Isolation and Identification of Hypoglycemic Agents from the Costus Family of Plants

The tropical plants of the Costus genus are abundant in the Caribbean area, especially in Puerto Rico. “Insulina” or the insulin plant is one of them (Costus speciosus, Costus spicatus, Costus spiralis, etc.) and a common practice in folk medicine is to prepare tea from its leaves and use it to reduce high blood-sugar levels (hypoglycemic agent). Identifying and separating a pharmacophore or several active ingredients of the insulin plant is the goal to achieve. A Soxhlet extraction is the method to be used in order to generate solutions containing the plant leaves’ essentials. Six (6) solvents (500 mL for each) with variant polarity are used for the extraction, in addition to acidic and basic aqueous solutions were also used. A weighed amount (100 g) of the leaves were cut into 2.54 cm (1 in) squares and placed in the Soxhlet extractor together with the 500 mL of solvent, heated to a boil in order to conduct the continuous extraction for a total of six (6) hours. The resulting extracts were analyzed by spectroscopic techniques (1H NMR, and 13C NMR) in order to determine functional groups and/or structural features present in the crude extract. Preliminary results from this spectroscopic analysis have indicated the presence, among others, of known compounds such as essential oils, proteins, and antioxidant components. Infrared spectroscopy will be conducted in order to find the presence of other known hypoglycemic agents such as sulfonylureas and corosolic acid (glucosol).