13C, 15N NMR and CP-MAS as well as FT-IR and PM5 studies of Schiff base of gossypol with l-phenylalanine methyl ester in solution and solid

Przybylski, Piotr; Schilf, Wojciech; Brzeziński, Bogumił

doi:10.1016/j.molstruc.2004.09.013

Cited by 26 publications

(7 citation statements)

References 25 publications

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“…Similar values of the isotope effect ( 190 ppb) were observed for the Schiff base being a derivative of gossypol and benzylamine, 25 occurring exclusively in the tautomeric form NH. 26,27 Deuterium isotope effects were also observed on the carboxylic C-2 0 carbon (¾50 ppb). This effect can be related to the long-range deuterium isotope effect or engagement of the COO group in hydrogen bond.…”

Section: Tetrabutylammonium Salts Of N-(2-hydroxynaphthylidene)-aminomentioning

confidence: 94%

Deuterium isotope effect on ¹³C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Rozwadowski

2006

Magnetic Reson in Chemistry

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Deuterium isotope effects on 13C chemical shift of tetrabutylammonium salts of Schiff bases, derivatives of amino acids (glycine, L-alanine, L-phenylalanine, L-valine, L-leucine, L-isoleucine and L-methionine) and various ortho-hydroxyaldehydes in CDCl3 have been measured. The results have shown that the tetrabutylammonium salts of the Schiff bases amino acids, being derivatives of 2-hydroxynaphthaldehyde and 3,5-dibromosalicylaldehyde, exist in the NH-form, while in the derivatives of salicylaldehyde and 5-bromosalicylaldehyde a proton transfer takes place. The interactions between COO- and NH groups stabilize the proton-transferred form through a bifurcated intramolecular hydrogen bond.

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Section: Tetrabutylammonium Salts Of N-(2-hydroxynaphthylidene)-aminomentioning

confidence: 94%

Deuterium isotope effect on ¹³C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Rozwadowski

2006

Magnetic Reson in Chemistry

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“…19) (35). The equilibrium between the various tautomeric Schiff's base structures (40a-c) has been extensively investigated by IR, NMR, and molecular modeling (125,(142)(143)(144)(145)(146)(147)(148)(149)(150)(151)(152)(153). For example, NMR experiments by Matlin and colleagues (144) on dianilinogossypol (R = -C 6 H 5 , Fig.…”

Section: Gossypol Reactionsmentioning

confidence: 99%

Reaction chemistry of gossypol and its derivatives

Kenar

2006

J Americ Oil Chem Soc

107

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Gossypol, a complex polyphenolic compound, is a naturally occurring highly colored yellow pigment found in the small intercellular pigment glands in the leaves, stems, roots, and seed of cotton plants. In cottonseed, gossypol contributes to its toxicity and therefore it is regarded as an unwanted processing component. It was not until its antitumor and male infertility activities were discovered that gossypol was considered as a valueadded natural product from cottonseed with useful physiological and chemical properties. These serendipitous discoveries created much excitement, and an enormous amount of research on gossypol has ensued. Since then, much research has focused on the preparation of suitable gossypol derivatives for medicinal applications. This review summarizes current knowledge about gossypol, its stereochemistry, tautomerism, and the many varied reactions the gossypol molecule can undergo.

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“…Przybyski et al have shown that the Schiff base formed between gossypol and l-phenylalanine exists in the enamine-enamine tautomer (Fig. 1) [7]. However, Nagamatsu et al have shown that in the case of salicylaldehyde, borate accelerates the formation of the Schiff base and the preferred tautomer is the stable borate-Schiff base complex shown in Fig.…”

Section: Hpce Optimizationmentioning

confidence: 98%

Capillary electrophoresis to quantitate gossypol enantiomers in cotton flower petals and seed

Vshivkov¹,

Pshenichnov²,

Golubenko³

et al. 2012

Journal of Chromatography B

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13C, 15N NMR and CP-MAS as well as FT-IR and PM5 studies of Schiff base of gossypol with l-phenylalanine methyl ester in solution and solid

Cited by 26 publications

References 25 publications

Deuterium isotope effect on ¹³C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Deuterium isotope effect on ¹³C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Reaction chemistry of gossypol and its derivatives

Capillary electrophoresis to quantitate gossypol enantiomers in cotton flower petals and seed

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13C, 15N NMR and CP-MAS as well as FT-IR and PM5 studies of Schiff base of gossypol with l-phenylalanine methyl ester in solution and solid

Cited by 26 publications

References 25 publications

Deuterium isotope effect on 13C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Deuterium isotope effect on 13C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Reaction chemistry of gossypol and its derivatives

Capillary electrophoresis to quantitate gossypol enantiomers in cotton flower petals and seed

Contact Info

Product

Resources

About

Deuterium isotope effect on ¹³C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids

Deuterium isotope effect on ¹³C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids