RÉSUMÉ
A pair of new tirucallane triterpenoid epimers, picraquassins M and N (1> and 2), were isolated from the stems of Picrasma quassioides (D. Don) Benn. Their structures were determined based on comprehensive spectroscopic and X-ray crystallographic analyses. In addition, their AChE inhibitory activity, cytotoxicity against five human tumour cell lines (SW480, MCF-7, HepG2, Hela, and PANC-1), and antimicrobial activity against two bacteria (Staphylococcus. aureus 209P and Escherichia coli ATCC0111) and two fungi (Candida albicans FIM709 and Aspergillus niger R330) were evaluated.
RÉSUMÉ
Objective: A method of reversed phase high performance liquid chromatogram-light scattering detector (RP-HPLC-ELSD) was developed to separate and prepare a large number of 25-OH-PPD epimeric mixture, in order to explore the best separation conditions between method of continuous sampling interval and off-line preparation method. Methods: The separation consequence of the method of continuous sampling interval and off-line preparation method were investigated respectively, under different proportion of mobile phase and concentration of sample volume, the optimum preparation method was screened by comparing the efficiency and transfer rate. Results: The suitable operation conditions of the two methods and the result of the preparation were obtained: method of continuous sampling interval as follow: the mobile phase is methanol and water (83:17), and the volume flow and injection volume are 20 mg/mL and 1 mL, respectively, while the flow rate is 20 mL/min; Under above conditions the preparation efficiency of 20(S)-25-OH-PPD and 20(R)-25-OH-PPD is 18.01 and 35.36 mg/h, respectively; Off-line preparation method, the mobile phase is methanol and water (81:19), and the volume flow and injection volume is 200 mg/mL and 2.5 mL, while the flow rate is 20 mL/min, The preparation efficiency of 20(S)-25-OH-PPD and 20(R)-25-OH-PPD is 50.55 and 51.93 mg/h, respectively. Conclusion: Preparation efficiency of off-line preparation method is higher than that of the method of continuous sampling interval; This method is convenient and reliable and has large amount of 20(S)-25-OH-PPD and 20(R)-25-OH-PPD, which can establish a good foundation for the separation and preparation of 25-OH-PPD isomer.
RÉSUMÉ
The phytochemical study of the rhizomes from Hedychium coronarium resulted in the isolation of benzoyl eugenol (1), along with the labdane diterpenes isocoronarin D (2) and ethoxy coronarin D (3), obtained as epimeric mixtures at C-14 and C-15, respectively. Structures were determined based on spectroscopic data, mainly 1D and 2D NMR.