A Novel Artemisinin-Derived Sesquiterpene from Bacopa gratioloides Volatile Oil by Sustainable and Enhanced Procedures
摘要
Bacopa gratioloides (Cham.) Chodat & Hassl., Plantaginaceae, is an aquatic species underexplored and found in the hostile biome Chaco, Brazil. In this work, a new sesquiterpene was obtained, which is accumulated in high levels in B. gratioloides volatile oil when extracted via an improved and eco-friendly hydrodistillation method (16 h—4 h/day). Bacopa gratioloides volatile oil was purified by recrystallization using methanol and deionized water (7:3, v/v) to isolate the new sesquiterpene, which was structurally characterized by MS, NMR, and 13C and 1H chemical shift simulations. The applied procedures improved the yield of B. gratioloides volatile oil (0.15%) by about 3.5 times and facilitated the isolation of the new sesquiterpene di-7,10-epi-dihydroartemisinic acid, since the most volatile compounds were reduced in the volatile oil. This sesquiterpene is a derivative of antimalarial artemisinin and it was isolated with a high yield (73%). The sesquiterpene di-7,10-dihydroartemisinic acid showed potential against B16F10-Nex2 melanoma cancer cells with a marked inhibition of cell migration and antiparasitic activity against Trypanosoma cruzi. These are the first phytochemical and biological studies of B. gratioloides, which is a promising source of di-7,10-epi-dihydroartemisinic acid on a large scale and through sustainable processes.
Graphical Abstract