ABSTRACT
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.
Subject(s)
Amylose/analogs & derivatives , Cellulose/analogs & derivatives , Chromatography, High Pressure Liquid/methods , Dioxanes/chemistry , Phenylcarbamates , Polysaccharides/chemistry , Amylose/chemistry , Carbamates/chemistry , Cellulose/chemistry , Chemical Phenomena , Chemistry , Kinetics , Models, Chemical , Stereoisomerism , Time FactorsABSTRACT
Further study of the wood of Calophyllum teysmannii Miq. var. inophylloide from Thailand yielded the xanthones 1,2,8-trimethoxyxanthone, 6-hydroxy-1,2,5,7-tetramethoxyxanthone and 3-(3'-carboxybutyl)-4-methoxyxanthone (teysmannic acid) in addition to scriblitifolic acid, 1,7-dihydroxyxanthone and the benzoic acid derivative leiocarpic acid.
Subject(s)
Plants, Medicinal/chemistry , Trees/chemistry , Xanthenes/isolation & purification , Magnetic Resonance Spectroscopy , Xanthenes/chemistryABSTRACT
Anastomose coloanal e o ultimo recurso cirurgico para preservacao do esfincter anal do paciente, evitando, portanto, uma colostomia definitiva. O carcinoma do reto medio, e algumas vezes do reto inferior, pode nao necessitar a resseccao do assoalho pelvico e anus para seu tratamento. Analisaram os 40 pacientes que realizaram anastomose coloanal no periodo de setembro/88 a dezembro/93, no HNSC, cujos diagnosticos foram: carcinoma em 34 pacientes, proctite actinica em 3, adenoma viloso em 1, adenoma viloglandular em 1 e linfoma em 1. Desses, 24 eram homens e 16 mulheres. A classificacao de Dukes modificada nos casos de carcinoma foi: A = 0 paciente, B = 6 pacientes, C = 24 pacientes e D = 4 pacientes. A distancia media da lesao a margem anal foi de 6 cm. Houve 3 casos de obito pos-operatorio e as complicacoes pos-operatorias vinculadas ao metodo ocorreram em 5 pacientes (12,5 por cento ) e nao vinculadas ao metodo em 11 (27,5 por cento ). Estenose de anastomose foi a complicacao mais comum no pos-operatorio tardio, ocorrendo em 7 pacientes. Apos fechar a colostomia, 35 pacientes ficaram continentes, com uma media diaria de 2,3 evacuacoes. A anastomose coloanal e uma boa alternativa para evitar uma colostomia definitiva. Contudo, nao deve substituir a amputacao abdomino-perineal para tumores extensos do reto inferior e a anastomose colorretal quando esta e tecnicamente factivel
