Chemical constituents and cytotoxic activity of Stachys pilifera Benth.

• The plant Stachys pilifera Benth. was subjected to identification of its chemical constituents. • The isolated compounds were identified using 1D and 2D-NMR analysis. • A monoglyceride with a new structure was identified together with 11 known compounds. • The in vitro cytotoxic activity of compounds against breast cancer cell line (MCF-7) was evaluated by MTT assay. • A preliminary SAR study was performed against the short series of flavonoids. Phytochemical investigation of the n -hexane extract of Stachys pilifera Benth. aerial parts resulted in the isolation of twelve compounds. Structures were elucidated using 1D and 2D-NMR, as well as HRMS. The purified compounds identified as one new monoglyceride (1), nine flavonoids (2–10), and two steroidal compounds. The cytotoxicity effects of purified compounds were evaluated against breast cancer cell line (MCF-7) and structural-activity relationship of the flavonoids were investigated. [ABSTRACT FROM AUTHOR]