Abstract: A new depside, vermicularin (1 ), C18H16O9, mp 221-223℃, has been isolated from the extracts of Thamnolia vermicularis (SW.) Ach. The structure of (1 ) was elucidated as 3'-formyl- 2, 2', 4'-trihydroxy- 4- methoxy- 3-carboxy- 6, 6'-dimethyl-depside by spectral and chemical data. Based on the pharmacologic test, vermicularin (1 ) possesses anti-inflammatory and anti-pyretic action.

Key words: Thamnolia vermicularis