Chemical studies on mexican plants used in traditional medicine, VI. Additional new 4-phenylcoumarins from Exostema caribaeum.

Six additional 4-phenylcoumarins have been isolated from the MeOH extract of the bark of Exostema caribaeum. Their structures were determined by physical and chemical methods as 4'-5'-dihydroxy-7-methoxy-4-phenyl-5,2'-oxidocoumarin [1], 5,7,4'-trimethoxy-4-phenylcoumarin [2], 5,3'-dihydroxy-7,4'-dimethoxy-4-phenylcoumarin [3], 5-O-beta-D-galactopyranosyl-7,4'-dimethoxy-4-phenylcoumarin [6], 5-O-beta-D-glucopyranosyl-3',4'-dihydroxy-7-methoxy-4-phenylcoumarin+ ++ [7], and 5-O-(6"-acetyl)-beta-D-galactopyranosyl-3', 4'-dihydroxy-7-methoxy-4-phenylcoumarin [9]. The last four compounds are new natural products.