A new phenolic compound, thamnolin (1), was isolated from the extract of Thamnolia vermicularis. Its structure was determined as 6-tricosyl-2,4-dimethoxy-phenol by spectral methods. A new phenolic compound, thamnolin (1), was isolated from the extract of Thamnolia vermicularis. Its structure was determined as 6-tricosyl-2,4-dimethoxy-phenol by spectral methods.