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CHIRAL TECHNOLOGIES, INC. has expanded its portfolio of the well-known Daicel columns by adding protein-based chiral columns: CHIRAL-AGP, CHIRAL-CBH and CHIRAL-HSA.
The chiral selector for the CHIRAL-AGP is α1-acid glycoprotein (AGP), while the chiral selector for CHIRAL-CBH is cellobiohydrolase, a stable enzyme. The selector for CHIRAL-HSA
is human serum albumin (HSA). The three chiral selectors are immobilized on 5-µm spherical silica particles. |
| The protein-based columns function entirely in the reversed-phase chromatographic mode, using buffers with low organic modifier content and at moderate pH values.
A vast variety of chiral compounds can be separated using the protein-based columns (See compound chart). |
| CHIRAL-AGP has extremely broad applicability for the separation of chiral drugs. CHIRAL-CBH is an effective complement to the CHIRAL-AGP column for separation
of basic drugs of many compound types, while CHIRAL-HSA can be used to separate acidic compounds directly, without derivatization prior to analysis, and also nonprotolytic compounds. The mobile
phases, with which these columns are used, are highly compatible with MS and MS/MS analyses and a number of literature papers demonstrate their utility in HPLC separations and detection. |
| Enantioselectivity can be easily controlled or improved by changes in the mobile phase composition: pH, buffer and organic modifier types and concentrations. |
| The protein-based columns are typically used for enantiomeric purity analysis of bulk drugs and also of finished drug formulations. Chromatograms below show some examples
of drug separations. |
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| Another exciting area of applications of the protein-based columns is their use in drug-protein binding studies. The degree of drug-protein binding directly affects pharmacokinetic and
pharmacodynamic characteristics of a drug. Drug-protein binding is the reversible interaction of drugs with proteins in plasma. A drug's potency, therefore, may be dependent on the degree to which it
binds to the plasma proteins and other blood constituents. Major blood proteins to which drugs bind are human serum albumin, α1-acid glycoprotein, lipoproteins and globulins. Understandably,
the unbound drug is active and exhibits pharmacologic effects.
Although a number of methods are available to measure the degree of the drug interaction with proteins in plasma, HPLC is also a convenient and fast way to determine the drug-protein binding properties.
Both CHIRAL-AGP and CHIRAL-HSA columns have been successfully used for these studies.
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