Methyl- P-cyclodextrin

The same authors studied the CL of 4,4,-[oxalylbis(trifluoromethylsulfo-nyl)imino]to[4-methylmorphilinium trifluoromethane sulfonate] (METQ) with hydrogen peroxide and a fluorophor in the presence of a, p, y, and heptakis 2,6-di-O-methyl P-cyclodextrin [66], The fluorophors studied were rhodamine B (RH B), 8-aniline-l-naphthalene sulfonic acid (ANS), potassium 2-p-toluidinylnaph-thalene-6-sulfonate (TNS), and fluorescein. It was found that TNS, ANS, and fluorescein show CL intensity enhancement in all cyclodextrins, while the CL of rhodamine B is enhanced in a- and y-cyclodextrin and reduced in P-cyclodextrin medium. The enhancement factors were found in the range of 1.4 for rhodamine B in a-cyclodextrin and 300 for TNS in heptakis 2,6-di-O-methyl P-cyclodextrin. The authors conclude that this enhancement could be attributed to increases in reaction rate, excitation efficiency, and fluorescence efficiency of the emitting species. Inclusion of a reaction intermediate and fluorophore in the cyclodextrin cavity is proposed as one possible mechanism for the observed enhancement. 

Potassium depletion Low-pH shock treatment Methyl-P-cyclodextrin... 

Methyl-P-cyclodextrin Inclusion complexes with Blocks clathrin also 16,42,46,47 s. 

The water-soluble methyl-P-cyclodextrin (mpCD) is known to form soluble inclusion complexes with cholesterol, leading to depletion of cholesterol from the plasma membrane (16,46,47). As a result, cholesterol-rich microdomains, which are involved in caveolae-mediated as well as clathrin-mediated endocytosis, are destroyed. mpCD therefore decreases both clathrin- and caveolae-mediated uptake. The two other well-known cyclodextrins [a-, and y-cyclodextrin (6 and 8 units of a-1,4 glucose)] do not bind cholesterol effectively (both are not specific for cholesterol, but might remove phospholipids from the plasma membrane) and have no significant effect (46). 

We begin with an excerpt from Environmental Science Technology (excerpt 4B). In a combined R D section, the authors tell us what happened when they coated different types of soil with randomly methylated P-cyclodextrins (RAMEB). Cyclodextrins are highly water-soluble, crystalline sugars their shape (referred to as toroidal) resembles a water pail without a bottom. The outer surfaces of the pail are hydrophilic (water-loving), which accounts for their solubility in water and their ability to attract water molecules. RAMEB alone adsorbs water molecules hence, the authors predicted that RAMEB-coated soils would adsorb more water than their noncoated counterparts. 

Let s begin with the excerpt on randomly methylated P-cyclodextrin (RAMEB)-enriched soils in chapter 4 (excerpt 4B). The authors use an iterative R D approach They state their first result (Rl), pertaining to clay-rich soils, and then immediately offer an interpretation (Dl) of that result. This is followed by a result and interpretation for clay-poor soils (R2D2) and a result and interpretation for medium-clay-content soils (R3D3). Thus, the result-discussion sequence is iterated three times. In each case, the discussion immediately follows the result hence, submove 1.1 (which reminds readers of the result) is not needed. 

P16 Two CD derivatives are most commonly used for soil remediation hydroxypropyl and random methylated P-cyclodextrins (HPBCD and... 

Jozefaciuk, G. Muranyi, A. Fenyvesi, E. Effect of Randomly Methylated P-Cyclodextrin on Physical Properties of Soils. Environ. Sci. Technol 2003, 37, 3012-3017. 

Programmed temperature (120 -200°C) chiral separation on a 0.25-mm x 25-m open tubular column with a 0.25-nm-thick stationary phase containing 10 wt% fully methylated p-cyclodextrin chemically bonded to dimethyl polysiloxane. [From W. Vetter and W. Jun, Elucidation of a Polychlorinated Bipyrrole Structure Using Enantioselective GC," Anal. Chem. 3002, 74,4287.]... 

The pharmacokinetics fCD and HlftCD after intravenous administration have been assessed (Frijlinket al., 1990). As determined at doses of 25,100, and 200 mg/kg in permanently cannulated rats, plasma levels of both CDs decreased rapidly upon injection. Within 24 h after administration, most of the doses were excreted unchanged via urine. There was no evidence forsigniLcant metabolism of the intravenously administered CDs. The pharmacokinetics and the tissue concentrations of methyl-p-cyclodextrin (MEBCD) and doxorubicin (DOX) in rabbits following administration of MEBCD and DOX, alone or in combination were studied (Grosse et al., 1999). Results indicated that DOX did not modify MEBCD pharmacokinetic proLle, but MEBCD reduced signiLcantly the distribution half-life of DOX. Tissue determination showed that MEBCD did not enhanced the cardiac accumulation of DOX. 

Many CDs have been successfully used to solubilize insoluble drugs, here are a partial list of CD derivatives reported in the literature fflFCD, SBE-ft-CDs, randomly methylated-P-cyclodextrin (RM-p-CD), 2,3,6-partially methylat flcyclodextrin (PM-ft-CD), glucosyl-ft-CD (G1-P-CD), maltosyl-p-cyclodextrin (G2- -CD), hydroxyethyl-p-cyclodextrin (He-p-CD), diethyl-P-cyclodextrin (DE-p-CD)P-carboxymethyl-Qethyl- -cyclodextrin (CME-p-CD), and (2,6-oG>-methyl)-p-cyclodextrin (DOM-p-CD). 

T. Imai, T. Irie, M. Otagiri, K. Uekama, and M. Yamasaki, Comparative study of antiinflammatory drug flurbiprofen with P-cyclodextrin and methylated P-cyclodextrins, J. Inclusion Phenom. 2. 597-604 (1984). 

Among the cyclodextrins, the use of DMpCD was shown to have the highest effect on the transnasal bioavailability of insulin in rats. Several studies reported on their concentration-dependent effect. Besides for peptides, the methylated p-cyclodextrins have shown to be useful in nasal delivery of lipophilic drugs. The toxicological profile of dimethyl p-cyclo-dextrins and of randomly methylated p-cyclodextrins appeared excellent. Attention should be paid, if possible, onbioavailability differences between animal and human models. 

Maupas, B. Letellier, S. Guyon, E. Determination of the formation constant for the inclusion complex of methyl-P-cyclodextrin with anticoagulant drugs warfarin and 8-chlorowarfarin in aqueous solution. J. Inclusion Phenom. Mol. Recognit. Chem. 1996,23 (4), 259-267. 

Hirayama, F. Kurihara, M. Uekama, K. Improving the aqueous stability of prostaglandin E2 and prostaglandin A2 by inclusion complexation with methylated-P-cyclodextrins. Chem. Pharm. Bull. 1984, 32 (10), 4237-4240. 

Mielcarek, J. Photochemical stability of the inclusion complexes of nicardipine with a-, y-cyclodextrin, methyl-P-cyclodextrin, and hydroxypropyl-P-cyclodextrin in the solid state and in solution. Pharmazie 1996, 51 (7), 477-479. 

Ou, D. Ueda, H. Nagase, H. Endo, T. Nagai, T. Some pharmaceutical properties of 2,3,6-partially methylated-P-cyclodextrin and its solubilizing and stabilizing abihties. Drug Dev. Ind. Pharm. 1994, 20 (12), 2005-2016. 

Zukowski, J. Sybilska, D. Bojarski, J. Szejtli, J. Resolution of chiral barbiturates into enantiomers by reversed-phase high-performance hquid chromatography using methylated P-cyclodextrins. J. Chromatogr. 1988,463 (3), 381-390. 

Dichlorophenoxy) propionic acid 0.05 M lithium acetate containing heptakis-(2,6-di-0-methyl)-P-cyclodextrin UV 200 nm [21]... 

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