Discriminação quiral por CLAE em carbamatos de polissacarídeos: desenvolvimento, aplicações e perspectivas

Cass, Quézia B.; Tiritan, Maria Elizabeth; Bassi, Ana Karolina Zamprônio; Calafatti, Silvana A.; Degani, Ana Luiza G.

doi:10.1590/s0100-40421997000100007

Cited by 7 publications

(7 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…18,19 These phases have been used extensively, with success, not only in the analytical mode 20 but also on the preparative scale 21 and have proved to be effective in normal, reversed-phase, and polar mode of elution. 22 -26 Recent results obtained in the use of polysaccharide-based phases with multimodal elution, in which the performances of the phases were maintained while changing from one elution mode to another, prompted us to attempt a similar strategy.…”

Section: Resultsmentioning

confidence: 99%

Enantiomeric resolution of kielcorin derivatives by HPLC on polysaccharide stationary phases using multimodal elution

et al. 2004

View full text Add to dashboard Cite

Analytical HPLC methods using carbamate chiral stationary phases of polysaccharide derivatives were developed for the enantiomeric resolution of five racemic mixtures of xanthonolignoids: rac-trans-kielcorin C, rac-cis-kielcorin C, rac-trans-kielcorin D, rac-trans-isokielcorin D, and rac-trans-kielcorin E. The separations were evaluated with the stationary phases cellulose tris-3,5-dimethylphenylcarbamate, amylose tris-3,5-dimethylphenylcarbamate, amylose tris-(S)-1-phenylethylcarbamate, and amylose tris-3,5-dimethoxyphenylcarbamate under normal, reversed-phase, and polar organic elution conditions. Chiral recognition of those chiral stationary phases, the influence of mobile phases on the enantiomers separation, and the effects of structural features of the solutes on the chiral discrimination observed are discussed. The best performance was achieved on an amylose tris-3,5-dimethylphenylcarbamate phase. Polar organic conditions gave shorter retention factors and better resolutions and were a valuable alternative to the alcohol-hexane or reversed-phase conditions.

show abstract

Section: Resultsmentioning

confidence: 99%

Enantiomeric resolution of kielcorin derivatives by HPLC on polysaccharide stationary phases using multimodal elution

et al. 2004

View full text Add to dashboard Cite

show abstract

“…31 The highly versatile cellulose tris(3,5-dimethylphenyl carbamate) 27,28 was selected for investigation and, based on previous experience, was coated onto a small diameter, microporous aminopropylated silica support (particle size, 5 µm; pore size, 120 Å.). 31 The highly versatile cellulose tris(3,5-dimethylphenyl carbamate) 27,28 was selected for investigation and, based on previous experience, was coated onto a small diameter, microporous aminopropylated silica support (particle size, 5 µm; pore size, 120 Å.).…”

Section: Resultsmentioning

confidence: 99%

First direct resolution of gossypol enantiomers on a chiral high‐performance liquid chromatography phase

Cass¹,

Bassi²,

Matlin³

1999

Chirality

Self Cite

View full text Add to dashboard Cite

The first direct resolution of gossypol enantiomers has been achieved by HPLC on a chiral stationary phase consisting of cellulose tris-(3,5-dimethylphenyl carbamate) coated onto microporous aminopropyl-silica eluted in the reverse phase mode. Chirality 11: 46-49, 1999. © 1999 KEY WORDS: enantiomers of gossypol; direct resolution; chiral HPLC phase; carbohydrate carbamate coating; cellulose tris-(3,5-dimethylphenyl carbamate)Gossypol (Fig. 1), a binaphthyl pigment isolated from the cotton plant and also present in a number of other members of the Malvaceae, is chiral due to steric hindrance to rotation about the internaphthyl bond.1 The standard isolation procedure developed for the extraction of gossypol from the cotton plant 1 affords racemic gossypol as a 1:1 complex with acetic acid. However, investigations have shown that there are wide variations in the ratio of gossypol enantiomers present in different species of cotton plant (Gossypium species) and even within different tissues in the same plant. 2-5There has been considerable interest in the pharmacological properties of gossypol and it has been shown to be potent as an anti-spermatogenic agent 1,6,7 and anti-tumor agent, 8,9 and to possess activity against the HIV-1 virus 10 and the Entamoeba histolytica organism responsible for amoebiasis. 11,12 In all these cases, the (−)-enantiomer of gossypol has been shown to be substantially more active than the (+)-isomer. [13][14][15][16][17][18][19][20][21] Interest in studies of the varied biological activities of the enantiomers of gossypol [13][14][15][16][17][18][19][20][21] and of its unequal enantiomeric distribution in different Malvaceae species [2][3][4][5] has resulted in a need for simple and rapid methods for the analysis of the enantiomeric composition of gossypol samples, as well as for large-scale methods for the resolution of the racemic compound. Previous efforts to resolve gossypol enantiomers directly by HPLC on chiral stationary phases have been unsuccessful, and as a result it was necessary to develop indirect methods, in which gossypol was converted into Schiff's base derivatives that could be separated on either chiral or achiral phases. [22][23][24][25] For the first time, we have now identified conditions suitable for the direct resolution of gossypol enantiomers, using a chiral carbohydrate carbamate phase under reverse phase conditions. MATERIAL AND METHODS ChemicalsAminopropyl-silica (Hypersil-APS, Shandon, UK) had the following properties: particle size, 5 µm; pore size, 120 Å.Isocyanates were purchased from Aldrich (Milwaukee, WI). Solvents were either HPLC grade from Carlo Erba (Milan, Italy) or were purified as usual. 26 Cellulose used was Avicel from Merck. HPLC dead times (t 0 ) were estimated using acetonitrile. (±)-Gossypol acetic acid was isolated from cotton seeds and its separated (−) and (+) enantiomers obtained as described previously. 22-24 EquipmentThe HPLC system consisted of a Shimadzu LC-10AD pump (Kyoto, Japan), a Rheodyne 7125 injector fitted with a 20-µl ...

show abstract

“…32,36,[38][39][40][41][42][43][44] Uma variedade de polissacarídeos, tais como celulose, amilose, quitosana, quitina e xilan, foram eficientemente derivados e usados como seletores quirais para separação de diferentes classes de compostos quirais. 39,40,42,43,45 A CSP tris(benzoato) de celulose (Chiralcel ® OB) e especialmente a tris(4-metilbenzoato) de celulose (Chiralcel ® OJ), comercializadas pela Daicel Chemical Industries, exibem excelentes habilidades de reconhecimento quiral para diversos compostos racêmicos. 38,40 Nestes derivados tris-benzoatos, os grupos carbonila dos ésteres podem interagir com os enantiômeros por meio de ligações de hidrogênio e interações dipolo-dipolo.…”

Section: Polissacarídeosunclassified

“…45 4 cavidades macrocíclicas com 7 anéis aromáticos. Há 22 grupos hidroxila, 2 amino, 6 amida e um grupo metil éster.…”

Section: Figura 4 Fases Quirais Derivadas De Fenilcarbamatos De Celuunclassified

Fases estacionárias quirais para cromatografia líquida de alta eficiência

2010

Self Cite

View full text Add to dashboard Cite

Discriminação quiral por CLAE em carbamatos de polissacarídeos: desenvolvimento, aplicações e perspectivas

Cited by 7 publications

References 70 publications

Enantiomeric resolution of kielcorin derivatives by HPLC on polysaccharide stationary phases using multimodal elution

Enantiomeric resolution of kielcorin derivatives by HPLC on polysaccharide stationary phases using multimodal elution

First direct resolution of gossypol enantiomers on a chiral high‐performance liquid chromatography phase

Fases estacionárias quirais para cromatografia líquida de alta eficiência

Contact Info

Product

Resources

About