摘要:
Application of a reference mixture of natural products for systematic analysis and comparison of the properties of biphasic solvent systems in counter-current/partition chromatography. Because the reference mixture is comprised of compounds with varying polarities, functional groups, and structural features it provides a rational method for mapping the optimal resolution polarity range of a particular solvent system. The mapping of optimal resolution polarity ranges of solvent systems provided for the description of the overall optimal resolution polarity range of a solvent system family, comprised of the same solvents in different proportions. By comparing the reference mixture performance in the individual members of a solvent system family, the solvent system that best functions as the representative of, or portal to, the solvent system families is determined. Use of the reference mixture also afforded a method to compare the overall optimal resolution polarity ranges of solvent system families. Based on performance of reference mixture chromatograms, the CCC properties of solvent systems, can be compared and their CCC potential examined. The methods of the invention employing the reference mixture provides was used to identify a quaternary solvent system, hexane/t-butylmethylether/acetonitrile/water (HterAcWat), which was found to be useful for CCC of mixtures containing natural products.
摘要:
Provided herein are various methods and systems for analyzing natural products by quantitative proton nuclear magnetic resonance (qHNMR). A method is provided for quantitative and qualitative determination of a natural product by 1HNMR and decoupling 13C nuclei from the protons in the sample containing the natural product. The resultant spectrum wherein the decoupling provides a cleaner spectrum is used to provide both structural and quantitative information about species within the sample. In an aspect, the decoupling is provided by globally optimized alternating-phase rectangular pulses (GARP). The methods presented herein are optionally used to detect impurities in a reference material and verify the purity level of a reference material.
摘要:
Various methods for visualization of output from a liquid-liquid chromatographic instrument are provided. One or more analytes detected by a liquid-liquid chromatographic instrument are visualized by providing a data set comprising a plurality of data points corresponding to one or more analytes detected by the instrument, wherein the data points comprise at least one parameter related to a K-value or a parameter from which a K-value can be determined. A K-value is calculated for at least a portion of the data set, and at least a portion of those K-values transformed by a reciprocal transformation to generate output data having a transformed K-value, wherein the transformed K-value is a real number for all K undergoing the transformation, thereby ensuring that all analytes detected by the instrument are plotted in a single chromatogram. The output data is provided to a user. The output data may be used for instrument performance testing, design, calibration, or for selecting suitable solvent systems to detect analytes of interest.
摘要:
Application of a reference mixture of natural products for systematic analysis and comparison of the properties of biphasic solvent systems in counter-current/partition chromatography. Because the reference mixture is comprised of compounds with varying polarities, functional groups, and structural features it provides a rational method for mapping the optimal resolution polarity range of a particular solvent system. The mapping of optimal resolution polarity ranges of solvent systems provided for the description of the overall optimal resolution polarity range of a solvent system family, comprised of the same solvents in different proportions. By comparing the reference mixture performance in the individual members of a solvent system family, the solvent system that best functions as the representative of, or portal to, the solvent system families is determined. Use of the reference mixture also afforded a method to compare the overall optimal resolution polarity ranges of solvent system families. Based on performance of reference mixture chromatograms, the CCC properties of solvent systems, can be compared and their CCC potential examined. The methods of the invention employing the reference mixture provides was used to identify a quaternary solvent system, hexane/t-butylmethylether/acetonitrile/water (HterAcWat), which was found to be useful for CCC of mixtures containing natural products.
摘要:
Various methods for visualization of output from a liquid-liquid chromatographic instrument are provided. One or more analytes detected by a liquid-liquid chromatographic instrument are visualized by providing a data set comprising a plurality of data points corresponding to one or more analytes detected by the instrument, wherein the data points comprise at least one parameter related to a K-value or a parameter from which a K-value can be determined. A K-value is calculated for at least a portion of the data set, and at least a portion of those K-values transformed by a reciprocal transformation to generate output data having a transformed K-value, wherein the transformed K-value is a real number for all K undergoing the transformation, thereby ensuring that all analytes detected by the instrument are plotted in a single chromatogram. The output data is provided to a user. The output data may be used for instrument performance testing, design, calibration, or for selecting suitable solvent systems to detect analytes of interest.