OBJECTIVETo study the chemical constituents of Usnea longissima.

METHODThe compounds were isolated and purified by the methods of solvent extraction and chromatographic technique, and their structures were identified on the basis of the analysis of spectral data or comparison with those of authentic sample.

RESULTThirteen compounds were obtained and identified as ethyl hematommate (1), friedelin (2), beta-amyrin (3), beta-sitosterol (4), methyl-2,4-dihydroxy-3,6-dimethylbenzoate (5), barbatinic acid (6), zeorin (7), ethyl orsellinate (8), 3beta-hydroxy-glutin-5-ene (9), oleanolic acid (10), (+)-usnic acid (11), methylorsellinate (12), and 4-methyl-2,6-dihydroxy-benzaldehyde (13).

CONCLUSIONCompounds 2, 3, 5, and 8-10 were isolated from this genus for the first time, and compounds 1,4 were obtained from this plant for the first time.