() 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.