Chem. Pharm. Bull. 53(1) 86—89 (2005)

and comprises six species. One of these is Amberboa ramosa JAFRI, which is an annual herbaceous plant found in India and Pakistan. The plant has tonic, aperient, febrifuge, deobstruent, cytotoxic, and antibacterial activities. Previously triterpenoids, flavanoids, steroids, and steroidal glycosides have been reported from this species. Here we report the isolation and structure elucidation of long-chain esters 1 and 2, along with two known compounds tricontane (3) and apigenin (4). Tyrosinase (EC 1.14.18.1) is a multifunctional copper-containing enzyme widely distributed in plants and animals. It catalyzes the oxidation of monophenols, o-diphenols, and o-quinones. Tyrosinase is known to be a key enzyme for melanin biosynthesis in plants and animals. Tyrosinase inhibitors therefore can be clinically useful for the treatment of some dermatologic disorders associated with melanin hyperpigmentation. They also find use in cosmetics for whitening and depigmentation after sunburn. It has recently been shown that other factors such as metal ions and the TRP-1 and TRP-2 enzymes also contribute to the production of melanin. However, tyrosinase plays a critical regulatory role in melanin biosynthesis. Therefore many tyrosinase inhibitors that suppress melanogenesis have been actively studied with the aim of developing preparations for the treatment of hyperpigmentation. Compounds 1 and 2 showed strong to moderate inhibitory activity against tyrosinase.