Refine
Has Fulltext
- no (108)
Year of publication
Document Type
- Article (108) (remove)
Language
- English (108)
Is part of the Bibliography
- yes (108)
Keywords
- Conformational analysis (6)
- Cytotoxicity (5)
- Leguminosae (5)
- Antiplasmodial (4)
- DFT calculations (4)
- NMR (4)
- NMR spectroscopy (4)
- antiplasmodial (4)
- cytotoxicity (4)
- conformational analysis (3)
- Antiplasmodial activity (2)
- Asteraceae (2)
- Candida yeast (2)
- Drimys winteri (2)
- Dynamic NMR (2)
- Flavone (2)
- Isoflavone (2)
- Mycobacterium tuberculosis (2)
- Plasmodium falciparum (2)
- Surface exudates (2)
- Tephrosia purpurea (2)
- Theoretical calculations (2)
- modified Mannich reaction (2)
- (+)-Tephrodin (1)
- 1-Methylthio-1-phenyl-1-silacyclohexane (1)
- 10-Methoxy-10,7 '-(chrysophanol anthrone)-chrysophanol (1)
- 3,4-Dihydroisoquinoline (1)
- 3-Hydroxyisoflavanone (1)
- 3-Oxo-14 alpha, 15 alpha-epoxyschizozygine (1)
- 4-Substituted cyclohexanones (1)
- 4-methylene-cyclohexyl pivalate (1)
- 6 alpha-Hydroxy-alpha-toxicarol (1)
- 8-oxohobartine (1)
- ALTONA equation (1)
- Alkenyl cyclohexanone (1)
- Alkenyl cyclohexenone (1)
- Aminonaphthol (1)
- Aminonaphthols (1)
- Anthraquinone (1)
- Anti-Plasmodial activity (1)
- Anti-inflammatory (1)
- Anticancer (1)
- Antileishmanial (1)
- Antimalarial plants (1)
- Antimicrobial (1)
- Antimicrobial activities (1)
- Apoptosis (1)
- Aristotelia chilensis (1)
- Asphodelaceae (1)
- Azadironolide (1)
- Benzazepine (1)
- Benzylbenzofuran (1)
- Biflavonoid (1)
- Block copolymer (1)
- Bulbine frutescens (1)
- C-13 (1)
- C. bonducella (1)
- Cancer (1)
- Carvotacetones (1)
- Cassiamin A (1)
- Cassiamin B (1)
- Celastraceae (1)
- Chalcone (1)
- Charge transfer (1)
- Chelates (1)
- Chemotaxonomy (1)
- Cladosporium antarcticum (1)
- Conformational equilibrium (1)
- Coumaronochromone (1)
- Coumestan (1)
- D. melleri (1)
- DFT and MP2 calculations (1)
- DFT structural study (1)
- DSC (1)
- Dalbergia melanoxylon (1)
- Dianellin (1)
- Dimeric anthraquinone (1)
- Diterpenoid (1)
- Docking (1)
- Dodonaea angustifolia (1)
- Dorstenia kameruniana (1)
- Dynamic NMR spectroscopy (1)
- E. schliebenii (1)
- Escherichia coli (1)
- F-19 (1)
- Flavanone (1)
- Furanocoumarin (1)
- Fusarium proliferatum (1)
- Fusicoccane diterpenes (1)
- GWD (1)
- Gas phase electron diffraction (1)
- H-1 (1)
- H. pubescens (1)
- Halogenation (1)
- Hammett-Brown plots (1)
- Hypoestes verticillaris (1)
- Isoflavanones (1)
- Isolations (1)
- Kenusanone F 7-methyl ether (1)
- Kniphofia foliosa (1)
- Knipholone cyclooxanthrone (1)
- LCST (1)
- Lannea rivae (1)
- Lannea schweinfurthii (1)
- Ligand design (1)
- Lignans (1)
- Limonoid (1)
- Lobelia tupa (1)
- Lonchocarpus bussei (1)
- Lonchocarpus eriocalyx (1)
- Low-temperature C-13 and Si-29 NMR (1)
- Malaria (1)
- Mammea usambarensis (1)
- Mammea-type coumarins (1)
- Maytenus boaria (1)
- Maytenus disticha (1)
- Maytenus spp. (1)
- Millettia dura (1)
- Millettia dura; (1)
- Millettia lasiantha (1)
- Millettia leucantha (1)
- Millettia micans (1)
- Millettia oblata ssp teitensis (1)
- Mitochondrial ROS (1)
- Modified Mannich reaction (1)
- Moraceae (1)
- Multi-drug resistance (1)
- Mundulea sericea (1)
- Naphthoxazines (1)
- Naphthoxazinoquinazolines (1)
- Naphthoxazinoquinazolinones (1)
- Ormocarpum kirkii (1)
- Oxidation (1)
- P-31 NMR (1)
- PWD (1)
- Palladium (1)
- Penicillium digitatum (1)
- Pentylsedinine (1)
- Phenylanthraquinone (1)
- Piperidine alkaloid (1)
- Platycelphium voense (1)
- Platyisoflavanone (1)
- Pleurotus ostreatus (1)
- Pterocarpan (1)
- Quantum chemical calculations (1)
- Quinazolines (1)
- RAFT polymerization (1)
- Reaction products (1)
- Reagents (1)
- Renewable resources (1)
- Responsive polymer (1)
- Ring current effect (1)
- Roots (1)
- S li-gands (1)
- Schizophrenic self-assembly (1)
- Schizozygane indoline alkaloid (1)
- Schizozygia coffaeoides (1)
- Senecio roseiflorus (1)
- Simulation of H-1 NMR spectra (1)
- Sophoronol-7-methyl ether (1)
- Sphaeranthus bullatus (1)
- Staphylococcus aureus (1)
- Stem (1)
- Stem bark (1)
- Stereochemistry (1)
- Structure revision (1)
- Sulfobetaine methacrylate (1)
- Tephrosia aequilata (1)
- Tephrosia subtriflora (1)
- Tephrosia villosa (1)
- Terpurinflavone (1)
- Thienopyridine (1)
- Toonacilin (1)
- Toonapubesins F (1)
- Turraea nilotica (1)
- Turraea robusta (1)
- UCST (1)
- Xanthone (1)
- Zanthoxylum holstzianum (1)
- Zanthoxylum leprieurii (1)
- [4+2] cycloaddition (1)
- activity (1)
- aequichalcone A (1)
- aequichalcone B (1)
- aequichalcone C (1)
- alkaloid (1)
- antileishmanial (1)
- antimycobacterial activity (1)
- benzophenanthridine alkaloid (1)
- beta-dihydroagarofuran-type sesquiterpene (1)
- biocontrol (1)
- biotransformation (1)
- chalcone (1)
- crystal structure (1)
- cyclic imines (1)
- cycloaddition (1)
- cytotoxic (1)
- dihydro-beta-agarofuran (1)
- dihydromyricetin (1)
- dihydromyricetin-3-O-beta-glucoside (1)
- drimane sesquiterpenoids (1)
- drimendiol (1)
- dynamic NMR spectroscopy (1)
- epidrimendiol (1)
- exo-methylene conformational effect at cyclohexane (1)
- flavanonol (1)
- flavonol (1)
- holstzianoquinoline; (1)
- indole alkaloids (1)
- isoflavone (1)
- isotadeonal (1)
- lanosterol 14 alpha-demethylase (1)
- lanosterol 14-α-demethylase (1)
- leguminosae (1)
- marker compound (1)
- medicinal mushrooms (1)
- molecular dynamics (1)
- nAChR (1)
- norcaesalpin D (1)
- ortho-quinone methide (o-QMs) (1)
- phytomedicine (1)
- prenylated flavanonol (1)
- pristimerin (1)
- pterocarpan (1)
- pterocarpene (1)
- quantum chemical calculations (1)
- restricted N-S rotation (1)
- retrochalcone (1)
- rutaceae (1)
- seco-Anthraquinone (1)
- sesquiterpene (1)
- spectroscopy (1)
- starch phosphorylation (1)
- subtriflavanonol (1)
- trans-fagaramide (1)
- tuberculosis (1)
- winterdial (1)
Institute
The anisotropic effects of the phenyl, alpha- and beta-naphthyl moieties in four series of 1,3-oxazino[4,3- a]isoquinolines on the H-1 chemical shifts of the isoquinoline protons were calculated by employing the Nucleus Independent Chemical Shift (NICS) concept and Visualized as anisotropic cones by a through-space NMR shielding grid. The signs and extents of these spatial effects on the H-1 chemical shifts of the isoquinoline protons were compared with the experimental H-1 NMR spectra. The differences between the experimental delta (H-1)/ppm values and the calculated anisotropic effects of the aromatic moieties are discussed in terms of the steric compression that occurs in the Compounds studied.
Through the reactions of 1-aminomethyl-2-naphthol and substituted 1-aminobenzyl-2-naphthols with 3,4-dihydroisoquinoline or 6,7-dimethoxy-3,4-dihydroisoquinoline under microwave conditions, naphth[1,2-e][1,3]oxazino[2,3-a]-isoquinoline derivatives were prepared in good yields. The latter reaction was extended by using 2-aminoarylmethyl-1-naphthols, leading to isomeric naphth-[2,1-e][1,3]oxazino[2,3-a] isoquinolines. Beside the detailed NMR spectroscopic and theoretical study of both stereochemistry and dynamic behaviour of these new conformational flexible heterocyclic ring systems an unexpected dynamic process between two diastereomers was observed in solution, studied by variable temperature H-1 NMR spectroscopy and the mechanism proved by theoretical DFT computations.
The crude methanol extract of the seeds of Derris trifoliata showed potent and dose dependent larvicidal activity against the 2nd instar larvae of Aedes aegypti. From this extract two unusual rotenoid derivatives, a rotenoloid (named 7a-O-methyl-12a-hydroxydeguelol) and a spirohomooxarotenoid (named spiro-13-homo-13-oxaelliptone), were isolated and characterised. In addition a rare natural chromanone (6,7-dimethoxy-4-chromanone) and the known rotenoids rotenone, tephrosin and dehydrodeguelin were identified. The structures were assigned on the basis of spectroscopic evidence. The larvicidal activity of the crude extract is mainly due to rotenone. (c) 2006 Elsevier Ltd. All rights reserved
From the stem bark of Erythrina burttii, a new isoflavone, 5,2',4'-trihydroxy-7-methoxy-6-(3- methylbut-2-enyl)isoflavone (trivial name, 7-O-methylluteone) and a new flavanone, 5,7-dihydroxy-4'-methoxy- 3'-(3-methylbutadienyl)-5'-(3-methylbut-2-enyl)flavanone (trivial name, burttinonedehydrate) along with three known isoflavonoids (8-prenylluteone, 3-O-methylcalopocarpin and genistein) were isolated. The structures were detd. on the basis of spectroscopic evidence.
Bioassay-guided screening of Hypoestes verticillaris whole plant CH2Cl2: MeOH (1:1) extract for anti-plasmodial activity yielded four new compounds: two lignans 2, 6-dimethoxysavinin (1), 2,6-dimethoxy-(7E)-7,8-dehydroheliobuphthalmin (2); and two fusicoccane diterpenoids: 11(12)-epoxyhypoestenone (3) and 3(11)-epoxyhypoestenone (4). The chemical structures were determined using various spectroscopic techniques: UV-vis, IR, CD, 1D, 2D and MS. Two fractions (RAO-43B and RAO-43D) and the isolated compounds were tested for activity against CQ susceptible (D6) and resistant (W2) Plasmodium falciparum parasite strains, in vitro and the IC50 values determined. While the whole extract and some resultant fractions displayed moderate activity, the isolated compounds exhibited mild anti-plasmodial activity against the both strains ranging from IC50 value of 328 mu M in 1 to 93 mu M in 3 against W2 strain.
From the stem bark of Erythrina sacleuxii two new isoflavanones, (R)-5,7-dihydroxy-2',4',5'- trimethoxyisoflavanone (trivial name, (R)-2,3-dihydro-7-demethylrobustigenin) and (R)-5-hydroxy- 2',4',5'-trimethoxy-2'',2''- dimethylpyrano[5'',6'':6,7]isoflavanone (trivial name, (R)-saclenone) were isolated. In addition the known compounds shinpterocarpin, 2,3-dehydrokievitone, abyssinone V, abyssinone V-4'-methyl ether, erythrinasinate and 4'-O-methylsigmoidin B were isolated. The structures were determined on the basis of spectroscopic evidence.
As part of a project studying the secondary metabolites extracted from the Chilean flora, we report herein three new beta-agarofuran sesquiterpenes, namely (1S,4S,5S,6R,7R,8R,9R,10S)-6-acetoxy-4,9-dihydroxy-2,2,5a,9-tetramethyloctahydro-2H-3,9a-methanobenzo[b] oxepine-5,10-diylbis(furan-3-carboxylate), C27H32O11, (II), (1S,4S,5S,6R,7R,9S,10S)-6-acetoxy-9-hydroxy-2,2,5a, 9-tetramethyloctahydro-2H-3,9a-methanobenzo[ b] oxepine-5,10-diyl bis(furan-3-carboxylate), C27H32O10, (III), and (1S,4S,5S,6R,7R,9S,10S)-6-acetoxy-10-(benzoyloxy)-9-hydroxy-2,2,5a,9-tetramethyloctahydro-2H-3,9a-methanobenzo[b]oxepin-5-yl furan-3-carboxylate, C29H34O9, (IV), obtained from the seeds of Maytenus boaria and closely associated with a recently published relative [Paz et al. (2017). Acta Cryst. C73, 451-457]. In the (isomorphic) structures of (II) and (III), the central decalin system is esterified with an acetate group at site 1 and furoate groups at sites 6 and 9, and differ at site 8, with an OH group in (II) and no substituent in (III). This position is also unsubstituted in (IV), with site 6 being occupied by a benzoate group. The chirality of the skeletons is described as 1S, 4S, 5S, 6R, 7R, 8R, 9R, 10S in (II) and 1S, 4S, 5S, 6R, 7R, 9S, 10S in (III) and (IV), matching the chirality suggested by NMR studies. This difference in the chirality sequence among the title structures (in spite of the fact that the three skeletons are absolutely isostructural) is due to the differences in the environment of site 8, i.e. OH in (II) and H in (III) and (IV). This diversity in substitution, in turn, is responsible for the differences in the hydrogen-bonding schemes, which is discussed.
From the root bark of Erythrina burttii three new isoflav-3-enes, 7,4'-dihydroxy-2'-methoxy-6- (1'',1''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-A), 4'-hydroxy-2'- methoxy-(2'',2''-dimethylpyrano[5'',6'':8,7]isoflav-3-ene (trivial name, burttinol-B), 7,4'-dihydroxy-2'-methoxy-8-(3'',3''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-C), and a new 2-arylbenzofuran, 6,4'-dihydroxy-2'-methoxy-5- (1'',1''-dimethylallyl)-2-arylbenzofuran (trivial name, burttinol-D) were isolated. In addition, the known compounds, abyssinone V-4'-methyl ether, bidwillol A, calopocarpin, erybraedin A, erythrabyssin II, isobavachalcone, phaseollidin and phaseollin were identified. The structures were determined on the basis of spectroscopic evidence.
From the fruits of Bulbine abyssinica three new dimeric anthracene derivatives, (P)-8,9,1',8'- tetrahydroxy-3,3'-dimethyl[10,7'-bianthracene]-1,4,9',10'- tetraone (trivial name abyquinone A), (10R)-1,4,8,1',8-pentahydroxy-3,3'-dimethyl-[10,7'-bianthracene]9,9',10' (10H)-trione (trivial name abyquinone B), and (10R)-3,4'-dihydro-1,4,8,3',8',9'-hexahydroxy-3,3'- dimethyl-[10,7'-biant hracene]9,1'(10H,2'H)-dione (trivial name abyquinone Q were isolated. Despite their structural differences, these three compounds are connected to each other by the apparently biomimetic conversion of abyquinone C (a preanthraquinonylanthrone with two stereogenic centers) into B (an anthraquinonylanthrone with one stereogenic center) and finally into A (an axially chiral bianthraquinone) under mild conditions, involving a highly efficient center-to-axis chirality transfer. In addition, the known anthraquinones islandicin and chrysophanol were identified. The structures were determined on the basis of spectroscopical evidences, chemical transformations, and quantum chemical CD calculations. (C) 2005 Elsevier Ltd. All rights reserved