Edieidia Souza Pina

Biosynthetic investigation of quinonemethide triterpenoid 22β-hydroxy-maytenin (2) from in vitro root cultures of Peritassa laevigata (Celastraceae) was conducted using ¹³C-precursor. The mevalonate pathway in P. laevigata is responsible for the synthesis of the quinonemethide triterpenoid scaffold. Moreover, anatomical analysis of P. laevigata roots cultured in vitro and in situ showed the presence of 22β-hydroxy-maytenin (2) and maytenin (1) in the tissues from transverse or longitudinal sections with an intense orange color. MALDI-MS imaging confirmed the distribution of (2) and (1) in the more distal portions of the root cap, the outer cell layers and near the vascular cylinder of P. laevigata in vitro roots suggesting a role in plant defense against infection by microorganisms as well as in the root exudation processes.

Establishment of adventitious root cultures ofPeritassa campestris(Celastraceae) was achieved from seed cotyledons cultured in semisolid Woody Plant Medium (WPM) supplemented with 2% sucrose, 0.01% PVP, and 4.0 mg L⁻¹IBA. Culture period on accumulation of biomass and quinone-methide triterpene maytenin in adventitious root were investigated. The accumulation of maytenin in these roots was compared with its accumulation in the roots of seedlings grown in a greenhouse (one year old). A rapid detection and identification of maytenin by direct injection into an atmospheric-pressure chemical ionization ion trap tandem mass spectrometer (APCI-IT-MS/MS) were performed without prior chromatographic separation.In vitro, the greatest accumulation of biomass occurred within 60 days of culture. The highest level of maytenin—972.11 μg·g⁻¹dry weight—was detected at seven days of cultivation; this value was 5.55-fold higher than that found in the roots of seedlings grown in a greenhouse.

The biosynthetic route for epoxyangelate esters of the sesquiterpene lactones (STL) uvedalin and enhydrin from in vitro cultures of Smallanthus sonchifolius (Asteraceae) was investigated with ¹³C-precursors for the first time in the literature. Photomicroscope analyses and studies using MALDI-MS imaging confirmed that glandular trichomes accumulate STL.

Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) is considered as a medicinal plant by Argentineans and Brazilians, being popularly used as sedative, eupeptic and carminative agent. The high amount of carvone produced by this species could justify its use in the treatment of some digestive disorders. The aim of this work was to evaluate the effect of the time of leaf harvesting on the composition of A. polystachya essential oil. The antimicrobial activity of this essential oil was evaluated against Escherichia coli, Staphylococcus aureus, three Candida strains and Trichophyton rubrum. Essential oils from dry and fresh leaves obtained by hydrodistillation were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). The chemical profile of A. polystachya essential oils varied according to day-time harvesting of the plant material though they were basically composed of carvone and limonene. The antifungal activity of the essential oils against clinical isolates of Tricophyton rubrum, Candida albicans, C. krusei and C. famata was validated. Key words: Verbenaceae, antimicrobial activity, limonene, carvone.