A bioactive fraction obtained from Xylocarpus that is useful for the treatment of diabetes and dyslipidemia. This fraction can be provided in a pharmaceutical composition that is useful as antidiabetic and antidyslipidemic agent, or can be used in a method of treating diabetes and dyslipidemia in a subject. Also, a process for the preparation of bioactive fraction from Xylocarpus. Novel isomeric xyloccensins and the preparation of such compounds. Also, pharmaceutical compositions comprising a therapeutically effective amount of such novel isomeric xyloccensins optionally along with one or more pharmaceutically acceptable carriers, additives, lubricant and diluents and the use of such pharmaceutical compositions in a method for treating dyslipidemia.