Structural elucidation and evaluation of multidrug-resistance modulatory capability of amarissinins A–C, diterpenes derived from Salvia amarissima

"Three new diterpenes (amarissinins A-C, 1–3) containing several oxygenated functionalities were isolated from the leaves and flowers of Salvia amarissima. The structures of these compounds were established through the analysis of their NMR spectroscopy and mass spectrometry data. The structures of compounds 1 and 2 were confirmed by single crystal X-ray diffraction. Compound 2was identified as a C-10 epimer of dugesin F (5). The cytotoxic activity of these compounds against five human cancer cell lines was determined. Additionally, the capability to modulate the multidrug resistance (MDR) in the MCF-7 cancer cell line resistant to vinblastine was tested.

NMR analysis and crystal structure of hydroxyclerodanes from Mexican Salvia species

"NMR and single crystal X-ray diffraction analysis of seven clerodanes from Mexican Salvia species was performed. We focused on clerodanes with tertiary hydroxyl group at C-4, C-8, and C-10, in which the establishment of absolute configuration around these chiral centers is nontrivial and the 13C NMR signals can be misassigned. In addition, the analysis by 1H NMR in aprotic solvent allowed us to establish a common pattern that correlates the chemical shift with the position of the hydroxyl groups, which constitute a good methodology for future structural elucidation of these kinds of compounds. The obtained data allowed us to establish the absolute configuration of five of these diterpenes and the structural revision of salvimicrophyllin D (7).

The arabidopsis-trichoderma interaction reveals that the fungal growth medium is an important factor in plant growth induction

"Trichoderma spp colonizes the plant rhizosphere and provides pathogen resistance, abiotic stress tolerance, and enhance growth and development. We evaluated the Arabidopsis-Trichoderma interaction using a split system in which Trichoderma atroviride and Trichoderma virens were grown on PDA or MS medium. Arabidopsis growth was significantly increased at 3 and 5 days post-inoculation with both Trichoderma species, when the fungal strains were grown on PDA in split interaction. The analysis of DR5:uidA reporter line revealed a greater auxin accumulation in root tips when the fungi were grown on PDA in a split interaction. The root hair-defective phenotype of Arabidopsis rhd6 mutant was reverted with both Trichoderma species, even in split interactions. At 12 °C, Trichoderma species in split interactions were able to mitigate the effects of cold stress on the plant, and also Trichoderma induced the AtERD14 expression, a cold related gene. Volatile organic compounds analysis revealed that Trichoderma strains produce mainly sesquiterpenes, and that the type and abundance of these compounds was dependent on the fungal strain and the culture medium. Our results show that fungal nutrition is an important factor in plant growth in a split interaction.