Gniditrin is the main diterpene ester in the bark of daphne species

Daphne species are noted as poisonous members of the plant family Thymeleaceae. The plants are evergreen or deciduous shrubs distributed mainly in Europe, Asia, and North Africa. Daphne species are a rich source of diterpenes which are known to cause gastrointestinal diseases when consumed orally or rashes after handling of fresh twigs. The diterpene ester mezerein is often reported as a major toxic substance in various cited literature. In the reported work methanolic extracts of the bark of various Daphne spp. were tested for the presence and identification of gniditrin as the main diterpene ester in these aforementioned species. Gniditrin was isolated from the methanolic extract of D. alpina using two-step HPLC and the isolated fraction was characterized for structural features using ¹H-, ¹³C-, H-H-cosy-, hmbc- and hmqc- NMR spectroscopy. This is the first report for a complete NMR spectroscopic evaluation of gniditrin.