Abstract:From the acetone extract of Thamnolia vermicularis(Sw.)Ach.,a new phenolic compound,thamnolin(1),was isolated,along with eight known constituents,squamatic acid(2),barbatinic acid(3),baeomycesic acid(4),5,8-epidioxy-5α-,8α-ergosta-6,22E-dien-3β-ol(5).