Yunchao He,Yaling Wu,Lingping Cheng,Shanshan He,Qiuhua Wang,Huiying Wang,Yanxiong Ke
Ketorolac has been widely applied in clinical medicine for its antipyretic, analgesic and anti-inflammatory pharmacological activity. Research showed that the analgesic effect of the S enantiomer is 230 times stronger than that of the R enantiomer. Getting the high-purity S enantiomer of Ketorolac has profound significance but still remains a challenging topic. In this work, the separation of the R and S enantiomers of Ketorolac was investigated on polysaccharide-based chiral stationary phases. Chiralcel AD-H, OD-H, OJ-H and AS-H columns were evaluated using polar organic and normal phase mode, respectively, in which the OJ-H column showed the best performance with high selectivity and resolution for Ketorolac with α = 2.43 and R S = 9.04 by using methanol/formic acid (100:0.1, v/v) as the mobile phase. The influences of acid additive, composition of mobile phase and temperature were examined. The coating amount of cellulose tris- (4-methylbenzoate) has significant influence on the sample loadability. The high loadability of chiral stationary phases coated with 40% of cellulose tris- (4-methylbenzoate) allows preparative separation up to 16 mg on an analytical column of 250 × 4.6 mm id in a single run for Ketoroac using methanol/formic acid (100:0.1, v/v) as mobile phase, which shows a potential application in industrial preparation.
Yang Xu,Yanfang Liu,Han Zhou,Rong Wang,Dongping Yu,Zhimou Guo,Xinmiao Liang
Natural products , especially alkaloids, are one of the most valuable, potential drug leads in drug discovery. As an efficient tool for complex samples, two-dimensional liquid chromatography (2D-LC) has become a powerful means of analysis and separation of natural alkaloids. Method development of 2D-LC is of great importance because it helps to enhance the selectivity, resolution and peak capacity of a separation system. However, due to the diversity of the nature and subclasses of natural alkaloids, peak tailing occurs frequently, making alkaloid separation complicated and time-consuming. To conquer such difficulties, we proposed a guide for column selection and combination in 2D-LC so as to improve the alkaloid separation. Based on a comprehensive evaluation of applicability and orthogonality of several columns, this guide would provide a simple but clear starting point for column selection of 2D-LC method development. The evaluation included seven columns to involve most separation mechanisms reported in alkaloid separation, and 49 natural alkaloid standards of various subclasses and natures. Detailed studies of peak shapes of every column were carried out as well, providing useful references to better understand the peak tailing issues of some analytes on specific columns. Subsequently, a 2D-LC method was developed using our guide to isolate an alkaloid sample from U. rhynchophylla , generating symmetrical peaks and a high orthogonality of 80.3%. Further, this evaluation process would help to have a quick understanding when a new stationary phase is designed.
危险品化学品经营许可证（带存储）