Root cultures of Monteverdia floribunda (Reissek) Biral grown in air sparging systems are sources of quinonemethide triterpenes

Quinonemethide triterpenes (QMTs) are chemotaxonomic markers of the family Celastraceae that are known to possess anti-inflammatory, antioxidant and anti-tumor properties. The production of QMT-derived phytopharmaceuticals is, however, limited because the metabolites are accumulated in low concentrations in the roots of trees, and chemical synthesis is not practicable because of the complexity of the molecules. The aim of the study was to test the hypothesis that in vitro root cultures of Monteverdia floribunda represent superior sources of QMTs than the roots of plants in natura. For this purpose, we monitored biomass formation and QMTs accumulation during the growth cycle of root cultures, and compared the production of QMTs by roots cultured in conical flasks and in a vessel with an air sparger (VAS) with those of roots in natura. Levels of the QMTs maytenin, 22β-hydroxy-maytenin and celastrol were higher by factors of 9.33, 6.47 and 17.08, respectively, in root cultures compared with in natura roots, although the concentration of pristimerin was lower by a factor of 20.28. Around 0.3% of the three main QMTs produced by cultured roots was excreted into the growth medium. Accumulations of maytenin, 22β-hydroxy-maytenin, celastrol and pristimerin in roots grown in VAS were significantly (P < 0.05) higher by factors of 3.10, 2.13, 2.07 and 2.21, respectively, in comparison with roots cultured in conical flasks. These results suggest that the biotechnological production of QMTs in VAS may be a reliable and sustainable method for securing these valuable compounds as a practical alternative to harvesting plant roots. The culture of Monteverdia floribunda roots in bubble column reactors is a practical, reliable and sustainable method for the large-scale production of quinonemethide triterpenes with phytotherapeutic potential.