Leaf flavonoid aglycone patterns in the species of Dipterocarpaceae in Sri Lanka

Abstract

A flavonoid aglycone survey was carried out on 46 taxa of the family Dipterocarpaceae belonging to the genera Cotylelobium, Dipterocarpus, Hopea, Shorea, Stemonoporus, Vateria and Vatica. After acid hydrolysis the main aglycones found were the flavonols quercetin and kaempferol, and the flavone apigenin. The flavone luteolin was present in all the species of the genus Shorea and was absent in the rest of the species of the family, giving a chemotaxonomic significance to its presence. The flavonol myricetin was detected in only three species of Shorea, S. affinis, S. trapezifolia, and S. gardneri. Proanthocyanidins were only found in 13 species of Shorea and two species of Dipterocarpus. These two genera can be regarded as the most primitive with respect to the flavonoid patterns and the other five genera have more advanced patterns, recognizing Stemonoporus as the most advanced. The aglycone results do not completely agree with the existing classifications, and suggests the need for a revision of the species and sectional levels in the family Dipterocarpaceae in Sri Lanka.