elucidated on the basis of spectroscopic data. Compounds 1 and 2 showed significant antioxidant activity (IC₅₀ 187.151 ± 0.821 μM, and 92.079±0.513 μM, respectively), whereas compounds 3 and 4 showed moderate activity in DPPH free radical scavenging assays. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 295–297, May–June, 2009.     

A new stilbene glycoside from the <Emphasis Type="Italic">n</Emphasis>-butanol fraction of <Emphasis Type="Italic">Veratrum dahuricum</Emphasis>

A new stilbene glycoside, 5-methylresveratrol-3,4′-O-β-D-diglucopyranoside (1), was isolated from the n-butanol fraction of the rhizomes of Veratrum dahuricum, together with five known stilbenoids: resveratrol-3-O-β-D-glycoside (2), 4′-methylresveratrol-3-O-β-D-glycoside (3), oxyresveratrol-4′-O-β-D-glycoside (4), oxyresveratrol-3-O-β-D-glycoside (5), and oxyresveratrol-3,4′-O-β-D-diglycoside (6), and found for the first time in the investigated plant. The structures of six isolates were identified on the basis of 1D and 2D NMR data. Compounds 1–6 showed platelet aggregation inhibition, and compound 1 had an IC₅₀ value of 383.6 μM against platelet aggregation induced by AA. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 279–282, May–June, 2009.     

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.     

Minor polyphenols from <Emphasis Type="Italic">Maackia amurensis</Emphasis> wood

The rare α,4,2′,4′-tetrahydroxydihydrochalcone, flavanones liquiritigenin and naringenin, isoflavones calycosin and 5-methoxydaidzein, and reduced stilbene dihydroresveratrol were isolated for the first time from Maackia amurensis wood. The structures of the pure compounds were established using 2D NMR COSY, NOE, HMBC, and HSQC experiments. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 575–577, November–December, 2008.     

Iridoids from <Emphasis Type="Italic">Symphoricarpos albus</Emphasis>

Twelve compounds including secologanin, loganin, the aglycon of loganin, and a new iridoid called glucologanin were isolated from fruit of common snowberry Symphoricarpos albus (L.) Blake. The structure of glucologanin was confirmed using PMR and mass spectroscopy and chemical transformations. 2′,3′,4′,6′,7-Penta-O-acetylloganin and 2′,3′,4′,6′-tetra-O-acetylloganin were synthesized. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 37–40, January–February, 2009.     

A new component from <Emphasis Type="Italic">Eupatorium cannabinum</Emphasis>

A new compound of formula C₂₈H₄₈O with mp 179-180°C (aqueous ethanol) that was called eucanbin was isolated pure by column chromatography of the ethanol extract of the aerial part of Eupatorium cannabinum L. The structure 24α-methylcholest-20(21)-en-3β-ol was assigned based on chemical and spectral data. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 318–320, May–June, 2009.     

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.     

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.     

New flavonoid-<Emphasis Type="Italic">C</Emphasis>-glycosides from <Emphasis Type="Italic">Triticum aestivum</Emphasis>

Two new flavonoid-C-glycosides named triticuside A (1a) and triticuside B (1b) were isolated from bran of Triticum aestivum L. The structures of the two new compounds were elucidated by spectral techniques including ¹H NMR, ¹³C NMR as well as HSQC, HMBC, and COSY. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 135–137, March–April, 2008.     

<Emphasis Type="Italic">k</Emphasis>-resonance in Toroidal Polyhexes*

This paper considers the k -resonance of a toroidal polyhex (or toroidal graphitoid) with a string (p, q, t) of three integers (p ≥ 2, q ≥ 2, 0 ≤ t ≤ p − 1). A toroidal polyhex G is said to be k-resonant if, for 1≤ i ≤ k, any i disjoint hexagons are mutually resonant, that is, G has a Kekulé structure (perfect matching) M such that these hexagons are M-alternating (in and off M). Characterizations for 1, 2 and 3-resonant toroidal polyhexes are given respectively in this paper. *This work is supported by FRG, Hong Kong Baptist University; NSFC and TRAPOYT.     

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.     

Screening and Immobilization <Emphasis Type="Italic">Burkholderia</Emphasis> sp. GXU56 Lipase for Enantioselective Resolution of (<Emphasis Type="Italic">R</Emphasis>,<Emphasis Type="Italic">S</Emphasis>)-Methyl Mandelate

Microorganisms producing lipase were isolated from soil and sewage samples and screened for enantioselective resolution of (R,S)-methyl mandelate to (R)-mandelic acid. A strain designated as GXU56 was obtained and identified as Burkholderia sp. Preparing immobilized GXU56 lipase by simple adsorption on octyl sepharose CL-4B, the optimum temperature was shifted from 40 °C (free lipase) to 50 °C (immobilized lipase), and the optimum pH was shifted from 8.0 (free lipase) to 7.2 (immobilized lipase). The immobilized enzyme displayed excellent stability in the pH range of 5.0–8.0, at the temperatures below 50 °C and in organic solvents compared with free enzyme. Enantioselectivity ratio for (R)-mandelic acid (E) was dramatically improved from 29.2 to more than 300 by applying immobilized lipase in the resolution of (R,S)-methyl mandelate. After five cycles of use of immobilized lipase, conversion and enantiomeric excess of (R)-mandelic acid were 34.5% and 98.5%, respectively, with enantioselectivity ratio for (R)-mandelic acid (E) of 230. Thus, octyl-sepharose-immobilized GXU56 lipase can be used as a bio-resolution reagent for producing (R)-mandelic acid.     

Determination of epoxides by high-performance liquid chromatography following derivatization with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diethyldithiocarbamate

A reversed-phase, high-performance liquid chromatography (RP-HPLC) method that allows quantitation of low levels of epoxides has been described. The method involved derivatization of epoxides using 100- to 1,000-fold excess N,N-diethyldithiocarbamate (DTC) at 60 °C for 20 min at neutral pH. The unreacted DTC was then decomposed to CS₂ and diethyl amine by acidification of the reaction mixture to pH 2 using orthophosphoric acid. The first two steps could be performed in the same reaction vessel by sequential addition of reagents. In the final step, an aliquot (20 μL) of the derivatized sample was analyzed for the presence of stable esters of DTC by RP-HPLC using a Supelcosil LC-18-S (150 × 4.6-mm) column and a mobile phase consisting of 40% (v/v) acetonitrile in water at a flow of 1 mL min⁻¹. Using UV detection at 278 nm, the epoxides gave linear responses in the concentration range of 0.25 to 50 μM. The method is robust, and as low as 5 pmol of the analyte could be successfully detected and quantified with recoveries of ≥94%. Following a minimal pretreatment such as ultrafiltration (molecular weight cutoff 5,000 Da), the method is suitable for analysis of epoxides in complex physiological fluids (e.g., fetal bovine serum). The method has been rigorously evaluated and adapted in our laboratory for routine analysis and determination of stability of epoxides of 1,3-butadiene and other alkenes added to cell cultures.     

The group-theoretical structure of the atomic g shell: connection with the alternating group <Emphasis Type="Italic">A</Emphasis><Subscript>6</Subscript> as <Emphasis Type="Italic">L</Emphasis><Subscript>2</Subscript>(9)

The special projective linear groups PSL(2ℓ + 1) or L ₂(2ℓ + 1) of order 2ℓ(2ℓ + 1)(ℓ + 1) can be used to study atomic shells of electrons with angular momentum quantum number ℓ corresponding to the atomic p, d, f, and g shells for ℓ = 1, 2, 3, 4, respectively. For the atomic g shell the group L ₂(9) is isomorphic with the alternating group A ₆ on six objects of order 360 or the symmetry group of the 5-dimensional simplex, a 5-dimensional analogue of the tetrahedron with 6 vertices and 15 edges. This leads to the subgroup chain SO(9) ⊃ SO(5) ⊃ L ₂(9) for the atomic g shell analogous to the subgroup chain SO(7) ⊃ G ₂ ⊃ L ₂(7) ≈⁷ O for the atomic f shell. In the L ₂(9) group only the representations of spherical harmonics or sums thereof, Γ(Y_ℓ), with dimensions dim Γ(Y_ℓ) or dim Γ(Y_ℓ) ± 1 divisible by 9 are found to be individually reducible to irreducible representations (irreps) or sums of irreps of L ₂(9). This leads to term groupings such as S, PD, G, PF, DH, L, PK, DI, FH, M, FI, PO, DN, HK, R, etc., of increasing total dimension for the irreps of SO(9) for various g ⁿ configurations in the atomic g shell.     

A new C-glucoside from <Emphasis Type="Italic">Commelina communis</Emphasis>

A new C-glucoside, 3,4-epoxy-5-hydroxymethyl benzoate 2-C-β-glucoside (1), together with a known alkaloid, 1H-indole-3-carbaldehyde (2), were isolated from the whole plant of Commelina communis L. The structures of these compounds were determined by 1D, 2D NMR and MS techniques. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 51–52, January–February, 2009.     

New acyl derivatives of <Emphasis Type="Italic">N</Emphasis>-deacetyllappaconitine

New N-acylates of the norditerpenoid alkaloid N-deacetyllappaconitine that were modified in the aromatic ring and are interesting as potential pharmacologically valuable compounds were prepared. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 275–279, May–June, 2008.     

Structure of a new xanthone from <Emphasis Type="Italic">Securidaca inappendiculata</Emphasis>

A new xanthone (1, 1,7-dihydroxy-2-methoxyxanthone), in addition to the known metabolites 1,7-dihydroxyxanthone (2), 24(R)-stigmast-7,22 (E)-dien-3α-ol (3), and 1,7-dimethoxyxanthone (4), was isolated from the roots of Securidaca inappendiculata. Compounds 1–4 were evaluated by anti-HIV assay and 1–3 showed anti-HIV-1inhibitory activity in vitro. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 348–349, July–August, 2008.     

Functional Expression of <Emphasis Type="Italic">Bacillus anthracis</Emphasis> Protective Antigen in <Emphasis Type="Italic">E. coli</Emphasis>

The protective antigen (PA) of Bacillus anthracis is a potent immunogen and an important candidate vaccine. In addition, it is used in monitoring systems like enzyme-linked immunosorbent assay to assess antibodies against PA in immunized subjects. The low level of PA production in B. anthracis and the difficulty of separating it from other bacterial components have made the researchers do different studies with the aim of producing recombinant PA (rPA). In this study, to produce rPA as a recombinant protein vaccine, the partial sequence of protective antigen of B. anthracis, amino acids 175–764, as a potent immunogenic target was inserted in pET21b(+). This is a prokaryotic plasmid that carries an N-terminal T7.tag sequence. The integrity of constructed plasmid was confirmed using restriction enzyme mapping. rPA was expressed after induction with isopropyl β-d-1-thiogalactopyranoside in Escherichia coli BL21. Purification of rPA was done with an affinity system using anti T7.tag antibody. Electrophoresis and Western blotting confirmed the specificity of the expressed protein. BALB/c mice were immunized with obtained PA protein and evaluation of specific immunoglobulin G antibodies against PA in sera using Western blotting method and showed that rPA is immunogenic. The challenge of immunized mice with virulent strain of B. anthracis showed that rPA is functional to protect against pathogenic strain.     

Balanoinvolin,a new steroid derivative from <Emphasis Type="Italic">Balanophora involucrate</Emphasis>

A new compound, β-sitosterylglucoside-3′-O-linoleate, named balanoinvolin, and three known compounds coniferin, methylconiferin, and 4-O-β-D-glucopyranosylconiferyl aldehyde, were isolated from Balanophora involucrate Hook. f. and their structures were determined by MS and 1D/2D NMR spectra. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 315–317, May–June, 2009.     

Cytotoxic metabolites of <Emphasis Type="Italic">Streptimonospora salina</Emphasis>

Streptimonospora salina gen. nov., sp. nov. was found to produce three phenoxazinone antibiotics, 2-amino-3H-phenoxazin-3-one (1), 2-methylamino-3H-phenoxazin-3-one (2), 2-acetylamino-3H-phenoxazin-3-one (3), and one phenazine antibiotic, phenazine-1-carboxylic acid (4). The chemical structures of the compounds were determined using 1D and 2D NMR spectrometry and electrospray mass spectrometry (ESMS). Compounds 1-4 exhibited modest cytotoxicity against a human renal carcinoma cell line ACHN with IC₅₀ values of 35.4, 12.4, 65.4, and 82.9 μM, respectively. Compound 2 was discovered for the first time from a biological origin. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 405–406, July–August, 2008