Chemistry of the shellfish toxin domoic acid: characterization of related compounds

1994 ◽  
Vol 72 (2) ◽  
pp. 430-436 ◽  
Author(s):  
John A. Walter ◽  
Michael Falk ◽  
Jeffrey L.C. Wright
Keyword(s):  
Molecular Modelling ◽  
Domoic Acid ◽  
Conformational Flexibility ◽  
Spectroscopic Methods ◽  
Clear Cut ◽  
Nmr Data ◽  
Shellfish Toxin ◽  
New Compounds ◽  
Related Compounds

Five new compounds related to the neurotoxin domoic acid have been characterized by spectroscopic methods. They include a diastereoisomer that occurs naturally with domoic acid in mussels and four hydrogenation products. The stereochemistry of the two epimeric tetrahydro derivatives could not be assigned on the basis of the NMR data alone because of high conformational flexibility. However, a clear-cut assignment was possible by molecular modelling in combination with the NMR data.

scholarly journals Darstellung und Charakterisierung einfacher α-Sila- und α,ω-Disilaalkane als Vorstufen für die CVD-Erzeugung von amorphem Silicium a-SiC:H / Synthesis and Characterization of Simple α-Sila- and α,ω-Disilaalkanes: Precursors for the CVD Production of Amorphous Silicon a-SiC:H

1987 ◽  
Vol 42 (9) ◽  
pp. 1088-1096 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Cornelia Dörzbach
Keyword(s):  
Amorphous Silicon ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Synthesis And Characterization ◽  
Nmr Data ◽  
Functional Derivatives ◽  
New Compounds

Preparative methods have been explored for the synthesis of small, volatile polysilaalkanes, which could serve as starting materials for the production of amorphous silicon a-SiC:H. High yield pathways have been developed for H3SiCH2CH2SiH3 and H3SiCH2CH2CH2SiH3. These compounds can be converted into symmetrically halogen-functional derivatives through the reac­tions with SnCl4 or Br2. The homologous H3SiCH2CH2SiH2CH3 has also been prepared and halogenated, starting from the corresponding vinylsilane via the hydrosilylation route. Allylsilanes were the source of the synthesis of H3SiCH2CH=CH2, CH3SiH2CH2CH=CH, SiH2(CH2CH = CH2)2, SiH2(CH2CH2CH2SiH3)2, or HSi(CH2CH2CH2SiH3)3. Methylated deriva­tives are also available. - Some physical and spectroscopic properties of the new compounds have been investigated. In particular. NMR data were collected and used for an assessment of structure and isomerism.

Synthesis and Characterization of Indolylfulgide Photochromic Colorants

2013 ◽  
Vol 821-822 ◽  
pp. 522-526
Author(s):  
Ning Ning Lv ◽  
An Guo Sang ◽  
Yan Zhang
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
Synthesis And Characterization ◽  
Indole Derivatives ◽  
Thermal Stabilities ◽  
Nmr Data ◽  
New Compounds

This paper describes the synthesis of two photochromic 2-indolyl-fulgides by stobbe condensation of the corresponding 2-acyl-1,3-dimethyl-indole derivatives with diethyl isopropylidene succinate in the presence of hexamethyldisilazane potassium. The overall yields was up to 41% for 3 steps. Both prepared compounds are sensitive to UV light and change colors upon irradiation. And the two fulgides can be switched back and forth 100 times without obvious degradation. Thermal stabilities of the fulgides in acetonitrile at room temperature for 30 days and at 80 °C for 12 h were measured using UV-vis and 1H NMR spectroscopy. The absorption spectra of both forms did not exhibit any sign of degradation. The NMR data indicated that no new compounds were detected. The utilization of these materials for use in photochromic textiles were discussed.

Avarol and Related Compounds from the New Zealand Marine Sponge Dysidea sp.

1997 ◽  
Vol 50 (4) ◽  
pp. 341 ◽  
Author(s):  
Michael Stewart ◽  
Patrick M. Fell ◽  
John W. Blunt ◽  
Murray H. G. Munro
Keyword(s):  
New Zealand ◽  
Marine Sponge ◽  
Spectroscopic Methods ◽  
New Compounds ◽  
Related Compounds

Bioassay and t.l.c. guided separation of extracts from the New Zealand marine sponge Dysidea sp. has led to the isolation of avarol (1), six other known compounds (2)–(4) and (6)–(8), and seven new compounds (9)–(15). All but one of these, compound (8), are related to avarol. The structures of all the compounds have been established by spectroscopic methods.

scholarly journals Preparation and Characterization of New Amino-Substituted Crowns and Podands

1992 ◽  
Vol 47 (4) ◽  
pp. 547-552 ◽  
Author(s):  
Zeynel Kılıç ◽  
Edwin Weber ◽  
Necla Gündüz ◽  
Emine Kılıç ◽  
Hasan Nazır ◽  
...  
Keyword(s):  
Hydrazine Hydrate ◽  
Potentiometric Titration ◽  
Spectroscopic Data ◽  
Building Blocks ◽  
Pka Values ◽  
Nitro Derivatives ◽  
New Compounds ◽  
Related Compounds

A number of macrocyclic (1b-3b) and linear oligoether compounds (4b-8b) with 2,2'- methylenebis(4-aminophenol) or 2-aminophenol characteristic building blocks have been synthesized by reduction of the corresponding nitro derivatives with Pd -C/hydrazine hydrate. The pKa' values of the new compounds have been determined by potentiometric titration. These and the observed spectroscopic data are discussed and compared with related compounds. A crystalline 1:1 complex of the diamino crown 3b with NaSCN has also been prepared and characterized.

scholarly journals New Angucyclinones from the Marine Mollusk Associated Actinomycete Saccharothrix espanaensis An 113

2008 ◽  
Vol 3 (10) ◽  
pp. 1934578X0800301 ◽  
Author(s):  
Nataliya I. Kalinovskaya ◽  
Anatoly I. Kalinovsky ◽  
Lyudmila A. Romanenko ◽  
Mikhail A. Pushilin ◽  
Pavel S. Dmitrenok ◽  
...  
Keyword(s):  
Spectroscopic Methods ◽  
Two Dimensional ◽  
Marine Mollusk ◽  
Nmr Data ◽  
New Compounds

Three new angucyclinones, saccharothrixins A (6), B (7) and C (8), together with five known analogues, X-14881 A (1), X-14881 E (2), ochromycinone (3), X-14881 C (4) and X-14881 B (5), were isolated from the actinomycete Saccharothrix espanaensis An 113 associated with the marine mollusk Anadara broughtoni. The structures of the new compounds were elucidated by spectroscopic methods including one- and two-dimensional NMR and by comparison of the NMR data with those of the structurally related known angucyclinone X-14881 A (1).

Tetranortriterpenoids and related compounds. Part 25. Two 3,4-secotirucallane derivatives and 2′-hydroxyrohitukin from the bark of Guareacedrata (Meliaceae)

1980 ◽  
Vol 58 (17) ◽  
pp. 1865-1868 ◽  
Author(s):  
John A. Akinniyi ◽  
Joseph D. Connolly ◽  
David S. Rycroft ◽  
B. Lucas Sondengam ◽  
N. Patience Ifeadike
Keyword(s):  
Dioic Acid ◽  
Nmr Data ◽  
New Compounds ◽  
Related Compounds ◽  
Monomethyl Ester ◽  
C Nmr

Three new compounds, 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic acid 1, the corresponding 3-monomethyl ester 12, and 2′-hydroxyrohitukin 13, have been isolated from the bark of Guareacedrata (Meliaceae). The structures of 1 and 12 were confirmed by correlation with methyl 3-oxotirucalla-8,24-dien-21-oate (methyl isoelemonate) 6. The 1H and 13C nmr data are reported.

Coordination Compounds of Some 3d-Transition Metal Ions with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)- thiosemicarbazide

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu
Keyword(s):  
Coordination Compounds ◽  
Magnetic Moments ◽  
Thermo Gravimetric Analysis ◽  
Electronic Spectroscopy ◽  
Transition Metal Ions ◽  
Synthesis And Characterization ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
New Compounds

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.

Unexpected Keto-enol Tautomerism in the Cyclopyridinophane Class Direct and indirect proofs

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Paul Ionut Dron ◽  
Neculai Doru Miron ◽  
Gheorghe Surpateanu
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Stable Conformer ◽  
Ph Measurements ◽  
Theoretical Methods ◽  
Nmr Data ◽  
Tautomeric Forms ◽  
New Compounds

The paper presents the synthesis of cyclo (bis-paraquat p-phenylene p-phenylene-carbonyl) tetrakis (hexafluorophosphate), named �CETOBOX�, and the closely related structural determinations. This compound exists in three tautomeric forms. These forms were evidentiated by NMR-data (1H-NMR, TOCSY, COSY, NOESY), UV-Vis spectra coupled with pH measurements and by synthesis. As the �CETOBOX� gives �in situ� only the corresponding monoylide, the synthesis of a new fluorescent indolizine cyclophane has been performed by a 3+2 cycloaddition. All structures of the new compounds presented herein have been established by NMR spectroscopy. Also, theoretical methods (MM3, AM1, AM1-COSMO and B88LYPDFT) have been used to determine the most stable conformer structures.

scholarly journals Sulfation of vitamin D3-related compounds-identification and characterization of the responsible human cytosolic sulfotransferases

FEBS Letters ◽  
2017 ◽  
Vol 591 (16) ◽  
pp. 2417-2425 ◽  
Author(s):  
Katsuhisa Kurogi ◽  
Yoichi Sakakibara ◽  
Masahito Suiko ◽  
Ming-Cheh Liu
Keyword(s):  
Vitamin D3 ◽  
Related Compounds ◽  
Identification And Characterization
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