Objective

2

To establish a high performance liquid chromatography （HPLC） fingerprint of branches of

Juglans mandshurica

and to evaluate the quality of the samples from different producing areas and in different harvest periods.

Method

2

Chromatographic separation was performed on an Agilent Poroshell 120 SB-C

18

column （2.1 mm×100 mm， 2.7 μm） for gradient elution with mobile phase of 0.2% formic acid solution （A）-0.2% formic acid acetonitrile solution （B） （0-5 min， 5%-10%B； 5-25 min， 10%-16%B； 25-40 min， 16%-22%B； 40-45 min， 22%-45%B； 45-50 min， 45%-65%B； 50-52 min， 65%-100%B； 52-55 min， 100%B） at a flow rate of 0.3 mL·min

-1

. The column temperature was 30 ℃ and the detection wavelength was 270 nm. The quality of branches of

Juylans mandshurica

was evaluated by similarity evaluation， cluster analysis， principal component analysis and partial least squares-discriminant analysis. The chemical constituents of the samples were identified by HPLC coupled with quadrupole time-of-flight mass spectrometry （HPLC-Q-TOF-MS/MS）. The mass spectrometry was conducted in negative ion mode with electrospray ionization（ESI）. Data were acquired over a range of

m

/

z

100-1 700 for MS and

m

/

z

50-1 700 for MS/MS.

Result

2

A total of 19 common peaks were confirmed in 40 batches of samples， and the similarity ranged from 0.430 to 0.995， of which the similarity of samples collected in spring and winter seasons （April， May and December） was greater than 0.90， while the similarity of most samples collected in summer （July to September） was low. Multivariate statistical analysis showed that the samples were divided into two groups according to the harvest time， but there was no obvious classification rule for the samples from different producing areas. The contents of most constituents in the samples collected in spring and winter were higher than those collected in summer. The result illustrated that different harvest periods had great influence on the quality of branches of

J

.

mandshurica

. Compared with the samples collected in summer， the quality of samples collected in spring and winter was better. A total of 22 peaks were proved to be the main constituents that contributed to the difference between samples collected in different seasons. A total of 83 chemical components were identified by HPLC-Q-TOF-MS/MS， including 49 tannins， 7 organic acids， 14 naphthalene derivatives， 1 flavonoid， 6 anthracene derivatives， 2 lignans， 3 diarylheptanoids and 1 saccharide. Totally 13 common peaks were identified. Of the peaks that contributed to discriminate samples collected in different season， 19 peaks were identified and most of them were tannins.

Conclusion

2

The established HPLC fingerprint can provide useful information for the quality evaluation of branches of

J

.

mandshurica

. Tannin is the main constituents in the samples. Harvest period has great influence on the quality of branches of

J

.

mandshurica

.