Cyclodextrins composition

Jeon JD, Kwak SY (2008) Nafion/sulfated p-cyclodextrin composite membrane. J Power Sources 185 49-54... 

Lu D, Lin S, Wang L, Li T, Wang C, Zhang Y (2014) Sensitive detection of luteolin based on poly (diallyldimethylammonium chloride)-functionalized graphene-carbon nanotubes hybrid/p-cyclodextrin composite film. J Solid State Electrochem 18(l) 269-278 Ma Y, Wu D, Liu Y, Li X, Qiao H, Yu Z-Z (2014a) Electrically conductive and super-tough polypropylene/carbon nanotube nanocomposites prepared by melt compounding. Compos B Eng 56 384-391... 

Figure 3.7 shows some early examples of this type of analysis (39), illustrating the GC determination of the stereoisomeric composition of lactones in (a) a fruit drink (where the ratio is racemic, and the lactone is added artificially) and (b) a yoghurt, where the non-racemic ratio indicates no adulteration. Technically, this separation was enabled on a short 10 m slightly polar primary column coupled to a chiral selective cyclodextrin secondary column. Both columns were independently temperature controlled and the transfer cut performed by using a Deans switch, with a backflush of the primary column following the heart-cut. 

Most published work on the design and fabrication of nanostructures from biological macromolecules relate to DNA and proteins the use of other biopolymers, such as cyclodextrins [2], was far less developed. Because the use of DNA is intensively covered in Chapter 10 of this volume (also see Ref 3), as well as recently described by Seeman [4,5] this chapter will focus on proteins as a potential tool for the construction of nanostructures. Hence this chapter is focused on literature that may provide a basis for the identification of gnidelines, methodologies, and examples having potential for farther development of new protein-based composite nanostrnctnres integrating strnctnral and bioactive components. 

In an attempt to change and broaden the capabilities of the vancomycin CSP, the glycopeptide was derivatized with (R)- and (S )-(l-naphthylethyl) isocyanate (NEIC) and then bonded to a silica-gel support [48]. A variety of chiral compounds was tested on the two composite stationary phases and the results were compared with the ones obtained using the underivatized vancomycin CSP. The advantages of the NEIC derivatization were not as obvious or substantial as they were in the case of cyclodextrin phases [49]. Moreover, the exact chemical structures of the synthesized NEIC derivatives of vancomycin were not reported. 

Spherical pellets containing 5% triamcinolone acetonide were prepared by Villar-Lopez and co-workers [59] by extrusion/spheronization following formulation with microcrystalline cellulose and/or a hydrophilic excipient like lactose, sodium earbox-ymethylcellulose, or P-cyclodextrin. Their suitability for coating, with a view toward colonic drug deliveiy, was assessed in terms of their size, sphericity, and dissolution test response. The best results were afforded by a 5 90 5 composition of microcrystalline cellulose, P-cyclodextrin, and triamcinolone acetonide, prepared by complex-ation of triamcinolone acetonide with P-cyclodextrin prior to the addition of microcrystalline cellulose. 

Although Freudenberg s hypothesis that complex-formation occurred by inclusion within the cavity was generally accepted, there was no direct evidence for this, either in solution or in the solid state. Broser and Lautsch had found by spectrophotometric titration that the complexes of a series of dyes with the cyclodextrins in solution obeyed the mass action law with a stoichiometry of 1 1. They suggested that association on the outside of the ring might not have a defined stoichiometric composition, and they thus interpreted their results as being consistent with inclusion by cyclodextrin. Their results were not conclusive, however. 

Ravid U, Putievsky E, Katzir I, Ikan R, Determination of the enantiomeric composition of terpinen-4-ol in essential oils using a permethylated 3-cyclodextrin coated chiral capillary column. Flavour Fragr/7 49—52, 1992. 

K Otsuka, S Honda, J Kato, S Terabe, K Kimata, N Tanaka. Effects of compositions of dimethy 1-/3-cyclodextrins on enantiomer separations by cyclo-dextrin-modified capillary zone electrophoresis. J Pharm Biomed Anal 17 1177-1190, 1998. 

Chemical compositions of a-cyclodextrin (a-CD) = C36H60O30, /J-CD = C42H70O35, and y-CD = C48H80O40. b Uncomplexed-hydrated cyclodextrins. c Guest molecules are largely disordered. 

Some work was also done by Consaga et al. on cyclodextrin nitrates with a view to replacing NC [5]. The composites of this invention are mixtures of (i) a cyclodextrin nitrate or a mixture of cyclodextrin nitrates and (ii) an energetic organic nitrate plasticizer. These composites are useful as replacements for nitrocellulose (NC) because they are more thermally stable and less sensitive to impact and yet have comparable or greater energy content than NC. However, cyclodextrin nitrates are dry powders that are sensitive to electrostatic discharge (ESD). 

There are a number of inert binders such as polyester, epoxy, polysulfide, polyurethane which have been reported as binders for composite propellants and plastic bonded explosives (PBXs). At present, hydroxy-terminated polybutadiene (HTPB) is regarded as the state-of-the-art workhorse binder for such applications. However, the recent trend is to use energetic binders such as poly [3,3-bis(azidomethyl oxetane)] [poly(BAMO)], poly (3-azidomethyl-3-methyl oxetane) [poly(AMMO)], PNP, GAP diol and triol, nitrated HTPB(NHTPB), poly(NiMMO), poly(GlyN) and nitrated cyclodextrin polymers poly(CDN) for PBXs and composite propellants in order to get better performance. 

S.L. (1992) Energetic composites of cyclodextrin nitrate esters and nitrate ester plasticizers, US Patent 5,114,506. 

Figure 10 Capillary electrophoresis characterization of the composite nature of sulfobuty-lether7 (SBE7)- 3-cyclodextrin CD. Roman numerals indicate the degree of substitution of each SBE band (I = SBEl-fi-CD,. .., IX = SBE9-fi-CD).

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