Qualitative and quantitative analysis of flavonoids of the strawberry tree - Arbutus unedo L. (Ericaceae).

The leaves and fruits of strawberry tree - Arbutus unedo L., collected from two separate geographic locations in Croatia were investigated to determine their flavonoid composition and content. Quercitrin, isoquercitrin, hyperoside and rutin were identified in all leaf samples by means of thin-layer chromatography; the fruits contained only isoquercitrin. Chlorogenic acid was present in some leaf samples. The content of flavonoids depended on the plant organ investigated, date of collection and the locality. Spectrophotometric determination of the flavonoids indicated that the leaves are richer in flavonoids (0.52-2.00%) than fruits (0.10-0.29%).