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Nucleodex是在高性能5um，100 A規(guī)格Nucleosil球形硅膠上衍生環(huán)糊精系列液相手性色譜柱。包括β-OH、α-PM、β-PM、和γ-PM四個(gè)系列。能夠滿足農(nóng)藥和醫(yī)藥領(lǐng)域大量手性化合物的反相分離。MN商品名稱

德國(guó)MN液相色譜柱定相組成

分離原理

Nucleodex β-OH

化學(xué)鍵合相：β-環(huán)糊精

立體對(duì)位原理（Cavity）

Nucleodex α-PM

化學(xué)鍵合相：預(yù)甲基化α-環(huán)糊精

Nucleodex β-PM

化學(xué)鍵合相：預(yù)甲基化β-環(huán)糊精

Nucleodex γ-PM

化學(xué)鍵合相：預(yù)甲基化γ-環(huán)糊精

PM系列中的環(huán)糊精所有羥基被羥甲基所取代，產(chǎn)生了不同的選擇特性。如下圖所示，由于PM環(huán)糊精與被測(cè)樣品的共價(jià)作用只有氧，所以通常條件下，PM環(huán)糊精對(duì)樣品的保留時(shí)間比OH環(huán)糊精要短。例如在常見(jiàn)的巴妥類(lèi)樣品Prominal，PM甲基化的環(huán)糊精就能夠得到滿意的分析結(jié)果。
 β-OH中的羥基不能對(duì)樣品手性分離產(chǎn)生作用，結(jié)果只是增加保留時(shí)間，不提高手性分離度。NUCLEODEX

Cyclodextrin-modified silica phases
for HPLC enantiomer separation

Features

Base material NUCLEOSIL® silica, particle size 5 μm, pore size 100 Å
modified cyclodextrins as chiral selectors

NUCLEODEX β-OH: β-cyclodextrin (R = H; n = 2) ? USP L45
Separation based on hydrogen bonds and dipole interactions between functional groups of the analyte and hydroxyl groups of the cyclodextrin
Examples for successful enantiomer separations: chlorthalidone and other compounds, which require free hydroxyl groups for enantioselective interactions
Eluent in column CH3OH – 0.1 % TEAA pH 4 (55:45)

NUCLEODEX α-PM: permethylated α-cyclodextrin (R = CH3; n = 1)
For all permethylated phases the ability to form hydrogen bonds is reduced, the hydrophobicity of the phase is increased compared to β?OH, resulting in shorter retention times .
Examples for successful enantiomer separations: mecoprop and dichlorprop as free carboxylic acids,trans-stilbene oxide and styrene oxide
Eluent in column CH3OH – 50 mM phosphate pH 3 (70:30)

NUCLEODEX β-PM:
permethylated β-cyclodextrin (R = CH3; n = 2) ? USP L45
Examples for successful enantiomer separations:
mephobarbital (prominal), pesticides derivatives mecoprop-methyl etfenoxaprop-ethyl
Eluent in column CH3OH – 0.1 % TEAA pH 4 (65:35)

NUCLEODEX γ-PM:
permethylated γ-cyclodextrin (R = CH3; n = 3)
Examples for successful enantiomer separations:
steroids or other larger molecules
Eluent in column CH3OH – 0.1 % TEAA pH 4 (55:45)

NUCLEODEX phases are especially suited for the control of optical purity, but also for semipreparative separations and for the analysis of positional and cis-trans isomers.
For more applications click here.