摘要:

Biosynthetic studies of two bithiophenes, [5-(3-buten-1-ynyl)-2,2′-bithiophene (BBT) and 5-(4-acetoxy-1-butynyl)-2,2′-bithiophene (BBTOAc)], were performed in hairy root cultures ofTagetes patulausing [1-13C]-, [2-13C]- and [1,2-13C2]-labeled sodium acetate as precursors. The data support previous biogenetic proposals and demonstrate that hairy root cultures provide a highly suitable medium for biosynthetic studies of root constituents.

ISSN:0038-7010    

DOI:10.1080/00387019108020662

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The semisepulchrate type complexes Ni2+bisperchlorate tris(((aminoethyl)amino)methyl)amine and Ni2+perchloratechloride tris(((aminoisopropyl)amino)methyl)amine have been obtained and characterized by means of IR, Raman, UV-VIS and proton NMR study. Vibrational spectra have been interpreted on the basis of the deuteration and metal isotope shift data. The capping group vibrations were found near 890 cm−1, 630 cm−1and 470 cm−1. Crystal field parameters were estimated from the UV-VIS spectra. The Dq parameter equals 1232 cm−1for the first complex and 1224 cm−1for the second, Racah'a parameter B equals 767 cm−1and 787 cm−1respectively. The position of N(CH2)3capping group proton resonances were found to be in the region 161–159 ppm.

ISSN:0038-7010    

DOI:10.1080/00387019108020663

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Elucidation of the structure and conformation of a hitherto unknown novel derivative of chromanone, 8-(3′-Methyl - but - 2′ - en - 1′ - oyl) - 7 - hydroxy - 2,2,5 - trimethyl-2H-chromanone, obtained as a byproduct in the Friedel-Crafts acylation of active phenolic compounds by NMR methods is reported. A combination of the 1D-NOE difference spectroscopy and Molecular Mechanics calculation was used to assign the conformation of the title compound.

ISSN:0038-7010    

DOI:10.1080/00387019108020664

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

1,3-benzodioxole derivatives [figure 1(A, B)] have been much studied for their biological activities.1–12Nevertheless, apart from our preceding papers13, 14only few works have been done as concerns their spectroscopic behaviour and their electronic structures.15, 16All the derivatives which have been studied in our recent works display a -CH2X group [Bzd-CH2X] in para to one of the oxygens of the five membered oxygenated fused ring (X being -H, -OH, -NH2, -NH+3, -COCH3etc…). We want to study here more strongly perturbating substituents with X directly linked to the benzene chromophore [figure 1(C)] [Bzd-X].

ISSN:0038-7010    

DOI:10.1080/00387019108020665

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The mass spectral fragmentation patterns of a various 2,4-dinitrophenyl-4′-substituted phenyl sulfides and sulfones help define the role of substituent effects under electron impact, and subsequently determines the appearance of the base peak. These substituent effects correlated well with the Hammett σ-values. The mass spectral features arise from the elimination of the sulfur atom with recombination of the terminal end groups or with scission across 4′-substituted phenyl ring in sulfides, whereas in sulfones the most abundant ion is formed through the sci-ssion of the rearranged aryl sulfinate ester. A comparison between the spectra of the two types is discussed. The results suggest that the skeletal rearrangement of the molecular ion occurring in these S-bridged compounds is a sensitive diagnostic tool in structure elucidation.

ISSN:0038-7010    

DOI:10.1080/00387019108020666

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The electron-impact induced fragmentation of some 4,5-dihydro-1,2,4-triazole derivatives was studied by conventional mass spectrometry. Some major fragment ions observed in the spectra were interpreted and fragmentation patterns involving McLafferty rearrangements were proposed.

ISSN:0038-7010    

DOI:10.1080/00387019108020667

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A method is presented for the determination of three tranquilizer-antipressant mixtures namely perphenazine amitriptyline, chlordiazepoxide-amitriptyline and trifluoperazine-isopropamide. The method depend on the application of first and second derivative spectrophotometric methods to resolve the interferance due to spectral overlapping. The method was applied to the determination of these compounds in synthecic mixtures and in pharmaceutical preparations. The coefficient of variation was less than 2%.

ISSN:0038-7010    

DOI:10.1080/00387019108020668

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

In this paper, two-component mixtures (spironolactone with hydrochlorothiazide, captopril with hydrochlorothiazide, and spironolactone with furosemide) were assayed by U.V. (A), first derivative (dA/dłD) and second derivative (d2A/dłD2) spectrophotometric methods, applying “Zero-Crossing” technique of measurement.

ISSN:0038-7010    

DOI:10.1080/00387019108020669

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Unequivocal assignments of the uncoupled protons at H-3 and H-6/H-8 of pyranoflavones by 2D-NOESY experiments have made it possible to distinguish linear and angular isomers. This study also suggests that the linear structure (carpachromene,1) assigned to a pyranoflavone isolated fromAtalantia ceylanicashould be revised to angular form (atalantoflavone,4). 2D-NOESY is also useful for differentiating 3′4′- and 2′4′- disubstituted B-ring flavones.

ISSN:0038-7010    

DOI:10.1080/00387019108020670

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387019108020661

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor