Abstract: The present invention provides novel water-soluble compositions comprising sesquiterpene coumarin enriched fractions containing different ratios of sesquiterpene coumarin derived from Ferula species for the treatment of Parkinson's disease via inhibition of MAOenzyme (MAO-A and MAO-B). The invention also provides a method of preparation of ethyl-acetate extract and sesquiterpene coumarin enriched fractions from asafoetida (Hing) that is oleo-gum-resin of Ferula assafoetida using silica gel column chromatography wherein the mobile phase consists of differing compositions of hexane, toluene, chloroform,ethyl-acetate, and methanol. The invention provides the method to prepare the formulation using a multistep process comprising of preparing sesquiterpene coumarin enriched fraction followed by preparing water-soluble formulation. The final composition improves the water solubility, imparts long-term stability, exerts MAO inhibitory activity, and improves pharmaceutical compliance.