Chemical composition and anti-complement activity of Glechomae Herba collected in different months.

Glechomae Herba (GH) is derived from the dried aerial part of Glechoma longituba (Nakai) Kupr., which is harvested from spring to autumn. It has the effects of clearing heat and detoxification. The purpose of this paper was to study the chemical composition and the anti-complement activity of GH collected in different months. Ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) based on predicted compounds screening and diagnostic ion filter strategy was developed for identifying the chemical composition of GH collected in different months. A total of 102 compounds, including 40 chlorogenic acids (CGAs), 32 phenolic acids and 30 flavonoids, were reasonably identified in GH. 34 CGAs were discovered in GH for the first time. The correlations between chemical compositions and anti-complement activities of GH collected in different months were analyzed. It was showed that phenolic acids and flavonoids were negatively correlated with anti-complement activity, and CGAs were positively correlated with anti-complement activity. At the same time, six CGAs standards had obvious anti-complement activity. It was demonstrated that different harvest months had a significant impact on the difference of chemical composition and anti-complement activity of GH. And CGAs might play an important role in the anti-complement effect of GH.