Fingerprint analysis of Ligusticum chuanxiong using hydrophilic interaction chromatography and reversed-phase liquid chromatography.

Fingerprint analysis is considered one of the most powerful approaches to quality control in traditional Chinese medicines (TCMs). In this study, a binary chromatographic fingerprint analysis was developed using hydrophilic interaction chromatography (HILIC) and reversed-phase liquid chromatography (RPLC) to gain more chemical information about polar compounds and weakly polar compounds. This method was used to construct a chromatographic fingerprint of Ligusticum chuanxiong. The two chromatographic methods demonstrated good precision, reproducibility, and stability, with relative standard deviations of <2% for retention time and 7% for peak area for both HILIC and RPLC separations. Data from the analysis of 14 samples by HILIC and RPLC were processed with similarity analysis, with correlation coefficients and congruence coefficients. This binary fingerprint analysis, using two chromatographic modes, is a powerful tool for characterizing the quality of samples, and can be used for the comprehensive quality control of TCMs.

Characterization of C-glycosyl quinochalcones in Carthamus tinctorius L. by ultraperformance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

C-Glycosyl quinochalcones are unique components in Carthamus tinctorius L. The reported C-glycosyl quinochalcones have the same quinochalcone skeleton with a hydroxyl group at the 5'-position and a glucose linked to this position with a carbon-carbon bond. In this study, the standard hydroxysafflor yellow A and water-extracted fraction of Carthamus tinctorius L. were analyzed by ultraperformance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOFMS) in both positive and negative ion modes. The fragmentation pathways of C-glycosyl quinochalcones were interpreted and validated by accurate mass measurement. Their fragmentation showed a special cleavage at the C-C bond except for the typical internal cleavage at the sugar moiety of other C-glycosyl flavonoids. In positive ion mode, cleavage of the 5'-glucose produced an [M+H-162](+) ion by a neutral loss, while cleavage of the 5'-glucose in negative ion mode led to an [M-H-163](-.) ion by radical cleavage. The cleavage from the carbonyl group produced fragment ions containing an A or a B ring. The fragment ions containing an A ring were common product ions of seven compounds in both ion modes, and fragment ions containing the B ring were used to judge the different substituent groups at the 3'-position. The fragmentation patterns of seven structurally related C-glycosyl quinochalcones were analyzed systematically and the formation of the fragment ions in two modes is explained in detail in this report. UPLC/Q-TOFMS is an effective tool for characterizing a complex sample, which gives higher resolution separation and generates accurate mass measurement of the product ions.

Rapid prediction and optimization of concentration conditions for preparative fractions by solid-phase extraction.

SPE is an effective tool for concentrating preparative fractions isolated from a complex sample. To guarantee high efficiency and recovery of concentration, the concentration conditions could be optimized by predicting the breakthrough volume (V(B)). In this study, a method of predicting V(B )of unknown compounds in preparative fractions at any isocratic mobile phase composition with the analytical retention parameters a and c is described. The a and c values and the relationship between half peak width (W(1/2)) and retention time of a model analyte were measured using the analytical elution mode on an SPE column, and the V(B )and retention volume (V(R)) predicted with the a and c values were validated with breakthrough experiments. However, it is impossible to measure the a and c values of multiple compounds in a complex system directly on an SPE column with a low number of theoretical plates. The correlation of the a and c values between the SPE and analytical columns was developed so that the analytical data could be transferred to the SPE column. With the calculated a and c values, we could optimize the concentration conditions on the basis of the predicted V(B )and the volume of the preparative fraction.