Objective To study the changes of volatile components in Euonymus sanguineus var. paedidus flowers at 5 development stages (V1 to V5) and the causes of its pungent odor.

Method The volatile components at various development stages and in petal (Y1) and disk (Y2) of E. sanguineus var. paedidus were analyzed by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) as well as principal component analysis (PCA) and hierarchical cluster analysis (HCA).

Result A total of 58 components accounting for 96.51%-98.56% of total were separated and identified. The major constituents were linalool (0.15%-70.79%), leaf alcohol (0.41%-65.51%), phenylacetonitrile (0.04%-62.20%), 2-ethenyl-1, 1-dimethyl-3-methylene-cyclohexane (0.02%-32.99%), (E)-β-ocimene (0.25%-21.26%), α-pinene (0.02%-20.41%), D-limonene(1.01%-11.74%)and methyl salicylate(0.14%-6.14%). The volatile components in all samples were dominated by alcohols (11.93%-69.66%), followed by hydrocarbons (14.47%-57.94%). Analysis of the volatile components revealed the qualitative differences among the samples studied. According to principal component analysis (PCA) and hierarchical cluster analysis (HCA), the volatile constituents at various development stages and in parts of E. sanguineus var. paedidus flowers were grouped into four different chemotypes. V1 and V2 were leaf alcohol (type I), V3 and V4 were complex and not obvious (type II), V5 and Y1 were linalool, (type III) Y2 was phenylacetonitrile (IV).

Conclusion The volatile constituents of E. sanguineus var. paedidus are different at different development stages and the pungent odor is mainly related to phenylacetonitrile released by flower disk at flowering.