Gas chromatographic-mass spectrometric analysis of major indole alkaloids of Catharanthus roseus

Simultaneous quantitative determination of five alkaloids in Catharanthus roseus by HPLC-ESI-MS/MS

AIM

To establish a method to simultaneously determine the main five alkaloids of Catharanthus roseus for trace samples, a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) analysis method was developed.

METHOD

The five Catharanthus alkaloids, vinblastine, vincristine, vinleurosine, vindoline, and catharanthine were chromatographically separated on a C18 HPLC column. The mobile phase was methanol-15 nmol·L(-1) ammonium acetate containing 0.02% formic acid (65 : 35, V/V). The quantification of these alkaloids was based on the Multiple Reaction Monitoring (MRM) mode.

RESULTS

This method was validated, and the results achieved the aims of the study. The intra- and inter-day precision and accuracy of the five alkaloids were within 1.2%-11.5% (RSD%) and -10.9%-10.5% (RE%). The recovery rates of the five alkaloids of samples were from 79.9% to 91.5%. The five analytes were stable at room temperature for 2 h, at 4 °C for 12 h, and at -20 °C for two weeks. The developed method was applied successfully to determine the content of the five alkaloids in three plant parts of three batches of C. roseus with a minute amount collected from three regions of China.

CONCLUSION

The HPLC-ESI-MS/MS method can be used for the simultaneous determination of five important alkaloids in trace C. roseus samples.

Production of indole alkaloids by selected hairy root lines of Catharanthus roseus

Hairy root cultures of Catharanthus roseus were established by infection of seedlings with Agrobacterium rhizogenes 15834. Approximately 150 transformants from four different. C. roseus cultivars were screened for desirable traits in growth and indole alkaloid production. Five hairy root clones grew well in liquid culture with doubling times similar to those reported for cell suspensions. Fast growing clones had similar morphologies, characterized by thin, straight, and regular branches with thin tips. The levels of key alkaloids, ajmalicine, serpentine, and catharanthine, in these five clones, also compared well with literature data from cell suspensions, yet HPLC and GC-MS data indicate the presence of vindoline in two clones at levels over three orders of magnitude greater than the minute amounts reported in cell culture. These results suggest that further optimization may result in hairy roots as a potential source of vindoline and catharanthine, the two monomers necessary to synthesize that antineoplastic drug, vinblastine.

Optimization of the separation of Vinca alkaloids by nonaqueous capillary electrophoresis

A rapid method for the determination of Vinca alkaloids by nonaqueous capillary electrophoresis with diode array detection has been developed. A group of 11 alkaloids (catharanthine, vinorelbine, anhydrovinblastine, vinflunine, vindoline, 4-O-deacetylvinorelbine, 4-O-deacetylvinflunine, vindesine, vinblastine, 4'-deoxy-20',20'-difluorovinblastine, vincristine) could be readily separated within 10 min. The compounds were separated using a capillary of 38 cm effective length, a running buffer composed of 50 mM ammonium acetate and 0.6 M acetic acid in a methanol-acetonitrile (75:25, v/v) mixture. A constant voltage of 25 kV with a ramp time of 1 min and a 344.7 x 10(3) Pa pressure, applied simultaneously to inlet and outlet buffer vials, were used during sample analysis. Five of these alkaloids were selected for optimization of the separation and for validation studies with respect to specificity, linearity, range, limits of quantification and detection and then accuracy. The feasibility of the assay was demonstrated by analyzing a commercial sample of vinorelbine (Navelbine, ampoule at 10 mg/ml of vinorelbine base). The results were compared with a high-performance liquid chromatography method.