The present invention provides an improved process for the isolation of oleane compounds from the bark of Terminallia arjuna (Roxb.). More particularly, the present invention relates to an improved process for the isolation of arjunic acid and its derivates from the bark of Terminallia arjuna (Roxb.). The present invention further provides the identification of arjunic acid [1] and its derivatives as anticancer agent useful in the treatment of various types of cancer in humans.