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At least 271 records · Page 15Linked to original sources
PubMed1993

Enzymatic synthesis of a novel trisaccharide, glucosyl lactoside.

Cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus produced a series of oligosaccharides by the transglycosylation reaction with cyclomaltohexaose as a glycosyl donor and D-lactose as its acceptor. The content of oligosaccharide A as the main transfer product was 22.1% of the total sugar. The content was increased to 34.1% by hydrolysis with glucoamylase. Oligosaccharide A was isolated by column chromatography and crystallized. By chemical and enzymatic analyses, oligosaccharide A was found to be a novel non-reducing trisaccharide; O-beta-D-galactopyranosyl-(1-->4)-O- beta-D-glucopyranosyl alpha-D-glucopyranoside.

Carbohydrate Sequence↗
PubMed1999

Enzymatic synthesis of N-acetylglucosaminyl-cyclodextrin by the reverse reaction of N-acetylhexosaminidase from jack bean.

Novel heterobranched cyclodextrins (CDs), N-acetylglucosaminyl-cyclodextrins (GlcNAc-CD), were synthesized from a mixture of GlcNAc and alpha, beta, or gamma CD by the reverse reaction of N-acetylhexosaminidase from jack bean. Optimum pH and temperature for the production of GlcNAc-alpha CD by N-acetylhexosaminidase were pH 4.9 and 50-70 degrees C, respectively. The maximum yield of GlcNAc-alpha CD was 17.5% (mol/mol) at the concentration of 1 M GlcNAc and 0.25 M alpha CD. The reverse reaction product, GlcNAc-alpha CD, was separated into two peaks by HPLC analysis on the ODS column. Their structures were identified as 6-O-beta-D-N-acetylglucosaminyl-alpha CD and 2-O-beta-D-N-acetylglucosaminyl-alpha CD by FAB-MS and NMR spectroscopies. N-Acetylhexosaminidase from jack bean also synthesized N-acetylgalactosaminyl-alpha CD from N-acetylgalactosamine and alpha CD.

Chromatography↗
PubMed1992

Bile acid and sterol solubilization in 2-hydroxypropyl-beta-cyclodextrin.

The use of 2-hydroxypropyl-beta-cyclodextrin has made it possible to prepare stable aqueous solutions of cholesterol, 26-hydroxycholesterol, 7 alpha-hydroxycholesterol, and monohydroxy bile acids such as lithocholic and 3 beta-hydroxy-5-cholenoic acids. These solutions are suitable for cell culture studies and for parenteral administration to animals.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed1989

[Preventive effect of OP-41483-alpha-CD on cyclosporine A-induced renal tubular and arterial damages].

The aim of this study is to test whether a stable analogue prostaglandin I2 (OP-41483-alpha-CD) (OP) is effective to prevent Cyclosporine A (CsA)-induced nephrotoxicity. Male Lewis rats were administrated with CsA (50 or 100 mg/kg/day, per os) and treated with OP (25 micrograms/kg/day, subcutaneously). For the quantitativeness of qualitative changes, percent area of tubular vacuolization and the grade of renal arteriolar changes were evaluated at light microscopic level, then further examined under electron microscopy. CsA trough levels in the whole blood were also analyzed with HPLC and prostaglandin I2 was assayed by radioimmunoassay of its stable degeneration product 6-keto-PGF1-alpha. As a result, 1) ultrastructurally, perinuclear vacuoles in arteriolar media consisted of cellular intervaginated cytoplasmic processes of neighboring cells, suggesting spastic vasoconstriction induced by CsA, 2) survival rate of OP-treated rats were significantly high compared to that of rats with CsA alone, 3) pathologically, tubular and arterial damages were reduced in OP-treated models, 4) pharmacokinetic studies revealed that CsA trough levels were not different from those of CsA-received alone and OP-treated models, and 5) mean blood 6-keto-PGF1-alpha excretion in rats given CsA was higher than in normal rats.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

The effect on the cornea of alpha cyclodextrin vehicle for cyclosporin eye drops.

We tested four different combinations of alpha-CD and CYA: 0.075% and 80 mg/mL alpha-CD, 0.025% CYA and 40 mg/mL alpha-CD, 0.009% CYA and 20 mg/mL alpha-CD, and 0.003% CYA and 10 mg/mL alpha-CD. We found that 0.025% CYA (alpha-CD[40 mg/mL]) resulted in the least corneal toxicity and penetrated in the cornea 5 to 10 times more than did lipophilic vehicle with CYA.

Administration, Topical↗
PubMed1994

[The beneficial effects of PGI2 analogue (OP-41483-alpha-CD) on hepatic dysfunction after warm ischemic damage].

The purpose of the experimental study was to investigate the beneficial effects of aPGI2 analogue (OP-41483-alpha-CD; aPGI2) on hepatic dysfunction after warm ischemia and reperfusion. Hepatic warm ischemia was produced by temporary clamping of the portal vein and hepatic artery. Experimental groups were divided into three groups: Group I; 60-minutes ischemia, Group II; 90-minutes ischemia, Group III; 90-minutes ischemia with intravenous aPGI2 (0.25 microgram/kg/min) infusion. The results were as follows: 1; In groups I and III, hepatic tissue flow showed a marked increase after reperfusion when compared to Group II. 2; Arterial ketone body ratio in Groups I and III recovered significantly faster than those of Group II. 3; The tissue total adenine-nucleotide levels in Groups I and III were significantly higher than those of Group II. 4; In the comparison of the radical intensity which was measured by ESR spectroscopy, the free radical of the hepatic venous blood was markedly generalized after reperfusion in Group II. However, production of free radical has significantly suppressed in Group III when compared to Group II. These results suggest that aPGI2-treatment might improved the ischemic damaged liver and might improve the prognosis of the transplanted patient.

Alanine Transaminase↗
PubMed1993

Effects of OP-41483.alpha-CD, a stable prostacyclin analog, on cultured endothelial cell dysfunction caused by 15(S)-hydroperoxy-5,8,11,13-eicosatetraenoic acid (15-HPETE) in vitro.

We studied the effect of OP-41483.alpha-CD, a stable prostacyclin analog, on, 15-HPETE induced bovine endothelial cell dysfunction, which was assessed by measuring a number of endothelial cells attached to plastic plates. 15-HPETE decreased the number of attached endothelial cells in a concentration- and time-dependent manner. OP-41483.alpha-CD and PGI2 significantly inhibited 15-HPETE induced dysfunction of the cells at a concentration of more than 10(-9)M. Besides, DDA (10(-6) - 10(-4)M) an adenylate cyclase inhibitor, diminished the inhibitory effect of OP-41483.alpha-CD on 15-HPETE induced cell dysfunction in a concentration-dependent manner. Furthermore, OP-41483.alpha-CD increased cAMP levels in the endothelial cells in the range of 10(-10) to 10(-8)M in a dose-dependent manner. These data suggest that OP-41483.alpha-CD could exert an inhibitory action on 15-HPETE induced endothelial cell dysfunction via partly increasing its effect on the intracellular cAMP level.

Alprostadil↗
PubMed1993

Cholesterol and 27-hydroxycholesterol 7 alpha-hydroxylation: evidence for two different enzymes.

The use of 2-hydroxypropyl-beta-cyclodextrin as a vehicle for solubilizing cholesterol and 27-hydroxycholesterol has led to a study of their rates of 7 alpha-hydroxylation in microsomal preparations from hamster liver and HepG2 cells. Addition of the vehicle alone to the cholesterol 7 alpha-hydroxylase assay always caused a several-fold increase in activity. Preloading the vehicle with cholesterol further augmented the rate of 7 alpha-hydroxycholesterol formation. Preloading the vehicle with 27-hydroxycholesterol or 27-hydroxycholestanol (molar ratio 1/1.2) minimally decreased cholesterol 7 alpha-hydroxylase activity (-12%), compared with preloading with cholestanol (-50%), a known competitive inhibitor of the enzyme. Microsomes from hamster liver yielded rates of 7 alpha,27-dihydroxcholesterol formation of 1.5 to 3.0 nmol/min per mg protein, compared with 0.3 nmol/min per mg protein for 7 alpha-hydroxycholesterol. Although cholesterol and cholestanol had minimal effects on the rate of 7 alpha-hydroxylation of 27-hydroxycholesterol, addition of an approximately equimolar amount of 27-hydroxycholestanol inhibited the rate of formation by 65%. Attempts to separate and identify the two C-27 sterol 7 alpha-hydroxylases chromatographically led to the finding that Emulgen 913 selectively inactivates 7 alpha-hydroxylation of 27-hydroxycholesterol. These results indicate that the metabolic pathway for bile acid synthesis from 27-hydroxycholesterol is not governed by cholesterol 7 alpha-hydroxylase.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed1993

[Intracavernous injection of lipo prostaglandin E1 for the diagnosis of impotence: a comparative study with prostaglandin E1-CD].

Intracavernous injection of 20 micrograms prostaglandin E1-CD (PGE1-CD, 8 cases), 5 micrograms lipo prostaglandin E1 (Lipo PG-E1, 8 cases) or 10 micrograms Lipo PGE1 (9 cases) was performed in patients with functional impotence in order to comparatively analyze the diagnostic efficacy of these drugs. Full erection was observed in all patients who received intracavernous injection of 20 micrograms PGE1-CD or 10 micrograms Lipo PGE1. However, full erection was observed in 4 out of 8 patients administered 5 micrograms Lipo PGE1. RigiScan was used on all patients, and latency until erection (achievement of maximum rigidity of the base) after injection, maximum rigidity of the penile tip and base and circumferential expansion rate of the penile tip and base were measured. With regard to these RigiScan data and duration of erection, there were no significant differences among the 3 groups. There were no severe side effects in any of the patients. These findings indicate that 10 micrograms Lipo PGE1 and 20 micrograms PGE1-CD have similar effects and that Lipo PGE1 may be an effective drug for the diagnosis and treatment of impotence.

Adult↗
PubMed1997

Evaluation of two homogeneous methods for measuring high-density lipoprotein cholesterol.

We evaluated the performance of two homogeneous assays for quantifying HDL cholesterol (HDL-C) and compared them with the phosphotungstic acid (PTA)/ MgCl2 assay. Both homogeneous HDL-C assays were precise, having a within-run CV of < 1.20% and a between-run CV of < 4.07%. The HDL-C values (y) measured by the two homogeneous methods correlated well with those by the PTA/MgCl2 method (x): y = 1.00x + 64.98 mg/L, r = 0.987, Sy/x = 27.99 mg/L (n = 152) for the polyethylene glycol-modified enzymes/alpha-cyclodextrin sulfate (PEGME) assay (Kyowa), and y = 0.84x + 106.51 mg/L, r = 0.984, Sy/x = 26.10 mg/L (n = 152) for the polyanion-polymer/detergent (PPD) assay (Daiichi). The specificity of the PEGME method seemed better than that of the PPD method, as the PPD method was markedly interfered with by supplemental LDL-C. Addition of 20 g/L triglycerides produced a negative error of approximately 18% in both homogeneous assays. Bilirubin and hemoglobin had little influence on the PEGME method; hemoglobin had little effect on the PPD method. Bilirubin, however, markedly decreased the readings by the PPD method. We found the PEGME assay superior to the PPD assay for routine HDL-C testing, because the PPD assay is relatively inaccurate and not specific.

Bilirubin↗
PubMed1997

NMR study of per(3,6-anhydro) alpha cyclodextrin as a potential agent for the biological decontamination of lead.

The ability of per(3,6-anhydro) alpha cyclodextrin(3,6CD) to capture lead from a preformed glutathion (GSH)-lead complex was investigated by NMR spectroscopy. Such a removal strongly depends on the nature and pH of the buffer used in the competition experiments. It was found that an almost complete removal of lead can be achieved at pH 5.5, especially when lead nitrate is used. The capture also strongly depends on the nature of the lead species as well as of the counter ion present in the medium. These observations imply that decontamination of lead by this process should be optimal under acidic conditions, i.e. in the acidic tractus (stomach). Conversely, lead decontamination at neutral pH was of poor efficiency or required a large excess of (3,6CD). This was particularly the case when human plasma was used as solvent.

Chelating Agents↗