Two new malic acid derivatives, namely eucomic acid 1-methyl ester (2) and 6'''-acetylmilitaline (7), together with ten known compounds (1, 3-6, 8-12), were isolated from the dry tubers of Bletilla striata (Thunb.) Reichb. F., a perennial traditional Chinese medicinal herb, which was used for the treatment of pneumonophthisis, pneumonorrhagia, tuberculosis, and hemorrhage of the stomach or lung. Their structures were elucidated by spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS.
Keywords: Bletilla striata; Orchidaceae; malic acid derivatives; spectroscopic analyses.