Hydroxycitric acid lactone and its salts: Preparation and appetite suppression studies

(−) Hydroxycitric acid lactone (HCAL) has been prepared in pure form (>98%) and converted into different salts of Group-IA and IIA metals with definite composition for the first time. The lactone is stable at room temperature but in aqueous solution it exists in equilibrium with its acid counterpart. An HPLC method has been developed to quantify (−) hydroxycitric acid (HCA) and its lactone. In-vivo studies, using male rats of the Wistar albino strain, revealed the interesting finding that HCAL exhibited better appetite suppression than did hydroxycitric acid. The continuous shift in equilibrium between HCA and HCAL due to the depletion of HCA in animal systems (slow release mechanism) could be the possible reason for this improved activity.