Caper spurge (Euphorbia lathyris L.) seed oil contains a series of diterpenoids known as Euphorbia factors, or L-factors, L1–L9. They are esters of several polyols (lathyrol, epoxylathyrol, 7-hydroxylathyol, isolathyrol and jolkinol subtypes) and account for about 3%–5% of the oil.
These lathyrane diterpenes have a unique macrocyclic structure, display activities against HIV-1 replication, and vasoconstriction, and are apoptosis inducers and multidrug-resistance modulators. Their unique structures and potential applications necessitate the development of a method for the reliable, fast and low-cost analysis of this class of compounds.
Mass spectrometry (MS), especially tandem mass spectrometry (MS/MS), is one of the important physicochemical methods for the identification of trace natural products because of its rapidity and sensitivity, with low levels of sample consumption. Some lathyrane polyols and their esters (lathyrol, 7-hydroxylathyrol and epoxylathyrol subtypes) have been analyzed rapidly with high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS).
In the laboratory, a series of lathyrane diterpenes , including lathyrol, 7-hydroxylathyrol, epoxylathyrol, jolkinol and isolathyrol subtypes, were isolated from the seeds of Euphorbia lathyris. To our knowledge, this series of lathyrane diterpenes has not been studied by ESI-MS/MS.
To obtain sufficient information on the structural characteristics of this class of compounds, such as their degradation products, metabolites, and biosynthetic intermediates, the detailed fragmentation patterns of the lathyrane diterpenes were studied with collision-induced dissociation (CID)-MS/MS using an ESI quadrupole time-of-flight (QTOF) MS/MS hybrid instrument in positive-ion mode.
Prof.WU Zhijun from Chengdu Institute of Biology carried out this research.