A new steroidal saponin, named as (25R)-6α- [(β-D-glucopyranosyl) 2) was isolated from the flowers of Cestrum elegans. In addition, a known steroidal saponin (1), a flavonoid compound (3) along with a triterpene saponin (4) were isolated for the first time in genus Cestrum and identified based on their chromatographic properties, chemical and spectral data (HR-ESI-MS, 1 H, 13 C NMR, 1 H-1 H COSY, HSQC, and HMBC). The four compounds were evaluated for their antibacterial, antifungal and antiviral activities. The maximum non-toxic concentration (MNTC) on vero cell line was 1.56 µg/mL for all compounds. While, compound 1 and 3 showed antiviral activity of 34.3% and 25%, respectively.