RESUMEN
To investigate the chlorogenic acids resources in Eucommia ulmoides Olive leaves, Lonicera japonica Thunb. leaves and Houttuynla cordata Thunb. leaves, methanolic extracts of these three materials have been analysed qualitatively for chlorogenic acids and their derivatives by structure-diagnostic LC-MSn. Three monocaffeoylquinic acids (3-CQA, 4-CQA, 5-CQA) were detected. 5-CQA dominated this subgroup in Eucommia ulmoides Olive and Lonicera japonica Thunb. leaves, but 3-CQA and 4-CQA dominated this subgroup of chlorogenic acids in the leaves of Houttuynla cordata Thunb. Caffeoylquinic acid-glycosides were detected for the first time from Eucommia ulmoides leaves. 5-FQA was found in Lonicera japonica Thunb. leaves, and 3-FQA and 4-pCoQA have been identified in Houttuynla cordata Thunb. This is the first report of the chlorogenic acid profile in Houttuynla cordata Thunb. The comparatively unusual profile of caffeoylquinic acids in Houttuynla cordata Thunb. makes it a convenient source of 3-CQA and 4-CQA that are not commercially available.