A comparative study of Lonicera japonica with related species: Morphological characteristics, ITS sequences and active compounds

Morphological characteristics, ITS sequences, and active compounds have been used to differentiate between species of Lonicera used in the traditional Chinese medicines Flos Lonicerae Japonicae (FLJ) and Flos Lonicerae (FL). FLJ includes L. japonica whereas FJ includes Lonicera macranthoides, Lonicera hypoglauca, Lonicera confusa and Lonicera fulvotomentosa. FLJ could be distinguished from FL using four quantitative and 10 qualitative characters, ITS sequences, chlorogenic acid and luteoloside contents. Analyses revealed that L. japonica was very different from the other species. The results have implications for the identification and quality control of species of Lonicera used medicinally, suggesting that species should not be interchanged in medicinal preparations.