Vitexilactone is a new diterpene from Vitex cannabifolia, V. cannabinifolia, V. trifolia and Tinospora rumphii. This plant is known well as a treatment for HIV-AIDS and shown anti HIV-1 RT activities. Vitexilactone has shown anti HIV activities. Vitexilactone dramatically induced apoptosis both on tsFT210 and K562 cells at higher concentrations while at lower concentrations they inhibited the cell cycle progression of both tsFT210 and K562 cells at the G0/G1 phase.