Ecdysteroids in Sida tuberculata R.E. Fries (Malvaceae): Chemical composition by LC–ESI-MS and selective anti-Candida krusei activity

Abstract

Sida tuberculata is found in a region of South America and has traditionally been consumed as an infusion or tea. The chemical composition and antifungal activity of aqueous infusions from leaves and roots were investigated. LC–ESI-MS mass spectra were successfully obtained and used to identify four ecdysteroids: 20-hydroxyecdysone-3-O-β-d-glycopyranoside, 20-hydroxyecdysone, 20-hydroxyecdysone-3-O-β-d-xylose and a hydroxyecdysterone derivative. The in vitro antifungal activity was studied, and the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were established against Candida krusei isolates. The antibiofilm activity was evaluated by the determination of the biofilm removal efficiency in contaminated central venous catheter (CVC) coupons. The preparations exhibited antifungal activity against the species tested, with MICs ranging from 3.90 to 62.50μg/ml. The infusion removed the C. krusei biofilm after 90min of exposure. The observed bioactivity and composition of ecdysteroids will contribute to the future development of antifungal substances for clinical use or as food additives.