Synthesis of phenyl azides bearing (E)-2-halovinyl group

A series of phenyl azides bearing (E)-2-halovinyl groups were synthesized in high yields by treatment of (E)-3-(4-azidophenyl)- and (E)-3-(2-azidophenyl)acrylic acid with N-halosuccinimide in the presence of LiOAc. (E)-4-(2-bromovinyl) phenyl azide, one of the synthesized intermediates, was selected to transform to a diverse range of phenyl-1, 2, 3-triazoles bearing (E)-4-(2-bromovinyl) groups by Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction.     

STUDIES IN THE HETEROCYCLIC COMPOUNDS V1. SOME REACTIONS OF 5-CHLORO-2-THIOPHENESULFONYL DERIVATIVES

Abstract

The reactions of 5-chloro-2-thiophenesulfonyl chloride are described. Treatment of the sulfonyl chloride with ammonia, hydrazine hydrate, sodium azide, indole and imidazole gave the sulfonamides (5), sulfonohydrazide (4), sulfonyl azide (3), 1-(5-chloro-2-thiophenesulfonyl)indole (27) and 1-(5-chloro-2-thiophenesulfonyl)-imidazole (26), respectively. The sulfonyl chloride was reacted further with 20 aryl-and cycloalkyl-amines to give the corresponding sulfonamides (6)-(25). Attempted chlorination of the sulfonyl chloride (2) with sulfuryl chloride or bromination of the sulfonyl azide (3) with pyridinium bromide perbromide failed. However, nitration of the sulfonyl chloride (2) with fuming nitric acid gave the 4-nitro-sulfonyl chloride (28), which with sodium azide afforded the 5-chloro-4-nitro-sulfonyl azide (29). The sulfonyl azides, (3) and (29), have been reacted with triphenylphosphine, triethylphosphite, norbornene and cyclohexene. The azides reacted further with indole and 1-methylindole to give the 2-sulfonyl-iminoindolines (34)-(36). The infra-red spectra and mass spectra of some of the substituted thiophenesulfonyl derivatives are discussed.     

Furofuran lignans from the bark of <Emphasis Type="Italic">Magnolia kobus</Emphasis>

A new furofuran lignan (1) along with four knownones (2-5) were isolated from the bark of Magnolia kobus. Their structures were elucidated as (+)-2α-(3’,4’-dimethoxyphenyl)-6α-(3″-hydroxy-4″,5″-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (+)-sesamin (2), (+)-yangambin (3), (+)-kobusin (4), and (+)-eudesmin (5) on the basis of their comprehensive spectroscopic analysis, including 2D NMR, and by comparison of their spectral data with those of related compounds. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 338–341, July–August, 2008.     

Quantitative <Superscript>2</Superscript>H NMR spectroscopy

The selectivity of deuterium distribution between the nonequivalent positions in 3-carene (1), 4-α-acetyl-2-carene (2), and 4-(1-hydroxyethyl)-2-carene (3) has been measured by ²H-{¹H} NMR spectroscopy at the natural abundance of deuterium. These “H/D-isotope portraits” were shown to be typical of terpenes and terpenoids produced in plants via the biosynthetic DXP pathway. The mechanism of acylation of 1 was studied by the density functional theory method (PBE functional, TZ2p basis set). The six-membered ring in compound 1 is planar. However, the endo attack of electrophiles on this ring is more favorable both kinetically and thermodynamically. It was shown both experimentally and theoretically that the elimination of a hydrogen atom in the second reaction step proceeds stereoselectively at the C(2) atom from the anti position with respect to the three-membered ring and occurs with pronounced nucleophilic assistance from the carbonyl group. For Part 2, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1657–1664, August, 2008.     

A furostanol saponin and phytoecdysteroid from roots of <Emphasis Type="Italic">Helleborus orientalis</Emphasis>

A furostanol saponin mixture and a known phytoecdysteroid were isolated from the roots of Helleborus orientalis Lam. Their structures were established as 26-[(β-D-glucopyranosyl)oxy]-22α-hidroxyfurosta-5,25(27)-dien-1β,3β,11α-triol (1a), 26-[(β-D-glucopyranosyl)oxy]-22α-methoxyfurosta-5,25(27)-dien-1β,3β,11α-triol (1b), and 20-hydroxy-β-ecdyson-3-O-β-D-glycoside (2). Acid hydrolysis of 1a,b gave (1β,3β,11α,22α)-22,26-dimethoxyfurosta-5,25(27)-dien-1,3,11-triol (aglycone 1) and of 2 gave 20-hydroxy-β-ecdyson (aglycone 2). Their structures were elucidated by spectral analysis. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 75–77, January–February, 2007.     

Metabolites from the marine fungus <Emphasis Type="Italic">Eurotium repens</Emphasis>

1,8-Dihydroxy-6-methoxy-3-methyl-9,10-anthracenedione (physcion, 1), 3,4-dihydro-3,6,9-trihydroxy-8-methoxy-3-methyl-1(2H)-anthraceneone (asperflavin, 2), and 2,5-dihydroxy-3-(3-methyl-2-butenyl)-6-[(1E)-1-heptenyl]-benzaldehyde (tetrahydroauroglaucin, 3) were shown to be the main pigments of the marine isolate of the fungus Eurotium repens. In addition to the pigments, the fungal metabolites included the diketopiperazine alkaloid echinulin (4). The structures of the compounds were identified using NMR spectroscopy and mass spectrometry. The cytotoxic activity of 1–3 toward sex cells of the sea urchin Strongylocentrotus intermedius was determined. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 327–329, July–August, 2007.     

Triterpene Glycosides from <Emphasis Type="Italic">Cussonia paniculata</Emphasis>. II. Acetylated Glycosides from Leaves

Structures of 13 new acetylated triterpene glycosides from leaves of Cussonia paniculata (Araliaceae) were established as 28-O-(2-O-acetyl- and 3-O-acetyl-α-L-rhamnopyranosyl)-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β -D-glucopyranosides of 23-hydroxybetulinic acid (1a and 1b) and hederagenin (2a and 2b), 3-O-α-L-arabinopyranosyl-28-O-(2-O-acetyl- and 3-O-acetyl-a-L-rhamnopyranosyl)-(1→ 4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glycopyranosides of oleanic (3a and 3b) and ursolic (3c and 3d) acids, 3-O-α-L-arabinopyranosyl-28-O-(4-O-acetyl-, 2-O-acetyl-, and 3-O-acetyl-α-L-rhamnopyranosyl)-(1→4)-O-β-D-glucopyranosyl-(1→ 6)-O-β-D-glucopyranosides of hederagenin (4, d5a and 5b), and 3-O-β-D-glucopyranosyl-(1→2)-O-α-L-arabinopyranosyl-28-O-(2-O-acetyl- and 3-O-acetyl-α-L-rhamnopyranosyl)-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D- glucopyranosides of oleanic acid (6a and 6b). The structures of the compounds were established using chemical methods and NMR spectroscopy. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 351–356, July–August, 2005.     

Chemistry and cytotoxic activities of polyketides produced by the mangrove endophytic fungus <Emphasis Type="Italic">Phomopsis</Emphasis> SP. ZSU-H76

A new polyketide, 2-(7′-hydroxyoxooctyl)-3-hydroxy-5-methoxybenzeneacetic acid ethyl ester (1), together with three known compounds dothiorelone A (2), B (3), and C (4) were isolated from the mangrove endophytic fungus Phomopsis sp. ZSU-H76 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Primary bioassays showed that 1 exhibited cytotoxicity against HEp-2 and HepG2 cells with IC₅₀ values of 25 and 30 μg/mL, respectively.     

Secondary metabolites from the endophytic fungus <Emphasis Type="Italic">Annulohypoxylon boveri</Emphasis> var. <Emphasis Type="Italic">microspora</Emphasis> BCRC 34012

A chemical study on the n-BuOH-soluble fraction of the 95% EtOH extract of long-grain rice (Oryza sativa) fermented with the endophytic fungus Annulohypoxylon boveri var. microspora (BCRC 34012) has resulted in the isolation of one new natural azaphilone derivative, designated as annulohypoxyboverin (1) together with 12 known compounds, (3R,6R,7E)-3-hydroxy-4,7-megstigma-dien-9-one (2), α-tocopheryl quinone (3), isofraxidin (4), coumarin (5), cinnamic acid (6), a mixture of palmitic acid (7) and stearic acid (8), N-cis-feruloyltyramine (9), luteolin (10), kaempferol (11), kaempferitrin (12), and 4,5,4′,5′-tetrahydroxy-1,1′-binaphthyl (13). Annulohypoxyboverin (1) contains a dihydrobenzofuran-2,4-dione backbone, 1-hydroxyhexyl side chain, and one γ-lactone ring. Their structures were elucidated by spectroscopic analyses including 1D and 2D NMR experiments, and by HR-ESI-MS. The relative configuration of 1 was confirmed by NOESY experiment. Other known compounds were identified by comparing their spectral data with those of literature data.     

Phenolic constituents from the stems of <Emphasis Type="Italic">Acanthopanax senticosus</Emphasis>

A new phenolic glycoside was isolated from the stems of Acanthopanax senticosus together with sixteen known compounds. The structure of the new compound was determined to be 2,6-dimethoxy-4-[(1E)-3,3-dimethoxy-1-propenyl]phenyl β-D-glucopyranoside (1) by means of physical, chemical, and spectroscopic methods. Of the known compounds, salvadoraside (7), (7R,8S)-dihydrodehydrodiconiferyl alcohol 4,9′-di-O-β-D-glucopyranoside (8), 3-(4-O-β-D-glucopyranosylferuloyl)quinic acid (15), rel-5-(1R,5S-dimethyl-3R,4R,8S-trihydroxy-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (16), and lycoperodine-l (17) were first reported from the title plant. The inhibitory activities of the isolated compounds against α-glucosidase from rat intestine were also reported.     

A new cerebrogalactoside from <Emphasis Type="Italic">Juglans mandshurica</Emphasis>

A new cerebrogalactoside, Juglans cerebroside A (1), together with five known compounds, quercetin-3-O-β-D-galactopyranoside (2), myricetin-3-O-β-D-galactopyranoside (3), 2″E-quercetin-3-O-β-D-(6″″-O-[3″(4′″-hydroxyphenyl) propylene acyl]) glucopyranoside (4), gallic acid (5), and 2-methyl-1-hexadecanol (6) were isolated from the leaves of Juglans mandshurica Maxim. The structures of these compounds were determined by 1D, 2D NMR, and MS techniques.     

Regularities in the stabilization by hemoglobin of binuclear iron complexes [Fe<Subscript>2</Subscript>(μ-N—C—SR)<Subscript>2</Subscript>(NO)<Subscript>4</Subscript>] containing benzimidazolylthiol and benzothiazolylthiol ligands

The NO-donor ability of new binuclear tetranitrosyl complexes of the μ-N—C—S type, namely, bis(5-methylbenzimidazol-2-ylthio)- (1), bis(benzimidazol-2-ylthio)- (2), and bis(benzothiazol-2-ylthio)(tetranitrosyl)diiron (3), was studied in aqueous solutions by spectrophotometry. All kinetic regularities obtained for complexes 1–3 are well described in terms of formalism of pseudo-first-order reactions. The apparent first-order reaction rate constants for NO evolution by the complexes to solution were determined. Complexes 1–3 are good donors of NO. The structures of the complexes and the effect of their stabilization by hemoglobin were compared. The stabilization effect is explained by different basicities of the sulfur-containing ligands in the complexes studied.     

Synthesis of (1<Emphasis Type="Italic">R</Emphasis>,2<Emphasis Type="Italic">R</Emphasis>)-1,2-bis-(5-(4-hydroxynaphthalen-1-ylazo)-[1,3,4]thiadiazol-2-yl)-ethane-1,2-diol

In this study, (1R,2R)-1,2-bis-(5-amino-1,3,4-thiadiazol-2-yl)ethane-1,2-diol (2), was synthesized by using (2R,3R)-(+)-Tartaric acid (1) as starting compound. Then the diazo component 3 was obtained from 2 and 1-naphthol. In addition, the structures of the synthesized compounds 2 and 3 were confirmed by elemental analyses, IR, ¹H-NMR, and ¹³C-NMR spectra. __________ Published in Kimiya Prirodnikh Soedinenii, No. 5, pp. 465–466, September–October, 2005.     

A bicyclo[3.2.1]octanoid neolignan and toxicity of the ethanol extract from the fruit of <Emphasis Type="Italic">Ocotea heterochroma</Emphasis>

A new bicyclo[3.2.1]octanoid neolignan rel-(7S,8R,1′S,2′R,3′S)-Δ8′-2′-hydroxy-5,1′,3′-trimethoxy-3,4methylenedioxy-7,3′,8,1′-neolignan (1) was isolated from ethanol extract from the fruit of Ocotea heterochroma Mez & Sodiro ex Mez as well as the known compounds β-friedelanol (2), meso-dehydroguaiaretic acid (3), and yangambin (4), whose structures were elucidated on the basis of their comprehensive spectroscopic analysis including 2D NMR data. Lethality bioassay using brine shrimp (Artemia salina Leach) was evaluated with the ethanol extract from the Ocotea heterochroma’s fruit. The toxicity of this extract was greater than the toxicity of those fractions obtained in a first solvent partition (benzene, ethyl acetate, and butanol subfractions) and that of a mixture of acetylated 2′-epimers from the new neolignan 1. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 158–160, March–April, 2009.     

A new flavanone glucoside from <Emphasis Type="Italic">Abrus precatorius</Emphasis>

A new flavanone glycoside, (2S)5,7,4′-trihydroxyflavanone-8-C-β-D-(6″-O-acetyl)glucopyranoside (1), together with six known flavonoids, isohemiphloin (2), vitexin (3), cirsimaritin (4), hispidulin (5), apigenin (6), and eupatorin (7), was isolated from the leaves and stems of Abrus precatorius. Their structures were elucidated on the basis of physical and spectral analysis. Rotamers exist for compounds 1, 2, and 3. Compounds 1–3, 6, and 7 were isolated from this plant for the first time.     

Tetrahydroprotoberberine alkaloids from <Emphasis Type="Italic">Corydalis saxicola</Emphasis>

Thirteen tetrahydroprotoberberines, 2,9,10-thrihydroxy-3-methoxytetrahydroprotoberberine (1), cavidine (2), thalictrifoline (3), mesotetrahydrocorysamine (4), stylopine (5), sinactine (6), apocavidine (7), cheilanthifoline (8), 13-β-hydroxystylopine (9), tetrahydropalmatine (10), tetrahydropalmatrubine (11), isocorypalmine (12), and scoulerine (13) have been isolated from the herb of Corydalis. Saxicola Bunting. Of these alkaloids, 2,9,10-thrihydroxy-3-methoxytetrahydroprotoberberine (1) was a new base. The alkaloids mesotetrahydrocorysamine (4), stylopine (5), sinactine (6), apocavidine (7), cheilanthifoline (8), 13-β-hydroxystylopine (9), tetrahydropalmatine (10), tetrahydropalmatrubine (11), isocorypalmine (12), and scoulerine (13), although previously known, were isolated for the first time from Corydalis saxicola Bunting. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 143–144, March–April, 2007.     

A new flavonol derivative from <Emphasis Type="Italic">Fagopyrum dibotrys</Emphasis>

A new flavonol derivative 3, 8-dihydroxy-10-methoxy-5-H-isochromeno[4, 3-b]chromen-7-one (1) together with four known compounds, glutinone (2), luteolin (3), acacetin 7-O-α-L-rhamnopyranosyl- (1→6)-β-D-glucopyranoside (4), and rutin (5) were isolated from the dried roots of Fagopyrum dibotrys. Their structures were determined by UV, IR, MS, ¹H, and ¹³C NMR spectroscopic analysis, including 2D NMR. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 567–568, November–December, 2008.     

Components of the heartwood of <Emphasis Type="Italic">Populus euphratica</Emphasis> from an ancient tomb

To probe the organic constituents of over 2000-year-preserved Populus euphratica found in an ancient tomb, a chemical investigation was undertaken, which led to the isolation of a new compound, 2-(4′-hydroxy-3′-methoxyphenyl)-2-oxoacetamide (1), together with 12 known compounds (2–13) by column chromatography. Their structures were elucidated on the basis of spectroscopic evidence. It is the first time that compounds 2–13 were isolated from this plant. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 7–9, January–February, 2008.     

A novel compound from <Emphasis Type="Italic">Flos carthami</Emphasis> and its bioactivity

A novel compound, 4-{1′-hydroxy-1′-mercapto-1′-[1′′-2′′(N→O)-isoquinolyl]}yl-1-benzoic acid (1), together with six known compounds, 6-hydroxykaempferol-3-O-β-D-glucopyranoside (2), rutin (3), quercetin-3-O-β-D-glucopyranoside (4), kaempferol-3-O-β-D-glucopyranoside (5), cartormin (6), hydroxysafflor yellow A (7), were isolated by chromatography from the n-BuOH fraction of 50% ethanol extraction of Flos carthami. Their structures were elucidated on the basis of spectral analysis and comparison with published data. Among them, compound 1 was shown to possess a weak protective effect against cerebral ischemic damage in rats. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 339–341, May–June, 2009.     

Isolation and characterization of a new flavone diglucoside from <Emphasis Type="Italic">Salix denticulata</Emphasis>

A new flavone diglucoside named 7,3′-dihydroxy-4′-methoxyflavone-5-O-β-D-glucopyranosyl (6″ → 1‴)-β-D-glucopyranoside (1), along with four known flavonoids, luteolin (2), isoquercetin (3), catechin (4), and diosmetin (5), has been isolated and characterized from Salix denticulata. The structure of the new flavone diglucoside was characterized by means of high field 1D and 2D NMR and MS spectral analysis.