共查询到20条相似文献,搜索用时 15 毫秒
1.
Chakapong Intaraudom Aibrohim DramaeSumalee Supothina Somjit KomwijitPattama Pittayakhajonwut 《Tetrahedron》2014
Eight new compounds including 9′-[2-amino-3-(4″-O-methyl-α-rhamnopyranosyloxy) phenyl]nonanoic acid (1), 9′-[2-amino-3-(4″-O-methyl-α-ribopyranosyloxy)phenyl] nonanoic acid (2), 11′-[2-amino-3-(4″-O-methyl-α-rhamnopyranosyloxy)phenyl]undecanoic acid (3), 11′-[2-amino-3-(4″-O-methyl-α-ribopyranosyloxy)phenyl]undecanoic acid (4), 8-(4′-O-methyl-α-rhamnopyranosyloxy)-3,4-dihydroquinolin-2(1H)-one (5), 8-(4′-O-methyl-α-ribopyranosyloxy)-3,4-dihydroquinolin-2(1H)-one (6), 8-(4′-O-methyl-α-rhamnopyranosyloxy)-2-methyquinoline (7), and 8-(4′-O-methyl-α-ribopyranosyloxy)-2-methylquinoline (8) were isolated from Actinomadura sp. BCC27169. The chemical structures of these compounds were determined based on NMR and high-resolution mass spectroscopy. The absolute configurations of these monosaccharides were revealed by the hydrolysis of compounds 7 and 8. Compounds 3 and 8 exhibited antitubercular activity at MIC 50 μg/mL. Only compound 3 showed cytotoxicity against KB cell at IC50 18.63 μg/mL, while other isolated compounds were inactive at tested maximum concentration (50 μg/mL). 相似文献
2.
Santosh Kurhade Vandana Rajopadhyay Satheesh Veerappa Avaragolla Summon Koul Parimi Atchuta Ramaiah Debnath Bhuniya 《Tetrahedron letters》2014
l-(N-Cbz)-7-azaisotryptophan, l-(N-Cbz)-1a, a new isostere of tryptophan, was synthesized by reacting Li2-(N-Boc)-2-amino-3-picoline, Li2-(N-Boc)-2a, with appropriately protected l-aspartic acid followed by simple functional group manipulation. This synthetic success led us to access a set of analogs of azaisotryptophan (4a–c; 6a–c) as well as a new class of chiral amines (7a–c; 8a–c) for future application in asymmetric synthesis and design of homochiral ligands. Further, we have generalized the method substantiating a variety of new azaindol-2-yl derivatives (10aa–10lc) with functionalized substituents. In a preliminary luminescence characterization, l-(N-Cbz)-1a has exhibited about 30 nm bathochromic shifted fluorescence emission compared to tryptophan and (N-Cbz)-tryptophan. 相似文献
3.
Two new Lycopodium alkaloids, lycopladines F (1) and G (2), have been isolated from the club moss Lycopodium complanatum, and the structures and relative stereochemistries of 1 and 2 were elucidated on the basis of spectroscopic data. Lycopladine F (1) is a rare C16N2-type Lycopodium alkaloid possessing an amino acid residue (C4N). 相似文献
4.
Guo-Lin Xu 《Journal of organometallic chemistry》2003,683(2):388-397
Three diruthenium(III) compounds Ru2(L)4Cl2, where L is mMeODMBA (N,N′-dimethyl-3-methoxybenzamidinate, 1a), DiMeODMBA (N,N′-dimethyl-3,5-dimethoxy benzamidinate, 1b), or DEBA (N,N′-diethylbenzamidinate, 1c), were prepared from the reactions between Ru2(OAc)4Cl and respective HL under reflux conditions. Metathesis reactions between 1 and LiC2Y resulted in bis-alkynyl derivatives Ru2(L)4(C2Y)2 [Y=Ph (2), SiMe3 (3), SiiPr3 (4) and C2SiMe3 (5)]. The parent compounds 1 are paramagnetic (S=1), while bis-alkynyl derivatives 2-5 are diamagnetic and display well-solved 1H- and 13C-NMR spectra. Molecular structures of compounds 1b, 1c, 2c, 3c and 4b were established through single crystal X-ray diffraction studies, which revealed RuRu bond lengths of ca. 2.32 Å for parent compounds 1 and 2.45 Å for bis-alkynyl derivatives. Cyclic voltammograms of all compounds feature three one-electron couples: an oxidation and two reductions, while the reversibility of observed couples depends on the nature of axial ligands. 相似文献
5.
Akira Yogi Jae-Hwan Oh Takanori Nishioka Rika Tanaka Eiji Asato Isamu Kinoshita Satoshi Takara 《Polyhedron》2010
The syntheses and characterization of novel ruthenium(II) complexes containing bis(3,5-dimethylpyrazol-1-yl)acetato (bdmpza), a new class of scorpionate ligands, are reported herein. [RuCl(bdmpza)(η4-1,5-cyclooctadiene)] (1) was found to be a versatile precursor to synthesize a wide range of new ruthenium(II) complexes with the bdmpza ligand. The treatment of 1 with pyridine (py), diphenylphosphinoethane (dppe), 2,2′-bipyridyl (bpy), 1,10-phenanethroline (phen), or bispicolylamine (Hbpica) in refluxing N,N-dimethylformamide resulted in displacement of the 1,5-cyclooctadiene ligand to afford [RuCl(bdmpza)(py)2] (2), [RuCl(bdmpza)(dppe)] (3), [RuCl(bdmpza)(bpy)] (4), [RuCl(bdmpza)(phen)] (5), and [Ru(bdmpza)(Hbpica)]Cl (6Cl) in good yields, respectively. The structures of 1–4, and 6 were determined by X-ray structure analyses. 相似文献
6.
The C,N-(trimethylsilyliminodiphenylphosphoranyl)silylmethylmetal complexes [Fe(L)2] (3), [Co(L)2] (4), [ZrCl3(L)]·0.83CH2Cl2 (5), [Fe(L)3] (6), [Fe(L′)2] (7) and [Co(L′)2] (8) have been prepared from the lithium compound Li[CH(SiMe2R)P(Ph)2NSiMe3] [1a, (R = Me) {≡ Li(L)}; 1b, (R = NEt2) {≡ Li(L′)}] and the appropriate metal chloride (or for 7, FeCl3). From Li[N(SiMe3)C(Ph)C(H)P(Ph)2NSiMe3] [≡ Li(L″)] (2), prepared in situ from Li(L) (1a) and PhCN, and CoCl2 there was obtained bis(3-trimethylsilylimino- diphenylphosphoranyl-2-phenyl-N-trimethylsilyl-1-azaallyl-N,N′)cobalt(II) (9). These crystalline complexes 3-9 were characterised by their mass spectra, microanalyses, high spin magnetic moments (not 5) and for 5 multinuclear NMR solution spectra. The X-ray structure of 3 showed it to be a pseudotetrahedral bis(chelate), the iron atom at the spiro junction. 相似文献
7.
Lena Hammerschmidt Abdessamad Debbab Tu Duong Ngoc Victor Wray Catalina Perèz Hemphil WenHan Lin Heike Broetz-Oesterhelt Matthias U. Kassack Peter Proksch Amal H. Aly 《Tetrahedron letters》2014
Five new polyketide derivatives, 6′-hydroxypestalotiopsone C (1), acropyrone (2), bicytosporone D (3), waol acid (4), and pestalotiopene C (5), together with seven known metabolites (6–12), were obtained from extracts of the endophytic fungus Acremonium strictum, isolated from the mangrove tree Rhizophora apiculata. The structures of the isolated compounds were elucidated on the basis of comprehensive NMR and MS analysis. Compounds 6, 7, and 9 showed moderate cytotoxic activity against human cisplatin-sensitive (IC50 values 27.1, 76.2, and 8.3 μM, respectively) and resistant A2780 cell lines (IC50 values 12.6, 30.1, and 19.0 μM, respectively), whereas only 9 exhibited antibacterial activity against Staphylococcus aureus (MIC value 14.3 μM). 相似文献
8.
Reversed-phase HPLC analysis of the methanol extract of the seeds of Centaurea montana afforded a flavanone, montanoside (4), six epoxylignans, berchemol (7), berchemol 4′-O-β-d-glucoside (5), pinoresinol (10), pinoresinol 4-O-β-d-glucoside (8), pinoresinol 4,4′-di-O-β-d-glucoside (6), pinoresinol 4-O-apiose-(1→2)-β-d-glucoside (9), two quinic acid derivatives, trans-3-O-p-coumaroylquinic acid (1), cis-3-O-p-coumaroylquinic acid (2), and eight indole alkaloids, tryptamine (3), N-(4-hydroxycinnamoyl)-5-hydroxytryptamine (11), cis-N-(4-hydroxycinnamoyl)-5-hydroxytryptamine (12), centcyamine (16), cis-centcyamine (17), moschamine (13), cis-moschamine (14) and a dimeric indole alkaloid, montamine (15). While the structures of two new compounds, montanoside (4) and montamine (15), were established unequivocally by UV, IR, MS and a series of 1D and 2D NMR analyses, all known compounds were identified by comparison of their spectroscopic data with literature data. The antioxidant properties of these compounds were assessed by the DPPH assay, and their toxicity towards brine shrimps and cytotoxicity against CaCo-2 colon cancer cells were evaluated by the brine shrimp lethality and the MTT cytotoxicity assays, respectively. The novel dimer, montamine (15), showed significant in vitro anticolon cancer activity (IC50=43.9 μM) while that of the monomer, moschamine (13), was of a moderate level (IC50=81.0 μM). 相似文献
9.
A large number of novel N-aryl modified monocyclic γ-lactam derivatives have been prepared via Pd(0) catalyzed heteroarylation in the N-aryl part of (±) cis and (±) trans γ-lactam carboxylate derivatives 3(a–f) and 6(a–f), respectively, with furan-2-boronic acid and thiophen-2-boronic acid. (±) cis Methyl 1-(2-bromoaryl)-5-oxo-3-aryl/heteroarylpyrrolidin-2-carboxylate derivatives 3(a–f), were prepared in good yields from 1(a–f) via hydrolysis, stereoselective decarboxylation, followed by esterification. Corresponding trans isomers 6(a–f) were prepared by the standard method already reported by us. 相似文献
10.
Jon Erik Aaseng 《Tetrahedron》2010,66(46):8982-8991
This paper describes the total synthesis of the hydrochloride salts of (2S)-2-amino-7-methoxytetralin (21-HCl) and (2S)-2-amino-6-fluoro-7-methoxytetralin (ST1214), from a common enantiomerically pure aziridine 4b, which was available from l-aspartic acid β-tert-butyl ester. The synthesis of 21-HCl and ST1214 proceeded in nine steps and 5 and 6% overall yields, respectively. Key steps are the regioselective ring-opening of 4b with ArMgBr/CuBr·SMe2 and the intramolecular Friedel-Crafts cyclisation providing α-tetralone. Substituted naphthalenes were formed as side products in the latter reaction. 相似文献
11.
Cu(I)-catalyzed 1,3-dipolar cycloaddition (click reaction) of 1 mol equiv of N,N′-di-prop-2-ynyl-phthalamide (1a), N,N′-di-prop-2-ynyl-isophthalamide (1b), and pyridine-2,6-dicarboxylic acid bis-prop-2-ynylamide (1c), respectively with 2 mol equiv of 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl azide (2a), 2-azidoethyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyranoside (2b), and 2-azidoethyl 2,3,4,6-tetra-O-acetyl-α-d-mannopyranoside (2c), respectively, afforded the corresponding bis-cycloadducts 3-5, containing two 1,2,3-triazole moieties each, in 38-76% yield. Reaction of 1 mol equiv of 2c with 1 mol equiv of 1c under otherwise identical conditions gave the mono-cycloadduct 6, containing one 1,2,3-triazole and one 2-propynylamide moiety, in 77% yield. Reaction of 6 with 2a afforded 7, containing two different sugar moieties, in 67% yield. 相似文献
12.
Palladium catalyzed cross-coupling of 3-amino- and 3-acylamido-2-bromopyridines 1a-f with triethyl phosphite allowed the synthesis of 3-amino- and 3-acylamido pyridine-2-phosphonic acid diethyl esters 2a-f, whereas nickel catalysts, although providing access to related anilido-2-phosphonates, proved inactive. Reduction of the aminophosphonate 2a with LiAlH4 afforded 3-amino-2-phosphinopyridine (3a), which was cyclocondensed with dimethylformamide dimethyl acetal (DMFA) via phosphaalkene intermediates 4a to the novel pyrido[b]-anellated 1,3-azaphosphole 5a. Reaction of amidophosphonates 2b-f with LiAlH4 did not result in the expected reductive cyclization, as shown by closely related anilido-2-phosphonates, but led to product mixtures containing N-secondary 3-amino-2-phosphinopyridines 3b-f as the main or major component. The conversion of 3b,d,e with DMFA to 5b,d,e provides first examples of N-substituted pyrido[b]-anellated azaphospholes. Structures were confirmed by multinuclear NMR and X-ray crystallography (for 2c, 3b). 相似文献
13.
Shin-ichi NayaMakoto Nitta 《Tetrahedron》2003,59(21):3709-3718
Novel condensation reaction of tropone with N-substituted and N,N′-disubstitued barbituric acids in Ac2O afforded 5-(cyclohepta-2′,4′,6′-trienylidene)pyrimidine-2(1H),4(3H),6(5H)-trione derivatives (8a-f) in moderate to good yields. The 13C NMR spectral study of 8a-f revealed that the contribution of zwitterionic resonance structures is less important as compared with that of 8,8-dicyanoheptafulvene. The rotational barriers (ΔG‡) around the exocyclic double bond of mono-substituted derivatives 8a-c were obtained to be 14.51-15.03 kcal mol−1 by the variable temperature 1H NMR measurements. The electrochemical properties of 8a-f were also studied by CV measurement. Upon treatment with DDQ, 8a-c underwent oxidative cyclization to give two products, 7 and 9-substituted cyclohepta[b]pyrimido[5,4-d]furan-8(7H),10(9H)-dionylium tetrafluoroborates (11a-c·BF4− and 12a-c·BF4−) in various ratios, while that of disubstituted derivatives 8d-f afforded 7,9-disubstituted cyclohepta[b]pyrimido[5,4-d]furan-8(7H),10(9H)-dionylium tetrafluoroborate (11d-f·BF4−) in good yields. Similarly, preparation of known 5-(1′-oxocycloheptatrien-2′-yl)-pyrimidine-2(1H),4(3H),6(5H)-trione derivatives (14a-d) and novel derivatives 14e,f was carried out. Treatment of 14a-c with aq. HBF4/Ac2O afforded two kinds of novel products 11a-c·BF4− and 12a,c·BF4− in various ratios, respectively, while that of 14d-f afforded 11d-f. The product ratios of 11a-c·BF4− and 12a-c·BF4− observed in two kinds of cyclization reactions were rationalized on the basis of MO calculations of model compounds 20a and 21a. The spectroscopic and electrochemical properties of 11a-f·BF4− and 12a-c·BF4− were studied, and structural characterization of 11c·BF4− based on the X-ray crystal analysis and MO calculation was also performed. 相似文献
14.
A series of 5-amino-1-aroylpyrazoles 3 are synthesized directly by the reaction of β-aminocrotononitrile 1 with some structures containing the hydrazine moiety (X-NHNH2) 2 by refluxing ethanol in presence of sodium acetate. When semicarbazide 3i was used (X = CONH2), the reaction afforded the unexpected 7-aminopyrazolo[1,5-a]pyrimidine 4. 相似文献
15.
Guan-Wu Wang Ting-Hu ZhangEr-Hong Hao Li-Juan JiaoYasujiro Murata Koichi Komatsu 《Tetrahedron》2003,59(1):55-60
The solvent-free reactions of fullerenes and N-alkylglycines with and without aldehydes (RCHO) 2a-e under high-speed vibration milling (HSVM) conditions have been investigated. Fulleropyrrolidines 4a-e (C60(CH2N(CH3)CHR), R=H (4a), C6H5 (4b), p-NO2-C6H4 (4c), p-CH3O-C6H4 (4d), p-(CH3)2N-C6H4 (4e)) were obtained in moderate yields from reactions of C60 with aldehydes 2a-e and N-methylglycine (Prato reaction). In all these solvent-free reactions, 4a was found to be formed besides 4b-e, indicating that fullerenes can react with N-substituted glycines in the absence of aldehyde to give fulleropyrrolidines. For this novel reaction, a possible reaction mechanism involving an electron transfer process has been proposed. Intrigued by this observation, the dependence of the yield on the reagent ratio for the reaction of C60 with paraformaldehyde and/or N-methylglycine was examined to search the optimal conditions. The reaction of C70 with paraformaldehyde and/or N-methylglycine under HSVM conditions was also studied and was found to give the positional isomers of [70]fulleropyrrolidines. 相似文献
16.
Almudena García-Fernández Josefina Díez Ángel Manteca Jesús Sánchez M. Pilar Gamasa Elena Lastra 《Polyhedron》2008
A series of half-sandwich ruthenium(II) complexes containing κ3(N,N,N)-hydridotris(pyrazolyl)borate (κ3(N,N,N)-Tp) and the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA) [RuX{κ3(N,N,N)-Tp}(PPh3)2−n(PTA)n] (n = 2, X = Cl (1), n = 1, X = Cl (2), I (3), NCS (4), H (5)) and [Ru{κ3(N,N,N)-Tp}(PPh3)(PTA)L][PF6] (L = NCMe (6), PTA (7)) have been synthesized. Complexes containing 1-methyl-3,5-diaza-1-azonia-7-phosphaadamantane(m-PTA) triflate [RuCl{κ3(N,N,N)-Tp}(m-PTA)2][CF3SO3]2 (8) and [RuX{κ3(N,N,N)-Tp}(PPh3)(m-PTA)][CF3SO3] (X = Cl (9), H (10)) have been obtained by treatment, respectively, of complexes 1, 2 and 5 with methyl triflate. Single crystal X-ray diffraction analysis for complexes 1, 2 and 4 have been carried out. DNA binding properties by using a mobility shift assay and antimicrobial activity of selected complexes have been evaluated. 相似文献
17.
The synthesis and full characterization of a number of amino acid and dipeptide derivatives with sulfur-containing side chains derived from ferrocene carboxylic acid and ferrocene-1,1′-dicarboxylic acid is presented. In particular, compounds Fc-CO-(Aaa)n-OMe (4) and Fe[C5H4-CO-(Aaa)n-OMe]2 (3) with (Aaa)n = Cys(Bzl) (a), Cys(Bzl)-Cys(Bzl) (b), Cys(p-OMe-Bzl) (c), Cys(p-OMe-Bzl)-Cys(p-OMe-Bzl) (d), Met (e), and Met-Met (f) were prepared. Also, the free acid derivatives Fe[C5H4-CO-Met-OH]2 (6e) and Fc-CO-Met-OH (7e) were prepared and characterized. The solid state structures of 3a, 4b, and 4e were determined by single crystal X-ray diffraction. Compound 3a shows a 1,3′ substitution pattern on the Cp rings in the solid state. Structures in solution were determined by NMR, IR and CD spectroscopy, with particular emphasis on the question of hydrogen bonding and helical chirality of the metallocene. As an example, the full assignment for the Cp signals in the disubstituted derivative 3a was achieved by simulation of the 1H NMR signals from the cyclopentadienyl ring in combination with 2D-NOESY spectra. In solution, 3a has the known 1,2′ substitution pattern, which is stabilized by intramolecular hydrogen bonds. 相似文献
18.
Rosenani A. Haque Abbas Washeel Salman Teoh Siang Guan Hassan Hadi Abdallah 《Journal of organometallic chemistry》2011,696(22):3507-3512
Mononuclear mercury complexes (1, 2, and 3) bearing bis-N-heterocyclic carbene (NHC) ligands of the form [(NHC)2-μ-Hg]+2 have been prepared and structurally characterised. The complexes were derived from three bis-imidazolium salts as precursors to NHC; either 1,3-bis(N-methylimidazolium-1-ylmethyl)benzene bis(hexafluorophosphate) (I·2PF6), 1,3-bis(N-butylimidazolium-1-ylmethyl)benzene bis(hexafluorophosphate) (II·2PF6) or 3,5-bis(N-butylimidazolium-1-ylmethyl)toluene bis(hexafluorophosphate) (III·2PF6) treated with mercury(II) acetate. Interestingly X-ray crystal structure analysis revealed a close interaction between the Hg metal centre with one carbon atom of the aryl linker in addition to coordination with two NHCs. 相似文献
19.
The neutral arene ruthenium azido complexes [(η6-p-cymene)Ru(LL)(N3)], [LL = acetylacetonato (acac) (4), benzoylacetonato (bzac) (5) diphenylbenzoyl methane (dbzm) (6)] undergo [3+2] cycloaddition reaction with a series of activated alkynes and fumaronitrile to produce the arene ruthenium triazolato complexes: [(η6-p-cymene)Ru(LL){N3C2(CO2R)2}] [LL = (acac), R = Me (7); LL = (bzac), R = Me (8); LL = (dbzm), R = Me (9); LL = (acac), R = Et (10); LL = (bzac), R = Et (11); LL = (dbzm), R = Et (12) and [(η6-p-cymene)Ru(LL)(N3C2HCN)]; LL = acac (13), bzac (14); dbzm (15). However, cationic azido complexes, [(η6-p-cymene)Ru(dppe)(N3)]+ and [(η6-p-cymene)Ru(dppm)(N3)]+ do not undergo such cycloaddition reactions. The complexes were characterized on the basis of microanalyses, FT-IR and NMR spectroscopic data. Crystal structures of representative complexes were determined by single crystal X-ray diffraction. 相似文献
20.
A novel modulator of multidrug resistance (MDR) in tumor cells, kendarimide A (1), was isolated from an Indonesian marine sponge of Haliclona sp. Compound 1 reversed MDR in KB-C2 cells mediated by P-glycoprotein (P-gp) at a 6 μM concentration, and the chemical structure of 1 was characterized to be a linear peptide composed of N-methylpyroglutamic acid (pyroMeGlu), N-methylated eight-membered cysteinyl-cysteine (ox-[MeCys-MeCys]) together with many N-methyl amino acid residues. The amino acid sequence of 1 was determined by 2D NMR and FAB MS analysis. The absolute configuration of the amino acid residues in 1 except for the MeCys part was determined to be l-form respectively, based on interpretation of the HPLC analysis of Marfey's derivatives of the hydrolysates of 1 and the synthetic method for the pyroMeGlu residue. 相似文献