ABSTRACT
New chirally modified p-tert-butylthiacalix[4]arenes were synthesized via conformation- and/or regioselective etherification with ethyl bromoacetate followed by hydrolysis of the ester moiety and then subsequent amidation with (S)-1-phenyl-ethylamine or (S)-1-(1-naphthyl)ethylamine. These chiral selectors were coated with OV-17 on capillary columns to examine their ability as chiral stationary phases (CSPs) for discrimination of enantiomeric amino acid, amine and alcohol derivatives. It was found that CSP-(S)-4 prepared from cone-shaped tetra-(S)-1-phenylethylamide (S)-4 showed good to fair separations for all the samples examined. On the contrary, the corresponding CSP-(S)-14 prepared from the cone-shaped tetraamide (S)-14 of the parent p-tert-butylcalix[4]arene did not indicate any enantioseparation at all for the same samples, showing that the bridging group of the calix[4]arene ring is critical for the advent of enantioselectivity. The effect of the types and the numbers of the chiral amide groups in the chiral selectors on enantioselectivity was also discussed.
ABSTRACT
Illexin A, illexin B, and illexin C, isolated from ink of the squid Illex argentinus, have been reported to have a structure consisting of linear repeating units of (-6GalNAc alpha 1-3GlcA beta 1-3Fuc alpha 1-)n [Biochem. Biophys. Res. Commun. 198, 560 (1994)]. This structure was further investigated using NOESY and atmospheric pressure MS/MS measurement of PA-trisaccharide obtained by acid hydrolysis of illexin C. The results indicated that the structure is, in fact, branched. Observation of both [GalNAc-Fuc-PA]- and [GlcA-Fuc-PA]+ obtained as product ions from the molecular ion of PA-trisaccharide on the MS/ MS spectra suggested a branched repeating unit. NOEs between H-1 of GalNAc and H-3 of Fuc, and between H-1 of GlcA and H-4 of Fuc, revealed the positions of glycosidic linkages, and from the results of sodium periodate oxidation of illexin C and PA-trisaccharide, the structure was determined to be (-3GlcA beta 1-4(GalNAc alpha 1-3)Fuc alpha 1-)n.
Subject(s)
Decapodiformes/chemistry , Glycosaminoglycans/chemistry , Animals , Carbohydrate Conformation , Carbohydrate Sequence , Chromatography, Gel , Chromatography, Ion Exchange , Glycosaminoglycans/isolation & purification , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Sequence DataABSTRACT
Squid ink, which has little commercial use and is usually discarded, was extracted using a Tris-HCl buffer (pH 6.8). The extract was fractionated using DEAE Sephacel ion-exchange chromatography and Sephacryl S-300 gel filtration to give a peptidoglycan fraction which exhibited strong antitumor activity against Meth-A fibrosarcoma in BALB/c mice following intraperitoneal administration. The fraction was composed of 7.8% peptide, 57% polysaccharide and 30% pigment. The polysaccharide component had a unique structure with equimolar ratios of GlcA, GalNAc and Fuc. Since the fraction has no direct cytotoxic effect on Meth-A cells, inhibition of tumor growth may be due to stimulation of host-mediated responses.
Subject(s)
Antineoplastic Agents/isolation & purification , Decapodiformes/metabolism , Fibrosarcoma/drug therapy , Peptidoglycan/isolation & purification , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Cell Division/drug effects , Chemical Fractionation , Chromatography, Ion Exchange , Female , Hydrogen-Ion Concentration , Mice , Mice, Inbred BALB C , Neoplasm Transplantation , Peptidoglycan/chemistry , Peptidoglycan/pharmacology , Peptidoglycan/therapeutic use , Pronase/metabolism , Tumor Cells, CulturedABSTRACT
Three fucose-rich glycosaminoglycans (GAGs), illexin A, illexin B and illexin C, were isolated from squid ink of Illex argentinus. The GAGs were obtained by the method of Actinase E digestion, DEAE Sephadex A-50 ion-exchange chromatography and Sephacryl S-300 gel filtration. They gave a single band on the electrophoresis using cellulose acetate membrane and contained equimolar ratios of Fuc, GlcA and GalNAc. Molecular weights of illexin A, illexin B, and illexin C were determined by Sephacryl S-300 gel filtration to be 50,000, 50,000-80,000, and 80,000, respectively. These GAGs were not digested with any glycosaminoglycanases. On the basis of one and two dimensional NMR spectra, glycosidase treatment and periodate oxidation of the pyridylaminated trisaccharide obtained by acid hydrolysis of illexin C, the unique repeating structure of the GAGs was determined to be (-6GalNAc alpha 1-3GlcA beta 1-3Fuc alpha 1-)n.
Subject(s)
Decapodiformes/chemistry , Fucose/analysis , Glycosaminoglycans/chemistry , Trisaccharides/chemistry , Amino Acids/analysis , Amino Sugars/analysis , Animals , Carbohydrate Sequence , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Monosaccharides/analysis , Sulfates/analysisABSTRACT
This report concerns two boys with minimal change nephrotic syndrome progressed to renal failure. The first case aged 17 being a steroid sensitive infrequent relapse developed acute renal failure at his third relapse and recovered soon after the treatment with diuretics and corticosteroids. The second case aged 15 being a steroid dependent frequent relapse became steroid resistant at his 11th relapse and progressed to renal failure seven months later. As the causes of renal failure, acute tubular necrosis and tubular obstruction by casts were suspected in the former. Renal vein thrombosis, morphological transition of renal histology, hemodynamic change and change in glomerular permeability might be occurred in the latter. Renal failure is a rare complication of minimal change nephrotic syndrome and the cause is variable. Precise diagnosis and prompt treatment should be needed to improve the prognosis.
