A fast and efficient LC-MS/MS method for detection, identification and quantitative analysis of bioactive sesterterpenes in Salvia dominica crude extracts.

Sesterterpenes are a small group of terpenoids showing a number of interesting pharmacological properties, including cytotoxicity, anti-inflammatory, anti-microbial and anti-angiogenic activities and platelet aggregation inhibition. Recently, some sesterterpene lactones isolated from Salvia dominica have been shown to modulate enzymatic activity of tubulin tyrosine ligase (TTL), a promising target for new anticancer therapeutic strategies. However, to allow a direct use of S. dominica extracts as a source of TTL inhibitors, analytical method aimed to their fast qualitative and quantitative characterization is required. Despite the structural features and diverse biological activities of sesterterpenoids, actually no analytical method for their quantization into complex mixtures has been published. Here we describe an LC-MS/MS method aimed to qualitative and quantitative analysis of sesterterpenes lactones in the crude extracts obtained from different parts of S. dominica. This approach allowed us to characterize all the sesterterpenes by a single step analysis and also to identify two unknown compounds. Moreover, a quantitative comparison of the composition in sesterterpenes of extracts obtained from S. dominica leaves, roots and leaf galls was performed, leading to the definition of both leaves and leaf galls as suitable sources of TTL inhibitors.