Five new compounds, including three new stilbene-derived glycosides, one novel arylbenzofuran derivative, and one new coumarin glycoside, along with ten known compounds were isolated from the H 2 O extract of the bark of Morus alba L. The new compounds were assigned to the structures of 4'-O-b- (5) by spectroscopic means, and acid and enzymatic hydrolyses. Three compounds, 2'- (8), and 6,7-dihydroxycoumarin 7-(6-O-a-rhamnopyranosyl-b-d-glucopyranoside) (9), were found for the first time in Morus alba.Introduction. -Morus alba L. (Moraceae) is widely distributed in the Anhui, Hunan, and Shanxi provinces in China. Its root bark is extensively used as an antitussive and antiasthmatic agent [1] in traditional Chinese medicines. Although many compounds such as stilbenes, flavonoids, benzofuran derivatives, and coumarins have been identified in Morus alba [2 -6], there have been few reports on its pharmacological properties. In our previous study, we investigated the absorbed constituents in rats following oral administration of the H 2 O extract of the bark of Morus alba [7] [8], and several stilbene derivatives were identified in the plasma, urine, and bile of rats. Further pharmacological studies showed that mulberroside A, a major stilbene constituent in the H 2 O extract, displayed a significant antitussive and antiasthmatic effect in animals [9]. In our ongoing search for the bioactive constituents from the H 2 O extract of Morus alba L., a systematic investigation on the chemical constituents of water extract of Morus alba was carried out, and resulted in the isolation of eight stilbene glycosides, three arylbenzofuran derivatives, and four coumarin glycosides. This article reports the isolation and structural elucidation of the three new stilbene glycosides 1 -3 1 ), the novel arylbenzofuran derivative 4, and the new coumarin glycoside 5. Ten known compounds were identified as mulberroside A (6)
