Phytochemical study of the roots of Derris malaccensis Prain. led to the isolation of a new rotenoid, namely, 6-oxo-dehydroelliptone, along with six known compounds, 12-deoxo-12α-acetoxyelliptone, 12a-hydroxyelliptone, tephrosin, dehydroelliptone, deguelin and elliptone. Chemical examination of the stems of Carissa carandas L. led to the isolation of two new compounds, namely, (6S,7R,8R)-7a-[(β-glucopyranosyl)oxy]lyoniresinol and carandoside, along with three known compounds. The known compounds are (6R,7S,8S)-7a-[(α-glucopyranosyl)oxy]lyoniresinol, (-)-carissanol and (-)-nortrachelogenin. From the stems of C. spinarum L., twelve known compounds were isolated, including (-)-carissanol, (-)-nortrachelogenin, scopoletin, (-)-carinol, (+)-cycloolivil, (+)-8-hydroxypinoresinol, (-)-olivil, (-)-secoisolariciresinol, (+)-pinoresinol, carissone, digitoxigenin 3-O-β-D-digitalopyranoside and evomonoside. The structures of all of these isolates were determined on the basis of spectroscopic evidence, including comparison of their UV, IR, MS and NMR properties with previously reported data. These isolated compounds were evaluated for their free radical scavenging, anti-herpes simplex virus (HSV-1 and HSV-2), antibacterial and cytotoxic activities. Ten lignans were found to posses moderate free radical scavenging activity whereas two compounds showed weak activity. Two compounds, tephrosin and elliptone, exhibited moderate activity against HSV-1 and HSV-2 in post-treatment and inactivation assays while evomonside showed moderate activity against both types of virus only in the inactivation method. In addition, no compounds showed antibacterial activity at the concentration 128 µg/mL. Interestingly, elliptone possessed cytotoxicity against cancerous cells A549 and MCF7 but showed no toxicity against WI-38 normal cells.