The plants of the genus Phyllanthus (Euphorbiaceae) are widely distributed throughout tropical and subtropical coun-

widely distributed throughout tropical and subtropical countries. They have been used in China, India, the Philippines, Nigeria, East and West Africa, the Caribbean, and Central and South America by traditional medicinal practitioners for the treatment of different types of diseases. Several therapeutic properties such as antipyretic, antibacterial, antiparasitic, antinocioceptive, and antiviral activities have been attributed to this genus. Crude extracts of species such as Phyllanthus amarus and Phyllanthus emblica have been reported to provide antioxidant and/or antigenotoxic protection. Moreover, phyllanthostatins 1—6, which exhibited potent antineoplastic activity, have been isolated from the roots of Phyllanthus acuminatus. P. emblica L. is a shrub or tree growing in the tropical and subtropical parts of Southeast Asia, particularly in southern China, India, Indonesia, and the Malay Peninsula. It has been used widely for its antiinflammatory and antipyretic effects in many local traditional medicinal systems, such as Chinese herbal medicine, Tibetan medicine, and Ayurvedic medicine. The fruit is edible and the fruit juice is produced as a beverage in Yunnnan Province, People’s Republic of China. The air-dried fruit is also used for the treatment of cancer in Tibetan and Egyptian medicines. The active principles or extracts of P. emblica have been shown to possess several pharmacologic actions, e.g., antitumor, and cytotoxic activities. Our previous chemical investigation of this plant led to the isolation of several novel sesquiterpenoids from the roots, new organic acid gallates and polyphenols from the fruit juice, and new ellagitannins and flavonoids from the branches and leaves. Among them, phyllaemblic acid (1) and its glycosides phyllaemblicins A—C (2—4) were the major sesquiterpenoids from the roots, and organic acid gallates, L-malic acid 2-O-gallate (5), and mucic acid 2-O-gallate (6) together with hydrolysable tannins, 1-O-galloyl-b-Dglucose (7), corilagin (8), and chebulagic acid (9) were found to be the major phenolic constituents of fruit juice. Elaeocarpusin (10) and putranjivain A (11) were the other two main ellagitannins obtained from the fruit juice. Moreover, seven other tannins and flavonoids, geraniin (12), phyllanemblinins C and E (13 and 14), prodelphinidin B1 (15), prodelphinidin B2 (16), (2)-epigallocatechin 3-O-gallate (17), and (S)-eriodictyol 7-[6-O-(E)-p-coumaroyl]-b-D-glucoside (18) were the main phenolic compounds isolated from the branches and leaves of the plant (Figs. 1, 2). Among these compounds, 1— 6, 13, 14, and 18 are newly isolated from P. emblica. Continuous studies on the 60% aqueous acetone extract of the roots of P. emblica led to the isolation of a major component, proanthocyanidin polymer phyllemtannin (19). Although many studies have so far been carried out on the chemical components of P. emblica, its detailed active principles are generally not well known. This paper deals with the inhibitory activity of 19 together with the 18 main constituents 1—18 isolated previously from P. emblica on the proliferation of B16F10 (murine melanoma), HeLa (human uterine carcinoma), and MK-1 (human gastric adenocarcinoma) cells to determine their roles in the anticancer uses of this plant. The determination of proanthocyanidin polymer, phyllemtannin (19), from the roots is also described. February 2004 Notes Biol. Pharm. Bull. 27(2) 251—255 (2004) 251