The flowering tops of
Hypericum hirsutum, H. montanum, H. perforatum
angustifolium, H. perforatum
, collected from different locations in Croatia, were investigated to determine their flavonoid, phenolic acid, and amino acid composition. Thin-layer chromatography (TLC) on silica gel was used for separation and identification of the flavonoids and phenolic acids and TLC on cellulose was used for investigation of the amino acids. By use of these procedures ten flavonoids, three phenolic acids, and sixteen amino acids were detected and identified in the samples investigated. The composition of these compounds depended on the taxa investigated and the locality. Spectrophotometric analysis of the flavonoid content indicated that the three subspecies of
are richer in flavonoids than
H. montanum. H. perforatum
is the richest in flavonoids, phenolic acids, and amino acids. This is the first time these biologically active compounds have been identified in the some
, Flora Hrvatske: priručnik za odredivanje bilja, Školska knjiga, Zagreb, pp. 140–141.