Methylated beta-cyclodextrins

Rodal SK, Skretting G, Garred O, Vilhardt E, van Deurs B, Sandvig K. Extraction of cholesterol with methyl-beta-cyclodextrin perturbs formation of clathrin-coated endocytic vesicles. Mol Biol Cell 1999 10(4) 961-974. 

The inclusion modes of flurbiprofen with beta cyclodextrin and with heptakis(2,3,6-tri-0-methyl)-beta cyclodextrin have been studied by Imai and coworkers. They showed that, although the Cotton effects in the circular dichroic spectra induced by beta cyclodextrin in / (-) and 5(+) flurbiprofen are identical, those induced by heptakis(2,3,6-tri-0-methyl)-beta cyclodextrin differ from each other and from those induced by beta cyclodextrin. C.p.-m.a.s. C-n.m.r. experiments showed that the cyclodextrin ring is probably more distorted in the flurbiprofen inclusion complex with methylated beta cyclodextrin than in that with beta cyclodextrin. 

Francis, S.A., et al. 1999. Rapid reduction of MDCK cell cholesterol by methyl-beta-cyclodextrin alters steady state transepithelial electrical resistance. Eur J Cell Biol 78 473. 

Hll. Huang, D., Ou, B., Hampsch-Woodill, M., Flanagan, J. A., and Deemer, E. K., Development and validation of oxygen radical absorbance capacity assay for lipophilic antioxidants using randomly methylated beta-cyclodextrin as die solubility enhancer. J. Agric. Food Chem. 50, 1815-1821 (2002). 

Identification and quantification of cis-ketoconazole impurity in tablets Heptakis-(2,3, 6-tri-0-methyl)-beta-cyclodextrin CE-MS [207]... 

Szejtli, J, A Liptik and 1 Jodal (1980). Synthesis and 13C-NMR spectroscopy of methylated beta-cyclodextrins. Starch, 32(5), 165-169. 

Momose, T, M Mure, T lida, J Goto and T Nambara (1998). Method for the separation of the unconjugates and conjugates of chenodeoxycholic acid and deoxycholic acid by two-dimensional reversed-phase thin-layer chromatography with methyl beta-cyclodextrin. Journal of Chromatography A, 811(1-2), 171-180. 

Ryu, JW, HS Chang, YK Ko, JC Woo, DW Koo and DW Kim (1999). Direct chiral separation of tryptophan analogues using heptakis(3-0-Methyl)-beta-cyclodextrin-bonded stationary phase in reversed-phase liquid chromatography. Microchemical Journal, 63(1). 

Zhang L, Hu S, Gook L, and Dovichi NJ (2002) Analysis of aminophosphohpid molecular species by methyl-beta-cyclodextrin modified micellar electrokinetic capillary chromatography with laser-induced fluorescence detection. Electrophoresis 23 3071-3077. 

Franchi, P., Lucarini, M., Mezzina, E., Pedulli, G.F. (2004) Combining magnetic resonance spectroscopies, mass spectrometry, and molecular dynamics investigation of chiral recognition by 2,6-di-O-methyl-beta-cyclodextrin. /. Am. Chem. Soc.,126, 4343 354. 

L.O. Healy, J.P. Murrihy, A. Tan, D. Cocker, M. McEnery and J.D. Glennon, Enantiomeric separation of R,S-naproxen by conventional and nano-liquid chromatography with methyl-beta-cyclodextrin as a mobile phase additive, J. Chromatogr. A, 2001, 924, 459-464. 

Heptakls-(, 6-dl-0-methyl)-beta-cyclodextrin (DIMES) (Chinoin Pharm.-Chem. Works) At least 90% of the substance corresponds to the above mentioned chemical name. The remaining 10% is a mixture of different, very closely related methylated derivatives. The heavy metal content is less than 10 ppm, the organic solvent residue is less than 100 ppm. [a]o 161 (0.1% H2O). Sodium deoxycholate (Reanal) 9,10-3-H-stearic acid (Izocommerc), specific radioactivity >1110 GBq/mmol (labelled stearic acid was diluted with appropriate amount of non-labelled stearic acid (Reanal) before the experiments) edible oil. 

Some modifications to the cyclodextrin structure have also been found to improve their complexing ability. Casu and coworkers prepared 2,3,6-tri-O-methyl and 2,6-di-O-methyl derivatives of alpha and beta cyclodextrin. They observed that tri-O-methyl-alpha cyclodextrin shows an almost ten-fold increased stability of the complex with the guest, Methyl Orange, compared with the unmodified alpha cyclodextrin. A possible reason for this increase in stability is that the methyl groups are responsible for an extension of the hydrophobic cavity of the cyclodextrin. Other workers,however, observed a much smaller enhancement of stability of complexes on methylation of the cyclodextrin, and a decrease in stability has even been reportedfor the one host-two guests complex of tropaeolin with beta cyclodextrin. Thus, the effect of methylation on the stability of a complex varies with the guest species involved, and cannot be readily predicted. 

Salem LB, Bosquillon C, Dailey LA et al (2009) Sparing methylation of beta]-cyclodextrin mitigates cytotoxicity and permeability induction in respiratory epithelial cell layers in vitro. J Control Release 136(2) 110—116... 

Octakis (2,3,6-tri-0-methyl-gamma-cyclodextrin) was used to separate enantiomers of methyl esters of deltametrinic acid and permetrinic acid the positional isomers of nitrotoluene were also separated on the same column [17,18]. Various alkyl- and dialkyl-benzenes have been separated on beta- and gamma-cyclodextrin [19]. A complete review of the use of cyclodextrins in chromatography has been published by Hinze [20]. Cyclo-dextrins have been analyzed by packed-column gas chromatography as their dimethylsilyl ethers [21]. 

By using water-soluble organic solvents, usually referred to as precipitants, the reaction can be directed to produce only one cyclodextrin. In the presence of toluene, the enzyme from B. macerans produces only (3-cyclodextrin and linear starch chains. Beta-cyclodextrin can be separated from the soluble starch chains and recovered as a precipitated toluene complex. In the presence of decanol, a-cyclodextrin is the only cyclodextrin produced using the enzyme from B. macerans.21,22 Precipitants such as large cyclic compounds similar to musk oil23 or a-naphthol and methyl ethyl ketone (butanone)24 can be used to produce 8-cyclodextrin. 

Benzoylbenzene, 458 Benzoyl Peroxide, 43 Benzyl Acetate, 458, 570, 608 Benzyl Alcohol, 458, 570, 646 Benzyl Benzoate, 458, 647 Benzyl Butyrate, 458, 647 Benzyl n-Butyrate, 458 Benzyl Cinnamate, 458, 647 Benzyl Formate, 460, 608 Benzyl Isobutyrate, 460, 608 Benzyl Isovalerate, 460, 648, (Sl)60 Benzyl 3-Methyl Butyrate, 460 Benzyl 2-Methyl Propionate, 460 Benzyl Phenylacetate, 460, 608 Benzyl Propanoate, 460 Benzyl Propionate, 648 Benzyl Salicylate, 460, 682 Bergamot Oil, Coldpressed, 44, 575 beta Cyclodextrin, (Sl)15 Beta-1,3-Glucan, (S3)15 BHA, 44 BHT, 45... 

The effect of temperature, and of temperature and pH on the retention of a selected group of compounds using a beta-cyclodextrin column was studied. The results indicated that a plot of Ink vs. 1/T gave linear relationships for anthraquinone, methyl anthraquinone, ethyl anthraquinone, naphthalene and biphenyl using a mobile phase of methanol/water. However, a non linear relationship was observed for a selected group of dipeptides employing a mobile phase of methanol/ammonium acetate at the following pH s 1, 5.5 and 7. The retention times decreased with an increase in the temperature of the column except that for certain dipeptides the retention times increased. The separation factor (a) values decreased by approximately 10 with increase in column temperature from 25°C to 77°C. 

The cleavage of the ring of beta-cyclodextrin was accomplished by periodate oxidation. The kinetics of the oxidation of cyclodextrins with periodate have been studied by French et al. (10). During our work the Smith-degradation process was somewhat modified as the polyalcohol, obtained after the reduction, was converted into acetylated-, methylated and tosylated analogues. 

Key words Alpha, beta, gamma, cyclodextrin, epichlorohydrin, carbon NMR, methyl-j8-cyclodextrin, methyl orange, inclusion shift, solvent shift. 

Zhou, P.E, Yang, J.Z., Zhu, J.H., He, S.J. et al (2015) Effects of beta-cyclodextrin and methyl jasmonate on the production of vindoline, catharanthine, and ajmalicine in Cathamnthus roseus cam-bial meristematic cell cultures. Appl Microbiol Biotechnol, 99, 7035-7045,... 

Columns (stationary phase) CHIRALDEX G-TA (Gamma trifluoroacetyl) CHIRALDEX B-DP (Beta dipropionyl) Rt-BDEXsm (Beta dimethyl, mono-t-butyl) Cyclosil-B (Beta dimethyl, mono-t-butyl) A-DEX 120 (Alpha methyl) B-DEX 120 (20% Beta methyl) G-DEX 120 (Gamma methyl) Chrompak Cyclodextrin- -2,3,6-M-19 (Beta trimethyl) Chrompak Chirasil-Dex C B (Beta unknown bonded phase)... 

Crini et al., 2002 proposed the synthesis of cyclodextrin-carboxy-methyl cellulose gels. Results obtained with these gels showed that effective and efficient extraction of beta-naphtol is achieved. The presence of carboxyl groups in the polymer networks permit to increase significantly the sorption properties. The carboxylic acid groups present in the adsorbents plays an important role in the adsorption of Cu, Pb and Ni [94]. 

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