Iseluxine: A Novel Isoquinolinone Alkaloid from Isei a luxurians§

2000 ◽  
Vol 55 (11-12) ◽  
pp. 1023-1025 ◽  
Author(s):  
Thomas Schimming ◽  
Kristina Jenett-Siems ◽  
Karsten Siems ◽  
Ludger Witte ◽  
Mahabir P. Gupta ◽  
...  
Keyword(s):  
Structural Elucidation ◽  
Missing Link ◽  
H Nmr ◽  
Methyl Derivatives ◽  
Derivatives Of ◽  
C Nmr

A novel isoquinolinone alkaloid, iseluxine (1), has been isolated from the epigeal parts of Iseia luxurians (Moric.) O’Donell (Convolvulaceae), a climber indigenous to the tropical Americas. Structural elucidation was achieved by HRM S, 1H NMR, 13C NMR , and HMBC spectroscopy. N- and / or O-m ethyl derivatives of 1 are already known from certain Magnoliidae families, e.g., the Fumariaceae, the Lauraceae, or the Papaveraceae. Iseluxine, the “missing link” in the biosynthesis of these methyl derivatives from dopamine, is the first isoquinolinone alkaloid characterized by a catechol substructure.

Triazolopyridine nucleosides. II. Glycosylations of 3-oxo-s-triazolo[4,3-a]pyridines with accompanying conversions into 2-oxo-s-triazolo[1,5-a]pyridine nucleosides

1977 ◽  
Vol 55 (5) ◽  
pp. 831-840 ◽  
Author(s):  
Brian Maurice Lynch ◽  
Suresh Chandra Sharma
Keyword(s):  
General Structure ◽  
Spectroscopic Properties ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
H Nmr ◽  
Pyridine Nitrogen ◽  
Methyl Derivatives ◽  
Fragmentation Patterns ◽  
Ribose Moiety ◽  
C Nmr

3-Oxo-s-triazolo[4,3-a]pyridine and various C-methyl derivatives (general structure 1) have been converted into the 2-β-D-ribofuranosyl species 2 and thence 4 via Friedel–Crafts catalyzed reaction with tetra-O-acetyl-β-D-ribofuranose, followed by deblocking. During the course of these reactions, rearrangements into the isomeric 3-β-D-ribofuranosyl-2-oxo-s-triazolo[1,5-a]-pyridines occur through ring-opening of the pyridine rings yielding species 3 and 5. The proportion of rearrangement products is dependent upon the position and number of the C-methyl substituents.Structural assignments for these compounds are based upon comparisons of spectroscopic properties (1H nmr, 13C nmr, uv) with model compounds from each isomeric series; structural assignments for these models are based on unequivocal mass-spectral fragmentation patterns. Unlike related triazolopyridine nucleosides with the ribose moiety attached to a pyridine nitrogen (Lynch and Sharma (1976)), there are no unusual aspects in the conformations of the nueleosides of types 4 and 5.

β-Hydroxydithiozimtsäurederivate als Liganden. Synthese und Charakterisierung neuartiger 1,1-Ethendithiolato- und O,S-Chelatkomplexe / Derivatives of β -Hydroxydithiocinnamic Acids as Ligands. Syntheses and Characterisation of Novel 1,1-Ethenedithiolato and O,S-Chelate Complexes

2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand
Keyword(s):  
Bidentate Ligand ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Chelate Complexes ◽  
X Ray ◽  
H Nmr ◽  
Hexyl Ester ◽  
Elemental Analyses ◽  
Derivatives Of ◽  
C Nmr

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.

Synthesis, spectroscopic characterization and structural studies of organotin monothiocarbonates. Crystal structures of Ph3Sn[SCO2Me] and Ph3Sn[SCO2(i-Pr)]

2000 ◽  
Vol 78 (9) ◽  
pp. 1214-1221 ◽  
Author(s):  
John E Drake ◽  
Jincai Yang
Keyword(s):  
Intramolecular Interaction ◽  
Spectroscopic Characterization ◽  
Triclinic Space Group ◽  
Cell Parameters ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Trigonal Bipyramidal ◽  
Considerable Distortion ◽  
Derivatives Of ◽  
C Nmr

O-alkyl monothiocarbonate (monoxanthate) derivatives of tin were obtained by the reaction of a sodium salt of the monothiocarbonic acid with an organotin chloride to give Ph3Sn[SCO2R], Ph2Sn[SCO2R]2, and Me3Sn[SCO2R], where R = Me and i-Pr. The compounds have been characterized by infrared, Raman, 1H NMR, and 13C NMR spectroscopy, as well as mass spectrometry, and in two cases by X-ray crystallography. Ph3Sn[SCO2Me] (1) and Ph3Sn[SCO2(i-Pr)] (2), crystallize in the triclinic space group P[Formula: see text] (no. 2) with cell parameters a = 10.218(4), b = 10.568(6), c = 9.366(7) Å, α = 106.73(5), β = 96.99(5), γ = 85.55(4)°, V = 960(1) Å3, and Z = 2 for 1; and a = 14.793(2), b = 17.856(3), c = 9.813(3) Å, α = 103.86(5), β = 98.36(5), γ = 106.85(4)°, V = 2343(1) Å3, and Z = 2 for 2. The latter has two molecules in the asymmetric unit. The immediate environment about tin in both 1 and 2 is that of the expected distorted tetrahedron. However, the orientation of the monothiocarbonate group is such that there is an Sn-O intramolecular interaction of 3.040(8) for 1 and 3.05(2) Å on average for 2. Thus, the considerable distortion is consistent with a tendency to form a five-coordinate, trigonal bipyramidal species with one of the O-Sn-C angles approaching 180o (153.4(4) for 1 and an average of 157.1(6) for 2). Estimations of the Pauling partial bond orders suggest this weak Sn-O interaction is slightly stronger than the corresponding Ge-O interaction in the analogous germanium derivative, Ph3Ge[SCO2Me].Key words: structure, tin, methyl, phenyl, isopropyl, monothiocarbonates.

scholarly journals Synthesis and Antimicrobial Activity of Calycanthaceous Alkaloid Analogues

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101
Author(s):  
Shaojun Zheng ◽  
Longbo Li ◽  
Yu Wang ◽  
Rui Zhu ◽  
Hogjin Bai ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Structural Modification ◽  
Antimicrobial Agents ◽  
Pathogenic Fungi ◽  
Curvularia Lunata ◽  
Plant Pathogenic Fungi ◽  
H Nmr ◽  
High Degree ◽  
Derivatives Of ◽  
C Nmr

A series of 24 novel derivatives of the calycanthaceous alkaloids with a tetrahydropyrroloindol-based core structure was synthesized from tryptophan in good yields. Their structures were characterized by IR, 1H NMR, and 13C NMR spectroscopy and ESI-MS. The synthesized compounds were evaluated against a wide variety of plant pathogenic fungi. Compound a9 exhibited a high degree of activity against Curvularia lunata, with 91.0% activity at a concentration of 100 μg mL−1 and with an EC50 of 44.6 μg mL−1. a7, a8, a13, and a17 exhibited high degrees of activity against Sclerotinia sclerotiorum, with a8 being the most effective with an EC50 of 38.4 μg mL−1. Compound a9 illustrated activity against Botrytis cinerea, with an EC50 of 79.5 μg mL−1. Considering the compounds evaluated, the alkyl substituents of the chain may contribute to the significant variations in fungicidal potency. The structure antifungal activity relationships are also discussed. These results will pave the way for further design, structural modification, and development of calycanthaceous alkaloids as antimicrobial agents.

scholarly journals Synthesis and Antibacterial Activity of Some Derivatives of 2-Methylbenzimidazole Containing 1,3,4-Oxadiazole or 1,2,4-Triazole Heterocycle

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Cong Nguyen Tien ◽  
Duc Tran Thi Cam ◽  
Ha Bui Manh ◽  
Dat Nguyen Dang
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Spectral Data ◽  
H Nmr ◽  
Mold And Yeast ◽  
Derivatives Of ◽  
C Nmr

5-[(2-Methyl-1H-benzimidazol-1-yl)methyl]-1,3,4-oxadiazole-2-thiol or 5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4-(4-methylphenyl)-1,2,4-triazol-3-thiol which were prepared starting from 2-methylbenzimidazole in the reaction with appropriateN-aryl-2-chloroacetamides afforded two series ofN-aryl-2-{5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-1,3,4-oxadiazol-2-yl}sulfanylacetamides andN-aryl-2-{5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-4-(4-methylphenyl)-4H-1,2,4-triazol-3-ylthio}acetamides, respectively. The structures of the compounds were elucidated on the basis of IR, MS,1H-NMR, and13C-NMR spectral data. The compounds containing 1,3,4-oxadiazole or 1,2,4-triazole heterocycle also were tested for their antimicrobial activity against bacteria, mold, and yeast.

Coordination compounds of indium. Part 44. The oxidation of indium(I) halides by tetrahalogeno-ortho-quinones

1988 ◽  
Vol 66 (11) ◽  
pp. 2935-2940 ◽  
Author(s):  
Theodore A. Annan ◽  
Dennis G. Tuck
Keyword(s):  
Coordination Compounds ◽  
Nmr Spectra ◽  
Dynamic Behaviour ◽  
Addition Product ◽  
Donor Ligands ◽  
Chelate Complexes ◽  
H Nmr ◽  
Anionic Complexes ◽  
Derivatives Of ◽  
C Nmr

The reaction of indium(I) halides (InX; X = Cl, Br, I) with tetrahalogeno-ortho-quinones (Y4C6O2; Y = Cl, Br) gives the oxidative addition product Y4C6O2InX, These compounds have been isolated as adducts with neutral bidentate donor ligands (N,N,N′,N′-tetramethylethanediamine (tmen), 1,10-phenanthroline) or as salts of the anionic complexes [Y4C6O2InCl2]− or [Y4C6O2In(Cl)Br]−. The number of coordinated tmen molecules, and hence the structure, depends on the method of preparation. Infrared, 1H NMR, and 13C NMR spectroscopy all confirm that these products are all substituted-catecholato derivatives of indium(III), and the structure of these various neutral or anionic derivatives is discussed. The temperature dependence of the 13C NMR spectra shows that the dynamic behaviour of these compounds (in d6-dmso) is similar to that observed in previous studies of indium(III) chelate complexes.

scholarly journals Synthesis and Larvicidal Activity of Phrymarolin Derivatives against Culex Pipiens Pallens

2016 ◽  
Vol 11 (2) ◽  
pp. 1934578X1601100
Author(s):  
Fangfang Tan ◽  
Shaojun Zheng ◽  
Peng Gao ◽  
Shengkun Li ◽  
Zhaonong Hu ◽  
...  
Keyword(s):  
Larvicidal Activity ◽  
Culex Pipiens ◽  
Culex Pipiens Pallens ◽  
H Nmr ◽  
Data Analyses ◽  
Larvicidal Activities ◽  
Derivatives Of ◽  
Pipiens Pallens ◽  
C Nmr

Twenty-eight new phrymarolin derivatives, including twenty-one ethers, six esters and a dehydroxy phrymarolin, were prepared from phrymarolin I and the structures of all the derivatives were confirmed by 1H NMR and 13C NMR spectroscopic and MS data analyses. Larvicidal activities of these phrymarolin analogues were assayed against 4th instar larvae of Culex pipiens pallens. The ester derivatives of phrymarolin showed lower larvicidal activity than phrymarolin I, but some of the ether derivatives and dehydroxy phrymarolin showed much higher activity. Two ether derivatives, 1–18 and 1–19, showed significant larvicidal activity with LC50 values of 1.89 and 7.78 mg/L, respectively.

Seven-coordinate metal carbonyl derivatives of cis-(CH3)2AsC(CF3)=C(CF3)As(CH3)2

1976 ◽  
Vol 54 (16) ◽  
pp. 2548-2556 ◽  
Author(s):  
William R. Cullen ◽  
Lynn M. Mihichuk
Keyword(s):  
Metal Carbonyl ◽  
Activation Parameters ◽  
Nmr Studies ◽  
H Nmr ◽  
Carbonyl Derivatives ◽  
Derivatives Of ◽  
C Nmr

The seven-coordinate complexes (L—L)M(CO)3X2 (M = Mo, W; X = Br, I; (L—L) = cis-(CH3)2AsC(CF3)=C(CF3)As(CH3)2) were prepared and characterized. 1H and 13C nmr studies at 25 and −70 °C suggest that the complexes are nonrigid. Similarly 1H nmr studies indicate the seven-coordinate (L—L)LMo(CO)2Br2 complexes are also nonrigid. The (L—L)L2Mo(CO)Br2 complexes (L is a monodentate phosphite or phosphine) are rigid at 25 °C and nonrigid at higher temperatures. Activation parameters are calculated for the motion of two of the complexes and possible mechanisms are discussed.

Pd-catalyzed synthesis of C-C (Sonogashira, Suzuki, Heck, Stille), C-P and C-S linked products using gem -dibromovinyl BODIPY

2021 ◽  
pp. A-O
Author(s):  
Hasrat Ali ◽  
Brigitte Guérin ◽  
Johan E. van Lier
Keyword(s):  
Absorption Maximum ◽  
Palladium Catalysis ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Cross Coupling Reactions ◽  
Derivatives Of ◽  
C Nmr

The chemistry of gem-dibromovinyl derivatives has undergone a renaissance through the application of palladium catalysis and has been applied to pyrrole substituted gem-dibromovinyl BODIPY. gem-Dibromovinyl BODIPYs (substituted at either the [Formula: see text]-position of 8-phenyl or the [Formula: see text]-position of the pyrrole rings) were studied for cross-coupling reactions using Sonogashira, Suzuki, Heck and Stille conditions, and with phosphonates and thiols. The assigned structures were supported by MS and 1H NMR, [Formula: see text]C NMR, X-ray diffraction analysis as well as optical spectroscopy. The conjugates were investigated for their absorption, fluorescence and solvatochromic properties in different solvents. Substitution at the [Formula: see text]-position of 8-phenyl derivatives of gem-diethynyl BODIPYs did not induce any shift in the absorption maximum, while the [Formula: see text]-position pyrrole substituted derivatives showed a red shift. Aromatic compounds gave larger red shifts as compared to the aliphatic substituted analogs.

Synthesis and antimicrobial properties of N-substituted derivatives of (E)-2′,3″-thiazachalcones

2015 ◽  
Vol 70 (1-2) ◽  
pp. 45-50
Author(s):  
Asu Usta ◽  
Hacer Taşkıran
Keyword(s):  
Elemental Analysis ◽  
Antimicrobial Properties ◽  
Antibacterial Activities ◽  
Spectral Studies ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mass Spectral ◽  
H Nmr ◽  
Derivatives Of ◽  
C Nmr

Abstract N-alkyl substituted 2′,3″-thiazachalcones {3-[(1E)-3-(4-methylthiophene-2-yl)-3-oxoprop-1-en-1-yl]-1-alkyl (C5–12,14) pyridinium bromides} were synthesized by a two-step reaction. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectral studies. The synthesized compounds were tested for antibacterial activities and found to be more active against Gram-positive as compared to Gram-negative bacteria.

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